CLYYF / Celyad Oncology SA - Pengajuan SECLaporan Tahunan, Pernyataan Proksi

Celyad Oncology SA
US ˙ OTCPK ˙ BE0974260896

Mga Batayang Estadistika
LEI 549300ORR0M8XF56OI64
CIK 1637890
SEC Filings
All companies that sell securities in the United States must register with the Securities and Exchange Commission (SEC) and file reports on a regular basis. These reports include company annual reports (10K, 10Q), news updates (8K), investor presentations (found in 8Ks), insider trades (form 4), ownership reports (13D, and 13G), and reports related to the specific securities sold, such as registration statements and prospectus. This page shows recent SEC filings related to Celyad Oncology SA
SEC Filings (Chronological Order)
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February 9, 2024 EX-99.1

CELYAD ONCOLOGY ANNOUNCES INTENTION TO TERMINATE SEC REPORTING OBLIGATIONS

Exhibit 99.1 CELYAD ONCOLOGY ANNOUNCES INTENTION TO TERMINATE SEC REPORTING OBLIGATIONS Mont-Saint-Guibert, Belgium, February 8, 2024, 10.01 pm CET – inside information and regulated information – Celyad Oncology SA (Euronext: CYAD) (“Celyad Oncology” or the “Company”) announced that it will voluntarily file a Form 15F with the United States Securities and Exchange Commission (the “SEC”) to termin

February 9, 2024 15F-12B

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 15F CERTIFICATION OF A FOREIGN PRIVATE ISSUER’S TERMINATION OF REGISTRATION OF A CLASS OF SECURITIES UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR ITS TERMIN

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 15F CERTIFICATION OF A FOREIGN PRIVATE ISSUER’S TERMINATION OF REGISTRATION OF A CLASS OF SECURITIES UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR ITS TERMINATION OF THE DUTY TO FILE REPORTS UNDER SECTION 13(a) OR SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number: 001-37452 CELYAD

January 17, 2024 EX-99.1

Celyad Oncology provides fourth quarter 2023 business update and 2024 outlook

Exhibit 99.1 Press Release Celyad Oncology provides fourth quarter 2023 business update and 2024 outlook Three main pillars to unlock the potential of proprietary technology platforms and intellectual property: • A proprietary non-gene editing technology platform based on multiplexing of short hairpin ribonucleic acid (shRNAs)-derived sequences to broaden the capacities of CAR-Ts • Differentiated

January 17, 2024 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of January 2024 Commission File Number: 001-37

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of January 2024 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) 9 rue André Dumont 1435 Mont-Saint-Guibert, Belgium (Address of principal execu

December 21, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of December 2023 Commission File Number: 001-3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of December 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) 9 rue André Dumont 1435 Mont-Saint-Guibert, Belgium (Address of principal exec

December 21, 2023 EX-99.1

Publication of a transparency notification received from Fortress Investment Group LLC (Article 14 §1 of the Law of 2 May 2007)

Exhibit 99.1 Press Release - Regulated Information Publication of a transparency notification received from Fortress Investment Group LLC (Article 14 §1 of the Law of 2 May 2007) Mont-Saint-Guibert, Belgium, December 20, 2023, 10.01 pm CET—regulated information – Celyad Oncology SA (Euronext: CYAD) (“Celyad Oncology” or the “Company”) today announces, in accordance with Article 14 of the Belgian L

December 18, 2023 EX-99.1

Information on the Total Number of Voting Rights and Shares (Article 15 of the Law of 2 May 2007)

Exhibit 99.1 Press Release - Regulated Information Information on the Total Number of Voting Rights and Shares (Article 15 of the Law of 2 May 2007) Mont-Saint-Guibert, Belgium, December 15, 2023, 10:01 pm CET; regulated information – Celyad Oncology (Euronext: CYAD) (the “Company” or “Celyad Oncology”), today announces that 6,500,000 shares of CFIP CLYD (UK) Limited benefit from a double voting r

December 18, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of December 2023 Commission File Number: 001-3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of December 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) 9 rue André Dumont 1435 Mont-Saint-Guibert, Belgium (Address of principal exec

December 4, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of December 2023 Commission File Number: 001-3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of December 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) 9 rue André Dumont 1435 Mont-Saint-Guibert, Belgium (Address of principal exec

December 4, 2023 EX-99.1

Celyad announces management change

Exhibit 99.1 Regulated Information Inside Information Celyad announces management change December 1st 2023, Mont-Saint-Guibert, Belgium—Celyad Oncology (Euronext: CYAD), a cutting-edge biotechnology company dedicated to pioneering the discovery and advancement of revolutionary technologies for chimeric antigen receptor (CAR) T-cells announces that its CEO and managing director Georges Rawadi has d

December 4, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of December 2023 Commission File Number: 001-3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of December 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) 9 rue André Dumont 1435 Mont-Saint-Guibert, Belgium (Address of principal exec

December 4, 2023 EX-99.1

Publication of a transparency notification received from Tolefi SA (Article 14 §1 of the Law of 2 May 2007)

Exhibit 99.1 Press Release - Regulated Information Publication of a transparency notification received from Tolefi SA (Article 14 §1 of the Law of 2 May 2007) Mont-Saint-Guibert, Belgium, November 30, 2023, 10.01 pm CET - regulated information – Celyad Oncology SA (Euronext: CYAD) (“Celyad Oncology” or the “Company”) today announced, in accordance with Article 14 of the Belgian Law of 2 May 2007 r

November 24, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of November 2023 Commission File Number: 001-3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of November 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) 9 rue André Dumont 1435 Mont-Saint-Guibert, Belgium (Address of principal exec

November 24, 2023 EX-99.1

Celyad Oncology reports third quarter 2023 financial results and recent business highlights

Exhibit 99.1 Press Release - Regulated Information Celyad Oncology reports third quarter 2023 financial results and recent business highlights • Publication of data detailing the development of our microRNA (miRNA)-based multiplex shRNA approach, which allows to down-regulate several genes simultaneously, in Molecular Therapy – Nucleic Acids • Five posters were presented at the 38th SITC Annual Me

November 21, 2023 EX-99.1

Publication of a transparency notification received from Fortress Investment Group LLC (Article 14 §1 of the Law of 2 May 2007)

Exhibit 99.1 Press Release - Regulated Information Publication of a transparency notification received from Fortress Investment Group LLC (Article 14 §1 of the Law of 2 May 2007) Mont-Saint-Guibert, Belgium, November 21, 2023, 10.01 pm CET—regulated information – Celyad Oncology SA (Euronext: CYAD) (“Celyad Oncology” or the “Company”) today announced, in accordance with Article 14 of the Belgian L

November 21, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of November 2023 Commission File Number: 001-3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of November 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) 9 rue André Dumont 1435 Mont-Saint-Guibert, Belgium (Address of principal exec

November 21, 2023 EX-99.1

CELYAD ONCOLOGY SA Listed limited liability company Rue André Dumont, 9 1435 Mont-Saint-Guibert LER Nivelles 0891.118.115 CONVENING LETTER TO THE EXTRAORDINARY GENERAL MEETING OF SHAREHOLDERS OF 22 DECEMBER 2023

Exhibit 99.1 CELYAD ONCOLOGY SA Listed limited liability company Rue André Dumont, 9 1435 Mont-Saint-Guibert LER Nivelles 0891.118.115 CONVENING LETTER TO THE EXTRAORDINARY GENERAL MEETING OF SHAREHOLDERS OF 22 DECEMBER 2023 The board of directors has the honor to convene the shareholders and warrant holders of Celyad Oncology SA (the “Company”) to attend the extraordinary general meeting to be he

November 21, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of November 2023 Commission File Number: 001-3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of November 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) 9 rue André Dumont 1435 Mont-Saint-Guibert, Belgium (Address of principal exec

November 15, 2023 EX-99.1

Information on the Total Number of Voting Rights and Shares (Article 15 of the Law of 2 May 2007)

Exhibit 99.1 Press Release - Regulated Information Information on the Total Number of Voting Rights and Shares (Article 15 of the Law of 2 May 2007) Mont-Saint-Guibert, Belgium; November 14, 2023, 10:00 pm CET; regulated information – Celyad Oncology (Euronext: CYAD) (the “Company” or “Celyad Oncology”), today announces the below information following the issuance, on 14 November 2023, of 14,903,8

November 15, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of November 2023 Commission File Number: 001-3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of November 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) 9 rue André Dumont 1435 Mont-Saint-Guibert, Belgium (Address of principal exec

October 27, 2023 EX-99.1

CELYAD ONCOLOGY SA Listed limited liability company Rue André Dumont 9 1435 Mont-Saint-Guibert LER Nivelles 0891.118.115 CONVENING LETTER TO THE EXTRAORDINARY GENERAL MEETING OF SHAREHOLDERS OF 14 NOVEMBER 2023

Exhibit 99.1 CELYAD ONCOLOGY SA Listed limited liability company Rue André Dumont 9 1435 Mont-Saint-Guibert LER Nivelles 0891.118.115 CONVENING LETTER TO THE EXTRAORDINARY GENERAL MEETING OF SHAREHOLDERS OF 14 NOVEMBER 2023 The board of directors has the honor to convene the shareholders and warrant holders of Celyad Oncology SA (the “Company”) to attend the extraordinary general meeting to be hel

October 27, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of October 2023 Commission File Number: 001-37

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of October 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) 9 rue André Dumont 1435 Mont-Saint-Guibert, Belgium (Address of principal execu

September 26, 2023 EX-99.1

CELYAD ONCOLOGY ANNOUNCES THE TERMINATION OF ITS AMERICAN DEPOSITORY RECEIPT PROGRAM

Exhibit 99.1 Press Release – Regulated Information CELYAD ONCOLOGY ANNOUNCES THE TERMINATION OF ITS AMERICAN DEPOSITORY RECEIPT PROGRAM Mont-Saint-Guibert, Belgium, September 25, 2023, 10.01 pm CET—regulated information – Celyad Oncology SA (Euronext: CYAD) (“Celyad Oncology” or the “Company”) today announces that Citibank, N.A., as depositary (“Citibank”), shall issue the notice of terminating it

September 26, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2023 Commission File Number: 001-

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal ex

September 22, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2023 Commission File Number: 001-

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal ex

September 22, 2023 EX-99.1

CELYAD ONCOLOGY SA Listed limited liability company Rue Edouard Belin, 2 1435 Mont-Saint-Guibert LER Nivelles 0891.118.115 CONVENING LETTER TO THE EXTRAORDINARY GENERAL MEETING OF SHAREHOLDERS OF 25 OCTOBER 2023

Exhibit 99.1 CELYAD ONCOLOGY SA Listed limited liability company Rue Edouard Belin, 2 1435 Mont-Saint-Guibert LER Nivelles 0891.118.115 CONVENING LETTER TO THE EXTRAORDINARY GENERAL MEETING OF SHAREHOLDERS OF 25 OCTOBER 2023 The board of directors has the honor to convene the shareholders and warrant holders of Celyad Oncology SA (the “Company”) to attend the extraordinary general meeting to be he

September 18, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2023 Commission File Number: 001-

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principa

September 18, 2023 EX-99.1

Publication of a rectified transparency notification received from Fortress Investment Group LLC (Article 14 §1 of the Law of 2 May 2007)

EX-99.1 Exhibit 99.1 Press Release - Regulated Information Publication of a rectified transparency notification received from Fortress Investment Group LLC (Article 14 §1 of the Law of 2 May 2007) Mont-Saint-Guibert, Belgium, September 15, 2023, 10.01 pm CET – regulated information – Celyad Oncology SA (Euronext: CYAD) (“Celyad Oncology” or the “Company”) today announced, in accordance with Articl

September 13, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2023 Commission File Number: 001-

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal ex

September 13, 2023 EX-99.1

Publication of a transparency notification received from Tolefi SA (Article 14 §1 of the Law of 2 May 2007)

Exhibit 99.1 Press Release - Regulated Information Publication of a transparency notification received from Tolefi SA (Article 14 §1 of the Law of 2 May 2007) Mont-Saint-Guibert, Belgium, September 12, 2023, 10.01 pm CET—regulated information – Celyad Oncology SA (Euronext: CYAD) (“Celyad Oncology” or the “Company”) today announced, in accordance with Article 14 of the Belgian Law of 2 May 2007 re

September 11, 2023 EX-99.1

Publication of a transparency notification received from Fortress Investment Group LLC (Article 14 §1 of the Law of 2 May 2007)

EX-99.1 Exhibit 99.1 Press Release - Regulated Information Publication of a transparency notification received from Fortress Investment Group LLC (Article 14 §1 of the Law of 2 May 2007) Mont-Saint-Guibert, Belgium, September 7, 2023, 10.01 pm CET—regulated information – Celyad Oncology SA (Euronext: CYAD) (“Celyad Oncology” or the “Company”) today announced, in accordance with Article 14 of the B

September 11, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2023 Commission File Number: 001-

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principa

September 6, 2023 EX-99.1

Information on the Total Number of Voting Rights and Shares (Article 15 of the Law of 2 May 2007)

Exhibit 99.1 Press Release - Regulated Information Information on the Total Number of Voting Rights and Shares (Article 15 of the Law of 2 May 2007) Mont-Saint-Guibert, Belgium; September 05, 2023, 10:00 pm CET; regulated information – Celyad Oncology (Euronext: CYAD) (the “Company” or “Celyad Oncology”), today announces the below information following the issuance, on 04 September 2023, of 3,930,

September 6, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2023 Commission File Number: 001-

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal ex

September 5, 2023 EX-99.1

Celyad Oncology Reports First Half 2023 Financial Results and Recent Business Highlights

EX-99.1 Exhibit 99.1 Press Release - Regulated Information Celyad Oncology Reports First Half 2023 Financial Results and Recent Business Highlights • Georges Rawadi was appointed Chief Executive Officer as from April 27, 2023 • Celyad Oncology has received approximately EUR 9.8m in private placement commitments from historical shareholders • Encouraging progress in multiplex shRNA platform develop

September 5, 2023 EX-99.2

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

Exhibit 99.2 INTERIM FINANCIAL REPORT First Half 2023 REGULATED INFORMATION This Interim Financial Report has been prepared in accordance with the article 13 of the Belgian Royal Decree of November 14, 2007. Celyad Oncology publishes its Interim Financial Report in French. Celyad Oncology has also produced an English translation of this Interim Financial Report for convenience purposes only. In th

September 5, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2023 Commission File Number: 001-

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal ex

September 5, 2023 EX-99.7

AMENDED AND RESTATED SHAREHOLDERS’ RIGHTS AGREEMENT BY AND AMONG CFIP CLYD (UK) LIMITED CELYAD ONCOLOGY SA Dated as of September 4, 2023 TABLE OF CONTENTS

EX-99.7 2 ex7.htm EXHIBIT 7 - AMENDED AND RESTATED SHAREHOLDERS' RIGHTS AGREEMENT EXHIBIT 7 SPECIFIC TERMS IN THIS EXHIBIT HAVE BEEN REDACTED. THESE REDACTED TERMS HAVE BEEN MARKED IN THIS EXHIBIT WITH THREE ASTERISKS [***]. AMENDED AND RESTATED SHAREHOLDERS’ RIGHTS AGREEMENT BY AND AMONG CFIP CLYD (UK) LIMITED AND CELYAD ONCOLOGY SA Dated as of September 4, 2023 TABLE OF CONTENTS Page ARTICLE I D

September 5, 2023 SC 13D/A

CYAD / Celyad Oncology - ADR / Fortress Investment Group LLC - SCHEDULE 13D, AMENDMENT NO. 2 Activist Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 2)* Celyad Oncology SA (Name of Issuer) Ordinary shares, no nominal value per share (Title of Class of Securities) 151205200** (CUSIP Number) David N. Brooks Fortress Investment Group LLC 1345 Avenue of the Americas, 46th Floor New York, NY 10105 (212) 798-6100 (Name, Add

September 5, 2023 EX-99.8

JOINT FILING AGREEMENT PURSUANT TO RULE 13D-1(K)

EXHIBIT 8 JOINT FILING AGREEMENT PURSUANT TO RULE 13D-1(K) The undersigned acknowledge and agree that the foregoing statement on Amendment No.

August 25, 2023 EX-99.1

Page 1 of 4

Exhibit 99.1 Celyad Oncology receives approximately EUR 9.8m in private placement commitments from historical shareholders Mont-Saint-Guibert, Belgium, 24 August 2023, 22.01 CET, regulated information / inside information - Celyad Oncology SA (“Celyad” or the “Company”) today announced that it has obtained commitments from an affiliate of Fortress Investment Group (such affiliate, “Fortress”), Tol

August 25, 2023 EX-10.3

SUBSCRIPTION AGREEMENT AUGUST 24, 2023 TOLEFI SA CELYAD ONCOLOGY SA Allen & Overy LLP

Exhibit 10.3 SPECIFIC TERMS IN THIS EXHIBIT HAVE BEEN REDACTED. THESE REDACTED TERMS HAVE BEEN MARKED IN THIS EXHIBIT WITH THREE ASTERISKS [***]. SUBSCRIPTION AGREEMENT AUGUST 24, 2023 between TOLEFI SA and CELYAD ONCOLOGY SA Allen & Overy LLP CONTENTS 1.  Definitions 1 1.1 Defined Terms 1 1.2 Additional Defined Terms 3 2.  Subscription and Issuance of Ordinary Shares 4 3.  Closing Date; Deliverie

August 25, 2023 EX-10.1

SUBSCRIPTION AGREEMENT CFIP CLYD (UK) LIMITED CELYAD ONCOLOGY SA Dated as of August 24, 2023

Exhibit 10.1 SPECIFIC TERMS IN THIS EXHIBIT HAVE BEEN REDACTED. THESE REDACTED TERMS HAVE BEEN MARKED IN THIS EXHIBIT WITH THREE ASTERISKS [***]. SUBSCRIPTION AGREEMENT Between CFIP CLYD (UK) LIMITED AND CELYAD ONCOLOGY SA Dated as of August 24, 2023 TABLE OF CONTENTS Page 1. Definitions 1 1.1 Defined Terms 1 1.2 Additional Defined Terms 3 2. Subscription and Issuance of Ordinary Shares 6 3. Closi

August 25, 2023 EX-10.4

FORM OF SHAREHOLDER’S RIGHTS AGREEMENT

Exhibit 10.4 SPECIFIC TERMS IN THIS EXHIBIT HAVE BEEN REDACTED. THESE REDACTED TERMS HAVE BEEN MARKED IN THIS EXHIBIT WITH THREE ASTERISKS [***]. FORM OF SHAREHOLDER’S RIGHTS AGREEMENT THIS SHAREHOLDER’S RIGHTS AGREEMENT (this “Agreement”) is made as of [●] 2023, by and between Tolefi SA (“Tolefi”), a limited liability company incorporated and existing under the laws of Belgium, having its registe

August 25, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of August 2023 Commission File Number: 001-374

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of August 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal execu

August 25, 2023 EX-10.2

FORM OF AMENDED AND RESTATED SHAREHOLDERS’ RIGHTS AGREEMENT BY AND AMONG CFIP CLYD LLC, CFIP CLYD (UK) LIMITED CELYAD ONCOLOGY SA Dated as of [•], 2023

Exhibit 10.2 SPECIFIC TERMS IN THIS EXHIBIT HAVE BEEN REDACTED. THESE REDACTED TERMS HAVE BEEN MARKED IN THIS EXHIBIT WITH THREE ASTERISKS [***]. FORM OF AMENDED AND RESTATED SHAREHOLDERS’ RIGHTS AGREEMENT BY AND AMONG CFIP CLYD LLC, CFIP CLYD (UK) LIMITED AND CELYAD ONCOLOGY SA Dated as of [•], 2023 TABLE OF CONTENTS Page ARTICLE I DEFINITIONS Section 1.1 Certain Defined Terms 1 Section 1.2 Const

August 24, 2023 EX-99.4

SUBSCRIPTION AGREEMENT CFIP CLYD (UK) LIMITED CELYAD ONCOLOGY SA Dated as of August 24, 2023 TABLE OF CONTENTS

EX-99.4 2 ex4.htm EXHIBIT 4 - SUBSCRIPTION AGREEMENT Exhibit 4 SPECIFIC TERMS IN THIS EXHIBIT HAVE BEEN REDACTED. THESE REDACTED TERMS HAVE BEEN MARKED IN THIS EXHIBIT WITH THREE ASTERISKS [***] SUBSCRIPTION AGREEMENT Between CFIP CLYD (UK) LIMITED AND CELYAD ONCOLOGY SA Dated as of August 24, 2023 TABLE OF CONTENTS Page 1. Definitions 1 1.1 Defined Terms 1 1.2 Additional Defined Terms 3 2. Subscr

August 24, 2023 SC 13D/A

CYAD / Celyad Oncology - ADR / Fortress Investment Group LLC - SCHEDULE 13D, AMENDMENT NO. 1 Activist Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 1)* Celyad Oncology SA (Name of Issuer) Ordinary shares, no nominal value per share (Title of Class of Securities) 151205200** (CUSIP Number) David N. Brooks Fortress Investment Group LLC 1345 Avenue of the Americas, 46th Floor New York, NY 10105 (212) 798-6100 (Name, Add

August 24, 2023 EX-99.5

FORM OF AMENDED AND RESTATED SHAREHOLDERS’ RIGHTS AGREEMENT BY AND AMONG CFIP CLYD LLC, CFIP CLYD (UK) LIMITED CELYAD ONCOLOGY SA Dated as of , 2023 TABLE OF CONTENTS

EX-99.5 3 ex5.htm EXHIBIT 5 - FORM OF AMENDED AND RESTATED SHAREHOLDERS' RIGHTS AGREEMENT Exhibit 5 SPECIFIC TERMS IN THIS EXHIBIT HAVE BEEN REDACTED. THESE REDACTED TERMS HAVE BEEN MARKED IN THIS EXHIBIT WITH THREE ASTERISKS [***]. FORM OF AMENDED AND RESTATED SHAREHOLDERS’ RIGHTS AGREEMENT BY AND AMONG CFIP CLYD LLC, CFIP CLYD (UK) LIMITED AND CELYAD ONCOLOGY SA Dated as of , 2023 TABLE OF CONTE

May 16, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of May 2023 Commission File Number: 001-37452

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of May 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal exec

May 16, 2023 EX-99.1

Celyad Oncology announces receipt of Nasdaq delisting notice

EX-99.1 Exhibit 99.1 Press Release - Regulated Information May 15, 2023 10:00 pm CET Celyad Oncology announces receipt of Nasdaq delisting notice Mont-Saint-Guibert, Belgium - Celyad Oncology (Euronext & Nasdaq: CYAD) (the “Company”), is a biotechnology company focused on innovative technologies for chimeric antigen receptor (CAR) T-cell therapies. The Company had previously announced on April 4,

May 5, 2023 EX-99.1

CELYAD ONCOLOGY ANNOUNCES INTENT TO VOLUNTARILY DELIST AMERICAN DEPOSITORY SHARES FROM NASDAQ

EX-99.1 Exhibit 99.1 Press Release - Regulated Information May 5th, 2023 7:00 am CET CELYAD ONCOLOGY ANNOUNCES INTENT TO VOLUNTARILY DELIST AMERICAN DEPOSITORY SHARES FROM NASDAQ Mont-Saint-Guibert, Belgium - Celyad Oncology (Euronext & Nasdaq: CYAD) (the “Company”), a biotechnology company focused on innovative technologies for chimeric antigen receptor (CAR) T-cell therapies, today announced tha

May 5, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of May 2023 Commission File Number: 001-37452

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of May 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal exec

May 5, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of May 2023 Commission File Number: 001-37452

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of May 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal exec

May 5, 2023 EX-99.1

Celyad Oncology reports first quarter 2023 financial results and recent business highlights

EX-99.1 2 d322505dex991.htm EX-99.1 Exhibit 99.1 Press Release - Regulated Information May 5th, 2023 7:00 am CET Celyad Oncology reports first quarter 2023 financial results and recent business highlights • Presentation of updated data on our multiplex shRNA platform, which allows targeting of up to four genes simultaneously • Publication of results from the THINK trial, which provided proof-of-co

April 24, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of April 2023 Commission File Number: 001-3745

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of April 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal execut

April 24, 2023 EX-99.1

Celyad Oncology announces receipt of Nasdaq initial notification on ADS bid price

EX-99.1 Exhibit 99.1 Press Release - Regulated Information April 24th, 2023 10:01 pm CET Celyad Oncology announces receipt of Nasdaq initial notification on ADS bid price Mont-Saint-Guibert, Belgium – Celyad Oncology (Euronext & Nasdaq: CYAD) (the “Company”), a biotechnology company focused on innovative technologies for chimeric antigen receptor (CAR) T-cell therapies, received a letter (the “Bid

April 5, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of April 2023 Commission File Number: 001-3745

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of April 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal execut

April 5, 2023 EX-99.1

Celyad Oncology announces receipt of Nasdaq notice

EX-99.1 Exhibit 99.1 Press Release - Regulated Information April 4th, 2023 10:00 pm CET Celyad Oncology announces receipt of Nasdaq notice Mont-Saint-Guibert, Belgium - Celyad Oncology (Euronext & Nasdaq: CYAD) (the “Company”), a biotechnology company focused on innovative technologies for chimeric antigen receptor (CAR) T-cell therapies, received a letter (the “Letter”) on March 31, 2023 from The

April 4, 2023 EX-99.1

CELYAD ONCOLOGY SA Listed limited liability company Rue Edouard Belin, 2 1435 Mont-Saint-Guibert LER Nivelles 0891.118.115 CONVENING LETTER TO THE ORDINARY GENERAL MEETING OF SHAREHOLDERS OF 5 MAY 2023

EX-99.1 Exhibit 99.1 CELYAD ONCOLOGY SA Listed limited liability company Rue Edouard Belin, 2 1435 Mont-Saint-Guibert LER Nivelles 0891.118.115 CONVENING LETTER TO THE ORDINARY GENERAL MEETING OF SHAREHOLDERS OF 5 MAY 2023 The board of directors has the honor to convene the shareholders and warrant holders of Celyad Oncology SA (the “Company”) to attend the ordinary general meeting to be held on 5

April 4, 2023 EX-99.2

CELYAD ONCOLOGY S.A Société anonyme Rue Edouard Belin, 2, 1435 Mont-Saint-Guibert 0891.118.115 (RPM Brabant Wallon) (the « Company » or «Celyad»)

EX-99.2 Exhibit 99.2 CELYAD ONCOLOGY S.A Société anonyme Rue Edouard Belin, 2, 1435 Mont-Saint-Guibert 0891.118.115 (RPM Brabant Wallon) www.celyad.com [email protected] (the « Company » or «Celyad») SPECIAL REPORT OF THE BOARD OF DIRECTORS TO THE GENERAL SHAREHOLDERS’ MEETING IN ACCORDANCE WITH ARTICLE 7:228 OF THE BELGIAN COMPANIES AND ASSOCIATIONS CODE1 Ladies and Gentlemen, Shareholders, The Boa

April 4, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of April 2023 Commission File Number: 001-3745

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of April 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal execut

March 24, 2023 EX-99.1

Celyad Oncology appoints Georges Rawadi as its new CEO

EX-99.1 Exhibit 99.1 Press Release - Regulated Information March 24th, 2023 07:00 am CET Celyad Oncology appoints Georges Rawadi as its new CEO March 24, 2023 Mont-Saint-Guibert, Belgium - Celyad Oncology (Euronext & Nasdaq: CYAD) (the “Company”), a biotechnology company focused on innovative technologies for chimeric antigen receptor (CAR) T-cell therapies, is pleased to announce Georges Rawadi a

March 24, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of March 2023 Commission File Number: 001-3745

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of March 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal execut

March 23, 2023 EX-99.2

EX-99.2

Annual Report 2022 www.celyad.com 2022 ANNUAL REPORT 2022 Annual Report Page 1 | 172 Table of Contents SHAREHOLDERS NEWSLETTER 1. ACTIVITY REPORT ................................................................................................................................ 7 1.1 Who we are - Business Overview ........................................................................................

March 23, 2023 EX-13.1

Certification by the Principal Executive Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

EX-13.1 Exhibit 13.1 Certification by the Principal Executive Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 In connection with the annual report of Celyad SA (the “Company”) on Form 20-F for the fiscal year ended December 31, 2022 as filed with the U.S. Securities and Exchange Commission on the date hereof (the “Report”), I, Michel

March 23, 2023 EX-99.1

Celyad Oncology reports full year 2022 financial results and recent business highlights Starting in 2023, Celyad Oncology is now entirely focused on its new business strategy with one clear objective: help to overcome the current limitations of CAR-T

EX-99.1 Exhibit 99.1 Press Release - Regulated Information March 23rd, 2023 10:01 pm CET Celyad Oncology reports full year 2022 financial results and recent business highlights Starting in 2023, Celyad Oncology is now entirely focused on its new business strategy with one clear objective: help to overcome the current limitations of CAR-T approaches. It plans to do this via (i) strengthening of its

March 23, 2023 EX-12.2

Certification by the Principal Financial Officer pursuant to Securities Exchange Act Rules 13a-14(a) and 15d-14(a) as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

EX-12.2 Exhibit 12.2 Certification by the Principal Financial Officer pursuant to Securities Exchange Act Rules 13a-14(a) and 15d-14(a) as adopted pursuant to Section 302 of the Sarbanes- Oxley Act of 2002 I, David Georges, certify that: 1. I have reviewed this annual report on Form 20-F of Celyad Oncology SA; 2. Based on my knowledge, this report does not contain any untrue statement of a materia

March 23, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of March 2023 Commission File Number: 001-3745

6-K 1 d479733d6k.htm 6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of March 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Ad

March 23, 2023 EX-16.1

Letter from EY Réviseurs d’Entreprises / EY Bedrijfsrevisoren SRL/BV to the SEC, dated March 23, 2023 regarding the change in independent registered public accounting firm

EX-16.1 Exhibit 16.1 March 23, 2023 Securities and Exchange Commission 100 F Street, N.E. Washington, DC 20549 Ladies and Gentlemen: We have read Item 16F. Change in Registrant’s Certifying Accountant on page 145 of Form 20-F dated March 23, 2023, of Celyad Oncology SA and are in agreement with the statements contained in paragraphs one, four, five, six and seven. We have no basis to agree or disa

March 23, 2023 EX-12.1

Certification by the Principal Executive Officer pursuant to Securities Exchange Act Rules 13a-14(a) and 15d-14(a) as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

EX-12.1 Exhibit 12.1 Certification by the Principal Executive Officer pursuant to Securities Exchange Act Rules 13a-14(a) and 15d-14(a) as adopted pursuant to Section 302 of the Sarbanes- Oxley Act of 2002 I, Michel Lussier, certify that: 1. I have reviewed this annual report on Form 20-F of Celyad Oncology SA; 2. Based on my knowledge, this report does not contain any untrue statement of a materi

March 23, 2023 EX-15.1

Consent of EY Réviseurs d’Entreprises / EY Bedrijfsrevisoren SRL/BV, independent registered public accounting firm

EX-15.1 Exhibit 15.1 Consent of independent registered public accounting firm We consent to the incorporation by reference in the following Registration Statements: (1) Registration Statement (Form F-3 No. 333-248464) of Celyad Oncology SA, and (2) Registration Statement (Form S-8 No. 333-220737) pertaining to the Warrants plan 2017 of our reports dated March 23, 2023, with respect to the consolid

March 23, 2023 EX-1.1

Articles of Association (English translation)

EX-1.1 Exhibit 1.1 SCRL civile Berquin Notaires – avenue Lloyd George 11 – 1000 Bruxelles VAT BE 0474.073.840 – BRUSSELS Registry of Legal Entities – www.berquinnotaires.be Tel.: +32(2)645.19.45 Fax: +32(2)645.19.46 Coordinated Articles of Association of the listed société anonyme (a Belgian corporation) “Celyad Oncology” at 1435 Mont-Saint-Guibert, Rue Edouard Belin 2, company number 0891.118.115

March 23, 2023 EX-4.25

Warrants Plan 2022 (English Translation)

EX-4.25 3 d418841dex425.htm EX-4.25 Exhibit 4.25 CELYAD ONCOLOGY SA Listed limited liability company WARRANTS PLAN 2022 Template Template of incentive plan to be used for any grant of subscription rights (Warrants) established in accordance with the Companies and Associations Code and articles 41 to 47 of the Act of 26 March 1999 relating to the Belgian action plan for employment 1998 and having v

March 23, 2023 20-F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 20-F (Mark One) ☐ REGISTRATION STATEMENT PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SE

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 20-F (Mark One) ☐ REGISTRATION STATEMENT PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF

March 23, 2023 EX-13.2

Certification by the Principal Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

EX-13.2 Exhibit 13.2 Certification by the Principal Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 In connection with the annual report of Celyad SA (the “Company”) on Form 20-F for the fiscal year ended December 31, 2022 as filed with the U.S. Securities and Exchange Commission on the date hereof (the “Report”), I, David

March 15, 2023 EX-99.1

Celyad Oncology announces non-cash impairment

EX-99.1 Exhibit 99.1 Press Release - Regulated Information March 15th, 2023 07:00 am CET Celyad Oncology announces non-cash impairment Mont-Saint-Guibert, Belgium - Celyad Oncology (Euronext & Nasdaq: CYAD) (the “Company”), a biotechnology company focused on the discovery and development of innovative technologies for chimeric antigen receptor (CAR) T-cell therapies, today announced a non-cash imp

March 15, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of March 2023 Commission File Number: 001-3745

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of March 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal execut

March 8, 2023 EX-99.1

Letter to Shareholders

EXHIBIT 99.1 Press Release - Regulated Information Letter to Shareholders March 1st, 2023 07:00 am CET Letter to Shareholders Dear Shareholder, 2022 has been a crossroad year for Celyad Oncology (the “Company”), with important changes and turning points. Whilst our clinical programs had clear potential, as we pursued clinical development over the years, we systematically discovered more effective

March 8, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of March 2023 Commission File Number: 001-3745

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of March 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal execut

February 3, 2023 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of February 2023 Commission File Number: 001-3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of February 2023 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal exe

February 3, 2023 EX-99.1

Celyad Oncology provides fourth quarter 2022 business update and 2023 outlook

Exhibit 99.1 Press Release - Regulated Information February 3rd, 2023 Celyad Oncology provides fourth quarter 2022 business update and 2023 outlook Celyad Oncology has implemented a strategic shift from an organization focused on clinical development to one fully harnessing the true potential of its proprietary technology platforms and intellectual property • The company is now prioritizing intern

December 21, 2022 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of December 2022 Commission File Number: 001-3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of December 2022 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant?s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal exe

December 21, 2022 EX-99.1

Page 1 of 2

Exhibit 99.1 Regulated Information Inside Information Celyad Oncology provides an update on its strategic business model, continuing to focus on opportunities to fully harness the true potential of its proprietary technology platforms and intellectual property Mont-Saint-Guibert, Belgium?Celyad Oncology (Euronext & Nasdaq: CYAD) (the ?Company?), a biotechnology company focused on the discovery and

November 10, 2022 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of November 2022 Commission File Number: 001-3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of November 2022 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant?s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal exe

November 10, 2022 EX-99.1

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

Exhibit 99.1 Regulated Information Celyad Oncology Announces Third Quarter 2022 Financial Results and Recent Business Highlights ? Company continues to transition business focus to monetizing unique cell therapy intellectual property and prioritizing R&D discovery ? Clinical updates expected by end of year for the Phase 1 dose-escalation IMMUNICY-1 trial for lead shRNA-based allogeneic CAR T candi

October 12, 2022 EX-99.1

Regulated Information

Exhibit 99.1 Regulated Information Inside Information Celyad Oncology Provides Strategic Update Mont-Saint-Guibert, Belgium - Celyad Oncology (Euronext & Nasdaq: CYAD), a biotechnology company focused on the discovery and development of chimeric antigen receptor T cell (CAR T) therapies for cancer, today provided an update on its strategic business model, clinical trial programs, and the related o

October 12, 2022 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of October 2022 Commission File Number: 001-37

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of October 2022 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal exec

September 20, 2022 EX-99.1

Regulated Information

Exhibit 99.1 Regulated Information Inside Information Cellistic and Celyad Oncology Announce GMP Cell Therapy Manufacturing Operations Transaction Gosselies and Mont-Saint-Guibert, Belgium?Cellistic, the cell therapy development and manufacturing business of Ncardia BV, and Celyad Oncology (Euronext & Nasdaq: CYAD), a clinical-stage biotechnology company focused on the discovery and development of

September 20, 2022 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2022 Commission File Number: 001-

6-K 1 d665141d6k.htm 6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2022 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium

August 5, 2022 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of August 2022 Commission File Number: 001-374

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of August 2022 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal execu

August 5, 2022 EX-99.1

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

Exhibit 99.1 Regulated Information Celyad Oncology Reports First Half 2022 Financial Results and Recent Business Highlights August 5, 2022, 7:00 a.m. CEST ? Enrollment ongoing in Phase 1 dose-escalation IMMUNICY-1 trial for lead shRNA-based allogeneic CAR T candidate, CYAD-211, for relapsed/refractory (r/r) multiple myeloma (MM) ? In July 2022, the U.S. Food and Drug Administration (FDA) lifted th

August 5, 2022 EX-99.2

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

Exhibit 99.2 INTERIM FINANCIAL REPORT First Half 2022 REGULATED INFORMATION This Interim Financial Report has been prepared in accordance with the article 13 of the Belgian Royal Decree of November 14, 2007. Celyad Oncology publishes its Interim Financial Report in French. Celyad Oncology has also produced an English translation of this Interim Financial Report for convenience purposes only. In th

August 1, 2022 EX-99.1

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

Exhibit 99.1 Regulated Information Celyad Oncology Announces FDA Lifts Clinical Hold of CYAD-101-002 Phase 1b Trial Mont-Saint-Guibert, Belgium - Celyad Oncology SA (Euronext & Nasdaq: CYAD), a clinical-stage biotechnology company focused on the discovery and development of chimeric antigen receptor T cell (CAR T) therapies for cancer, today announced that the U.S. Food and Drug Administration (FD

August 1, 2022 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of August 2022 Commission File Number: 001-374

6-K 1 d386559d6k.htm FORM 6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of August 2022 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgi

June 24, 2022 EX-99.1

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

Exhibit 99.1 Regulated Information Inside Information June 24th, 2022 7:01 AM CET Celyad Oncology Announces Leadership Updates Mont-Saint-Guibert, Belgium ? Celyad Oncology SA (Euronext & Nasdaq: CYAD) (the ?Company?), a clinical-stage biotechnology company focused on the discovery and development of chimeric antigen receptor T cell (CAR T) therapies for cancer, today announced that the Board of D

June 24, 2022 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of June 2022 Commission File Number: 001-37452

6-K 1 d354488d6k.htm 6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of June 2022 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Add

May 6, 2022 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of May 2022 Commission File Number: 001-37452

6-K 1 d308730d6k.htm 6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of May 2022 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Addr

May 6, 2022 EX-99.2

Celyad Oncology SA Unaudited interim consolidated statement of comprehensive income (€‘000) For the three-month period ended March 31, 2022 2021 Revenue — — Cost of sales — — Gross profit — — Research and Development expenses (4.978 ) (4 739 ) Genera

Exhibit 99.2 Celyad Oncology SA Unaudited interim consolidated statement of comprehensive income (??000) For the three-month period ended March 31, 2022 2021 Revenue ? ? Cost of sales ? ? Gross profit ? ? Research and Development expenses (4.978 ) (4 739 ) General & Administrative expenses (2.750 ) (2 341 ) Change in fair value of contingent consideration (55 ) (2 220 ) Other income 1.123 670 Othe

May 6, 2022 EX-99.1

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

Exhibit 99.1 Regulated Information May 5th, 2022 4:01 PM ET Celyad Oncology Announces First Quarter 2022 Financial Results and Recent Business Highlights ? Enrollment continues in Phase 1 dose-escalation IMMUNICY-1 trial for lead shRNA-based allogeneic CAR T candidate, CYAD-211, for relapsed/refractory multiple myeloma (r/r MM) ? Dialogue continues with regulatory agencies concerning CYAD-101-002

March 25, 2022 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of March 2022 Commission File Number: 001-3745

6-K 1 d303068d6k.htm 6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of March 2022 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Ad

March 25, 2022 EX-99.1

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

Exhibit 99.1 Regulated Information March 24th, 2022 4:01 PM ET Celyad Oncology Reports Full Year 2021 Financial Results and Recent Business Highlights ? Phase 1 IMMUNICY-1 trial demonstrated encouraging data to date for CYAD-211 including a good tolerability profile and evidence of clinical activity in relapsed/refractory multiple myeloma (r/r MM) patients ? Investigation ongoing of findings in CY

March 24, 2022 EX-4.32

Warrants Plan 2021 (English Translation)

Exhibit 4.32 CELYAD ONCOLOGY SA 2021 WARRANTS PLAN Incentive plan relating to a grant of subscription rights (Warrants) established in accordance with the Companies and Associations Code and articles 41 to 47 of the Act of 26 March 1999 relating to the Belgian action plan for employment 1998 and having various provisions PREAMBLE This Warrants Plan of CELYAD ONCOLOGY SA (the ?Plan?) aims to motiva

March 24, 2022 EX-15.2

Consent of EY Bedrijfsrevisoren BV/Réviseurs d’Entreprises SRL, independent registered public accounting firm

Exhibit 15.2 Consent of independent registered public accounting firm We consent to the incorporation by reference in the following Registration Statements: (1) Registration Statement (Form F-3 No. 333-248464) of Celyad Oncology SA, and (2) Registration Statement (Form S-8 No. 333-220737) pertaining to the Warrants plan 2017 of our reports dated March 24, 2022, with respect to the consolidated fin

March 24, 2022 EX-12.1

Certification by the Principal Executive Officer and Principal Financial Officer pursuant to Securities Exchange Act Rules 13a-14(a) and 15d-14(a) as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

EX-12.1 Exhibit 12.1 Certification by the Principal Executive Officer and Principal Financial Officer pursuant to Securities Exchange Act Rules 13a-14(a) and 15d-14(a) as adopted pursuant to Section 302 of the Sarbanes- Oxley Act of 2002 I, Filippo Petti, certify that: 1. I have reviewed this annual report on Form 20-F of Celyad Oncology SA.; 2. Based on my knowledge, this report does not contain

March 24, 2022 EX-15.1

Consent of BDO Réviseurs d’Entreprises SRL, independent registered public accounting firm

Exhibit 15.1 Consent of independent registered public accounting firm Celyad Oncology SA Mont-Saint-Guibert, Belgium We hereby consent to the incorporation by reference in the Registration Statements on Form F-3 (No. 333-220285 and No. 333-248464) and Form S-8 (No. 333-220737) of Celyad Oncology SA of our report dated March 24, 2020, relating to the consolidated financial statements which appears

March 24, 2022 EX-4.31

Fifth Amendment to Exclusive License Agreement, dated as of December 14, 2021, by and between Celyad Oncology SA and Trustees of Dartmouth College

Exhibit 4.31 Certain portions of this exhibit have been omitted because they are not material and the registrant customarily and actually treats that information as private or confidential. FIFTH AMENDMENT TO EXCLUSIVE LICENSE AGREEMENT This Fifth Amendment to Exclusive License Agreement (this ?Amendment?) is made and entered into as of this 14 December, 2021 (the ?Amendment Effective Date?) by an

March 24, 2022 20-F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 20-F (Mark One) ☐ REGISTRATION STATEMENT PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SE

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 20-F (Mark One) ? REGISTRATION STATEMENT PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR ? ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF

March 24, 2022 EX-1.1

Articles of Association (English translation)

Exhibit 1.1 SCRL civile Berquin Notaires ? avenue Lloyd George 11 - 1000 Bruxelles VAT BE 0474.073.840 ? BRUSSELS Registry of Legal Entities ? www.berquinnotaires.be Tel.: +32(2)645.19.45 Fax: +32(2)645.19.46 Coordinated Articles of Association of the listed soci?t? anonyme (a Belgian corporation) ?Celyad Oncology? at 1435 Mont-Saint-Guibert, Rue Edouard Belin 2, company number 0891.118.115 - Brab

March 24, 2022 EX-13.1

Certification by the Principal Executive Officer and Principal Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

EX-13.1 Exhibit 13.1 Certification by the Principal Executive Officer and Principal Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 In connection with the annual report of Celyad S.A. (the “Company”) on Form 20-F for the fiscal year ended December 31, 2021 as filed with the U.S. Securities and Exchange Commission on the dat

March 2, 2022 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of March 2022 Commission File Number: 001-3745

6-K 1 d304157d6k.htm 6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of March 2022 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Ad

February 28, 2022 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of February 2022 Commission File Number: 001-3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of February 2022 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant?s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal exe

February 28, 2022 EX-99.1

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

Exhibit 99.1 Regulated Information Inside Information Celyad Oncology Announces Voluntary Pause of CYAD-101-002 Phase 1b Trial Mont-Saint-Guibert, Belgium ? Celyad Oncology SA (Euronext & Nasdaq: CYAD) (the ?Company?), a clinical-stage biotechnology company focused on the discovery and development of chimeric antigen receptor T cell (CAR T) therapies for cancer, today announced it has taken the de

January 21, 2022 CORRESP

January 21, 2022

January 21, 2022 U.S. Securities and Exchange Commission Division of Corporation Finance Office of Life Sciences Washington, D.C 20549 100 F Street, N.E Attention: Li Xiao, Daniel Gordon Re: Celyad Oncology SA Form 20-F for the Fiscal Year Ended December 31, 2020 Response dated June 3, 2021 File No. 001-37452 Dear Madam, Dear Sir, This letter is submitted on behalf of Celyad Oncology SA (the ?Comp

January 12, 2022 EX-99.1

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

Exhibit 99.1 Celyad Oncology Provides Outlook for 2022 ? KEYNOTE-B79 and IMMUNICY-1 clinical trials evaluating the Company?s allogeneic CAR T candidates, CYAD-101 and CYAD-211 respectively, expected to generate key data throughout 2022 ? Company?s proprietary non-gene edited shRNA technology clinically validated as a novel platform for the development of next-generation, allogeneic CAR Ts ? Precli

January 12, 2022 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of January 2022 Commission File Number: 001-37

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of January 2022 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant?s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal exec

December 17, 2021 EX-99.3

JOINT FILING AGREEMENT PURSUANT TO RULE 13D-1(K)

EXHIBIT 3 JOINT FILING AGREEMENT PURSUANT TO RULE 13D-1(K) The undersigned acknowledge and agree that the foregoing statement on Schedule 13D is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule 13D may be filed on behalf of each of the undersigned without the necessity of filing additional joint filing agreements.

December 17, 2021 SC 13D

CYAD / Celyad SA / Fortress Investment Group LLC - SCHEDULE 13D Activist Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. )* Celyad Oncology SA (Name of Issuer) Ordinary shares, no nominal value per share (Title of Class of Securities) 151205200** (CUSIP Number) David N. Brooks Fortress Investment Group LLC 1345 Avenue of the Americas, 46th Floor New York, NY 10105 (212) 798-6100 (Name, Addr

December 13, 2021 EX-99.1

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

Exhibit 99.1 Celyad Oncology Presents Updates on shRNA-Based CAR T Programs at the 63rd ASH Annual Meeting and Exposition ? Data continues to support the versatile potential of non-gene edited shRNA technology with updates from the CYAD-02 and CYAD-211 clinical programs ? Management to host conference call today December 13th at 2:30 p.m. CET / 8:30 a.m. EST MONT-SAINT-GUIBERT, Belgium, December 1

December 13, 2021 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of December 2021 Commission File Number: 001-3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of December 2021 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal exe

December 13, 2021 EX-99.2

Forward Looking Statements

2021 American Society of Hematology Meeting Update December 13, 2021 Exhibit 99.2 Forward Looking Statements ASH 2021 Virtual Webcast ? Agenda Topic Discussant Welcome & Introductions Filippo Petti Chief Executive Officer shRNA Background David Gilham, Ph.D. Chief Scientific Officer CYAD-02 CYCLE-1 Phase 1 Trial Results Charles Morris, M.D. Chief Medical Officer CYAD-211 IMMUNICY-1 Phase 1 Trial R

December 8, 2021 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of December 2021 Commission File Number: 001-3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of December 2021 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant?s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal exe

December 8, 2021 EX-99.1

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

Exhibit 99.1 Celyad Oncology Announces Closing of $32.5 Million Private Placement with Fortress Investment Group Affiliate Mont-Saint-Guibert, Belgium ? Celyad Oncology SA (Euronext & Nasdaq: CYAD) (?Celyad? or the ?Company?), a clinical-stage biotechnology company focused on the discovery and development of chimeric antigen receptor T cell (CAR T) therapies for cancer, today announced the closing

December 3, 2021 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of December 2021 Commission File Number: 001-3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of December 2021 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant?s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal exe

December 3, 2021 EX-10.1

Subscription Agreement dated December 2, 2021, by and between CFIP CLYD LLC and the registrant

Exhibit 10.1 SPECIFIC TERMS IN THIS EXHIBIT HAVE BEEN REDACTED. THESE REDACTED TERMS HAVE BEEN MARKED IN THIS EXHIBIT WITH THREE ASTERISKS [***]. SUBSCRIPTION AGREEMENT Between CFIP CLYD LLC AND CELYAD ONCOLOGY SA Dated as of December 2, 2021 TABLE OF CONTENTS Page 1.???Definitions 1 1.1??Defined Terms 1 1.2??Additional Defined Terms 4 2.???Subscription and Issuance of Ordinary Shares 5 3.???Closi

December 3, 2021 EX-99.1

Regulated Information

Exhibit 99.1 Regulated Information Inside Information Celyad Oncology Announces $32.5 Million Private Placement with Fortress Investment Group December 3, 2021 7:30 AM CET Mont-Saint-Guibert, Belgium ? Celyad Oncology SA (Euronext & Nasdaq: CYAD) (?Celyad? or the ?Company?), a clinical-stage biotechnology company focused on the discovery and development of chimeric antigen receptor T cell (CAR T)

December 3, 2021 EX-10.2

Shareholders’ Rights Agreement dated December 2, 2021, by and among CFIP CLYD LLC and the registrant

Exhibit 10.2 SPECIFIC TERMS IN THIS EXHIBIT HAVE BEEN REDACTED. THESE REDACTED TERMS HAVE BEEN MARKED IN THIS EXHIBIT WITH THREE ASTERISKS [***]. SHAREHOLDERS? RIGHTS AGREEMENT BY AND AMONG CFIP CLYD LLC AND CELYAD ONCOLOGY SA Dated as of December 2, 2021 TABLE OF CONTENTS Page ARTICLE I DEFINITIONS Section 1.1 Certain Defined Terms 1 Section 1.2 Construction 9 Section 1.3 Translation 9 ARTICLE II

November 12, 2021 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of November 2021 Commission File Number: 001-3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of November 2021 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant?s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal exe

November 12, 2021 EX-99.1

November 12, 2021, 07:00 a.m. ET

Exhibit 99.1 November 12, 2021, 07:00 a.m. ET Celyad Oncology Presents Preclinical Data on Allogeneic CAR T Therapy Program and Highlights KEYNOTE-B79 Clinical Trial Design at the Society for Immunotherapy of Cancer (SITC) 36th Annual Meeting ? Preclinical data support armoring NKG2D CAR T cells with IL-18 to drive improved anti-tumor activity of the product candidate ? Development continues for s

November 10, 2021 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of November 2021 Commission File Number: 001-3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of November 2021 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant?s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal exe

November 10, 2021 EX-99.1

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

Exhibit 99.1 Regulated Information Celyad Oncology Announces Third Quarter 2021 Financial Results and Recent Business Highlights ? Phase 1b KEYNOTE-B79 trial set to evaluate CYAD-101 followed by KEYTRUDA? in metastatic colorectal cancer (mCRC) patients with microsatellite stable disease on track to begin by year-end 2021 ? Enrollment continues at the highest dose level in Phase 1 IMMUNICY-1 trial

November 10, 2021 EX-99.2

Celyad Oncology SA Interim consolidated statement of comprehensive income For the Nine-month period ended September 30, (€‘000) 2021 2020 Revenue — 5 Cost of sales — — Gross profit — 5 Research and Development expenses (15.233 ) (15.687 ) General & A

Exhibit 99.2 Celyad Oncology SA Interim consolidated statement of comprehensive income For the Nine-month period ended September 30, (??000) 2021 2020 Revenue ? 5 Cost of sales ? ? Gross profit ? 5 Research and Development expenses (15.233 ) (15.687 ) General & Administrative expenses (7.193 ) (7.308 ) Change in fair value of contingent consideration (3.219 ) (2.117 ) Other income 3.548 3.360 Othe

August 4, 2021 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of August 2021 Commission File Number: 001-374

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of August 2021 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant?s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal execu

August 4, 2021 EX-99.2

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

Exhibit 99.2 INTERIM FINANCIAL REPORT First Half 2021 REGULATED INFORMATION This Interim Financial Report has been prepared in accordance with the article 13 of the Belgian Royal Decree of November 14, 2007. Celyad Oncology publishes its Interim Financial Report in French. Celyad Oncology has also produced an English translation of this Interim Financial Report for convenience purposes only. In th

August 4, 2021 EX-99.1

Celyad Oncology SA Interim Consolidated Statement of Comprehensive Income (Unaudited) For the Six-month period ended June 30, For the Six-month period ended June 30, (€‘000) 2021 2020 Revenue — 5 Cost of sales — — Gross profit — 5 Research and Develo

Exhibit 99.1 Regulated Information Celyad Oncology Reports First Half 2021 Financial Results and Recent Business Highlights August 4, 2021, 10:00 p.m. CEST ? Enrollment continues at dose level three in Phase 1 IMMUNICY-1 trial evaluating CYAD-211 in relapsed/refractory multiple myeloma (r/r MM); next clinical update expected by year-end 2021 ? Phase 1b KEYNOTE-B79 trial set to evaluate CYAD-101 wi

July 21, 2021 EX-99.2

Forward Looking Statements

Research and Development Day Virtual Webinar July 20, 2021 Exhibit 99.2 Forward Looking Statements Today?s Agenda Topic Speaker Welcome & Introductions Filippo Petti Redefining Allogeneic CAR T Filippo Petti Update on CYAD-211 for r/r MM Charlie Morris, M.D. shRNA Platform Armored CAR T Franchise Introduction to CYAD-203 Optimized for Multiplexed CAR Ts Future programs David Gilham, Ph.D. Update o

July 21, 2021 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of July 2021 Commission File Number: 001-37452

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of July 2021 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant?s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal executi

July 21, 2021 EX-99.1

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

Exhibit 99.1 Celyad Oncology Presents Updates on Allogeneic CAR T Clinical Candidates and shRNA-based Preclinical Concepts at Research & Development Day ? Phase 1 IMMUNICY-1 trial evaluating CYAD-211 in relapsed/refractory multiple myeloma (r/r MM) showed dose dependent engraftment up to dose level three (300?106 cells per infusion) with no Graft-versus-Host disease reported to date ? Submission o

June 11, 2021 EX-99.2

Forward Looking Statements

European Hematology Association Virtual Congress 2021 Redefining Allogeneic CAR Ts Using a Non-Gene Edited Approach June 11, 2021 Exhibit 99.

June 11, 2021 EX-99.1

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

Exhibit 99.1 Celyad Oncology Presents Preliminary Data from Phase 1 IMMUNICY-1 Trial of shRNA-based Allogeneic CAR T Candidate CYAD-211 in Relapsed/Refractory Multiple Myeloma at the European Hematology Association Virtual Congress ? Treatment with CYAD-211 generally well-tolerated at first two dose levels, with no evidence of Graft-versus-Host Disease observed ? Two partial responses observed amo

June 11, 2021 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of June 2021 Commission File Number: 001-37452

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of June 2021 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant?s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal executi

June 3, 2021 CORRESP

Attributable to owners of the parent

June 3rd, 2021 U.S. Securities and Exchange Commission Division of Corporation Finance Office of Life Sciences Washington, D.C 20549 100 F Street, N.E Attention: Li Xiao, Daniel Gordon Re: Celyad Oncology SA Form 20-F for the Fiscal Year Ended December 31, 2020 Filed May 5, 2021 File No. 001-37452 Dear Madam, Dear Sir, This letter is submitted on behalf of Celyad Oncology SA (the “Company”) in res

May 12, 2021 EX-99.1

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

Exhibit 99.1 Celyad Oncology to Present Data from Phase 1 IMMUNICY-1 Trial of Non-Gene Edited Allogeneic CAR T Candidate CYAD-211 in Relapsed/Refractory Multiple Myeloma at the European Hematology Association Virtual Congress May 12th, 2021 10:01 p.m. CEST ? No Grade ? 3 treatment-related adverse events nor evidence of Graft-versus-Host disease reported from the completed first dose-level (DL1) co

May 12, 2021 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of May 2021 Commission File Number: 001-37452

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of May 2021 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant?s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal executiv

May 7, 2021 EX-99.2

Celyad Oncology SA Interim consolidated statement of comprehensive income (€‘000) For the Three- month period ended March 31, 2021 Revenue — Cost of sales — Gross profit — Research and Development expenses (4,739 ) General & Administrative expenses (

Exhibit 99.2 Celyad Oncology SA Interim consolidated statement of comprehensive income (??000) For the Three- month period ended March 31, 2021 Revenue ? Cost of sales ? Gross profit ? Research and Development expenses (4,739 ) General & Administrative expenses (2,341 ) Change in fair value of contingent consideration (2,220 ) Other income 670 Other expenses (145 ) Operating Loss (8,774 ) Financia

May 7, 2021 6-K

Current Report of Foreign Issuer - 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of May 2021 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant?s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal executiv

May 7, 2021 EX-99.1

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

Exhibit 99.1 Regulated Information Celyad Oncology Announces First Quarter 2021 Financial Results and Recent Business Highlights ? Enrollment continues in second dose cohort of Phase 1 dose-escalation IMMUNICY-1 trial for lead shRNA-based allogeneic CAR T candidate, CYAD-211, for relapsed/refractory multiple myeloma (r/r MM); additional proof-of-concept data anticipated in second quarter 2021. ? E

May 5, 2021 CORRESP

1 | Page

May 05, 2021 U.S. Securities and Exchange Commission Division of Corporation Finance Office of Life Sciences Washington, D.C 20549 100 F Street, N.E Attention: Li Xiao, Daniel Gordon Re: Celyad Oncology SA Form 20-F for the Fiscal Year Ended December 31, 2020 Filed March 24, 2021 File No. 001-37452 Dear Madam, Dear Sir, This letter is submitted on behalf of Celyad Oncology SA (the ?Company?) in re

March 24, 2021 EX-13.1

Certification by the Principal Executive Officer and Principal Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

Exhibit 13.1 Certification by the Principal Executive Officer and Principal Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 In connection with the annual report of Celyad Oncology S.A. (the ?Company?) on Form 20-F for the fiscal year ended December 31, 2020 as filed with the U.S. Securities and Exchange Commission on the da

March 24, 2021 EX-4.25

Clinical Trial Collaboration and Supply Agreement, dated September 14, 2020, by and between the Company and MSD International GmbH.

Exhibit 4.25 Certain portions of this exhibit have been omitted because they are not material and the registrant customarily and actually treats that information as private or confidential. EXECUTION COPY CLINICAL TRIAL COLLABORATION AND SUPPLY AGREEMENT by and between MSD International GmbH, and Celyad Oncology SA Dated: September 14, 2020 TABLE OF CONTENTS Page 1. Definitions 1 2. Scope of the A

March 24, 2021 EX-4.3

Amended and Restated Services Agreement, dated March 24, 2021 between the registrant and ImXense SRL, represented by Frederic Lehmann

Exhibit 4.3 Certain portions of this exhibit have been omitted because they are not material and the registrant customarily and actually treats that information as private or confidential. AMENDED AND RESTATED SERVICES AGREEMENT BETWEEN: Celyad Oncology S.A., a company established under the laws of Belgium, with registered office at B-1435 Mont-Saint-Guibert, Rue Edouard Belin 2 (Belgium) and regi

March 24, 2021 EX-4.28

Non-Commercial Lease Agreement, dated July 2, 2020, between Axis Parc Fund SA and the registrant. (English translation

Exhibit 4.28 AXISPARC Office building located at 12 rue Edouard Belin in 1435 Mont-Saint-Guibert LEASE AGREEMENT BETWEEN: Axis Parc Fund SA [Soci?t? Anonyme - Public Limited Company], having its registered office at 7 Boulevard Roi Albert-II in 1210 Brussels, with company no. 0677.922.805 represented by Tribeca AIFM SA, manager AIFM, represented by Arise BVBA, Director, represented by its permanen

March 24, 2021 EX-4.2

Amended and Restated Services Agreement, effective March 24, 2021 between the registrant and NandaDevi SRL, represented by Philippe Dechamps

Exhibit 4.2 Certain portions of this exhibit have been omitted because they are not material and the registrant customarily and actually treats that information as private or confidential. SERVICES AGREEMENT BETWEEN: 1. Celyad Oncology S.A., a company established under the laws of Belgium, with registered office at B-1435 Mont-Saint-Guibert, Rue Edouard Belin 2 (Belgium) and registered with the co

March 24, 2021 EX-4.21

Research and Development Collaboration and License Agreement, dated June 27, 2018, by and between the Company and Horizon Discovery Limited

Exhibit 4.21 CONFIDENTIAL Certain portions of this exhibit have been omitted because they are not material and the registrant customarily and actually treats that information as private or confidential. R&D COLLABORATION AND LICENSE AGREEMENT This R&D collaboration and license agreement is made on the Effective Date between: (1) Celyad SA, having its registered office at Edouard Belin 2, 1435 Mont

March 24, 2021 EX-4.24

Amended and Restated Employment Agreement, dated March 24, 2021, by and between the registrant and Stephen Rubino, Ph.D.

Exhibit 4.24 Certain portions of this exhibit have been omitted because they are not material and the registrant customarily and actually treats that information as private or confidential. THIS amended and restated agreement is made as of March 24, 2021, between Celyad Inc., a Delaware corporation (the ?Corporation?), and Stephen Rubino (the ?Employee?). Introduction The Corporation is engaged in

March 24, 2021 EX-15.2

Consent of EY Bedrijfsrevisoren BV/Reviseurs d’Entreprises SRL, independent registered public accounting firm

Exhibit 15.2 Consent of independent registered public accounting firm We consent to the incorporation by reference in the following Registration Statements: (1) Registration Statement (Form F-3 No. 333-248464) of Celyad Oncology SA, and (2) Registration Statement (Form S-8 No. 333-220737) pertaining to the Warrants plan 2017 of our reports dated March 24, 2021, with respect to the consolidated fin

March 24, 2021 EX-15.1

Consent of BDO Réviseurs d’Entreprises SCRL, independent registered public accounting firm

EX-15.1 19 d45316dex151.htm EX-15.1 Exhibit 15.1 Consent of independent registered public accounting firm Celyad Oncology SA Mont-Saint-Guibert, Belgium We hereby consent to the incorporation by reference in the Registration Statements on Form F-3 (No. 333-220285 and No. 333-248464) and Form S-8 (No. 333-220737) of Celyad SA of our report dated March 24, 2020, relating to the consolidated financia

March 24, 2021 EX-4.16

Amended and Restated Services Agreement, dated March 24, 2021 between the registrant and MC Consult SRL, represented by Philippe Nobels

Exhibit 4.16 CONFIDENTIAL Certain portions of this exhibit have been omitted because they are not material and the registrant customarily and actually treats that information as private or confidential. AMENDED AND RESTATED SERVICES AGREEMENT BETWEEN : Celyad Oncology SA, having its registered office at rue Edouard Belin 2, 1435 Mont-Saint-Guibert (Belgium), registered with the register of legal e

March 24, 2021 EX-1.1

Articles of Association (English translation)

Exhibit 1.1 SCRL civile Berquin Notaires ? avenue Lloyd George 11 - 1000 Bruxelles VAT BE 0474.073.840 ? BRUSSELS Registry of Legal Entities ? www.berquinnotaires.be Tel.: +32(2)645.19.45 Fax : +32(2)645.19.46 Coordinated Bylaws of the listed soci?t? anonyme (a Belgian corporation) ?Celyad Oncology? at 1435 Mont-Saint-Guibert, Rue Edouard Belin 2, company number 0891.118.115 - Brabant Wallon Regis

March 24, 2021 EX-4.19

Amended and Restated Employment Agreement, dated March 24, 2021, by and between the registrant and Filippo Petti

Exhibit 4.19 Certain portions of this exhibit have been omitted because they are not material and the registrant customarily and actually treats that information as private or confidential. AMENDED AND RESTATED EMPLOYMENT AGREEMENT THIS AMENDED AND RESTATED EMPLOYMENT AGREEMENT (the ?Agreement?) is made as of 24 March, 2021 (the ?CEO Start Date?), between Celyad ONCOLOGY SA (?Celyad?), Celyad Inc.

March 24, 2021 EX-4.1

Amended and Restated Employment Contract, effective March 24, 2021 between the registrant and David Gilham

Exhibit 4.1 CONFIDENTIAL Certain portions of this exhibit have been omitted because they are not material and the registrant customarily and actually treats that information as private or confidential. AMENDED AND RESTATED EMPLOYMENT AGREEMENT BETWEEN : Celyad Oncology SA, with registered offices located at Rue Edouard Belin 2, 1435 Mont-Saint-Guibert (Belgium), registered with the register of leg

March 24, 2021 20-F

- 20-F

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 20-F (Mark One) ? REGISTRATION STATEMENT PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR ? ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2020 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF

March 24, 2021 EX-4.27

Non-Commercial Lease Agreement, dated July 2, 2020, between Axis Parc Fund SA and the registrant. (English translation)

Exhibit 4.27 AXISPARC Office building located at 12 rue Edouard Belin in 1435 Mont-Saint-Guibert LEASE AGREEMENT BETWEEN: Axis Parc Fund SA [Soci?t? Anonyme - Public Limited Company], having its registered office at 7 Boulevard Roi Albert-II in 1210 Brussels, with company no. 0677.922.805 represented by Tribeca AIFM SA, manager AIFM, represented by Arise BVBA, Director, represented by its permanen

March 24, 2021 EX-4.22

First Amendment to Research and Development Collaboration and License Agreement, dated June 27, 2018, by and between the Company and Horizon Discovery Limited

Exhibit 4.22 CONFIDENTIAL Certain portions of this exhibit have been omitted because they are not material and the registrant customarily and actually treats that information as private or confidential. FIRST AMENDMENT TO THE R&D COLLABORATION AND LICENSE AGREEMENT This First Amendment (?Amendment?) to the R&D Collaboration and License Agreement dated June 27th, 2018 (?Agreement?) is entered into

March 24, 2021 EX-4.20

Research and Development Collaboration and License Agreement, dated April 3, 2018, by and between the Company and Horizon Discovery Limited

Exhibit 4.20 CONFIDENTIAL Certain portions of this exhibit have been omitted because they are not material and the registrant customarily and actually treats that information as private or confidential. R&D COLLABORATION AND LICENSE AGREEMENT This R&D collaboration and license agreement is made on the Effective Date between: (1) Celyad SA, having its registered office at Edouard Belin 2, 1435 Mont

March 24, 2021 EX-12.1

Certification by the Principal Executive Officer and Principal Financial Officer pursuant to Securities Exchange Act Rules 13a-14(a) and 15d-14(a) as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

Exhibit 12.1 Certification by the Principal Executive Officer and Principal Financial Officer pursuant to Securities Exchange Act Rules 13a-14(a) and 15d-14(a) as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 I, Filippo Petti, certify that: 1. I have reviewed this annual report on Form 20-F of Celyad Oncology S.A.; 2. Based on my knowledge, this report does not contain any untr

March 24, 2021 EX-4.26

Warrants Plan 2020 (English Translation)

Exhibit 4.26 CELYAD ONCOLOGY SA WARRANTS PLAN Q4-2020 Incentive plan relating to a grant of subscription rights (Warrants) established in accordance with the Companies and Associations Code and articles 41 to 47 of the Act of 26 March 1999 relating to the Belgian action plan for employment 1998 and having various provisions PREAMBLE This Warrants Plan of CELYAD ONCOLOGY SA (the ?Plan?) aims to mot

February 2, 2021 SC 13G/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 ( Amendment No. )* Celyad SA (Name of Issuer) American Depositary Receipt (Title of Class of Securities) (CUSIP Number) Dec

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 ( Amendment No. )* Celyad SA (Name of Issuer) American Depositary Receipt (Title of Class of Securities) 151205200 (CUSIP Number) December 31, 2020 (Date of Event which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which thi

January 7, 2021 EX-10.1

Purchase Agreement dated January 6, 2021 between Celyad Oncology SA and Lincoln Park Capital Fund, LLC

EX-10.1 Exhibit 10.1 Execution Version PURCHASE AGREEMENT PURCHASE AGREEMENT (the “Agreement”), dated as of January 6, 2021, by and between CELYAD ONCOLOGY S.A., a public limited liability company (“naamloze vennootschap”) organized and existing under the laws of the Kingdom of Belgium, having its registered office at rue Edouard Belin 2, 1435 Mont-Saint-Guibert, Belgium and registered with the Re

January 7, 2021 EX-10.2

Registration Rights Agreement dated as of January 6, 2021 between Celyad Oncology SA and Lincoln Park Capital Fund, LLC

EX-10.2 Exhibit 10.2 Execution Versions REGISTRATION RIGHTS AGREEMENT REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of January 6, 2021, by and between CELYAD ONCOLOGY S.A., a public limited liability company (“naamloze vennootschap”) organized and existing under the laws of the Kingdom of Belgium, having its registered office at rue Edouard Belin 2, 1435 Mont-Saint-Guibert, Belgium an

January 7, 2021 424B5

Up to $40,000,000 Ordinary Shares in the Form of American Depositary Shares

424B5 Table of Contents Filed Pursuant to Rule 424(b)(5) Registration No. 333-248464 PROSPECTUS SUPPLEMENT (to Prospectus dated September 4, 2020) Up to $40,000,000 Ordinary Shares in the Form of American Depositary Shares This prospectus supplement relates to the issuance and sale of up to $40,000,000 of our American Depositary Shares, or ADSs, each representing one ordinary share, no nominal val

January 7, 2021 6-K

Current Report of Foreign Issuer - 6-K

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of January 2021 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal

January 7, 2021 EX-99.1

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

EX-99.1 Exhibit 99.1 Regulated Information Inside Information Celyad Oncology Announces Equity Purchase Agreement for up to $40 Million with Lincoln Park Capital January 7, 2021 7:01 a.m. CET Mont-Saint-Guibert, Belgium – Celyad Oncology SA (Euronext & Nasdaq: CYAD) (the “Company”), a clinical-stage biotechnology company focused on the discovery and development of chimeric antigen receptor T cell

December 7, 2020 6-K

Current Report of Foreign Issuer - 6-K

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of December 2020 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal

December 7, 2020 EX-99.1

Celyad Oncology Provides Updates on Allogeneic and Autologous CAR T Programs at 62nd ASH Annual Meeting and Exposition

EX-99.1 Exhibit 99.1 Regulated Information Inside Information Celyad Oncology Provides Updates on Allogeneic and Autologous CAR T Programs at 62nd ASH Annual Meeting and Exposition • First patient dosed in the CYAD-211 Phase 1 IMMUNICY-1 trial. Preclinical results for CYAD-211 for multiple myeloma showed robust antitumor activity with no demonstrable evidence of Graft-versus-Host Disease • Company

November 12, 2020 EX-99.1

Regulated Information

EX-99.1 2 d83174dex991.htm EX-99.1 Exhibit 99.1 Regulated Information Celyad Oncology Announces Third Quarter 2020 Financial Results and Recent Business Highlights November 10, 2020 10:01 p.m. CET • Established a clinical trial collaboration with MSD to evaluate CYAD-101 with KEYTRUDA® in patients with microsatellite stable mCRC • Expect to initiate the expansion cohort of the Phase 1 alloSHRINK t

November 12, 2020 6-K

Current Report of Foreign Issuer - 6-K

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of November 2020 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal

September 29, 2020 EX-99.1

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

EX-99.1 Exhibit 99.1 Regulated Information Inside Information Celyad Oncology Announces Clinical Trial Collaboration to Evaluate CYAD-101 with KEYTRUDA® (pembrolizumab) in Patients with Microsatellite Stable mCRC September 29, 2020 7:00 a.m. CEST Mont-Saint-Guibert, Belgium – Celyad Oncology SA (Euronext & Nasdaq: CYAD), a clinical-stage biotechnology company focused on the discovery and developme

September 29, 2020 6-K

Current Report of Foreign Issuer - 6-K

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2020 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principa

September 11, 2020 EX-1.1

OPEN MARKET SALE AGREEMENTSM

EX-1.1 Exhibit 1.1 OPEN MARKET SALE AGREEMENTSM September 11, 2020 JEFFERIES LLC 520 Madison Avenue New York, New York 10022 Ladies and Gentlemen: Celyad Oncology S.A., a public limited liability company (“naamloze vennootschap”) organized and existing under the laws of the Kingdom of Belgium, having its registered office at rue Edouard Belin 2, 1435 Mont-Saint-Guibert, Belgium and registered with

September 11, 2020 424B5

Up to $25,000,000 Ordinary Shares in the Form of American Depositary Shares

424B5 Table of Contents Filed Pursuant to Rule 424(b)(5) Registration No. 333-248464 PROSPECTUS SUPPLEMENT (to Prospectus dated September 4, 2020) Up to $25,000,000 Ordinary Shares in the Form of American Depositary Shares We have entered into an Open Market Sale AgreementSM, or the Sales Agreement, with Jefferies LLC, or Jefferies relating to American Depositary Shares, or ADSs, each representing

September 11, 2020 6-K

Current Report of Foreign Issuer - 6-K

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2020 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principa

September 3, 2020 CORRESP

-

CORRESP 1 filename1.htm Celyad Oncology SA Rue Edouard Belin 2 1435 Mont-Saint-Guibert Belgium September 3, 2020 Via EDGAR Transmission United States Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Re: Celyad Oncology SA: Registration Statement on Form F-3 filed August 28, 2020 (File No. 333-248464) Ladies and Gentlemen: Pursuant to Rule

August 28, 2020 F-3

- F-3

F-3 Table of Contents As filed with the U.S. Securities and Exchange Commission on August 28, 2020 Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM F-3 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 CELYAD ONCOLOGY S.A. (Exact name of Registrant as specified in its Charter) Belgium Not Applicable (State or other jurisdiction of incorporati

August 28, 2020 EX-4.1

Articles of Association, as amended (English translation)

EX-4.1 Exhibit 4.1 SCRL civile Berquin Notaires – avenue Lloyd George 11 – 1000 Bruxelles VAT BE 0474.073.840 – BRUSSELS Registry of Legal Entities – www.berquinnotaires.be Tel.: +32(2)645.19.45 Fax : +32(2)645.19.46 Coordinated Bylaws of the listed société anonyme (a Belgian corporation) “Celyad Oncology” at 1435 Mont-Saint-Guibert, Rue Edouard Belin 2, company number 0891.118.115 – Brabant Wallo

August 28, 2020 EX-4.6

Form of Senior Indenture

EX-4.6 Exhibit 4.6 CELYAD SA FORM OF SENIOR INDENTURE Dated as of [ ], 20[ ] [ ] Trustee Table of Contents Page Article I DEFINITIONS AND INCORPORATION BY REFERENCE 1 Section 1.01 Definitions 1 Section 1.02 Other Definitions 5 Section 1.03 Incorporation by Reference of Trust Indenture Act 5 Section 1.04 Rules of Construction 6 Article II THE SECURITIES 6 Section 2.01 Issuable in Series 6 Section 2

August 28, 2020 EX-16.1

Letter of BDO Réviseurs d’Entreprises SCRL regarding change in the Registrant’s independent registered public accounting firm

EX-16.1 Exhibit 16.1 August 28, 2020 Securities and Exchange Commission 100 F Street N.E. Washington, D.C. 20549 United States of America We have been furnished with a copy of the response to Item 5 of Form F-3 for the event that occurred on May 5, 2020, to be filed by our former client, Celyad Oncology SA. We agree with the statements made in response to that Item insofar as they relate to our Fi

August 28, 2020 EX-4.7

Form of Subordinated Indenture

EX-4.7 Exhibit 4.7 CELYAD SA FORM OF SUBORDINATED INDENTURE Dated as of [ ], 20[ ] [ ] Trustee TABLE OF CONTENTS Page ARTICLE I DEFINITIONS AND INCORPORATION BY REFERENCE 1 Section 1.01 Definitions 1 Section 1.02 Other Definitions 5 Section 1.03 Incorporation by Reference of Trust Indenture Act 5 Section 1.04 Rules of Construction 5 ARTICLE II THE SECURITIES 6 Section 2.01 Issuable in Series 6 Sec

August 7, 2020 EX-99.1

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

EX-99.1 2 d48496dex991.htm EX-99.1 Exhibit 99.1 Regulated Information Celyad Oncology Reports Half Year 2020 Financial Results and Second Quarter Business Highlights August 6, 2020 10:00 p.m. CEST • Interim analysis from alloSHRINK Phase 1 trial demonstrated mPFS of 3.9 months for mCRC patients with MSS disease treated with CYAD-101 following FOLFOX preconditioning; expansion cohort of alloSHRINK

August 7, 2020 6-K

August 7, 2020

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of August 2020 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal e

August 7, 2020 EX-99.2

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

EX-99.2 3 d48496dex992.htm EX-99.2 Exhibit 99.2 INTERIM FINANCIAL REPORT First Half 2020 REGULATED INFORMATION This report is prepared in accordance with article 13 of the Belgian Royal Decree of November 14, 2007. Celyad Oncology publishes its Interim Financial Report in French. Celyad Oncology has also produced an English translation of this Interim Financial Report for convenience purposes only

June 22, 2020 424B3

[FORM OF ADR]

Filed pursuant to Rule 424(b)(3) Registration Statement on Form F-6 Registration No.

June 10, 2020 EX-3.1

Articles of Association

EX-3.1 Exhibit 3.1 SCRL civile Berquin Notaires – avenue Lloyd George 11 – 1000 Bruxelles VAT BE 0474.073.840 – BRUSSELS Registry of Legal Entities – www.berquinnotaires.be Tel.: +32(2)645.19.45 Fax : +32(2)645.19.46 Coordinated Bylaws of the listed société anonyme (a Belgian corporation) “Celyad Oncology” at 1435 Mont-Saint-Guibert, Rue Edouard Belin 2, company number 0891.118.115 – Brabant Wallo

June 10, 2020 6-K

June 10, 2020

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of June 2020 Commission File Number: 001-37452 CELYAD ONCOLOGY SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal exe

June 10, 2020 EX-99.1

Celyad Oncology SA | Rue Édouard Belin 2, 1435 Mont-Saint-Guibert, Belgium | +32 10 39 41 00

EX-99.1 Exhibit 99.1 Celyad Rebrands as Celyad Oncology June 10, 2020 7:00 a.m. CEST • Shareholders approve new name which better reflects the Company’s ambition to pioneer CAR T cell therapies for cancer Mont-Saint-Guibert, Belgium – Celyad SA (Euronext & Nasdaq: CYAD), clinical-stage biotechnology company focused on the discovery and development of chimeric antigen receptor T cell (CAR T) therap

May 7, 2020 EX-99.1

Celyad Announces First Quarter 2020 Financial Results and Recent Business Highlights

EX-99.1 Exhibit 99.1 Press Release 7 May 2020 7:00 am CEST Regulated Information Celyad Announces First Quarter 2020 Financial Results and Recent Business Highlights Mont-Saint-Guibert, Belgium - Celyad (Euronext Brussels and Paris, and Nasdaq: CYAD), a clinical-stage biopharmaceutical company focused on the development of CAR-T cell therapies, today announced an update on operational developments

May 7, 2020 6-K

May 7, 2020

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of May 2020 Commission File Number: 001-37452 CELYAD SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal executive off

May 6, 2020 6-K

May 6, 2020

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of May 2020 Commission File Number: 001-37452 CELYAD SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal executive off

May 6, 2020 EX-99.1

Celyad Appoints Seasoned Industry Executives to Board of Directors

EX-99.1 Exhibit 99.1 Press Release 6 May 2020 7:00 am CEST Celyad Appoints Seasoned Industry Executives to Board of Directors Mont-Saint-Guibert, Belgium—Celyad (Euronext Brussels and Paris, and Nasdaq: CYAD), a clinical-stage biopharmaceutical company focused on the development of CAR-T cell-based therapies, today announced that Dr. Maria Koehler and Mr. Dominic Piscitelli have been appointed as

March 25, 2020 EX-4.28

Research and Development Collaboration and License Agreement, dated April 3, 2018, by and between the Company and Horizon Discovery Limited

EX-4.28 Exhibit 4.28 CONFIDENTIAL R&D COLLABORATION AND LICENSE AGREEMENT This R&D collaboration and license agreement is made on the Effective Date between: (1) Celyad SA, having its registered office at Edouard Belin 2,1435 Mont-Saint-Guibert (Belgium), registered with the register of legal entities under number 0891.118.115 (together with its Affiliates referred to as ‘’Celyad”); and (2) Horizo

March 25, 2020 EX-4.26

Amended and Restated Employment Agreement, dated April 1, 2019, by and between Celyad Inc. and Filippo Petti

EX-4.26 Exhibit 4.26 CELYAD INC. By: Philippe Dechamps Title: Chief Legal Officer Employee Filippo Petti Address: 12 Fox Hollow Lane Old Westbury, NY 11568 26. Successors and Assigns. This Agreement shall inure to the benefit of and be binding upon the Corporation, Celyad, their successors and assigns, and the Employee, Employee’s heirs and legal representatives. Employee acknowledges that the Ser

March 25, 2020 EX-4.29

Research and Development Collaboration and License Agreement, dated June 27, 2018, by and between the Company and Horizon Discovery Limited

EX-4.29 Exhibit 4.29 CONFIDENTIAL R&D COLLABORATION AND LICENSE AGREEMENT This R&D collaboration and license agreement is made on the Effective Date between: (1) Celyad SA, having its registered office at Edouard Belin 2,1435 Mont-Saint-Guibert (Belgium), registered with the register of legal entities under number 0891.118.115 (together with its Affiliates referred to as “Celyad”); and (2) Horizon

March 25, 2020 EX-4.33

Asset Purchase Agreement, dated November 22, 2019, by and between CorQuest Medical, Inc. and CorQuest MedTech

EX-4.33 Exhibit 4.33 Execution copy ASSET PURCHASE AGREEMENT This ASSET PURCHASE AGREEMENT (the “Agreement”), dated 22 November, 2019 (“Effective Date”), is made by and between: 1. CorQuest Medical, Inc., a Delaware corporation, with registered office at 2711 Centerville Road, Suite 400, Wilmington, Delaware 19808, County of Newcastle (“Seller”), 2. CorQuest MedTech, a société à responsabilité lim

March 25, 2020 EX-1.1

Articles of Association (English translation)

EX-1.1 Exhibit 1.1 SCRL civile Berquin Notaires – avenue Lloyd George 11 - 1000 Bruxelles VAT BE 0474.073.840 – BRUSSELS Registry of Legal Entities – www.berquinnotaires.be Tel.: +32(2)645.19.45 Fax : +32(2)645.19.46 Amalgamated Bylaws of the société anonyme (a Belgian corporation) that has invited or is inviting investment by the public “Celyad” at 1435 Mont-Saint-Guibert, Rue Edouard Belin 2, co

March 25, 2020 EX-2.3

Description of Securities

EX-2.3 Exhibit 2.3 DESCRIPTION OF SECURITIES The following description of the capital stock of Celyad SA ( “Celyad,” “us,” “our,” “we” or the “Company”) is a summary of the rights of our ordinary shares and certain provisions of our articles of association in effect as of [March 24], 2020. This summary does not purport to be complete and is qualified in its entirety by the provisions of our articl

March 25, 2020 EX-4.27

Employment Agreement, dated January 30, 2020, by and between Celyad Inc. and Stephen Rubino

EX-4.27 Exhibit 4.27 EMPLOYMENT AGREEMENT TH IS AGREEMENT is made as of January 30. 2020. between Celyad Inc., a Delaware corporation (the “Corporation”), and Stephen Rubino (the “Employee”). Introduction The Corporation is engaged in research and development of biological pharmaceutical products or medical devices, solely or in combination (the “Business”). The Corporation is a wholly owned subsi

March 25, 2020 EX-15.1

Consent of BDO Réviseurs d’Entreprises SCRL, independent registered public accounting firm

EX-15.1 Exhibit 15.1 Consent of independent registered public accounting firm Celyad SA Mont-Saint-Guibert, Belgium We hereby consent to the incorporation by reference in the Registration Statements on Form F-3 (No. 333-220285) and Form S-8 (No. 333-220737) of Celyad SA of our report dated March 24, 2020, relating to the consolidated financial statements which appears in this Annual Report on Form

March 25, 2020 20-F

Form 20-F

20-F Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.

March 25, 2020 EX-4.25

Warrants Plan 2019 (English translation)

EX-4.25 Exhibit 4.25 CELYAD SA WARRANTS PLAN 2019 PREAMBLE This Warrant Plan of Celyad SA (the “Plan”) aims to motivate and inspire loyalty among the Beneficiaries. Well aware of the fact that their contribution is essential to the development of its activities and the growth of its results, the Company wishes to give the Beneficiaries the opportunity to become shareholder or to increase their par

March 25, 2020 EX-12.1

Certification by the Principal Executive Officer and Principal Financial Officer pursuant to Securities Exchange Act Rules 13a-14(a) and 15d-14(a) as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

EX-12.1 Exhibit 12.1 Certification by the Principal Executive Officer and Principal Financial Officer pursuant to Securities Exchange Act Rules 13a-14(a) and 15d-14(a) as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 I, Filippo Petti, certify that: 1. I have reviewed this annual report on Form 20-F of Celyad S.A.; 2. Based on my knowledge, this report does not contain any untru

March 25, 2020 EX-99.1

Celyad Reports Full Year 2019 Financial Results and Provides Business Update

EX-99.1 Exhibit 99.1 Press Release 24 March 2020 11:00 pm CET Regulated Information Celyad Reports Full Year 2019 Financial Results and Provides Business Update • First patient successfully dosed in expansion cohort of autologous CYAD-01 THINK trial for patients with relapsed/refractory (r/r) acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) • CYCLE-1 trial of autologous CYAD-02 for

March 25, 2020 EX-4.31

Consultancy Agreement, dated April 1, 2019, by and between the Company and Life Science Strategy Consulting SRL

EX-4.31 Exhibit 4.31 CONSULTANCY AGREEMENT Between CELYAD SA And LIFE SCIENCE STRATEGY CONSULTING SPRL Dated April 1st, 2019 1 THIS AGREEMENT is entered into on April 1st, 2019, BETWEEN (1) CELYAD, a public limited liability company (société anonyme) incorporated under the laws of Belgium, making of having made a public appeal on savings, with registered office at 1435 Mont-Saint-Guibert (Belgium)

March 25, 2020 EX-4.30

First Amendment to Research and Development Collaboration and License Agreement, dated June 27, 2018, by and between the Company and Horizon Discovery Limited

EX-4.30 Exhibit 4.30 CONFIDENTIAL FIRST AMENDMENT TO THE R&D COLLABORATION AND LICENSE AGREEMENT This First Amendment (“Amendment”) to the R&D Collaboration and License Agreement dated June 27th, 2018 (“Agreement”) is entered into as of December 19, 2018 (“Effective Date”) by and between (1) Celyad SA, having its registered office at Edouard Belin 2, 1435 Mont-Saint-Guibert (Belgium), registered w

March 25, 2020 6-K

March 25, 2020

6-K 1 d826686d6k.htm 6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of March 2020 Commission File Number: 001-37452 CELYAD SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of

March 25, 2020 EX-13.1

Certification by the Principal Executive Officer and Principal Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

EX-13.1 Exhibit 13.1 Certification by the Principal Executive Officer and Principal Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 In connection with the annual report of Celyad S.A. (the “Company”) on Form 20-F for the fiscal year ended December 31, 2019 as filed with the U.S. Securities and Exchange Commission on the dat

March 25, 2020 EX-4.32

Termination Agreement, dated April 1, 2019, by and between the Company and Life Science Strategy Consulting SRL

EX-4.32 Exhibit 4.32 TERMINATION AGREEMENT Between CELYAD SA And LIFE SCIENCE STRATEGY CONSULTING SPRL And Mr. CHRISTIAN HOMSY Dated April 1st, 2019 THIS AGREEMENT is entered into on April 1st, 2019, BETWEEN (1) CELYAD, a public limited liability company (société anonyme) incorporated under the laws of Belgium, making of having made a public appeal on savings, with registered office at 1435 Mont-S

March 11, 2020 6-K

March 11, 2020

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of March 2020 Commission File Number: 001-37452 CELYAD SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal executive o

March 11, 2020 EX-99.1

Celyad Appoints Stephen Rubino as Chief Business Officer

EX-99.1 Exhibit 99.1 Press Release 02 March 2020 07:00 am CET Celyad Appoints Stephen Rubino as Chief Business Officer Mont-Saint-Guibert, Belgium – Celyad (Euronext Brussels and Paris, and Nasdaq: CYAD), a clinical-stage biopharmaceutical company focused on the development of CAR-T cell-based therapies, today announced that Stephen Rubino, Ph.D. has been appointed Chief Business Officer. Dr. Rubi

January 30, 2020 SC 13G/A

CYAD / Celyad SA / VICTORY CAPITAL MANAGEMENT INC Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 ( Amendment No. )* Celyad SA (Name of Issuer) American Depositary Receipt (Title of Class of Securities) 151205200 (CUSIP Number) December 31, 2019 (Date of Event which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which thi

October 2, 2019 6-K

CYAD / Celyad SA 6-K - Current Report of Foreign Issuer - 6-K

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of October 2019 Commission File Number: 001-37452 CELYAD SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal executive

October 2, 2019 EX-99.1

Celyad to Present Update on mCRC Clinical Program at the 2019 SITC Annual Meeting

EX-99.1 Exhibit 99.1 Press Release 02 October 2019 07:00 am CEDT Celyad to Present Update on mCRC Clinical Program at the 2019 SITC Annual Meeting • Poster presentations to highlight allogeneic and autologous NKG2D-based CAR-T therapies for the treatment of advanced metastatic colorectal (mCRC) cancers Mont-Saint-Guibert, Belgium—Celyad (Euronext Brussels and Paris, and Nasdaq: CYAD), a clinical-s

September 16, 2019 EX-99.1

Celyad Announces Closing of $20 Million Global Offering

EX-99.1 Exhibit 99.1 Press Release 16 September 2019 10:01 pm CEST Inside Information Regulated Information Celyad Announces Closing of $20 Million Global Offering Mont-Saint-Guibert, Belgium—Celyad (Euronext Brussels and Paris, and Nasdaq: CYAD), a clinical-stage biopharmaceutical company focused on the development of CAR-T cell therapies, today announced the closing of a global offering of 2,000

September 16, 2019 6-K

CYAD / Celyad SA 6-K - Current Report of Foreign Issuer - 6-K

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2019 Commission File Number: 001-37452 CELYAD SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal executi

September 12, 2019 EX-1.1

Underwriting Agreement, dated as of September 11, 2019, among the Company and Wells Fargo Securities, LLC, William Blair & Company, L.L.C. and Bryan, Garnier & Co. Limited, as representatives of the several underwriters named therein.

EX-1.1 Exhibit 1.1 CELYAD SA (a public limited liability company (“naamloze vennootschap”) organized and existing under the laws of the Kingdom of Belgium) 282,609 Ordinary Shares (without nominal value) and 1,717,391 Ordinary Shares (without nominal value) delivered in the form of 1,717,391 American Depositary Shares UNDERWRITING AGREEMENT Dated: September 11, 2019 CELYAD SA (a public limited lia

September 12, 2019 6-K

CYAD / Celyad SA 6-K - Current Report of Foreign Issuer - 6-K

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2019 Commission File Number: 001-37452 CELYAD SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal executi

September 12, 2019 424B5

2,000,000 Ordinary Shares Including Ordinary Shares in the Form of American Depositary Shares

424B5 Table of Contents Filed pursuant to Rule 424(b)(5) Registration No. 333-220285 PROSPECTUS SUPPLEMENT (TO PROSPECTUS DATED OCTOBER 6, 2017) 2,000,000 Ordinary Shares Including Ordinary Shares in the Form of American Depositary Shares We are offering 2,000,000 ordinary shares in a global offering. We are offering ordinary shares in the form of an equal number of American Depositary Shares (ADS

September 10, 2019 424B5

SUBJECT TO COMPLETION DATED SEPTEMBER 10, 2019

424B5 Table of Contents Filed pursuant to Rule 424(b)(5) Registration No. 333-220285 This preliminary prospectus supplement relates to an effective registration statement under the Securities Act of 1933, as amended, but is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell these securities and we are not soliciting offe

September 5, 2019 6-K/A

CYAD / Celyad SA 6-K/A - Current Report of Foreign Issuer - 6-K/A

6-K/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K/A REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2019 Commission File Number: 001-37452 CELYAD SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal exe

September 4, 2019 EX-99.1

Celyad Successfully Doses First Patient with CYAD-01 Produced with OptimAb Manufacturing Process

EX-99.1 EXHIBIT 99.1 Press Release 4 September 2019 7:00 am CEST Celyad Successfully Doses First Patient with CYAD-01 Produced with OptimAb Manufacturing Process Mont-Saint-Guibert, Belgium - Celyad (Euronext Brussels and Paris, and Nasdaq: CYAD), a clinical-stage biopharmaceutical company focused on the development of CAR-T cell-based therapies, today announced the successful administration of CY

September 4, 2019 6-K

CYAD / Celyad SA 6-K - Current Report of Foreign Issuer - 6-K

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of September 2019 Commission File Number: 001-37452 CELYAD SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal executi

September 4, 2019 EX-99.2

Forward-Looking Statements This presentation may contain forward-looking statements, including statements regarding the safety and efficacy of our drug product candidates and the manufacturing methods used to manufacture these drug product candidates

EX-99.2 Corporate Presentation September 2019 EXHIBIT 99.2 Forward-Looking Statements This presentation may contain forward-looking statements, including statements regarding the safety and efficacy of our drug product candidates and the manufacturing methods used to manufacture these drug product candidates; statements concerning the ongoing and planned clinical development of our drug product ca

August 23, 2019 EX-99.2

CONTINGENT CONSIDERATION AND OTHER FINANCIAL LIABILITIES ROLL FORWARD

EX-99.2 Exhibit 99.2 INTERIM FINANCIAL REPORT H1.2019 REGULATED INFORMATION This report is prepared in accordance with article 13 of the Belgian Royal Decree of November 14, 2007. Celyad publishes its Interim Financial Report in French. Celyad has also produced an English translation of this Interim Financial Report for convenience purposes only. In the event of differences of interpretation betwe

August 23, 2019 6-K

CYAD / Celyad SA 6-K - Current Report of Foreign Issuer - 6-K

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of August 2019 Commission File Number: 001-37452 CELYAD SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal executive

August 23, 2019 EX-99.1

Celyad Reports Half Year 2019 Financial Results and Second Quarter Business Highlights

EX-99.1 2 d757786dex991.htm EX-99.1 Exhibit 99.1 Press Release 22 August 2019 10:00 pm CEST Regulated Information Celyad Reports Half Year 2019 Financial Results and Second Quarter Business Highlights Mont-Saint-Guibert, Belgium—Celyad (Euronext Brussels and Paris, and NASDAQ: CYAD), a clinical-stage biopharmaceutical company focused on the development of CAR-T cell therapies, today announced its

July 9, 2019 EX-99.1

Celyad Presents Clinical Update for CYAD-01 at 24th Congress of the European Hematology Association

EX-99.1 Exhibit 99.1 Press Release 17 June 2019 7:00 am CEST Celyad Presents Clinical Update for CYAD-01 at 24th Congress of the European Hematology Association • Results from the ongoing Phase 1 THINK and DEPLETHINK trials evaluating CYAD-01 for the treatment of relapsed or refractory (r/r) acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) continue to support the therapeutic clinica

July 9, 2019 6-K

CYAD / Celyad SA 6-K - Current Report of Foreign Issuer - 6-K

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of July 2019 Commission File Number: 001-37452 CELYAD SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal executive of

July 8, 2019 EX-99.1

Celyad Presents Update on Autologous & Allogeneic NKG2D-based CAR-T Therapies in Solid

EX-99.1 Exhibit 99.1 Press Release 5 July 2019 9:21 a.m. CEDT Celyad Presents Update on Autologous & Allogeneic NKG2D-based CAR-T Therapies in Solid Tumors • Preliminary interim results from the alloSHRINK Phase 1 trial demonstrate no evidence of GvHD for first-in-class, non-gene edited allogeneic NKG2D-based CAR-T candidate CYAD-101 when administered concurrently with FOLFOX chemotherapy for the

July 8, 2019 6-K

CYAD / Celyad SA 6-K - Current Report of Foreign Issuer - 6-K

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of July 2019 Commission File Number: 001-37452 CELYAD SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal executive of

July 8, 2019 EX-99.1

Celyad to Host Conference Call to Review Clinical Update from ESMO 21st World GI Congress

EX-99.1 Exhibit 99.1 Press Release 2 July 2019 10:01 pm CEST Celyad to Host Conference Call to Review Clinical Update from ESMO 21st World GI Congress Mont-Saint-Guibert, Belgium - Celyad (Euronext Brussels and Paris, and Nasdaq: CYAD), a clinical-stage biopharmaceutical company focused on the development of CAR-T cell-based therapies, today announced that Professor Dr. Eric Van Cutsem from Univer

July 8, 2019 6-K

CYAD / Celyad SA 6-K - Current Report of Foreign Issuer - 6-K

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of July 2019 Commission File Number: 001-37452 CELYAD SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal executive of

July 3, 2019 EX-99.1

Celyad Announces Strategic Updates to the Autologous r/r AML and MDS Program

EX-99.1 Exhibit 99.1 Press Release 1 July 2019 10:01 pm CEDT Celyad Announces Strategic Updates to the Autologous r/r AML and MDS Program • Regulators accept proposal to utilize OptimAb manufacturing process, which enriches for T cells with memory-like phenotype, with CYAD-01 under current IND application • FDA accepts IND application, including OptimAb manufacturing process, for CYAD-02 - next-ge

July 3, 2019 6-K

CYAD / Celyad SA 6-K - Current Report of Foreign Issuer - 6-K

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of July 2019 Commission File Number: 001-37452 CELYAD SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal executive of

May 15, 2019 EX-99.1

Celyad Announces First Quarter 2019 and Recent Business Highlights

EX-99.1 Exhibit 99.1 Press Release 9 May 2019 7:00 am CEST Regulated Information Celyad Announces First Quarter 2019 and Recent Business Highlights Mont-Saint-Guibert, Belgium - Celyad (Euronext Brussels and Paris, and NASDAQ: CYAD), a clinical-stage biopharmaceutical company focused on the development of CAR-T cell therapies, today announced an update on operational developments for the first qua

May 15, 2019 6-K

CYAD / Celyad SA 6-K Current Report of Foreign Issuer 6-K

6-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the Month of May 2019 Commission File Number: 001-37452 CELYAD SA (Translation of registrant’s name into English) Rue Edouard Belin 2 1435 Mont-Saint-Guibert, Belgium (Address of principal executive off

April 5, 2019 EX-15.2

Consent of BDO Réviseurs d’Entreprises SCRL, independent registered public accounting firm

EX-15.2 Exhibit 15.2 Consent of independent registered public accounting firm Celyad SA Mont-Saint-Guibert, Belgium We hereby consent to the incorporation by reference in the Registration Statements on Form F-3 (No. 333-220285) and Form S-8 (No. 333-220737) of Celyad SA of our report dated April 5, 2019, relating to the consolidated financial statements which appears in this Annual Report on Form

April 5, 2019 EX-15.1

Consent of PricewaterhouseCoopers Réviseurs d’Entreprises sccrl

EX-15.1 Exhibit 15.1 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We hereby consent to the incorporation by reference in the Registration Statements on Forms F-3 (No. 333-220285) and S-8 (No. 333-220737) of Celyad S. A. of our report dated April 4, 2017 except for the change in the manner in which the company accounts for revenue from contracts with customers discussed in Note 2 to the

April 5, 2019 EX-4.23

Employment Agreement, dated July 30, 2018 between Celyad Inc and Filippo Petti

EX-4.23 Exhibit 4.23 EMPLOYMENT AGREEMENT THIS AGREEMENT is made as of 30 July 2018, between Celyad Inc., a Delaware corporation (the “Corporation”), and Filippo Petti (the “Employee”). Introduction The Corporation is engaged in research and development of biological pharmaceutical products or medical devices, solely or in combination (the “Business”). The Corporation is a wholly owned subsidiary

April 5, 2019 EX-12.1

Certification by the Principal Executive Officer and Principal Financial Officer pursuant to Securities Exchange Act Rules 13a-14(a) and 15d-14(a) as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

EX-12.1 Exhibit 12.1 Certification by the Principal Executive Officer and Principal Financial Officer pursuant to Securities Exchange Act Rules 13a-14(a) and 15d-14(a) as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 I, Filippo Petti, certify that: 1. I have reviewed this annual report on Form 20-F of Celyad S.A.; 2. Based on my knowledge, this report does not contain any untru

April 5, 2019 EX-13.1

Certification by the Principal Executive Officer and Principal Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

EX-13.1 Exhibit 13.1 Certification by the Principal Executive Officer and Principal Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 In connection with the annual report of Celyad S.A. (the “Company”) on Form 20-F for the fiscal year ended December 31, 2018 as filed with the U.S. Securities and Exchange Commission on the dat

April 5, 2019 20-F

Form 20-F

20-F Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.

Other Listings
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