Celyad Oncology (CLYYF) 6-K Publication of a rectified transparency notification received from

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 executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40- F.

Form 20-F  ☒            Form 40-F  ☐

Celyad Oncology SA

Further to the press release on September 7, 2023, on September 15, 2023, Celyad Oncology SA (the “Company”) issued a press release announcing that in accordance with Article 14 of the Belgian Law of 2 May 2007 regarding the publication of major shareholdings in issuers whose securities are admitted to trading on a regulated market (the “Transparency Law”), it received a rectified notification of transparency dated September 13, 2023 indicating that CFIP CLYD (UK) Limited, an affiliate of Fortress Investment Group LLC, has crossed the statutory threshold of 25%. CFIP CLYD (UK) Limited holds 7,954,808 ordinary shares, with no nominal value per share (“Ordinary Shares”), representing 29.99% of the Company’s Ordinary Shares and 27.53% of voting rights as of September 4, 2023.

A copy of the Company’s press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

The information contained in this Current Report on Form 6-K, including Exhibit 99.1 is hereby incorporated by reference into the Company’s Registration Statements on Forms F-3 (File No. 333-248464) and S-8 (File No. 333- 220737).

EXHIBITS

Exhibit	Description
99.1	Press release issued by the registrant on September 15, 2023

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

		CELYAD ONCOLOGY SA
Date: September 18, 2023	By:	/s/ Georges Rawadi
		Georges Rawadi
		Chief Executive Officer