Celyad Oncology (CLYYF) 6-K Celyad Presents Update onCYAD-01

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE13a-16 OR15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the Month of December 2018

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 offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form20-F or Form40-F.

Form20-F  ☒            Form40-F  ☐

Indicate by check mark if the registrant is submitting the Form6-K in paper as permitted by RegulationS-T Rule 101(b)(1):  ☐

Indicate by check mark if the registrant is submitting the Form6-K in paper as permitted by RegulationS-T Rule 101(b)(7):  ☐

Celyad SA

On December 4^th, 2018, Celyad SA (the “Company”) issued a press release, a copy of which is attached hereto as Exhibit 99.1 and is incorporated by reference herein.

The information contained in this Current Report onForm 6-K, including Exhibit 99.1, except for the quote of Christian Homsy contained in Exhibit 99.1, is hereby incorporated by reference into the Company’s Registration Statements onForms F-3 (FileNo. 333-220285) andS-8 (FileNo. 333-220737).

EXHIBITS

Exhibit	Description
99.1	Press release issued by the registrant on December 4, 2018

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 SA
Date: December 4, 2018	By:	/s/ Christian Homsy
		Christian Homsy
		Chief Executive Officer