Report of Foreign Issuer Pursuant to Rule 13a-16 or 15d-16 (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: 001-40106

4D pharma plc

(Translation of Registrant’s name into English)

5th Floor, 9 Bond Court

Leeds

LS1 2JZ

United Kingdom

Tel: +44 (0) 113 895 013

(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 ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ____

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ____

On March 23, 2022, 4D pharma plc (the “Company,” “4D,” “4D pharma,” “we,” “us” or “our”) issued a press release entitled “4D pharma Announces Positive Interim Results from the Phase I/II Study of the Combination of MRx0518 and KEYTRUDA® (pembrolizumab) for the Treatment of Renal Cell Carcinoma.”

A copy of the press release is attached as Exhibit 99.1 to this current report on Form 6-K and is incorporated by reference herein.

INDEX TO EXHIBITS

Exhibit

Number

Exhibit Title

99.1

Press Release, dated March 23, 2022.

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.