ACHL Achilles Therapeutics PLC

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 of

the Securities Exchange Act of 1934

For the month of August 2021

Commission File Number: 001-40299

Achilles Therapeutics plc

(Exact name of registrant as specified in its charter)

245 Hammersmith Road

London W6 8PW

United Kingdom

Tel: +44 (0)20 8154 4600

(Address, Including Zip Code, and Telephone Number, Including Area Code, of Registrant’s 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):  ☐

Achilles Reports Second Quarter 2021 Financial Results and Recent Business Highlights

On August 10, 2021, Achilles Therapeutics plc (“Achilles” or the “Company”) issued a press release, a copy of which is furnished as Exhibit 99.1 to this Current Report on Form 6-K, reporting its financial results for the three and six month periods ended June 30, 2021 and providing an update on recent business highlights. Furnished (i) as Exhibit 99.2 to this Current Report on Form 6-K are the Company’s unaudited consolidated financial statements for the three and six month periods ended June 30, 2021 and (ii) as Exhibit 99.3 to this Current Report on Form 6-K is the Management’s Discussion and Analysis of Financial Condition and Results of Operations for the three and six month periods ended June 30, 2021.

The statements contained in this “Achilles Therapeutics Reports Second Quarter 2021 Financial Results and Recent Business Highlights” section of this Current Report on Form 6-K and the information contained in Exhibits 99.1 and 99.2 shall not be deemed “filed” for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and is not incorporated by reference into any of the Company’s filings under the Securities Act of 1933, as amended, or the Exchange Act, whether made before or after the date hereof, except as shall be expressly set forth by specific reference in any such filing.