8-K

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

Current Report

Pursuant to Section 13 or 15(d) of

the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): December 6, 2023

ADAPTIMMUNE THERAPEUTICS PLC

(Exact name of registrant as specified in its charter)

England and Wales	1-37368	Not Applicable
(State or other jurisdiction of incorporation)	(Commission File Number)	(IRS Employer Identification No.)

60 Jubilee Avenue, Milton Park

Abingdon, Oxfordshire OX14 4RX

United Kingdom

(Address of principal executive offices, including zip code)

(44) 1235 430000

(Registrant’s telephone number, including area code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Trading Symbol	Name of each exchange on which registered
American Depositary Shares, each representing 6 Ordinary Shares, par value £0.001 per share	ADAP	The Nasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 8.01    Other Events.

On December 6, 2023, Adaptimmune Therapeutics plc (the “Company”) issued a press release announcing the completion of the submission of its rolling Biologics License Application (BLA) to the U.S. Food and Drug Administration (FDA) for afami-cel, an investigational engineered T-cell therapy for advanced synovial sarcoma. A copy of the press release is furnished as Exhibit 99.1 hereto and incorporated by reference herein.

Item 9.01    Financial Statements and Exhibits.

(d)  Exhibits.

Exhibit No.	Description of Exhibit
99.1	Press release dated December 6, 2023.
104	Cover Page Interactive Date File (embedded within the Inline XBRL document)

SIGNATURES

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

	ADAPTIMMUNE THERAPEUTICS PLC
Date: December 6, 2023	By:	/s/ Margaret Henry
		Name:	Margaret Henry
		Title:	Corporate Secretary

EX-99.1

Exhibit 99.1

Adaptimmune Completes Submission of Rolling Biologics License Application (BLA) to U.S. FDA for Afami-cel for the Treatment of Advanced Synovial Sarcoma

First BLA for an engineered T-cell therapy for solid tumors submitted to U.S. Food and Drug Administration

Afami-cel data demonstrate better outcomes for people with synovial sarcoma compared to historical control data; pivotal trial has met primary endpoint for efficacy

PHILADELPHIA and OXFORD, UK, December 6, 2023 – Adaptimmune Therapeutics plc (Nasdaq: ADAP), a leader in cell therapy to treat cancer, today announced the completion of the submission of its rolling Biologics License Application (BLA) to the U.S. Food and Drug Administration (FDA) for afami-cel, an investigational engineered T-cell therapy for advanced synovial sarcoma. Afami-cel is eligible for a Priority Review, which would shorten the FDA’s review of the application to 8 months versus a standard review timeline of 12 months.

This submission is supported by positive data from Cohort 1 of the pivotal trial SPEARHEAD-1, which met its primary endpoint for efficacy. Data from the trial were recently presented at the Connective Tissue Oncology Society (CTOS) 2023 Annual Meeting.

Adrian Rawcliffe, Adaptimmune's Chief Executive Officer: “With this submission, we have completed a critical step toward making cell therapy a mainstream treatment option for people with solid tumors. I would like to thank the trial participants and clinical trial investigators, the synovial sarcoma community, and our afami-cel team for their diligent efforts in completing the BLA submission. We look forward to continued collaboration with the FDA as they review the first ever application for marketing approval for an engineered T-cell therapy for solid tumors. We continue to prepare for the commercial launch of afami-cel and the evolution of our sarcoma cell therapy franchise, which now includes lete-cel.”

Brandi Felser, Chief Executive Officer of the Sarcoma Foundation of America: "I celebrate the promise that breakthrough therapies like afami-cel offer to sarcoma patients. Such advancements offer hope and transformative possibilities for the sarcoma patient community, addressing critical unmet needs andoffering increasedand improved treatments for people diagnosed with sarcoma. I am hopeful for and excited about a new treatment choice for people diagnosed with synovial sarcoma."

The FDA granted Orphan Drug Designation (ODD) for afami-cel for the treatment of soft tissue sarcomas and Regenerative Medicine Advanced Therapy (RMAT) designation for the treatment of synovial sarcoma.

About Afami-cel

Afami-cel is an engineered T-cell receptor (TCR) T-cell therapy, targeted to the MAGE A4 cancer target, and designed as a single-dose treatment for advanced synovial sarcoma. The last FDA approved therapy for treatment in this setting was for Votrient in 2012. The BLA submission for afami-cel was supported by clinical data from the SPEARHEAD-1 pivotal trial, which has met its primary endpoint for efficacy. ~39% of patients who received afami-cel had clinical responses with a median duration of response of ~12 months (CTOS 2022). Median overall survival (mOS) was ~17 months in SPEARHEAD-1 compared to historical mOS of <12 months for people with synovial sarcoma who received two or more prior lines of therapy^[1]. Seventy percent of people with advanced synovial sarcoma who respond to afami-cel are alive two years post-treatment.

About synovial sarcoma

There are more than 50 different types of soft tissue sarcomas which are categorized by tumors that appear in fat, muscle, nerves, fibrous tissues, blood vessels, or deep skin tissues.¹ Synovial sarcoma accounts for approximately 5% to 10% of all soft tissue sarcomas (there are approximately 13,400 new soft tissue cases in the U.S. each year).² One third of patients with synovial sarcoma will be diagnosed under the age of 30.² The five-year survival rate for people with metastatic disease is just 20% and most people undergoing standard of care treatment for advanced disease experience recurrence and go through multiple lines of therapy, often exhausting all options.³

^1. https://www.cancer.org/cancer/types/soft-tissue-sarcoma/about/soft-tissue-sarcoma.html ^2.Synovial Sarcoma - NCI (cancer.gov)^3. Aytekin MN, et al. J Orthop Surg (Hong Kong). 2020;28(2)

About AdaptimmuneAdaptimmune is a clinical-stage biopharmaceutical company focused on designing, developing, and delivering cell therapies to transform the lives of people with cancer. The Company's unique engineered T-cell receptor (TCR) platform enables the engineering of T-cells to target and destroy cancers across multiple solid tumor types.

Forward-Looking StatementsThis release contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995 (PSLRA). These forward-looking statements involve certain risks and uncertainties. Such risks and uncertainties could cause our actual results to differ materially from those indicated by such forward-looking statements, and include, without limitation: the success, cost and timing of our product development activities and clinical trials and our ability to successfully advance our TCR therapeutic candidates through the regulatory and commercialization processes. For a further description of the risks and uncertainties that could cause our actual results to differ materially from those expressed in these forward-looking statements, as well as risks relating to our business in general, we refer you to our Annual Report on Form 10-K filed with the Securities and Exchange Commission for the year ended December 31, 2022, our Quarterly Reports on Form 10-Q, Current Reports on Form 8-K, and

other filings with the Securities and Exchange Commission. The forward-looking statements contained in this press release speak only as of the date the statements were made and we do not undertake any obligation to update such forward-looking statements to reflect subsequent events or circumstances.

Adaptimmune Contacts

Investor RelationsJuli P. Miller, Ph.D. - VP, Corporate Affairs and Investor RelationsT : +1 215 825 9310M : +1 215 460 8920Juli.Miller@adaptimmune.com

Media RelationsDana Lynch, Senior Director of Corporate CommunicationsM: +1 267 990 1217Dana.Lynch@adaptimmune.com

XML

Document and Entity Information	Dec. 06, 2023
Document and Entity Information [Abstract]
Document Type	8-K
Document Period End Date	Dec. 06, 2023
Entity File Number	1-37368
Entity Registrant Name	ADAPTIMMUNE THERAPEUTICS PLC
Entity Incorporation, State or Country Code	X0
Entity Tax Identification Number	00-0000000
Entity Address, Address Line One	60 Jubilee Avenue
Entity Address, Adress Line Two	Milton Park
Entity Address, City or Town	Abingdon, Oxfordshire
Entity Address, Postal Zip Code	OX14 4RX
Entity Address, Country	GB
City Area Code	44
Local Phone Number	1235 430000
Written Communications	false
Soliciting Material	false
Pre-commencement Tender Offer	false
Pre-commencement Issuer Tender Offer	false
Title of 12(b) Security	American Depositary Shares, each representing 6 Ordinary Shares, par value £0.001 per share
Trading Symbol	ADAP
Security Exchange Name	NASDAQ
Entity Emerging Growth Company	false
Entity Central Index Key	0001621227
Amendment Flag	false