Updated Data from Phase 1 ADP-A2M4 Trial Demonstrating Continued Clinical Benefit for People with Synovial Sarcoma

- Clinical responses in seven out of 14 patients with synovial sarcoma by RECIST 1.1 -

- Clinical benefit in 13 out of 14 patients -

- One RECIST response maintained for more than 9 months after SPEAR T-cell infusion -

PHILADELPHIA and OXFORDSHIRE, United Kingdom, Nov. 16, 2019 (GLOBE NEWSWIRE) -- Adaptimmune Therapeutics plc (Nasdaq:ADAP), a leader in T-cell therapy to treat cancer, presented updated data from people with synovial sarcoma treated in the ongoing Phase 1 trial with ADP-A2M4. The oral presentation by Brian Van Tine, MD, PhD of Washington University School of Medicine in St. Louis, took place earlier today at the Connective Tissue Oncology Society (CTOS) annual meeting in Tokyo, Japan. Today’s presentation was an update of the data that Dr. Van Tine presented at ESMO on September 30.

Out of the 14 patients with synovial sarcoma who have been treated in the expansion phase of this trial and have post-baseline scans, to date, seven have had clinical responses (including both confirmed and unconfirmed partial responses [PRs] by RECIST criteria) representing an overall response rate of 50%. Thirteen patients showed clinical benefit with best overall responses of PR (confirmed or unconfirmed; n=7) or stable disease (SD; n=6) – representing a disease control rate of 93%.

“This updated data set confirms that ADP-A2M4 continues to deliver clinical benefit, including RECIST responses, to patients with synovial sarcoma. It has also galvanized the support we have received from the sarcoma community, allowing us to rapidly open multiple sites and screen patients for the Phase 2 SPEARHEAD-1 trial,” said Elliot Norry, Adaptimmune’s acting Chief Medical Officer. “We expect that all sites for SPEARHEAD-1 will be open by the end of the first quarter in 2020, marking another step toward our goal of making this treatment available commercially to people with sarcoma in 2022.”

“The responses in this trial so far are encouraging because the patients had previously been treated unsuccessfully with standard treatments,” said Dr. Van Tine. “I am looking forward to seeing more results from this trial, and to recruiting patients in the ongoing Phase 2 trial. As there are few treatments, I feel that all sarcoma patients should be screened for their HLA and MAGE-A4 status.”

Data presented today, which are updated since ESMO, include post-baseline tumor assessments from two additional patients. Both of these patients had stable disease at the time of the CTOS data cut off. A previously reported patient who had been assessed as having an unconfirmed RECIST response in September now has a confirmed RECIST response.

Of the seven patients who have had best overall responses of confirmed or unconfirmed PRs, one patient has died, and six remain ongoing for follow up. Of these six patients, four have maintained a response for at least six months and one patient has maintained a response for more than nine months post-treatment.

Most adverse events were consistent with those typically experienced by cancer patients undergoing cytotoxic chemotherapy or other cancer immunotherapies.

About Adaptimmune
Adaptimmune is a clinical-stage biopharmaceutical company focused on the development of novel cancer immunotherapy products for people with cancer. The Company’s unique SPEAR (Specific Peptide Enhanced Affinity Receptor) T‑cell platform enables the engineering of T-cells to target and destroy cancer across multiple solid tumors. For more information, please visit http://www.adaptimmune.com.

Adaptimmune Forward-Looking Statements
This 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 Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (SEC) on November 6, 2019, and our other SEC filings. 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.

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