Adaptimmune Completes BLA for Cell Therapy for Solid Tumors

Adaptimmune Therapeutics has completed its rolling biologics license application (BLA) to the FDA for afamitresgene autoleucel (afami-cel), an engineered T-cell therapy for advanced synovial sarcoma, which are solid tumors that appear in fat, muscle, nerves, fibrous tissues, blood vessels, or deep skin tissues. Synovial sarcoma accounts for about 5% to 10% of all soft tissue sarcomas, with about 13,400 new cases in the United States each year. The five-year survival rate for people with metastatic disease is 20%.

Afami-cel is designed as a single-dose treatment for advanced synovial sarcoma. It targets MAGE A4, which is highly expressed in synovial sarcoma. In one trial, MAGE A4 was detected in 82.2% of synovial sarcomas. Afami-cel is eligible for a priority review, which would shorten the FDA's review of the application to eight months.

John A. Charlson, M.D.

“Engineered T-cell therapies, like afami-cel, have the potential to change the way we manage difficult to treat late-stage cancers like synovial sarcoma,” John A. Charlson, M.D., of the Medical College of Wisconsin and clinical trial investigator, said in a press release. “The current standard-of-care treatments for synovial sarcoma were approved more than two decades ago, have limited efficacy and their dosing schedules, and resulting side effects often negatively impact patients' lives so there is a tremendous unmet need for novel, effective treatments.”

The submission is supported by 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.

In this phase 2, open label trial, about 39% of the 44 patients who received afami-cel had clinical responses with a median duration of response of about 12 months. Median overall survival was about 17 months in compared with historical data for people with synovial sarcoma who received two or more prior lines of therapy. Additionally, 70% of people with advanced synovial sarcoma who responded to afami-cel are alive two years post-treatment.

Adverse events included cytokine release syndrome and reversible hematologic toxicities.

Cohort 2 of the SPEARHEAD-1 trial has completed recruitment and has an overall response rate similar to patients in cohort 1. Adaptimmune said the data will reported. Additionally, Adaptimmune said the FDA agreed that data from cohort 2 will serve as confirmatory evidence for full approval.

Cohort 3 of the study is ongoing to provide patient access to afami-cel in the interim.