Adaptimmune's Lete-cel Achieves Primary Endpoint in Pivotal Trial

Core Insights - Adaptimmune Therapeutics announced that 42% of patients with advanced or metastatic synovial sarcoma or myxoid/round cell liposarcoma (MRCLS) showed clinical responses to lete-cel, with six complete responses and twenty-one partial responses reported [1][3][4] - The company plans to initiate a rolling Biologics License Application (BLA) submission for lete-cel by the end of 2025, aiming to expand treatment options for these cancers [2][3] - The median duration of response for patients with synovial sarcoma was over 18 months, while for MRCLS it was over one year, indicating the potential for durable responses [3][4] Clinical Trial Data - The primary analysis included data from 64 patients who had previously received anthracycline-based therapy, with 27 out of 64 (42%) achieving RECISTv1.1 responses [3][4] - The response rates were 41% for synovial sarcoma (14/34) and 43% for MRCLS (13/30) [3] - The median duration of response was 12.2 months overall, with specific durations of 18.3 months for synovial sarcoma and 12.2 months for MRCLS [4] Safety Profile - Safety findings were consistent with previous data on lete-cel, with all patients experiencing treatment-emergent adverse events, including cytopenias, cytokine release syndrome (CRS), and rash [5] - Overall, the toxicities were manageable and aligned with an acceptable benefit-to-risk profile [5] Upcoming Events - Adaptimmune will present the findings at the Connective Tissue Oncology Society (CTOS) 2024 Annual Meeting from November 13-16, 2024, in San Diego [1][5] - A virtual Key Opinion Leader (KOL) event is scheduled for November 18, 2024, featuring Dr. Sandra D'Angelo, who will discuss the IGNYTE-ESO dataset and its implications for sarcoma treatment [6] About Lete-cel and the IGNYTE-ESO Trial - Lete-cel is an investigational engineered TCR T-cell therapy targeting the NY-ESO-1 antigen, which is highly expressed in synovial sarcoma and MRCLS [8][7] - The IGNYTE-ESO trial is a pivotal Phase 2, open-label study evaluating the efficacy, safety, and tolerability of lete-cel in patients with previously treated advanced synovial sarcoma or MRCLS [7]