A second sarcoma success for Adaptimmune

Just three months after seeing Tecelra cross the regulatory finish line, Adaptimmune has floated the possibility of having a second cell therapy approved for sarcoma. The anti-NY-ESO-1 engineered T-cell receptor lete-cel met the response rate goal of its uncontrolled phase 2 study Ignyte-ESO, Adaptimmune said, a development that should lead to a US filing by the end of 2025. At this year's ASCO conference lete-cel yielded a 40% ORR among 45 synovial sarcoma or myxoid/round cell liposarcoma patients whose tumours were positive for NY-ESO-1 and/or LAGE-1a. With 64 patients now evaluable, primary analysis has seen this number rise to 42%, Adaptimmune revealed in a late-breaker at the Connective Tissue Oncology Society meeting. Somewhat ironically lete-cel had been licensed to GSK (coded GSK3377794), but the UK big pharma group scrapped that deal two years ago, shortly after terminating a separate tie-up with Adaptimmune's sister company Immunocore, covering the anti-NY-ESO-1 soluble T-cell receptor GSK3537142. In August Adaptimmune's anti-MAGE-A4 T-cell receptor Tecelra was approved for MAGE-A4-expressing synovial sarcoma, causing the group's stock to fall on the prospects of a solo launch. A repeat of this likely awaits Adaptimmune if it can't find a new partner for lete-cel.

Summary of lete-cel activity in Ignyte-ESO trial in NY-ESO-1 and/or LAGE-1a positive sarcomas

Note: *2/45 patients died of adverse events said to be related to lymphodepletion (neutropenia & pulmonary alveolar haemorrhage). Source: ASCO, OncologyPipeline & company statement.