Adaptimmune announced Wednesday that its experimental cell therapy based on T cell receptors shrank tumors by at least 30% in nearly half of the patients in a pivotal clinical trial.
In 64 patients with previously treated synovial sarcoma or myxoid/round cell liposarcoma, six saw signs of cancer disappear completely. Another 21 had a partial response to the cell therapy, which is called lete-cel.
Adaptimmune now plans to start an FDA submission for the therapy in both cancers by the end of 2025. Detailed data from the study are set to be presented on Saturday at the Connective Tissue Oncology Society’s annual meeting in San Diego.
The median duration of response was 12.2 months, according to the
press release
, and median progression-free survival was 5.3 months. Adaptimmune noted that all patients experienced adverse events, which included cytopenias, cytokine release syndrome and rash.
Lete-cel targets NY-ESO-1, an antigen found on solid tumors. It’s a cell therapy that GSK once worked on with Lyell Immunopharma before the UK pharma walked away from the program.
In August, Adaptimmune won the first
FDA approval
for a cell therapy based on T cell receptors. That approval, also in synovial sarcoma, was granted to its MAGE-A4-targeted treatment, which is called Tecelra.