Exhibit 99.1
Adaptimmune Reports Positive Data with Lete-cel1 from an Interim Analysis of the Pivotal IGNYTE-ESO Trial for People with Synovial Sarcoma or MRCLS
40% (18/45) of people with synovial sarcoma or MRCLS and who have received ≥ 2 prior lines of therapy had clinical responses with lete-cel, by independent review2; primary efficacy endpoint requires 16/60 patients have responses
Median duration of response was ~11 months, data are immature and still evolving
80% (4/5) response rate by investigator assessment with lete-cel in a small substudy of treatment-naïve synovial sarcoma patients with all responses ongoing at the time of this analysis (CTOS 2023)3
PHILADELPHIA, PA. and OXFORD, UK, October 31, 2023 – Adaptimmune Therapeutics plc (Nasdaq: ADAP), a leader in cell therapy to treat cancer, is reporting the outcome of a protocol-defined interim analysis of data from the pivotal IGNYTE-ESO trial with lete-cel for people with synovial sarcoma or myxoid/round cell liposarcoma (MRCLS) who received ≥ 2 prior lines of therapy.
Additionally, Dr. Melissa Burgess of University of Pittsburgh Medical Center will present a poster summarizing results of Substudy 14 of the IGNYTE-ESO clinical trial exploring the feasibility, efficacy, and safety of lete-cel in the first-line setting for treatment-naïve patients with metastatic or unresectable synovial sarcoma or MRCLS on Thursday November 2nd at the Connective Tissue Oncology Society (CTOS) annual meeting taking place in Dublin, Ireland.
Elliot Norry, MD, Adaptimmune’s Chief Medical Officer: “The remarkable responses we are seeing in the interim analysis from IGNYTE-ESO provide us with a compelling opportunity to continue the clinical development of lete-cel for both synovial sarcoma and MRCLS. We’ll be able to leverage our learnings and capabilities from afami-cel as we consider next steps to further develop lete-cel.”
Interim analysis data from the IGNYTE-ESO pivotal trial with lete-cel
Lete-cel, an engineered T-cell therapy targeted against NY-ESO-1, is being investigated for the treatment of synovial sarcoma or MRCLS in the pivotal IGNYTE-ESO (NCT03967223) trial in patients who received ≥ 2 prior lines of therapy.
The interim analysis for efficacy includes data from 45 people with synovial sarcoma or MRCLS who have received lete-cel in the IGNYTE-ESO trial and who had at least 6 months follow up. At the time of this analysis, 18/45 (40%) (99.6% CI: 20.3%, 62.3%) people with synovial sarcoma or MRCLS had RECISTv1.1 responses by independent review with two complete responses and 16 partial
1 Adaptimmune and GSK have agreed terms for transfer of the lete-cel program back to Adaptimmune (announced April 2023) and the transition is still in progress.
2 Substudy 2 in patients who have received ≥ 2 prior lines of treatment; responses for primary efficacy endpoint by independent review
3 Substudy 1 in the first-line treatment setting
4 Substudy 1 in the first-line treatment setting