Achilles Therapeutics provides update on Phase I/IIa NSCLC results

Achilles Therapeutics announced interim Phase I/IIa data on the use of clonal neoantigen reactive T cells – cNeT – from the CHIRON study in advanced unresectable or metastatic non-small cell lung cancer – NSCLC – and the THETIS study in recurrent or metastatic malignant melanoma. The update includes data from 18 patients across dosed since the previous interim update in December 2022, with two CHIRON patients and one THETIS patient having received enhanced chemo-conditioning and IL-2 dosing aligned to standard tumor infiltrating lymphocyte – TIL – therapy in a new Cohort C. The VELOS manufacturing process continued to improve with a median 172 million cNeT dosed across the eighteen patients in the update compared to 18 million cNeT in the December 2022 update, with 10 products over 100 million cNeT and five over one billion cNeT. The next step is to evaluate cNeT persistence and clinical activity in patients with enhanced host conditioning, and Achilles plans to report a meaningful data update in the second half of 2024. Data shows continued favorable tolerability profile for cNeT, tolerability observations for cNeT compare well with standard TIL therapy, lymphopenia and neutropenia were the most common adverse events, which are principally associated with the conditioning regimen, and no dose limiting high-grade toxicities were observed. 25% of higher dose patients demonstrated stable disease with some reduction in tumor volume. All three patients dosed using the enhanced host conditioning regimen have shown improvement in cNeT engraftment and some tumor reduction in one case.