Adaptimmune presents updated data from ongoing MAGE-A10, MAGE-A4 studies
Adaptimmune Therapeutics presented initial data from the first two cohorts of its ongoing studies with its MAGE-A10 and MAGE-A4 SPEAR T-cells in two poster presentations earlier at the European Society for Medical Oncology Congress in Munich, Germany. Regarding MAGE-A10 studies: In the 8 patients treated in Cohort 1 across both studies, the disease progressed. In the 3 patients treated in Cohort 2 one patient died of pneumonia - unrelated to T-cell therapy -, one patient had stable disease at Week 4, but then progressed, and one patient had SD at Weeks 4 and 8, but progressed at Week 12. MAGE-A10 SPEAR T-cells at the 100 million and 1B target cell doses showed no evidence of toxicity related to off-target binding or alloreactivity. Of the 11 treated patients, 7 had serious AEs; 3 of whom had related SAEs including 2 patients with CRS, and 1 with hemoptysis. Transduced cells were detectable in peripheral blood at levels consistent with dose. To date, experience with MAGE-A10 SPEAR T-cells did not show a consistent relationship between T-cell infusion and elevation in serum IL-6, IL-8, or IFNgamma and/or CRS. Data from the ongoing MAGE-A4 "basket" study in NSCLC, bladder, melanoma, synovial sarcoma, myxoid/round cell liposarcoma, head & neck, ovarian, gastric, and esophageal cancers were updated: Of the 6 patients treated, best response was SD in 4 patients and progressive disease in 2 patients; 1 patient with SD had an overall 27% reduction of target lesions observed at Week 6, and at the time of the second scan, which took place after the ESMO poster cut-off date, was assessed as PD. MAGE-A4 SPEAR T-cells at the 100M and 1B target cell doses showed no evidence of toxicity related to off-target binding or alloreactivity. There were 4 patients with SAEs, 2 of whom had SAEs related to treatment including 1 patient with muscular weakness and 1 patient with SAEs of CRS and encephalopathy. A case study was provided in the poster for the patient who had SAEs of CRS and grade 2 encephalopathy. Transduced T-cells were detectable in the peripheral blood and expanded transiently, and greater persistence was related to higher T-cell dose. Overall, the most frequent AEs and treatment-related AEs are consistent with those typically experienced by cancer patients undergoing cytotoxic chemotherapy or other cancer immunotherapies. Based on experience with NY-ESO TCR therapy, the benefit of treatment may become evident at higher cell doses. These preliminary data support continued investigation of MAGE-A4 and MAGE-A10 SPEAR T-cells in these study populations.