Atara Biotherapeutics’ ATA188 did not meet primary endpoint in sclerosis trial

Atara Biotherapeutics announced primary analysis data from its Phase 2 EMBOLD study of ATA188 in non-active progressive multiple sclerosis, or PMS. The study did not meet the primary endpoint of confirmed disability improvement compared to placebo. In addition, fluid and imaging biomarkers did not provide further supportive evidence. Preliminary safety data showed there were no new safety signals in the EMBOLD study, reinforcing the favorable safety profile observed with ATA188 to date. Atara is actively reviewing the totality of the data, including a 6% disability improvement in the treatment arm compared to 33% disability improvement observed in the Phase 1 study, to determine the next steps for the program. Going forward, the company plans to significantly reduce its expenses on ATA188 and further focus resources on advancing its differentiated allogeneic CAR-T pipeline, in addition to executing the expanded tab-cel partnership with Pierre Fabre through the Biologics License Application transfer. These future actions are expected to meaningfully extend its cash runway beyond Q3 2025.