Atara Biotherapeutics, Inc. announced primary analysis data from its Phase 2 EMBOLD study of ATA188 in non-active progressive multiple sclerosis (PMS). The study did not meet the primary endpoint of confirmed disability improvement (CDI) by expanded disability status scale (EDSS) at 12 months compared to placebo. 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, in addition to identifying the factors related to a substantially greater than expected placebo rate of 16% for CDI at 12 months compared with an expected rate of 4-6% in non-active PMS patients. 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 (BLA) transfer.