Atara Biotherapeutics shares surge 15.87% after-hours as Pierre Fabre assumes tabelecleucel BLA amid FDA Priority Review.

Atara Biotherapeutics (NASDAQ:ATRA) surged 15.87% in after-hours trading following the announcement that Pierre Fabre Pharmaceuticals Inc. has assumed responsibility for the Biologics License Application (BLA) for tabelecleucel, an investigational allogeneic T-cell therapy for Epstein-Barr virus positive post-transplant lymphoproliferative disease. The BLA, now under FDA Priority Review with a target action date of January 10, 2026, marks a critical regulatory milestone for the therapy, which could become the first treatment for this ultra-rare condition. The transfer shifts clinical, regulatory, and commercial responsibilities to Pierre Fabre, potentially reducing Atara’s financial exposure while advancing the drug’s approval timeline. Analysts highlighted Atara’s undervalued valuation metrics (P/E of 26.18, PEG of 0.18) and noted the BLA resubmission in July 2025, accepted by the FDA with Priority Review, as key drivers of the post-market rally.