Atara Bio Unveils Pivotal Data On T Cell Therapy Tabelecleucel In Transplant Patients

Atara Biotherapeutics Inc (NASDAQ: ATRA) posted efficacy and safety results from its Phase 3 ALLELE study of tabelecleucel (tab-cel) for Epstein-Barr virus-positive post-transplant lymphoproliferative disease (EBV+ PTLD).

• EBV+ PTLD is a rare complication after a solid organ (SOT) or hematopoietic stem cell transplant (HSCT).
• The overall response rate was 50% in both the SOT and HCT groups. 
• 26.3% of patients overall achieved a complete response, and just under 23.7% reached a partial response.
• Eleven of the 19 responders saw a duration of response longer than six months. 
• Of the eight remaining responders, four patients experienced either disease progression or death, and four weren't evaluable for a six-month response at the data cut. 
• Patients who responded to tab-cel survived longer than the non-responders, with a one-year survival rate of 89.2% in the responder group versus 32.4% in the group that didn't respond. Median overall survival wasn't reached in the responder group.
• The Company also reported long-term results from Phase 2 and EAP trials, showing a median overall survival of 54.6 months. 
• The overall complete response rate was 42.1%, and the partial response rate was 21.1%. 
• Two-year survival rates for CR and PR patients were 86.2% and 86.5%, respectively.
• In November, Atara filed with the EMA and is expecting a decision in 2H of 2022. 
• Price Action: ATRA shares are up 9.45% at $17.14 during the premarket session on the last check Tuesday.
• Check out our coverage of the American Society of Hematology (ASH) Annual Meeting 2021 here.