 SOUTH SAN FRANCISCO, Calif.--BUSINESS WIRE--Atara Biotherapeutics, Inc. Nasdaq: ATRA, a pioneer in T-cell immunotherapy, leveraging its novel allogeneic EBV T-cell platform to develop transformative therapies for patients with serious diseases including solid tumors, hematologic cancers and autoimmune disease, today announced a combined long-term overall survival OS analysis from three clinical studies of tabelecleucel tab-cel in patients with Epstein-Barr virus-driven post-transplant 