Atara Biotherapeutics, Inc. announced that it is noted that it has not yet initiated the Biologics License Application (BLA) submission for tab-cel(R) (tabelecleucel), currently in Phase 3 development for Epstein-Barr virus- positive post-transplant lymphoproliferative disease (EBV(+) PTLD). The Company remains on track to complete the BLA filing in third quarter of 2021, based on several key points of agreement with FDA as previously announced. To initiate the BLA, Atara is awaiting a procedural decision from the FDA related to how the historical non-pivotal data should be presented in the BLA submission. Following the FDA agreement in October 2020 that the pivotal 302 ALLELE data will be the primary basis for approval, and that historical non-pivotal clinical data will be supportive, FDA needs to decide whether they view the drug product manufactured by academic partner used in historical, non-pivotal studies as comparable to the drug product manufactured by Atara used in the pivotal ALLELE study. This decision will then determine if the Company will submit in the clinical module the pivotal and non-pivotal data combined in pooled analyses or separately in parallel analyses. The type of analysis does not change expectations regarding the proposed product indication for previously treated patients with EBV(+) PTLD. The initial module for the rolling BLA for tab-cel(R) has been ready for submission since early December, and its content is not impacted by this decision. The Company remains on track to complete the BLA filing in third quarter 2021 and is simply awaiting this procedural decision from FDA to initiate the BLA.