Atara Biotherapeutics Presents New Long-Term Overall Survival Data from a Combined Analysis of Phase 2 Tab-cel® Studies for Epstein-Barr Virus-Driven Post-Transplant Lymphoproliferative Disease at The EBMT 2021 Annual Meeting
Atara Biotherapeutics (ATRA) announced positive long-term overall survival (OS) data for tabelecleucel (tab-cel®) in patients with Epstein-Barr virus-driven post-transplant lymphoproliferative disease (EBV+ PTLD) at the 47th Annual Meeting of the European Society for Blood and Marrow Transplantation. The analysis covered 50 patients from three studies, showing a 62% objective response rate and an 86% two-year survival rate. Atara plans to file a Biologics License Application (BLA) in Q3 2021 and a Marketing Authorization Application (MAA) in Europe in Q4 2021.
- 62% objective response rate (31 of 50 patients) for tab-cel® in EBV+ PTLD.
- 86% two-year survival rate with tab-cel® treatment.
- Plans to complete BLA filing in the U.S. by Q3 2021 and MAA submission in Europe by Q4 2021.
- None.
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 lymphoproliferative disease (EBV+ PTLD) after hematopoietic cell transplantation (HCT). The results were featured in an oral presentation at the 47th Annual Meeting of the European Society for Blood and Marrow Transplantation (EBMT 2021), taking place virtually from March 14 - 17, 2021.
Combined analysis from these investigator-assessed studies demonstrates patients with EBV+ PTLD after HCT that is relapsed or refractory (R/R) to rituximab who achieved either complete or partial response (CR or PR) after treatment with tab-cel® derived similar OS benefit. Treatment response and OS data were assessed from two completed single-arm, Phase 2 studies (NCT00002663, NCT01498484) and the multi‑center expanded access protocol (EAP-201) study (NCT02822495).
“Patients who develop EBV+ PTLD that is relapsed or refractory to rituximab after receiving hematopoietic cell transplant rapidly decline, with a median overall survival of only a few months,” said Jakob Dupont, M.D., Head of Global Research & Development at Atara. “Their prognosis is poor and time is of the essence for this high-risk population. Data from across three clinical studies suggest that tab-cel® may provide an effective treatment option marked by long-term overall survival regardless of partial or complete response.”
Atara has previously shown clinical benefit in patients with EBV+ PTLD after HCT who responded (CR or PR) to tab-cel® treatment, including an 86 percent two-year survival rate. Aggregated data presented at EBMT 2021 show patients who achieved a PR have similar one- and two-year probability of OS after tab-cel® treatment to those who achieved a CR. All patients received tab-cel® dose of 2x106 cells/kg on days 1, 8, and 15 in a 35-day treatment cycle. Patients received a median of two cycles (range, 1-5).
This data set included 50 HCT recipients who developed EBV+ PTLD R/R to rituximab that were treated with tab-cel®. Objective response rate (PR + CR) was 62 percent (31/50) with best overall response (BOR) of CR (n=24) or PR (n=7). Similar one-year survival rates of 86.7 and 85.7 percent and two-year survival rates of 81.6 and 85.7 percent for patients with CR and PR, respectively were observed. Treatment was generally well-tolerated, with no confirmed evidence for graft-versus-host disease (GvHD), cytokine release syndrome (CRS) or neurotoxicity attributable to tab-cel®.
“We are inspired by the consistency and clinical relevance of the tab-cel® data presented today, showing once again high overall response rates and favorable long-term survival in patients with EBV+ PTLD following HCT,” said Pascal Touchon, President and Chief Executive Officer of Atara. “Atara is moving with a sense of urgency to serve these patients with high disease burden and unmet need, and is on track to complete a BLA filing in the U.S. for the PTLD indication in Q3 2021 as well as a MAA submission in Europe in Q4 2021.”
Atara also presented findings from a comprehensive multiomic analysis of modes of activation for tab-cel®. Each component of the assessment contributes to building the overall understanding of tab-cel’s therapeutic activity, mechanisms of action and extended characteristics. Transcriptional data for tab-cel® demonstrate consistency of the product’s activation profile irrespective of donor and consistent enrichment of receptors targeting EBV-driven diseases.
Atara Presentations at EBMT 2021:
Title: Overall Survival by Best Overall Response with Tabelecleucel in Patients with Epstein-Barr Virus-Driven Post-Transplant Lymphoproliferative Disease after Allogeneic Hematopoietic Cell Transplant
Date & Time: Sunday, March 14, 2021; 08:30 a.m. – 6:45 p.m. CET/ 2:30 a.m. – 12:45 p.m. EDT
Oral session & Number: Cellular Therapy, Gene Therapy and New Drugs II; 5
Title: Comprehensive Activation Profiling of Tabelecleucel, an Off-the-Shelf, Allogeneic EBV-specific T cell therapy (ENCORE FROM TCT 2021)
Date & Time: Available for viewing during poster sessions throughout the meeting
Poster session & Number: P031, Cellular Therapies other than CARs
About Atara Biotherapeutics, Inc.
