Company: ATRA
Filing Date: 2025-03-07
Form Type: 10-K
Source: 0000950170-25-035507
Chunk: 23

Company: Atara Biotherapeutics, Inc.
Filing Date: 2025-03-07
Form: 10-K
Item: Item 1
Chunk 23
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Data from preclinical studies for ATA3219 suggest enhanced functional persistence, polyfunctional phenotype and efficient targeting of CD19-expressing tumor cells both in vitro and in vivo with a manufacturing process that focuses on T-cell stemness. Additional in vitro data demonstrate the CD19 antigen-specific functional activity of ATA3219 and CAR-mediated activity against B cells from SLE patients, leading to robust CD19-specific B-cell depletion compared to controls. This preclinical data was submitted as part of a late-breaking abstract which was presented at the International Society for Cell & Gene Therapy meeting held May 29-June 1, 2024. 

Based on academic data from a clinical study, an EBV T-cell platform has the potential to generate off-the-shelf, allogeneic CAR T immunotherapies with high response rates, durable responses and low risk of toxicity that can be rapidly delivered to patients. 

Our EBV CD19 CAR T program incorporates multiple clinically validated technologies designed for a memory phenotype, robust expansion, and retains the endogenous T-cell receptor without gene editing as a key survival signal for T cells contributing to functional persistence. We continue to make progress on the ATA3219 manufacturing process for scale-up. 

Data from an academic study (Curran et al ASH 2023) that used allogeneic EBV CAR T cells (CD28/CD3ζ co-stimulatory domain), demonstrated proof of principle for Atara’s allogeneic CAR T approach with overall survival up to 3 years in post-transplant B-cell malignancy patients. Atara’s ATA3219 builds upon this study with an improved process and construct that leverages multiple clinically validated technologies featuring a less differentiated phenotype and a novel 1XX costimulatory domain. 

In July 2023, we received a Safe to Proceed letter from the FDA in response to our IND submission for ATA3219 in r/r B-cell NHL. We initiated enrollment of a multi-center, Phase 1 open-label, dose escalation clinical trial for ATA3219 in NHL, including large B-cell lymphomas, follicular lymphoma, or mantle cell lymphoma. 

In February 2024, we received a Safe to Proceed letter from the FDA in response to our IND submission for use of ATA3219 as a monotherapy for the treatment of SLE with LN.  In July 2024, we expanded this Phase 1 study to add a new cohort in extrarenal SLE without lymphodepletion (LD).