Atara Biotherapeutics Faces Setbacks, Halves Workforce Amid FDA Hold

Atara Biotherapeutics, a leading allogeneic T-cell immunotherapy company, has announced significant restructuring measures in response to recent regulatory challenges. The company is laying off approximately 50% of its workforce as it grapples with a clinical hold imposed by the U.S. Food and Drug Administration (FDA) on its key programs.

FDA Clinical Hold Impacts Multiple Programs

The FDA has placed a clinical hold on Atara's investigational new drug (IND) applications for two of its most promising candidates:

1. Ebvallo (tabelecleucel): Approved in Europe for Epstein-Barr virus-positive post-transplant lymphoproliferative disease (EBV+PTLD), Ebvallo faces hurdles in its U.S. approval journey.

2. ATA3219: An allogeneic CD19-targeted CAR-T candidate for non-Hodgkin lymphoma and systemic lupus erythematosus.

The clinical hold stems from compliance issues at a third-party manufacturing facility, which were highlighted in a recent FDA inspection. While ATA3219 is manufactured at a separate facility, its starting materials are affected by the same compliance issues.

Strategic Restructuring and Program Terminations

In response to these setbacks, Atara has implemented a series of strategic decisions:

• Halting all work on the ATA3219 program
• Discontinuing development of ATA3431, another CAR-T candidate
• Laying off approximately 50% of its employees, to be completed by June 2025
• Estimating restructuring costs of around $3 million

This marks the third consecutive year of layoffs for Atara, following a 20% staff reduction in 2022 and a further 25% cut in 2024. The company has shifted its focus away from a failed multiple sclerosis cell therapy towards its CAR-T prospects, which are now facing significant challenges.

Implications for Ebvallo's U.S. Approval

Atara had been collaborating with Pierre Fabre Laboratories to secure U.S. approval for Ebvallo in EBV+PTLD patients who have received at least one prior therapy. The drug, which became the first allogeneic T-cell therapy approved in Europe in December 2022, now faces an uncertain future in the U.S. market.

The company has not provided any updates on progress towards lifting the FDA hold, leaving the timeline for potential U.S. approval of Ebvallo unclear. This setback could have significant implications for patients with EBV+PTLD who have limited treatment options.