Global Biopharma Layoffs September 2026

Arsenal Biosciences

📅 Sept. 2

Arsenal Biosciences is undergoing a major strategic realignment that will concentrate the company's resources on developing in vivo CAR T therapies. The shift is accompanied by a substantial workforce reduction affecting the majority of the company.

A total of 99 employees will be laid off from ArsenalBio's South San Francisco headquarters and Hayward, California, sites, a company spokesperson confirmed. The affected positions span teams and functions across the organization. ArsenalBio had 127 employees as of September 2025, following a 50% workforce reduction, but the company did not disclose how many employees will remain after the latest cuts.

Under the new strategy, announced Aug. 31, ArsenalBio will retain a smaller core team dedicated to advancing its in vivo CAR T programs. The remaining employees will also evaluate strategic options for the company's existing assets and technologies as ArsenalBio narrows its focus and reshapes its operations.

Cellares

📅 Sept. 1

Cellares is carrying out another round of layoffs following the termination of its partnership with Bristol Myers Squibb, this time eliminating 68 positions at its Bridgewater, New Jersey facility. According to a state WARN notice, the cuts are scheduled to take effect on Nov. 19.

The latest reduction comes shortly after Cellares disclosed plans to lay off 100 employees at its headquarters in South San Francisco. Those positions are scheduled to be eliminated on Oct. 20, bringing the total number of publicly disclosed job cuts across the company to 168 in recent weeks.

The workforce reductions follow BMS' decision to end its partnership with Cellares after determining that the company's cell therapy manufacturing system did not meet the requirements for producing commercial batches of Breyanzi, a CAR-T cell therapy. Cellares has disputed that assessment, saying it "strongly disagrees" with BMS' characterization of its manufacturing platform.

Layoffs Layoff Cellares Arsenal Biosciences

Table of Contents

• Arsenal Biosciences
• Cellares