One of the top fundraisers of 2024 is halving its workforce about a year after drawing in a $325 million series C. Cell therapy biotech Arsenal Biosciences has laid off 50% of its staff as it restructures itself as a clinical-stage company, an ArsenalBio spokesperson confirmed to Fierce Biotech.
“As we transition from early-stage research to a clinical-stage company focused on bringing innovative medicines to patients, we have undergone a restructuring to extend our cash runway and position the organization for our next phase of development,” the spokesperson said. “This reorganization will enable us to execute on our clinical programs and advance them through critical milestones.”
The company now employs 127 staffers, the spokesperson said.
This shift does not impact the Bay Area biotech’s long-standing collaboration with Bristol Myers Squibb, the spokesperson added. The companies first teamed up in December 2020 to pursue new CAR-T cell therapies for solid tumors, with ArsenalBio racking up its latest milestone payment in January 2025.
ArsenalBio’s lead asset is AB-2100, which is currently being tested in an open-label phase 1/2 trial for recurrent clear-cell renal cell carcinoma. AB-2100 was elevated above former top candidate AB-1015 in September 2024, around the same time the biotech closed its series C.
AB-1015 was in early clinical development for ovarian cancer, and ArsenalBio CEO Ken Drazan, M.D., told Fierce at the time that “hopefully someday we'll be able to come back to the ovarian program when resources are greater.”
The company’s wholly owned pipeline includes two other preclinical cell therapies, one in development for prostate cancer and another in an undisclosed indication. ArsenalBio intends to launch first-in-human studies for the prostate cancer asset in the first half of 2026, according to the biotech’s website.
Many cell therapy outfits have struggled this year, with numerous companies resorting to downsizing or shutting down entirely. Meanwhile, several high-value cell therapy deals have also been scrapped over the course of 2025. For example, Innate Pharma recently announced plans to cut its staff by 30%, including its chief scientific officer, and deprioritize its antibody-based natural killer cell engager.
And Gilead’s Kite Pharma and Roche’s Genentech have each terminated deals potentially worth more than $2 billion with Shoreline Biosciences and Adaptive Biotechnologies, respectively.