Agenus is now in the closing stretch of its multidecade effort to bring a drug to market. With the FDA set to decide whether to approve PD-1 drug balstilimab in December, Agenus has published the phase 2 data it hopes will secure authorization in cervical cancer.
The headline results, published in the journal Gynecologic Oncology this week, are the same as the findings Agenus shared at the American Society of Clinical Oncology annual meeting earlier this year. In 140 patients with recurrent or metastatic cervical cancer, balstilimab achieved a 15% response rate. Five patients had complete responses.
Notably, balstilimab achieved an 8% response rate in patients with PD-L1-negative tumors. While far lower than the 20% response rate seen in PD-L1-positive patients, the activity still offers Agenus a chance to set its checkpoint inhibitor apart from the competition.
Merck’s Keytruda is approved for use in cervical cancer patients whose tumors express PD-L1 at 1% or more. Other checkpoint inhibitors are yet to win approval in the indication. If Agenus can secure a broader label—and persuade physicians to use balstilimab in patients with PD-L1-negative tumors—it could carve out a niche despite its late entry into the checkpoint inhibitor market.
RELATED: Bristol Myers hands over $200M upfront, $1.36B in biobucks for Agenus' preclinical TIGIT asset
“The update continues to show differentiation from Keytruda in 2L cervical cancer and supports potential FDA approval on Dec 16,” analysts at Jefferies wrote in a note to investors. “We think the tumor responses will continue to deepen based upon the clinical experience of other PD-1 antibody drugs.”
Agenus will provide an update on another piece of its strategy next month when it releases data from a phase 2 cervical cancer trial that is giving balstilimab in combination with anti-CTLA-4 prospect zalifrelimab. The trial will show whether the combination, Agenus’ take on Bristol Myers Squibb’s Opdivo-Yervoy cocktail, improves on the efficacy of balstilimab as a single agent.