FDA Grants Fast Track Designation to Balstilimab Plus Zalifrelimab in Relapsed or Refractory Metastatic Cervical Cancer

The FDA has granted a Fast Track designation for the evaluation of balstilimab in combination with zalifrelimab for the treatment of patients with relapsed or refractory metastatic cervical cancer, according to a press release from Agenus, Inc., the developer of balstilimab. Comprehensive data supporting the potential of the combination served as the basis for the designation.¹

As a result of this regulatory action, Agenus plans to file 2 Biologics License Applications with the FDA for balstilimab plus zalifrelimab and balstilimab monotherapy, both as treatment of patients with metastatic cervical cancer.

Updated results from a pre-planned interim analysis showed robust and durable activity with the combination. There was a 26.5% overall response rate (ORR), which included 4 complete responses (CRs), 5 partial responses, and 8 cases of stable disease. The median duration of response was not yet reached in a non-biomarker population of patients with refractory disease who failed platinum chemotherapy with or without bevacizumab (Avastin).

Early data from the pre-planned interim analysis of balstilimab and zalifrelimab were announced in February, as were data from an analysis of balstilimab monotherapy. In 34 evaluable patients, there was an ORR of 20.6% observed in the combination arm, which included an 8.8% CR rate. Among the 44 patients evaluable in the balstilimab monotherapy analysis, the ORR was 11.4%.²

Clinical activity in both studies were found to be comparable with other agents in their classes. Additionally, the combination therapy and monotherapy were well-tolerated among patients with no new safety signals found.

"We are pleased that balstilimab and zalifrelimab have been granted Fast Track designation by FDA in recognition of the high unmet medical need in second-line cervical cancer. The Fast Track designation confers important benefits, including the potential eligibility for a Priority Review," said Jennifer Buell, PhD, president, and chief operating officer, Agenus. "We are excited about the prospect of making these novel agents available to women who suffer from metastatic cervical cancer. We look forward to continuing to work with FDA as we advance new treatment options for patients with cancer."

Balstilimab is a PD-1 inhibitor, and zalifrelimab is a CTLA-4 inhibitor. Balstilimab is currently under evaluation in combination with investigational PD-1 inhibitor AGEN1181 in a phase I dose-escalation study including patients with advanced solid tumors, which initiated in April of 2019.³

References

1. Agenus receives Fast Track designation for balstilimab & zalifrelimab in advanced cervical cancer [news release]. Lexington, Massachusetts: Agenus, Inc; March 12, 2020. https://bit.ly/2U4AifK. Accessed March 12, 2020.
2. Agenus announces positive interim data from balstilimab and zalifrelimab clinical trials in second-line cervical cancer [news release]. Lexington, Massachusetts: Agenus, Inc; February 20, 2020. https://bit.ly/3d3NLxg. Accessed March 12, 2020.
3. Agenus commences combination trial of its next-gen ctla-4 with its pd-1 antibody [news release]. Lexington, Massachusetts: Agenus, Inc; December 19, 2019. https://bit.ly/3aMVcqD. Accessed March 12, 2020.