Novel PD-1 inhibitor shows activity against PD-L1 positive recurrent or metastatic cervical cancer

Enlonstobart, a fully humanized and high-affinity anti-PD-1 immunoglobulin G4 monoclonal antibody, shows therapeutic potential in patients with PD-L1 positive recurrent or metastatic cervical cancer (r/mCC), while having an acceptable safety profile, according to an open-label phase II study.

The study included 107 patients with PD-L1-positive cervical cancer (median age 53 years, 64.5 percent had ECOG 1) who had progression on or intolerance to the first-line platinum-based chemotherapy. These patients received enlonstobart at 240 mg every 2 weeks for 24 months or until disease progression, intolerable toxicities, or other study discontinuation criteria were met.

The primary endpoint was confirmed objective response rate (ORR), as evaluated by an independent review committee.

Over a median follow-up of 14.0 months, the ORR was 29.0 percent. Response was complete in two patients and partial in 29 patients. The median duration of response was 16.6 months, and the disease control rate was 54.2 percent. Median progression free survival was 3.1 months, and median overall survival was not reached.

In terms of safety, treatment emergent adverse events (TEAEs) occurred in 104 patients (97.2 percent), including grade 3 or higher TEAEs in 38 (35.5 percent). The most frequent TEAEs were leukopenia (19.6 percent), increased aspartate aminotransferase (18.7 percent), anaemia (17.8 percent), increased alanine aminotransferase (15.9 percent), hypothyroidism (15.0 percent), neutropenia (15.0 percent), and hyperthyroidism (11.2 percent).