Incyte’s Retifanlimab (Zynyz) Extends Progression-Free Survival in Patients with Squamous Cell Anal Carcinoma (SCAC); Data Featured at ESMO 2024 Presidential Symposium

Incyte (Nasdaq:INCY) today announced results from the Phase 3 POD1UM-303/InterAACT2 trial of retifanlimab (Zynyz), a humanized monoclonal antibody targeting programmed death receptor-1 (PD-1), in combination with platinum-based chemotherapy (carboplatin–paclitaxel) for the treatment of adults with inoperable locally recurrent or metastatic squamous cell anal carcinoma (SCAC). These data were featured today in a Presidential Symposium (LBA 2) at the European Society for Medical Oncology (ESMO) Congress 2024, held in Barcelona and virtually.

The POD1UM-303/InterAACT2 trial results build on previously announced topline results, showing that the study met its primary endpoint by demonstrating a statistically significant and clinically meaningful improvement in progression-free survival (PFS) in patients with SCAC not previously treated with systemic therapy, as assessed by blinded independent central review (BICR) using RECIST v1.1. Adding retifanlimab to standard of care chemotherapy resulted in a clinically meaningful 37% reduction in the risk of progression or death (Hazard Ratio [HR]: 0.63; 95% Confidence Interval [CI] (0.47, 0.84); P=0.0006). Patients in the retifanlimab and chemotherapy combination group achieved a median PFS of 9.3 months compared to 7.4 months for patients in the placebo combination group.

“The POD1UM-303/InterAACT2 trial is the first and largest Phase 3 trial evaluating a checkpoint inhibitor for the treatment of patients with squamous cell anal carcinoma, a disease with significant medical need. The positive efficacy and safety data presented today at ESMO illustrate the potential of retifanlimab in combination with carboplatin and paclitaxel to become a new standard-of-care treatment for patients with advanced SCAC,” said Pablo J. Cagnoni, M.D., President and Head of Research and Development, Incyte. “We look forward to working with regulatory authorities to progress the supplemental Biologics License Application (sBLA) for retifanlimab and potentially bring the first-ever PD-1 or PD-L1 antibody to patients with SCAC.”

The trial also showed improvement in key secondary endpoints, including:

• In an interim analysis for overall survival (OS), patients that received retifanlimab in combination with chemotherapy achieved an approximately 6-month improvement in median OS versus the placebo combination group, with a strong trend toward statistical significance (median OS 29.2 months vs. 23 months [HR: 0.70; 95% CI (0.49, 1.01); P=0.0273]; OS follow-up is ongoing).
• Overall response rate (ORR) and duration of response (DOR) by BICR each showed improvement in the retifanlimab and chemotherapy combination group versus the placebo combination group (ORR of 56% vs. 44% [95% CI (48, 64) and (36, 52), respectively; nominal P=0.0129]; DOR of 14 months vs. 7 months [95% CI (8.6, 22.2) and (5.6, 9.3), respectively]).

Retifanlimab was generally well-tolerated, and safety was consistent with other chemotherapy plus checkpoint inhibitor regimens. The most common treatment-emergent adverse events (TEAEs) in the retifanlimab and chemotherapy combination group were anemia (66.2%), nausea (56.5%) and alopecia (51.3%).