Patients with advanced penile squamous cell carcinoma (PSCC) have poor outcomes and very limited therapeutic options are available. Most PSCC cases have high PD-L1 expression, which is associated with worse prognosis. Immunotherapy targeting PD-L1 could benefit patients with PSCC. Our aim was to evaluate the efficacy and safety of the anti-PD-1 antibody retifanlimab in patients with advanced/metastatic PSCC.
ORPHEUS was a single-arm, multicenter, phase 2 trial in 18 patients with advanced/metastatic PSCC, previously untreated with anti-PD-1/anti-PD-L1 agents. Patients received retifanlimab 500 mg intravenously every 4 wk for up to 2 yr. The primary endpoint was the objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumors v1.1. Secondary endpoints included the clinical benefit rate (CBR), disease control rate, duration of response (DoR), time to response, progression-free survival (PFS), overall survival (OS), maximum tumor shrinkage, and safety. The Wilson method was used for the primary endpoint, and the Clopper-Pearson and Kaplan-Meier methods for secondary endpoints.
Median follow-up was 7.2 mo. The ORR was 16.7% (95% confidence interval [CI] 5.8-39.2); three patients had a partial response. Median DoR was 3.3 mo (range 1.8-8.5). The CBR was 22.2% (95% CI 6.4-47.6%). Median PFS was 2.0 mo (95% CI 1.6-3.3) and median OS was 7.2 mo (95% CI 3.0-9.8). One patient (5.6%) experienced grade 3 treatment-related adverse events (AEs). There were no grade >= 4 treatment-related AEs. The small sample size is the main limitation.
Single-agent retifanlimab exhibited signals of clinical activity in advanced/metastatic PSCC, with no new safety signals. Further investigation of retifanlimab in this setting is warranted.
Advanced penile cancer of the squamous cell type is a rare tumor with poor prognosis. The aggressiveness of this cancer is usually associated with high levels of a protein called PD-L1. We investigated whether retifanlimab, an immunotherapy drug against PD-1, has activity against this type of penile cancer. Tumor regression or stabilization occurred in one-third of the patients and the side effects were manageable.
European urology oncology. 2024 May 14 [Epub ahead of print]
Xavier García Del Muro, David Páez López-Bravo, Miler Andrés Cuéllar-Rivas, Pablo Maroto, Patrizia Giannatempo, Daniel Castellano, Miguel A Climent, Begoña P Valderrama, Alfonso Gómez de Liaño, Laura López-Montero, Leonardo Mina, Daniel Alcalá-López, Miguel Sampayo-Cordero, Andrea Necchi
Medical Oncology Department, Catalan Institute of Oncology, IDIBELL, University of Barcelona, Barcelona, Spain. Electronic address: ., Oncology Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain., Medical Oncology Department, Catalan Institute of Oncology, IDIBELL, University of Barcelona, Barcelona, Spain., Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy., Oncology Department, Hospital Universitario Doce de Octubre, Madrid, Spain., Oncology Department, Instituto Valenciano de Oncología, Valencia, Spain., Oncology Department, Hospital Universitario Virgen del Rocío, Sevilla, Spain., Department of Medical Oncology, Complejo Hospitalario Universitario Insular-Materno Infantil, Las Palmas de Gran Canaria, Spain., Medica Scientia Innovation Research (MEDSIR), Barcelona, Spain and New Jersey, USA., Department of Medical Oncology, IRCCS Ospedale San Raffaele, Milan, Italy; Vita-Salute San Raffaele University, Milan, Italy.