A phase II study of retifanlimab, a humanized anti-PD-1 monoclonal antibody, in patients with solid tumors (POD1UM-203)

• Published in: ESMO open Vol. 9; no. 3; p. 102387
• Main Authors: Di Giacomo, A.M., Schenker, M., Medioni, J., Mandziuk, S., Majem, M., Gravis, G., Cornfeld, M., Ranganathan, S., Lou, S., Csoszi, T.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.03.2024; Elsevier
• Subjects: Antibodies, Monoclonal - pharmacology; Antibodies, Monoclonal - therapeutic use; B7-H1 Antigen; Carcinoma, Non-Small-Cell Lung - drug therapy; Carcinoma, Non-Small-Cell Lung - pathology; Carcinoma, Renal Cell - drug therapy; Carcinoma, Transitional Cell; checkpoint inhibitor; Humans; Immune Checkpoint Inhibitors - therapeutic use; Lung Neoplasms - drug therapy; Lung Neoplasms - pathology; Melanoma - drug therapy; Original Research; PD-1 inhibitor; phase II; retifanlimab; solid tumor; Urinary Bladder Neoplasms; solid tumor; phase II; PD-1 inhibitor; retifanlimab; checkpoint inhibitor
• ISSN: 2059-7029; 2059-7029
• DOI: 10.1016/j.esmoop.2024.102387

POD1UM-203, an open-label, multicenter, phase II study, evaluated retifanlimab, a humanized monoclonal antibody targeting programmed cell death protein-1 (PD-1) in patients with selected solid tumors where immune checkpoint inhibitor therapies have previously shown efficacy. Eligible patients (≥18 years) had measurable disease and included unresectable or metastatic melanoma, treatment-naive metastatic non-small-cell lung cancer (NSCLC) with high programmed death-ligand 1 (PD-L1) expression (tumor proportion score ≥50%), cisplatin-ineligible locally advanced/metastatic urothelial carcinoma (UC) with PD-L1 expression (combined positive score ≥10%), or treatment-naive locally advanced/metastatic clear-cell renal cell carcinoma (RCC). Retifanlimab 500 mg was administered intravenously every 4 weeks as a 30-min infusion. The primary endpoint was investigator-assessed overall response rate. Overall, 121 patients (35 melanoma, 23 NSCLC, 29 UC, 34 RCC) were enrolled and treated. The overall response rate [95% confidence interval (CI)] was 40.0% (23.9-57.9) in the melanoma cohort, 34.8% (16.4-57.3) in the NSCLC cohort, 37.9% (20.7-57.7) in the UC cohort, and 23.5% (10.7-41.2) in the RCC cohort. Median duration of response was 11.5 months (95% CI 2.2-not reached) in the UC cohort, and was not reached in the other cohorts. Retifanlimab safety was consistent with previous experience for PD-(L)1 inhibitors. Retifanlimab demonstrated durable antitumor activity in patients with melanoma, NSCLC, UC, or RCC. The efficacy and safety of retifanlimab were as expected for a PD-(L)1 inhibitor. These data support further study of retifanlimab in solid tumors. •Retifanlimab demonstrates clinical efficacy in PD-1 inhibitor-responsive tumors, including melanoma, UC, NSCLC, and RCC.•Clinical activity and pharmacokinetic data support a 30-min infusion of retifanlimab at a fixed dose of 500 mg.•Efficacy and safety support further clinical investigation of retifanlimab alone or as combination therapy in solid tumors.