Profound and durable responses with PD-1 immune checkpoint inhibitors in patients with metastatic penile squamous cell carcinoma

Abstract

Introduction: Penile squamous cell carcinoma (pSCC) is a rare disease characterized by a dismal prognosis in advanced stages. Systemic treatment options are very limited, and there is no standard treatment after progression on first line chemotherapy. Patients and methods: We report two patients with chemotherapy-refractory metastatic penile SCC, who were treated with PD-1 inhibitor cemiplimab (case 1) or pembrolizumab (case 2). Both cases were HPV-positive and showed expression of PD-L1. Results: Despite intensive pretreatment complete remission was achieved in both cases with prolonged duration of response of >14 months (patient 1) and >27 months (patient 2), respectively. Conclusions: These results suggest a high susceptibility of penile SCC to immune checkpoint inhibitor therapies. Since there is a high unmet need for this clinical situation, prospective evaluation of immunotherapy is urgently needed.

Keywords

• Squamous cell cancer of the penis
• Penile cancer
• Immunotherapy
• HPV positive
• Metastatic
• Recurrence