Anti-EGFR antibody plus anti-PD-1 antibody and chemotherapy as a neoadjuvant regimen for patients with locally-advanced penile squamous cell carcinoma: A prospective, single-arm, single-center, phase II clinical trial.

Abstract

5037 Background: Advanced penile squamous cell carcinoma (PSCC) is a rare disease with a poor prognosis. We performed a monocentric, Simon’s two-stage phase II study to evaluate the efficacy and safety of PD-1 blockade plus anti-EGFR target therapy and chemotherapy as neoadjuvant therapy in patients with locally advanced PSCC. We previously reported promising results in the first stage. The enrollment of the second stage had been completed by January 2022, herein we reported the updated results. Methods: Patients with chemotherapy-naive, locally-advanced PSCC (cT4 or cTxN3M0) were enrolled. The neoadjuvant regimen consists of anti–PD-1 antibody toripalimab, anti–EGFR antibody nimotuzumab, and chemotherapy (albumin-bound paclitaxel plus cisplatin and ifosfamide). Curative surgery was performed following a maximum of four cycles of treatment. The primary endpoint is the pathological complete response (pCR) rate. Secondary endpoints include overall response rate (ORR), relapse-free survival (RFS), overall survival (OS), and treatment-related adverse events (TRAEs). Results: A total of 29 patients were enrolled in two stages, with a median age of 57 (range 31-71) years. Till January 2022, 21 patients had completed the neoadjuvant treatment, 17 (81%) achieved an objective response, (CR 5, PR 12), 2 had SD, and 2 showed PD. Among 18 patients who underwent radical surgery, 11 showed no residual tumor on histopathology, with a pCR rate of 61.1% (11/18). The median follow-up time was 10.6 months. Two patients with PD died from disease, and 2 patients who experienced disease relapsed after radical surgery, in which 1 with SD, and 1 with PR. No relapse was observed among patients with pCR. The survival data are still immature. No unexpected toxicities and treatment-related death were recorded. Five out of 21 (23.8%) patients experienced grade 3 or 4 TRAEs. Grade 3 neutropenia occurred in 3 (14.3%) patients with 10 used G-CSF prophylaxis. No febrile neutropenia occurred. Other grades 3 toxicities included 1 case of peripheral sensory neuropathy and 1 anemia. The most common grade 1/2 TRAEs were alopecia (100%), decreased appetite (85.7%), nausea (71.4%), peripheral sensory neuropathy (66.7%), anemia (66.7%), neutropenia (33.3%), and infusion-related reactions (28.6%). The most common immune-related adverse events (IRAEs) were grade 1/2 hypothyroidism (19.0%), and grade 1 hyperthyroidism (4.8%). No severe IRAEs including pneumonitis, colitis, and myocarditis were observed. Conclusions: The triple combination is a provoking safe and efficacious neoadjuvant regimen for patients with advanced PSCC. Clinical trial information: NCT04475016.