Penile squamous cell carcinoma (PSCC) is a rare and aggressive disease with near-universal EGFR protein overexpression and frequent MET activation, representing a significant unmet medical need following the failure of first-line platinum-based chemotherapy. Amivantamab is a fully human bispecific antibody targeting both EGFR and MET.
Study Design and Administration:
Participants receive subcutaneous amivantamab monotherapy across 21-day cycles. Dosing is weight-based (1,600 mg for less than 80 kg; 2,240 mg for 80 kg or greater on Cycle 1 Day 1, followed by 2,400 mg or 3,360 mg on Days 8 and 15 of Cycle 1, and every 3 weeks starting from Cycle 2 onwards). Treatment continues during the core treatment phase for up to 24 weeks or until disease progression, unacceptable toxicity, or consent withdrawal. Patients without progression at 24 weeks may enter an extension phase.
Primary Endpoint:
Objective Response Rate (ORR) assessed by the investigator per RECIST v1.1.
Secondary Endpoints:
Independent Central Review ORR (ORR-ICR), Disease Control Rate (DCR), Duration of Response (DoR), Progression-Free Survival (PFS), Overall Survival (OS), safety and tolerability (NCI-CTCAE v6.0), treatment compliance, post-progression therapies, and Patient-Reported Outcomes (EORTC QLQ-C30).
Exploratory Biomarker Research:
Evaluation of baseline tissue/blood biomarkers (HPV status, EGFR/MET expression), longitudinal tracking of ctDNA and HPV copy numbers, and exploration of acquired resistance mechanisms.
Sample Size and Design:
Using Simon's two-stage design, each cohort aims to enroll 27 evaluable patients (up to 29 patients per cohort to account for non-evaluable participants, totaling up to 58 patients overall). Each cohort includes a Stage 1 futility analysis after enrolling 13 patients.