Abstract:Penile cancer is a rare malignancy, and treatment options for advanced stages are limited, often yielding unsatisfactory outcomes. This prospective, multicenter, phase 1 clinical study was conducted to evaluate the preliminary safety, tolerability, and antitumor activity of the anti‐epidermal growth factor receptor (EGFR) monoclonal antibody CDP1 in combination with chemotherapy, in patients with penile cancer. The trial comprised two parts: a 3 + 3 dose‐escalation CDP1 monotherapy study to determine the dose for the combination study, in which 12 patients with advanced solid tumors received CDP1 alone, and a CDP1‐chemotherapy combination study, in which 20 patients with recurrent or metastatic penile cancer received CDP1 combined with the paclitaxel‐ifosfamide‐cisplatin regimen (TIP). CDP1 monotherapy and combination treatment were well tolerated, and the maximum tolerated dose was not reached. The most common treatment‐related adverse events for CDP1 monotherapy included rash (83%), dry skin (50%), and hypomagnesemia (50%), while for CDP1 combined with chemotherapy, they were anemia (85%), nausea (80%), and white blood cell decreased (80%). Among penile cancer patients receiving the combination therapy, the objective response rate was 74%, tumor downstaging enabled surgery in seven patients (35%), and the median progression‐free survival was 6.9 months. In conclusion, the combination of an anti‐EGFR monoclonal antibody and chemotherapy was well tolerated and showed potential efficacy in penile cancer, supporting further investigation.