Gefitinib for patients with incurable cutaneous squamous cell carcinoma: A single-arm phase II clinical trial

Background: Preclinical data demonstrate a key role for the epidermal growth factor receptor (EGFR) in the carcinogenesis of cutaneous squamous cell carcinomas (CSCCs). There are, however, limited data on the efficacy of EGFR inhibitors in incurable, recurrent, and/or metastatic CSCC. Objective: To determine the response rate to gefitinib in patients with CSCC not amenable to curative therapy including surgery or radiation. Methods: This was a single-arm phase II study. A total of 40 patients were treated with gefitinib, 250 mg orally daily, until disease progression or intolerable toxicities. The prespecified target response rate of interest was 20%. Results: The overall response rate was 16% (95% confidence interval, 0.06-0.32; 6 partial responses in 37 evaluable patients). An additional 13 patients (35%) had stable disease at 8 weeks. The median durations of response and progression-free survival were 31.4 months (95% confidence interval, 3.91-not applicable) and 3.8 months (95% confidence interval, 2.2-5.7), respectively. The side effect profile was consistent with the previous experience with gefitinib in other tumor types. Limitations: This was a single-institution, single-arm study. The prespecified target response rate was not met. Conclusion: Gefitinib demonstrated modest activity in incurable CSCC, with a favorable adverse event profile.