Intermediate analysis of a phase II trial assessing gemcitabine and cisplatin in locoregional or metastatic penile squamous cell carcinoma.

Abstract

To perform a phase II study evaluating a combination of gemcitabine and cisplatin in a population of patients with squamous cell carcinoma (SCC) of the penis and unresected locoregional lymph nodes and/or distant metastases, who had a poor prognosis with no standard of chemotherapy. Eligible patients had histologically confirmed SCC of the penis with unresected locoregional lymph nodes and/or distant metastases, at initial diagnosis or at relapse, and measurable disease as defined by Response Evaluation Criteria in Solid Tumors (RECIST) criteria. Patients were treated with a combination of gemcitabine 1250 mg/m(2) on day 1 over 30 min and cisplatin 50 mg/m(2) on day 1 over 1 h, every 2 weeks. The primary endpoint was the objective response rate; secondary endpoints were time to progression (TTP) and overall survival (OS). In all, 25 patients were included in the first phase of the study between February 2004 and January 2010 and received a median of five cycles. For the intent-to-treat population, two patients (95% confidence interval [CI] 0.98-26.0) presented an objective response and 13 patients (52%) had stable disease (95% CI 35.5-76.8). The median TTP was at 5.48 months (95% CI 2.40-11.73). After a median follow-up of 26.97 months (95% CI 17.77, not reached), nine patients were still alive. The median OS and 2-year OS rate were respectively estimated at 14.98 months (95% CI 9.76-32.9) and 39.32% (95% CI 19.15-59.03). Eleven patients had a serious adverse event (44%), 24% being relied to chemotherapy. Every 2 weeks' administration of the combination of gemcitabine and cisplatin showed non-significant responses in patients with unresected locoregional or metastatic penile SCC. Despite manageable side-effects, this combination cannot be recommended as a standard of care, due to disappointing response rates seen in this negative study. Further regimens should be explored to improve the OS of these patients with poor prognosis.