A phase II trial of cabazitaxel as second line chemotherapy in relapsed locally advanced and/or metastatic carcinoma of the penis

Objectives To assess the efficacy and tolerability of cabazitaxel in relapsed penile cancer. Methods This Phase II single-arm trial was designed to recruit 17 patients with relapsed penile cancer. The primary endpoint was objective (complete + partial) response rate (ORR; Response Evaluation Criteria in Solid Tumours [RECIST] v1.1). Treatment comprised six 21-day cycles of cabazitaxel with restaging after cycles 2 and 4. The planned interim analysis was based upon the premise that if none of the first nine patients achieved ORR, trial would be stopped (α = 0.05, Simon’s 2-stage design). Results Nine patients were recruited from four UK centres between December 2014 and August 2016. The median age was 61 (range, 27–73.6) years, and seven patients had metastases. Patients received a median of two chemotherapy cycles (range, 2–5). None of the nine patients achieved ORR and the trial was stopped. Cabazitaxel was well tolerated with no dose reductions or delays. Three patients had grade 3/4 adverse events (anaemia, vomiting, or neutropenic sepsis). The median progression-free and overall survival were 1.3 and 5.6 months, respectively. Conclusions The trial did not reach the threshold for further continuation of single-agent cabazitaxel. However, the observed tolerability profile supports its further investigation in combination with other agents to improve patient outcomes.