Phase II study of vinorelbine in patients with androgen-independent prostate cancer

Purpose: To evaluate the efficacy and toxicity of vinorelbine in a phase II study in patients with progressive metastatic androgen-independent prostat e cancer. Patients and methods: Forty-seven men with progressive metastatic prostate cancer refractory to first-line or second-line hormonal therapy were treate d with vinorelbine, a semi-synthetic vinca-alkaloid. Vinorelbine was given, on an outpatient schedule, at 25 mg/m(2) weekly for at least eight weeks o r until progression or excessive toxicity. Results: Forty-seven patients were included in the study, 33 being evaluabl e for tumour response, 36 for response to PSA, 21 for clinical benefit and 45 for toxicity. Median actual weekly dose was 19 mg/m(2) (range 12.0-26.2 mg/m(2)). Six of thirty-six patients (17%) demonstrated a biologic response with a 50% or more decline in serum PSA on two consecutive measurements ta ken at least two weeks apart. The median duration of biologic response was 2.7 months. Two of three patients with measurable disease obtained an objec tive response but remained unconfirmed. No change disease was reported in 2 3 patients (49%). On entry into the study, 30 patients had symptomatic bone pain and required narcotic or non-narcotic analgesics. Clinical benefit fr om vinorelbine was achieved in 15 patients out of 21 (32% of the intent to treat analysis population and 71% of the assessable patients). Due to the l ow number of questionnaires (QLQ-C30) filled in, it was insufficient to all ow any statistical analysis. The median survival was 10.2 months. Toxicity was mainly haematologic with 51% of patients experiencing grade 3 or 4 gran ulocytopenia. Three patients developed deep vein thrombosis. Non-haematolog ic toxicity, mainly nausea and neurotoxicity, was mild. Conclusion: The administration of weekly vinorelbine appears to be a safe t reatment for those patients with androgen-independent prostate cancer and p oor prognosis features who require chemotherapy. These results provide data for future investigation of vinorelbine in combination regimens.