Vinorelbine Use in Hormone-Refractory Prostate Cancer- Study

In Phase II studies, vinorelbine was shown to be active both alone or in combination for hormone-refractory prostate cancer. Vinorelbine was shown to be well tolerated in elderly patients with a moderate toxicity profile.

Based on these positive results, researchers conducted a randomised phase III study comparing intravenous vinorelbine plus hormone therapy to hormone therapy alone on 414 patients with hormone-refractory prostate cancer. The primary endpoint was progression-free survival.The vinorelbine arm were given 30mg/m2 on days 1 and 8 every 3 weeks and 40mg/day of hydrocortisone. The other arm were given 40mg/day of hydrocortisone. Both arms had the option to add 1000mg/day of aminogluthimide to hydrocortisone as second-line hormone therapy. Further chemotherapy was allowed after disease progression.Researchers found that progression-free survival (PFS) was significantly prolonged in the vinorelbine arm of the study with a 6-month PFS rate of 33.2% compared to 22.8% in the hormone therapy alone arm. The prostate-specific antigen (PSA) response rate was also significantly higher in the vinorelbine arm at 30.1% compared to 19.2% in the other arm.Clinical benefit was defined as a decrease in pain intensity, analgesic consumption or an improvement in Karnofsky performance status for at least 9 weeks. Clinical benefit was more commonly seen in patients who took the vinorelbine with hormone therapy than those who took hormone therapy alone. However, there did not appear to be any benefit in overall survival.Researchers concluded that the combination of vinorelbine and hydrocortisone compared with hydrocortisone alone provides improved clinical benefit, PFS and PSA response rate. The combination is also well tolerated in elderly patients and offers an active and safe therapeutic option for patients with hormone-refractory prostate cancer.