Weekly docetaxel as second line treatment after mitozantrone for androgen-independent prostate cancer

Two recent phase III trials have shown an improvement in survival with the use of docetaxel in metastatic androgen-independent prostate cancer (AIPC) compared to mitozantrone. However no phase II trials have clearly defined the level of activity of docetaxel after mitozantrone.

We sought to define the activity and toxicity of weekly docetaxel as second line chemotherapy after mitozantrone in men with AIPC.

Twenty men were treated with docetaxel 40 mg/m2 weekly for 3 of every 4 weeks until progression or prohibitive toxicity. End-points included prostate specific antigen response, common toxicity criteria, time to progression and overall survival.

Nine patients (45%) had a 50% or greater reduction in PSA maintained for at least 1 month. Weekly docetaxel was well tolerated with few major toxicities: two patients had Grade 3 diarrhoea (10%) and six had grade 2-4 haematologic toxicities (30%). The median time to progression was 5 months (range 0-13) and median survival was 13 months (range 1-24) from starting docetaxel. The median survival from starting mitozantrone was 19 months. Men who had responded to mitozantrone were no more likely to respond to docetaxel (P = 0.2 Fischer's exact test).

Weekly docetaxel is a safe and active second-line treatment after mitozantrone for androgen-resistant prostate cancer, with similar levels of activity to the first-line setting.