A recent study has shown that a chemotherapy regimen combining vinorelbine (Navelbine) and mitoxantrone (Novantrone) with the corticosteroid prednisone is effective in the treatment of hormone-refractory prostate cancer . Specialists say this treatment should be offered to symptomatic patients earlier in their disease.
However researchers added that a larger phase 2 study of this treatment regimen is planned. From a group of 66 patients who had advanced prostate cancer, the investigators recruited 12 for whom previous hormone therapy had failed in at least 3 lines of treatment.
The investigators included patients who had undergone palliative radiotherapy at any point during their disease. The patient's median age was 67 years, with a range of 60 to 81 years. The patient's median Eastern Cooperative Oncology Group performance status was 1, with a range of 0 to 2. All the patients had bone metastases, some with multiple sites. One patient had lymph node metastasis, and 1 had visceral disease. Three patients had significant ischaemic heart disease.
Each treatment cycle consisted of 10 to 12 mg/m2 of mitoxantrone on day 1, followed by 20 mg/m2 of vinorelbine on days 1 through 8. This cycle was repeated every 3 weeks. The patients also received 12.5 mg daily of prednisone. A total of 95 cycles were given, with a median of 7 cycles per patient and a range of 5 to 9 cycles per patient. Two patients repeated the treatment at 6 months and 12 months after the initial treatment. Among these patients, 50% had a marked decrease in pain and improvement in ECOG performance status, according to specialists. In 8 cycles, due to the response to treatment, the dose of vinorelbine was reduced 50% and in 4 cycles it was reduced 75%. The mitoxantrone dose was reduced 50% in 5 cycles. Although 1 patient had a drop in prostate specific antigen (PSA) of more than 50%, the computed tomography findings did not show an equivalent response.
The patients' median time to progression was 10 months, with a range of 6 months to over 20 months. Two patients are living; 8 died due to disease progression; and 2 died of other causes. The toxicity episodes consisted of 6 neutropaenic events, all afebrile. Otherwise, the investigators documented no Grade 4 haematological toxicity and no non-haematological toxicity.