The tubulin-binding taxane cabazitaxel in combination with prednisone significantly extends overall survival in men with hormone-refractory prostate cancer previously treated with a docetaxel-containing regimen and also improves disease control, researchers said at the 26th Anniversary European Association of Urology (EAU) Congress.

Bertrand Tombal, MD, with Cliniques Universitaires Saint-Luc in Brussels, Belgium, and colleagues presented the results of their analysis of the effect of cabazitaxel plus prednisone on disease control, pain, and performance status (PS) measures in men enrolled in the 755-patient, phase III Treatment of Metastatic Hormone-Refractory Prostate Cancer Previously Treated with Taxotere (TROPIC) study.

Cabazitaxel’s recent marketing authorization by the European Union for the treatment of men with metastatic hormone-refractory prostate cancer previously treated with a docetaxel-containing regimen is based on the results of the TROPIC study. The novel taxane, which is the first approved agent to significantly lengthen survival in this population of men with advanced prostate cancer, was approved by the U.S. Food and Drug Administration (FDA) last year.

Trial participants had histologically or cytologically diagnosed prostate cancer with both documented progression of disease during or within 6 months of prior hormone therapy as well as disease progression during or after administration of a prior docetaxel-containing regimen. They also had measurable disease by Response Evaluation Criteria in Solid Tumors (RECIST) or non-measurable disease by rising prostate-specific antigen (PSA) level, or the appearance of a new lesion. All men had a European Cooperative Oncology Group (ECOG) performance status (PS) ranging from 0 to 2 and a life expectancy > 2 months.

All men were randomly assigned to 10 mg of oral prednisone daily and either 12 mg/m2 mitoxantrone or 25 mg/m2 cabazitaxel every 3 weeks.

An initial analysis of the results showed a median overall survival of 15.1 months in the cabazitaxel arm versus 12.7 months in the mitoxantrone arm, HR=0.70, p ˂0.0001. A similar survival benefit was seen in patients ˂65 years of age and patients ≥65.

Results also show disease control rates of 61.7% with cabazitaxel plus prednisone versus 47.5% with mitoxantrone plus prednisone (p=0.004) in the 405 men evaluable for tumor response.

The median number of treatment cycles was higher in the cabazitaxel plus prednisone group (6 versus 4).

The analysis also revealed that PS remained stable during treatment in most men (79% of cabazitaxel plus prednisone patients and 78% of mitoxantrone plus prednisone patients). The rates of worsening PS (20% versus 20%) or improved PS (1% versus 2%) were similar.

The study also documented similar changes in pain intensity and analgesic use in the two treatment cohorts.

Amit Bahl, MD, with Bristol Haematology & Oncology Centre in Bristol, UK, said that high-risk and advanced or metastatic disease requires multiple systemic therapies ideally administered within the multidisciplinary team approach. Multidisciplinary teams should include a urologist, specialist nurse, radiologist, pathologist, oncologist, and palliative care specialist.

Written by Jill Stein
Jill Stein is a Paris-based freelance medical writer.