Currently, patients with metastatic castration-resistant prostate cancer (mCRPC) have been treated with cytotoxic chemotherapy with the sequential use of single agent taxanes such as docetaxel and cabazitaxel, used as a “first-line” and “second-line” treatments, respectively.
During the American Society of Clinical Oncology meeting a team of researchers at The University of Texas MD Anderson Cancer Center presented the results of a clinical trial whre they examined the use of combination therapy with two or more chemotherapy agents in advanced disease.
The efficacy of using only cabazitaxel versus cabazitaxel in combination with carboplatin was compared in patients with mCRPC. For this study a total of 160 men were randomized to receive treatment with either the single or dual chemotherapy drug regimen for up to 10 chemotherapy cycles.
The researchers tracked changes in blood levels of prostate-specific antigen (PSA), Progression Free Survival and bone-specific alkaline phosphatase (BAP). Both groups were monitored for toxicity and safety.
Results showed that the median PFS was longer for the group of patients who received the combined regimen versus those treated with single agent (6.7 months versus 4.4 months). There was a reduction in the levels of PSA and BAP in the group of patients who received the combined regimen. In terms of PSA levels, patients treated with the combination therapy had reductions greater than 50% in 60% of the time versus 44% in those treated with only one drug. The results also showed a reduction in PSA levels greater than 90% in 28% of the time for those patients treated with the combined regimen versus 20% for those patients treated only with one drug.
In terms of BAP levels reduction, these were found to the greater than 50% for those patients treated with the combined regimen when compared to those treated only with one drug (63% and 25%). Importantly, adverse events were identical for both groups and included neutropenia, fatigue and anemia.
“We believe cabazitaxel-carboplatin combination chemotherapy may become the clinical standard for advanced prostate cancer once additional safety, efficacy and overall survival data is generated,” explained in a recent news release Paul Corn, M.D., Ph.D., an associate professor of genitourinary medical oncology at MD Anderson. “Dr. Ana Aparicio’s lab is currently developing tumor-specific biomarkers to identity patients with an aggressive variant of prostate cancer most likely to benefit from this approach.”