New chemo combo for advanced prostate cancer studied
Results of an MD Anderson clinical trial may change the perspective on a role for combination chemotherapy in advanced prostate cancer.
The study compared the effectiveness of cabazitaxel alone versus cabazitaxel combined with carboplatin — a type of platinum chemotherapy — in patients with metastatic castrate-resistant prostate cancer. To date, 160 men have been randomized to treatment with either the single or dual chemo drug regimen. Each patient received up to 10 cycles of chemo.
To monitor the effects of treatment, MD Anderson researchers tracked several variables including progression-free survival, as well as changes in blood levels of prostate-specific antigen (PSA) and bone-specific alkaline phosphatase (BAP), a marker of prostate cancer in bone cells. In addition, safety and toxicity were monitored for both patient groups.
Progression-free survival was significantly longer for patients receiving combination versus single agent chemotherapy (6.7 months versus 4.4 months, respectively). Furthermore, reductions in both PSA and BAP were greater for the combination therapy group. PSA reductions greater than 50% occurred 60% of the time with combined chemo, versus 44% with the single drug. PSA reductions greater than 90% occurred 28% of the time with two chemo drugs versus 20% with one. In addition, BAP reductions greater than 50% for combination versus single drug were 63% and 25%, respectively.
Side effects, such as fatigue, anemia and neutropenia were comparable for both the single-drug regimen and two-drug regimen. In addition, there were no significant toxicity events.
“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 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.”