(HealthDay News) — For heavily pretreated, advanced ovarian cancer patients, an oral tablet inhibitor of poly ADP ribose polymerase, olaparib, can be safely administered with a weekly carboplatin/paclitaxel regimen, according to a phase I study presented at the Marsha Rivkin Center for Ovarian Cancer Research-AACR Ovarian Cancer Research Symposium, held Sept. 8 to 9 in Seattle.
Saul Rivkin, M.D., from the Swedish Cancer Institute in Seattle, and colleagues established the maximum tolerated dose of olaparib and assessed dose-limiting toxicities and response to combination therapy with carboplatin/paclitaxel and an oral olaparib tablet. Olaparib was started at 50 mg twice daily administered orally and was increased until the maximum tolerated dose was obtained.
The researchers found that the maximum tolerated dose of olaparib was 150 mg twice daily, administered on three consecutive days of each week of the chemotherapy cycle. Fourteen patients were enrolled in the phase I study (median age, 58 years) with a median of four prior therapeutic regimens. No grade 4 toxicities were observed; neutropenia, leukopenia, lymphopenia, anemia, fatigue, and myelodysplastic syndrome were the most common grade 3 toxicities. Four patients had a complete response, three had partial response, three had stable disease, two had progressive disease, and two were not evaluable. The investigators plan to recruit up to 40 additional patients in the phase II extension.
“This treatment regimen provided a response rate of 66 percent in heavily pretreated ovarian cancer cancer patients,” Rivkin said in a statement. “It was surprisingly tolerable with no grade 4 toxicities.”
The study was funded by the Dulien Fund and AstraZeneca.