Drug Rucaparib Promising in Pretreated BRCA-Positive Ovarian Cancer
The drug rucaparib appears active in women with recurrent BRCA-positive ovarian cancer that has progressed after previous treatment. These findings were presented at 2015 Annual Meeting of the American Society of Clinical Oncology (May 29–June 2, Chicago, Illinois) and published in the Journal of Clinical Oncology.
Each year in the United States, roughly 22,000 women are diagnosed with ovarian cancer and more than 15,000 die of the disease. Treatment for ovarian cancer commonly involves surgery and/or chemotherapy. Researchers continue to study new approaches for improving the outcomes of all women affected by ovarian cancer.
Rucaparib is a targeted drug called a PARP inhibitor. The PARP enzyme plays a role in DNA repair, including the repair of DNA damage from chemotherapy. Drugs that inhibit this enzyme may contribute to cancer cell death and increased sensitivity to chemotherapy. Cancers (ovarian and breast) that have a BRCA mutation are thought to be particularly likely to respond to PARP inhibitors.
Researchers with a Phase II study evaluated rucaparib in 35 patients (ages 44–84) with BRCA-positive ovarian cancer that had returned after previous treatment. Participants had received between two and four prior chemotherapy regimens and had experience a progression-free survival interval of six months or more. For the study, patients were given 600 mg of rucaparib daily in 21-day cycles until ovarian cancer progressed.
The researchers used the RECIST (response evaluation criteria in solid tumors) criteria to determine objective response rate (the proportion of patients who had a decrease in tumor size) to rucaparib. More than half of the patients responded to treatment with rucaparib: the RECIST overall response rate was 65%. Patients who had the longest progression-free interval before the study had the highest RECIST ORR: 88%.
The most common side effects of treatment included nausea; anemia; fatigue; weakness, lack of energy, and loss of strength. These side effects were generally low grade, and no patients had to stop treatment as a result.
According to this study, rucaparib appears active in patients with BRCA-positive ovarian cancer who have undergone multiple previous treatments. This is encouraging news for women with pretreated ovarian cancer, who often have few effective treatment options.
Reference: Shapira-Frommer R, Oza AM, Domchek SM, et al. A phase II open-label, multicenter study of single-agent rucaparib in the treatment of patients with relapsed ovarian cancer and a deleterious BRCA mutation. Journal of Clinical Oncology. 33, 2015 (supplement; abstract 5513).