ASCO 2017: Olaparib Monotherapy in Metastatic Breast Cancer
The poly (ADP-ribose) polymerase (PARP) inhibitor olaparib reduced the chance of progression of BRCA-related advanced breast cancer by 42% compared with standard chemotherapy and delayed disease progression by about 3 months, according to the results of the phase III OlympiAD trial. These findings were presented by Mark E. Robson, MD, during the Plenary Session at the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract LBA4).
The trial compared oral olaparib monotherapy (n=205) with chemotherapy (n=91) in patients with HER2-negative metastatic breast cancer and a germline BRCA mutation who had received up to two prior lines of chemotherapy.
“This is the first demonstration of improved outcomes with a PARP inhibitor compared to standard treatment in women with BRCA mutation–associated breast cancer,” said Dr. Robson, Clinic Director of the Clinical Genetics Service and a medical oncologist at Memorial Sloan Kettering Cancer Center in New York. “This type of breast cancer is particularly difficult to treat and often affects younger women.”
The objective response rate was nearly 60% in patients who received olaparib, compared with 29% in those treated with chemotherapy. The median time to disease progression was 7 months with the study drug, versus 4.2 months with chemotherapy, and health-related quality of life improved in the olaparib group, the investigators reported.