NEW YORK (GenomeWeb) – The US Food and Drug Administration has approved Foundation Medicine's FoundationFocus CDxBRCA, the first next-generation sequencing-based companion diagnostic on the market.
The test is approved to identify advanced ovarian cancer patients who harbor BRCA mutations, and who are therefore more likely to respond to Clovis Oncology's PARP inhibitor Rubraca (rucaparib). The FDA granted accelerated approval to Rubraca — indicated for advanced ovarian cancer patients who have been treated with two or more chemotherapies and have deleterious BRCA1 and BRCA2 gene mutations — ahead of the Feb. 23, 2017 date by which the agency was slated to okay the drug.
The FDA in December 2014 approved AstraZeneca's PARP inhibitor Lynparza (olaparib) alongside Myriad Genetics' BRACAnalysis CDx to identify advanced ovarian cancer patients who have received three of more prior lines of chemo and have BRCA mutations. Myriad's test detects germline mutations in patients' blood, using PCR and Sanger sequencing to gauge single nucleotide variants and small indels, and multiplex PCR to assess large deletions and duplications.
This year, the National Cancer Institute estimated that more than 22,000 women will be diagnosed with ovarian cancer and over 14,000 will die from the disease. Between 15 percent and 20 percent of ovarian cancer patient have a BRCA mutation. FoundationFocus CDxBRCA detects these mutations in a patient's tumor tissue.
Clovis submitted data form two single-arm trials involving 106 previously treated ovarian cancer patients and Foundation's test confirmed the presence of BRCA mutations in 96 percent of study participants. In these studies, 54 percent of patients saw their tumors shrink, a response that lasted a median of 9.2 months.
Patients treated with Rubraca commonly experienced nausea, fatigue, vomiting, anemia, low blood platelet levels and breathing difficulties. Some experienced serious side effects, including bone marrow problems, acute myeloid leukemia, and fetal harm. Since Rubraca was approved in an accelerated fashion based on a surrogate endpoint, Clovis will have to continue to study the drug and submit data to prove its impact on patient outcomes.