After attesting to its use in ovarian, breast and pancreatic cancers, the trio of AstraZeneca, Merck & Co. and Myriad Genetics is now bringing the latter’s companion diagnostic to bear on metastatic castration-resistant prostate cancer.
In a phase 3 study, the BRACAnalysis CDx precision medicine test will be used to hunt for germline BRCA mutations in men eligible for the Big Pharmas’ PARP-inhibiting Lynparza therapy.
The clinical trial, estimated to wrap up in early 2021, could form the basis of an expanded premarket approval for the BRACAnalysis test in the population, according to Myriad.
AstraZeneca first began working with Myriad on Lynparza in 2007, and has since helped garner U.S. and Japanese approvals for the in vitro diagnostic in ovarian and breast cancers—starting in December 2014, when BRACAnalysis CDx became the first laboratory-developed test approved by the FDA.
Most recently, Japan’s Ministry of Health, Labour and Welfare approved the blood test in February as a companion diagnostic for first-line Lynparza maintenance therapy in advanced ovarian cancer. The FDA approved BRACAnalysis CDx in a similar indication last December in patients showing a complete or partial response to treatment with platinum-based chemotherapy.
But while the collaboration has led to advances in ovarian and breast cancer, “there is a significant unmet medical need in men with metastatic castration-resistant prostate cancer and BRCA1/2 mutations, which is an area where the utility of PARP inhibitors is being explored," Nicole Lambert, president of Myriad Oncology, said in a statement.
Another area is metastatic pancreatic cancer, where Lynparza and the BRACAnalysis test recently demonstrated positive results in a phase 3 study of patients with germline BRCA mutations following platinum-based chemotherapy.
While Lynparza was beating placebo in progression-free survival—and as the drug moves closer to becoming the first PARP inhibitor approved in pancreatic disease—Myriad’s diagnostic showed it could successfully identify patients that would benefit from the treatment, and the company said it plans to file a supplementary approval application with the FDA.