By Colin Kellaher 



  AstraZeneca PLC and Merck & Co. on Wednesday said the U.S. Food and Drug Administration approved the cancer drug Lynparza for its first indication in prostate cancer. 


  The drugmakers said the approval covers the treatment of patients with deleterious or suspected deleterious germline or somatic homologous recombination repair gene-mutated metastatic castration-resistant prostate cancer who have progressed following prior treatment with enzalutamide or abiraterone. 


  Such mutations occur in 20% to 30% of patients with metastatic castration-resistant prostate cancer, the companies said. 


  Merck and AstraZeneca said patients will be selected for therapy based on Myriad Genetics Inc.'s BRACAnalysis CDx genetic test, which the FDA has approved as a companion diagnostic test with Lynparza in the new indication. 


  AstraZeneca and Merck in 2017 formed a collaboration to co-develop and co-commercialize Lynparza for multiple cancer types. 


  Myriad's collaboration with AstraZeneca, which began in 2007, has resulted in seven regulatory approvals for its BRACAnalysis CDx in support of Lynparza. 


  Write to Colin Kellaher at colin.kellaher@wsj.com