Myriad Genetics received FDA approval for MyChoice CDx as a companion diagnostic to identify homologous recombination deficiency (HRD) and BRCA‑mutant advanced ovarian cancer patients eligible for maintenance therapy with GSK’s PARP inhibitor Zejula (niraparib). The test uses next‑generation sequencing to assess BRCA1/2 alterations and a genomic instability score derived from loss‑of‑heterozygosity and other metrics. Approval was supported by final PRIMA trial data in which MyChoice was used to stratify HRD patients. Myriad said the clearance reinforces its leadership in ovarian cancer diagnostics and will guide precision use of PARP inhibitors, given literature showing near 50% of advanced ovarian tumors are HRD‑positive. The cleared CDx is expected to be integrated into treatment pathways to select patients most likely to derive benefit from PARP maintenance therapy and could influence clinical adoption and payer coverage decisions.