In October 2019, the FDA approved a new indication for the PARP inhibitor Zejula (niraparib; from Tesaro) for the treatment of patients with homologous recombination deficiency (HRD)-positive advanced ovarian, fallopian tube, or primary peritoneal cancer, after receiving at least 3 chemotherapy regimens.
HRD is a type of genetic mutation defined by a deleterious or suspected deleterious BRCA mutation, or a genomic instability associated with disease progression more than 6 months after the tumor’s response to the last platinum-based chemotherapy.
Zejula has been previously approved by the FDA as maintenance treatment for patients these types of ovarian cancer but without HRD mutation.
Together with this new approval, the FDA also approved a new genetic test called Myriad myChoice CDx test, to identify patients with HRD mutation for Zejula therapy.
This new approval of Zejula was based on results of a clinical trial of patients with HRD-positive advanced ovarian cancer. Among the patients with HRD-positive status, 24% responded to treatment with Zejula, and the average duration of response was 8.3 months. Among patients with ovarian cancer and BRCA mutations, between 39% and 19% of patients responded to therapy with Zejula, depending on their response to platinum-based therapy.
Overall, 7% of patients had side effects with Zejula that required dose reduction or dose interruption, mostly because of infection, anemia, neutropenia, nausea, vomiting, fatigue, and abdominal pain.