Myriad Seeks FDA Approval of myChoice HRD CDx Diagnostic Test for Ovarian Cancer Patients

Myriad Genetics has submitted the first part of a premarket approval application with the U.S. Food and Drug Administration for myChoice HRD CDx, a diagnostic test designed to identify ovarian cancer patients more likely to benefit from treatment with the PARP inhibitor Zejula (niraparib).

Premarket approval is the FDA’s scientific and regulatory review to evaluate the safety and effectiveness of medical devices that support or sustain human life, are of substantial importance in preventing human health issues, or which present a potential, unreasonable risk of illness or injury.

myChoice HRD CDx identifies cancers with defects in homologous recombination, a pathway key for DNA repair. 

Tumors that lose their ability to activate this pathway as part of the cell’s response to DNA damage are unable to correctly repair cuts in the DNA, termed double-stranded breaks.

This makes those cancers more susceptible to DNA-damaging anticancer treatments such as platinum-based chemotherapies (e.g., cisplatin) or PARP inhibitors, including Tesaro’s Zejula.

Zejula is used as a maintenance treatment for women with recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer who are in a complete or partial response to platinum-based chemotherapy.

The myChoice test is intended as a companion diagnostic for platinum-sensitive patients who received three or more lines of therapy and whose tumors carry a BRCA mutation or are otherwise incapable of proper DNA repair.

It tests a patient’s tumor tissue for DNA repair defects, assessing mutations in the BRCA1 and BRCA2 genes, along with three biomarkers of homologous recombination deficiency — loss of heterozygosity, telomeric allelic imbalance, and large-scale state transitions.

Because tumors with such defects are more likely to respond to PARP inhibitors, Myriad says that myChoice can help patients and physicians make an informed decision on whether this type of therapy is the most appropriate choice.

In addition, by sampling the tumor rather than blood or saliva, the test is able to identify more patients under these conditions.

“This submission of myChoice HRD CDx to the FDA is a major milestone for Myriad’s companion diagnostic program in oncology and our first indication for a tumor-based test,” Nicole Lambert, president of Myriad oncology, said in a press release.

“In clinical studies, the myChoice HRD test effectively identified heavily pre-treated patients with ovarian, fallopian or primary peritoneal cancer who are likely to benefit from Zejula. We believe myChoice HRD CDx can help inform therapy selection and potentially improve outcomes for patients,” she added.