Labcorp, a global leader of innovative and comprehensive laboratory services, has officially published data from two explicit studies that demonstrate biomarker test’s value when it comes to closing testing gaps and guiding targeted therapies for patients with epithelial ovarian cancer (EOC). In one of the two studies, conducted alongside next-generation sequencing technology leader named Illumina, Labcorp evaluated 1,093 patients who had been diagnosed with EOC. Here, the two companies assessed real-world clinical practice patterns for ordering BRCA and Homologous Recombination Deficiency (HRD) testing. According to certain reports, when they combined the results of BRCA and HRD tests, the result emerged as capable of figuring out which patients are most likely to benefit from treatment with poly-ADP ribose polymerase (PARP) inhibitors. This meant patients who test negative for BRCA1 and BRCA2 can be HRD tested to gauge the degree of benefit they should expect from a PARP inhibitor. Talk about PARP inhibitors for a second, they are best known for reinventing standard of care, especially for women with germline or deleterious somatic mutations in BRCA1 or BRCA2. Having said so, over 40% of patients don’t respond to PARP inhibitors. If we look past that for a second, they may also experience with these inhibitors a longer treatment duration, potentially serious side effects, as well as higher overall costs.
Anyway, after an estimated 84% patients underwent evaluation for BRCA mutations or HRD testing, the researchers moved on to studying PARP inhibitor utilization. They also dug into the time to treatment discontinuation (TTD) among patients with germline/somatic BRCA mutations, tumors with HRD, and those that were homologous recombination proficient (HRP). Going by the available details, median TTD of first-line PARP inhibitor maintenance therapy was found to take longest for patients with germline or somatic BRCA mutations or HRD tumors. Furthermore, the test revealed that an estimated 77% of the patients with a germline BRCA mutation, 65.1% of patients with a somatic BRCA mutation, and 42.7% of those with HRD and BRCA wild-type continued PARP inhibitor therapy at 18 months, compared to 29% of patients in the HRP/BRCA wild-type group.
As for the second study, Labcorp studied real-world testing practice patterns for Folate-receptor Alpha (FRα) on primary tumors versus metastatic tumors. In case you weren’t aware, FRα is an actionable biomarker in ovarian cancer, a biomarker which is overexpressed in up to 90% of EOC patients. Hence, patients understood to be suffering from platinum-resistant EOC, whose tumors highly express FRα, may be eligible for treatment with Mirvetuximab soravtansine (MIRV), the only currently available targeted therapy that improves overall survival for patients with platinum-resistant EOC. Coming back to the research, though, the company performed a retrospective analysis of tumor samples from 432 patients with EOC undergoing standard-of-care testing. The results for this one displayed that, from the total lot, around 291 samples were from metastatic tumors, and 133 were from primary tumors. Furthermore, the study informed us on how 36.2% of patients had tumors that highly expressed FRα. Notably enough, tumor samples taken from primary sites were associated with much higher rates of FRα positivity than those from metastatic sites.
“This research emphasizes the power of comprehensive biomarker testing in advancing the treatment of ovarian cancer. By closing critical diagnostic gaps through precision testing, we are not just improving patient care but also propelling science and healthcare forward,” said Shakti Ramkissoon, M.D., Ph.D., vice president, head of oncology at Labcorp.