Labcorp companion test

Doctors now have a nationwide Labcorp test to find ovarian-cancer patients whose tumors qualify for Merck’s immunotherapy Keytruda. (prnewswire.com) The test is Agilent’s PD-L1 IHC 22C3 pharmDx, an FDA-approved companion diagnostic that checks whether a tumor makes enough PD-L1, a protein used to match some patients to immunotherapy. Labcorp said April 22 that it is offering the assay nationwide through its oncology network. (agilent.com) The Food and Drug Administration approved pembrolizumab, sold as Keytruda, with paclitaxel for adults with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer whose tumors test PD-L1 positive with a combined positive score of at least 1. The agency approved the Agilent assay as the required companion test in the same February decision. (fda.gov) A companion diagnostic is a gatekeeper test: it tells an oncologist whether a drug’s label fits a patient’s tumor before treatment starts. In this case, the label ties Keytruda use to a lab score, so access depends on both pathology capacity and the right paperwork. (fda.gov) That matters in ovarian cancer because platinum-resistant disease leaves patients with few options after chemotherapy stops working. The FDA said Keytruda plus paclitaxel is the first regimen in this setting to show an overall-survival benefit in a randomized trial for the PD-L1-positive group. (fda.gov) The approval was based on the phase 3 KEYNOTE-B96 trial. In patients with PD-L1-positive tumors, median overall survival was 18.2 months with pembrolizumab-based treatment versus 14.0 months with placebo-based treatment, and median progression-free survival was 8.3 months versus 7.2 months. (onclive.com) The tradeoff was toxicity. In the same PD-L1-positive group, grade 3 or higher adverse events occurred in 82.5% of patients on pembrolizumab-based therapy versus 70.8% on the control regimen, and serious adverse events were also more common. (onclive.com) Labcorp said it joined Agilent’s Early Validation Program before launch, which let it train staff and standardize the assay before the FDA decision. That kind of prep can shorten the gap between a drug approval and a billable test that community oncologists can actually order. (prnewswire.com) Agilent said this ovarian-cancer clearance is the seventh FDA-approved Keytruda companion-diagnostic indication for PD-L1 IHC 22C3 pharmDx. For patients, the practical change is narrower and more concrete: one pathology result can now determine whether a new immunotherapy option is on the table. (agilent.com)