Turn on cookies to sign in
Signing in saves your progress to your Curie account. We can only do that with cookies on — turn them on to continue.
A new PCR-based test just got the FDA's stamp of approval to help identify cancer patients who could benefit from pembrolizumab (Keytruda). The OncoMate MSI Dx Analysis System, developed by Promega and Merck, detects microsatellite instability–high (MSI-H) status in solid tumor tissue. This gives oncologists a precise, validated tool to match the right patients to this immunotherapy.
The FDA has approved the OncoMate MSI Dx Analysis System as a companion diagnostic for pembrolizumab (Keytruda), designed to identify patients with microsatellite instability–high (MSI-H) solid tumors who may be eligible for the immunotherapy. Developed by Promega Corporation in collaboration with Merck, the PCR-based assay evaluates MSI status directly from solid tumor tissue — giving clinicians a standardized, regulatory-grade tool to guide treatment decisions.
This approval pairs with pembrolizumab's existing full FDA approval (granted March 2023) for adult and pediatric patients with unresectable or metastatic MSI-H or mismatch repair–deficient (dMMR) solid tumors that have progressed after prior treatment. That approval was supported by pooled data from over 30 cancer types across three phase 2 trials.
By the Numbers:
Why it matters: Companion diagnostics are critical gatekeepers in precision oncology — they ensure the right patients receive therapies most likely to work. With pembrolizumab's broad tumor-agnostic indication, having a validated, high-quality MSI detection tool streamlines patient selection and could expand access to this effective immunotherapy.
