Labcorp Launches FDA-Approved Companion Diagnostic to Identify Patients with Ovarian Cancer Eligible for Keytruda
LH
Published on 04/22/2026 at 01:37 pm EDT
Labcorp announced the nationwide availability of Agilent Technologies' PD-L1 IHC 22C3 pharmDx, the only companion diagnostic approved by the U.S. Food and Drug Administration (FDA) to identify patients with platinum-resistant ovarian cancer who may be eligible for Merck's KEYTRUDA. KEYTRUDA (pembrolizumab) and KEYTRUDA QLEX (pembrolizumab and berahyaluronidase alfa-pmph) are the first FDA-approved PD-1 inhibitors available as part of a complete treatment regimen for eligible patients with platinum-resistant ovarian cancer. Approximately 80% of individuals with ovarian cancer experience recurrence after initial therapy, and many develop resistance to platinum-based chemotherapy, leading to limited treatment options and poor survival outcomes.
The approval of KEYTRUDA and KEYTRUDA QLEX in this setting introduces meaningful new treatment options that have been found to reduce the risk of disease progression and improve overall survival. Labcorp's nationwide availability of PD-L1 IHC 22C3 pharmDx enables clinicians to quickly identify patients who may benefit from these newly approved treatments. Following the FDA's February approval of KEYTRUDA and KEYTRUDA QLEX alongside PD-L1 IHC 22C3 pharmDx, Labcorp participated in Agilent Technologies' Early Validation Program to help support rapid testing availability.
Through standardized training and readiness activities, Labcorp was prepared to expand nationwide access quickly following approval. The FDA approved the PD-L1 IHC 22C3 pharmDx test from Agilent Technologies as a companion diagnostic that detects PD-L1 expression in epithelial ovarian, fallopian tube, or primary peritoneal carcinoma (EOC), and is indicated as an aid in identifying patients for treatment with KEYTRUDA, Merck's anti-PD-1 therapy. The FDA simultaneously approved KEYTRUDA (pembrolizumab) and KEYTRUDA QLEX (pembrolizumab and berahyaluronidase alfa-pmph) plus paclitaxel, with or without bevacizumab, for the treatment of adults with PD-L1+ (Combined Positive Score [CPS] =1), as determined by an FDA-authorized test, platinum-resistant epithelial ovarian, fallopian tube or primary peritoneal carcinoma, who have received one or two prior systemic treatment regimens.
The Phase 3 KEYNOTE-B96 (ENGOT-ov65) trial showed KEYTRUDA plus paclitaxel, with or without bevacizumab, demonstrated a statistically significant and clinically meaningful improvement in progression-free survival (PFS), the trial's primary endpoint, and overall survival (OS), a key secondary endpoint, for patients with platinum-resistant recurrent ovarian cancer whose tumors expressed PD-L1 (CPS =1) compared to placebo plus paclitaxel, with or without bevacizumab.