TEST:

LAG-3 IHC assay

LAG-3 is an immune checkpoint receptor with several anti-LAG-3 immunotherapies demonstrating clinical benefit, including relatlimab, which recently received FDA approval for treatment of metastatic melanoma in combination with nivolumab. LAG-3 status by RNA-seq and IHC in melanoma is significantly correlated. Further studies are needed to model RNA-seq cut-offs in a larger, more diverse melanoma cohort and assess expression levels in other tumor types with anti-LAG-3 immunotherapies currently in development. To implement an emerging immuno-oncology biomarker like LAG-3 into clinical practice, rapid, sensitive, and accurate assessment by multiple assays may be needed to reliably identify patients for precision immunotherapy.

Overall percentage agreement was 77.5% or greater for interplatform and BOND-RX intraplatform comparisons when LAG-3 positivity was determined using a 1% or greater cutoff. Data presented here demonstrate that LAG-3 expression can be robustly and reproducibly assessed across 3 major commercial IHC staining platforms using the 17B4 antibody clone.

"Finding treatment options for skin cancer may become easier with the launch of a new test by Labcorp...The new test measures Lymphocyte-activation gene 3 (LAG-3) expression levels by immunohistochemistry (IHC) in tumor tissue. LAG-3 is an immune-oncology target with demonstrable clinical benefit in patients with melanoma. The test is available for use in both clinical trials and for the care and treatment of patients."