The Test

CHECKMARK is the second Martell test of seven tests to be available at point-of-care by 2021. 


Martell is committed to providing proteomic blood immunoassays as an adjunct to cancer management.

We have begun to develop immunoassays for an additional six tumor biomarkers.


The most advanced is CHECKMARK, a serum test to measure soluble PD-L1. It is now available at the Martell CLIA reference laboratory and can be ordered by physicians upon request.


Soluble PD-L1 promises to be an important marker of native immunity: Rising serum PD-L1 levels seem to portend immune failure in patients with clear cell renal carcinoma. In a baseline study of 32 patients with non-small-cell lung cancer, all had elevated sPD-L1, but patients with higher levels were less responsive to nivolumab.  

Of the four criteria of tumor biomarker monitoring, CHECKMARK monitoring
has prognostic value independent of tissue testing. We support efforts to
evaluate the role of CHECKMARK in selecting and evaluating pembrolizumab and nivolumab treatment.