Approximately half of patients with advanced melanoma do not respond to anti-PD-1, and as such, biomarkers for predicting response/resistance are desirable. PD-1-PD-L1 proximity in the tumor microenvironment has been proposed a biomarker. The impact which cell type is expressing PD-1 and/or PD-L1, expression intensity, hot spot vs whole slide sampling, distance between these molecules optimize ...

Tumors have developed multiple immunosuppressive mechanisms to turn down the innate and the effector arms of the immune system, thus compromising most of the immunotherapeutic strategies that have been proposed during the last decade. Right after the pioneering success of Ipilimumab (anti-CTLA4) in metastatic melanoma, several groups have conducted trials aiming at subverting other immune check...

The ligation of programmed cell death-1 (PD-1) to its ligands PD-L1 and PD-L2 counteracts T-cell activation, which is critical in immune tolerance. The persistent high expression of PD-1 and PD-L1 are also observed on tumor-infiltrating lymphocytes and various tumor cells, maintaining the highly suppressive microenvironment in tumor sites and promoting tumor malignancies. The blockade of PD-1 a...