A PD-1 /PD-L1 proximity assay as a theranostic marker for PD-1 blockade in patients with metastatic melanoma.

PURPOSE Less than 50% of patients with melanoma respond to anti-PD1, and this treatment can induce severe toxicity. Predictive markers are thus needed to improve the benefit/risk ratio of immune checkpoint inhibitors (ICI). Baseline tumor parameters such as PD-L1 expression, CD8+ T cell infiltration, mutational burden and various transcriptomic signatures are associated with response to ICI but their predictive values are not sufficient....