Can immune biomarkers predict benefit from targeted agents in metastatic renal cell carcinoma?

We read with great interest the article by Flaifel and colleagues (1), who interrogated the predictive and prognostic value of (I) PD-L1 expression [on tumor and immune cells (IC)], (II) the extent of immune cell infiltrates and (III) the cMET expression in patients receiving targeted agents (TA). The authors analyzed pre-treatment tumor tissue obtained from patients from 2 randomized trials, the METEOR trial (2) (cabozantinib versus everolimus in 2^nd-line) and the CABOSUN trial (3) (cabozantinib versus sunitinib in 1^st-line). The main findings were first, that PD-L1 expression on tumor cells (TC) is associated with poor clinical outcome in all patients and independently of the TA received and second, that cabozantinib is superior to everolimus and sunitinib in terms of PFS and OS, irrespective of PD-L1 expression.