First-line therapy in advanced Renal Cell Carcinoma A randomized, open-label Phase-III-Study Evaluating the Efficacy and Safety of Pembrolizumab (MK-3475) in Combination with Axitinib compared to Sunitinib Monotherapy as First-Line Treatment for locally advanced or metastatic Renal Cell Carcinoma (mRCC) (Keynote-426) - AN 39/16 of the AUO