The purpose of this study is to determine the maximum tolerated dose (MTD), safety,
tolerability, Pharmacokinetic (PK), pharmacodynamic and clinical activity of M8891 as single
agent in participants with advanced solid tumors in Part 1 and to determine the safety,
tolerability, PK and antitumor activity of M8891 combined with cabozantinib in participants
with metastatic renal cell carcinoma (mRCC) in Part 2 (Part 2a and Part 2b) of the study.