Probably no one was surprised by the FDA’s recent nod for the combination of Alameda, Calif.-based Exelixis Inc.’s tyrosine kinase inhibitor, Cabometyx (cabozantinib), which targets MET, AXL and VEGF, and PD-1 drug Opdivo (nivolumab) from Bristol Myers Squibb Co. as a first-line treatment for advanced renal cell carcinoma (RCC), but investors may feel less confident about the odds for the pairing in a competitive space.