SAN FRANCISCO – Exelixis Inc. was 2015's top biopharma gainer on Wall Street and one of the top firms in 2016, according to BioWorld Insight. Riding high on the approval and strong launch for renal cell carcinoma drug Cabometyx (cabozantinib) and with a solid financial position of $379.6 million as of Sept. 30, the South San Francisco-based firm looks to build out its pipeline – or rebuild, rather.