Yee added that Amgen's acquisition was consistent with its "bolt-on" approach to acquiring companies with de-risked assets in late clinical phases (such as Five Prime Therapeutics, acquired by Amgen last year for approximately $1.9 billion ) or commercial stage (Amgen shelled out $13.4 billion cash in 2019 for Otezla from Celgene as it was about to be acquired by Bristol Myers Squibb for $74 billion ).