Big Pharmas finally strike with GSK, Merck acquisitions, signaling accelerating pace of M&A

After circling around the crop of biotechs ripe for a takeover, Big Pharma companies have finally decided to strike.

Merck & Co. made the first jab, taking Prometheus Biosciences and its bowel disease candidate in a $10.8 billion transaction Sunday. Then GSK struck Tuesday, offering $2 billion for Bellus Health to challenge its fellow pharma dealmaker in the cough market.