CHICAGO — For years, scientists said creating a drug around the KRAS protein was impossible. On Monday, Amgen (AMGN) showed it had developed a medicine that shrank tumors in 50% of lung cancer patients.
These lung cancer patients — just 10 of them because this is an early-stage clinical trial — all had tumors that tested positive for a particular mutation in KRAS, a cell-signaling protein. The 50% response rate to AMG 510 is an improvement over the 30% response rate first reported by Amgen last month. It also exceeds investor expectations.