** Shares of drug developer Erasca ERAS.O rise 8% to $10.92 premarket

** Erasca says it has signed a clinical trial collaboration and supply agreement with Merck MRK.N to test its experimental cancer pill, ERAS-0015, alongside Merck's Keytruda

** The trial will study the combination in patients with solid tumors caused by mutations in the RAS gene

** Erasca will run the study, while Merck will supply Keytruda at no cost

** Last month, Erasca said that a patient died in an early-stage trial of ERAS-0015

** In the same trial, ERAS-0015 shrank tumors in 62% of lung cancer patients who had undergone prior treatments without any success

** As of last close, ERAS up 172% YTD