** Shares of drug developer Edgewise Therapeutics EWTX.O rise 30.7% to $43.86 premarket

** Co says it will sell its muscle dystrophy business to French drugmaker Servier for up to $2.65 billion

** EWTX says Servier will gain access to its experimental drug sevasemten, which is being tested in Becker and Duchenne muscular dystrophy, two genetic disorders that cause progressive muscle weakness

** Co says the sale would strengthen its balance sheet and plans to use the proceeds for development of its lead candidate EDG-7500, which is being tested for the heart condition hypertrophic cardiomyopathy

** Up to last close, stock was up 37.7% YTD