 Shares of Viking Therapeutics Inc. VKTX, 4.42 jumped 55 in premarket trading on Monday after a company that is also developing a selective thyroid hormone receptor beta agonist as a treatment for non-alcoholic steatohepatitis NASH and fibrosis announced positive, late-stage data. Madrigal Pharmaceuticals Inc. MDGL, 1.43 said Monday it is aiming to get an accelerated approval in the U.S. for its drug. 