Shares of Esperion Therapeutics Inc. ESPR, -54.27% plunged about 56% in premarket trading on Thursday, the day after the company told investors that there is a dispute about a million milestone payment for its cholesterol-lowering treatment candidate worth up to $440 million.
Esperion said earlier this month that Nexletol reduced the risk of heart attack and other heart issues in people who can’t take statins. The company said in a securities filing that the milestone payment is tied to whether cardiovascular risk reduction data is included in the European label for the pill; however, Daiichi Sankyo Co. Ltd.’s 4568, +3.60% European business disagrees, saying the potential payment is tied to the primary endpoint. Esperion said it plans to submit for regulatory approval in the U.S. and Europe in the first half of this year. The company’s stock is up 0.2% this year, while the S&P 500 SPX, +1.76% has gained 1.7%.