After Esperion Therapeutics disclosed a conflict with Nexletol partner Daiichi Sankyo in an SEC filing earlier this month, the company has kicked it up a notch with a lawsuit claiming it's entitled to $300 million in milestone payments.
The dispute stems from a 2019 agreement in which Esperion gave Daiichi exclusive commercialization rights to its bempedoic acid, used in heart drug Nexletol, in Europe and Switzerland. The deal stipulated that Daiichi would make regulatory milestone payments to Esperion under certain outcomes, including in the event of a label expansion.
One of these payments is tied to a trial called the CLEAR outcomes study, which tested Nexletol’s ability to reduce the risk of heart attack and coronary revascularization, plus a range of cardiovascular outcomes grouped together in an endpoint called MACE-4. Nexletol is branded as Nilemdo in Europe.
The disagreement centers on the companies' focus on different trial endpoints. Specifically, the deal states that the $300 million milestone payment is owed if the study shows “a cardiovascular risk reduction” of 15% or greater. Esperion thinks it hit that goal because the drug showed a 27% lower risk of heart attacks.
Daiichi disagrees, pointing to the MACE-4 outcome, which showed a 13% cardiovascular risk reduction versus placebo. The Japanese drugmaker believes that the agreement requires that specific endpoint to be over 15%, which Esperion thinks is “inconsistent with the plain and unambiguous language of the agreement,” Esperion’s attorneys said in the lawsuit.
Esperion’s lawyers said the company will suffer economic harm without the payout. After it disclosed the conflict in an SEC filing on March 15, Esperion's stock price fell from $3.99 to $1.49.
Already, the dispute and delay of the payout have affected Esperion's financial position, the company has said.
Esperion reported 2022 full-year revenues of $75.5 million, down 4% from 2021’s $78.4 million. That’s following 2021 workforce cuts of 40%.
Daiichi and Esperion “share the same common goal” of fighting cardiovascular disease and have “built a partnership with regular and constructive interactions,” a Daiichi Sankyo spokesperson said in an emailed statement to Fierce Pharma. “Such interaction will continue in spite of our current differences in opinion by both parties concerning contractual provisions,” the spokesperson continued.