Tuesday, March 3, 2026

Esperion to acquire Corstasis to add Enbumyst to its CV portfolio

Esperion Therapeutics (NASDAQ: ESPR) and Corstasis Therapeutics have signed a definitive agreement under which Esperion plans to acquire privately held Corstasis. The deal centers on Enbumyst (bumetanide nasal spray), a U.S.-approved loop diuretic indicated for edema in adults with congestive heart failure as well as hepatic and renal disease, including nephrotic syndrome.

The companies expect the transaction to close in the second quarter of 2026, subject to customary closing conditions.

Product focus: intranasal loop diuretic positioned for outpatient use

According to the announcement, the U.S. Food and Drug Administration approved Enbumyst in September 2025. The therapy is positioned as a self-administered outpatient option and is intended to complement existing oral and intravenous diuretic approaches.

Esperion says it plans to leverage its established cardiovascular commercial infrastructure to support Enbumyst and expand its cardiovascular franchise.

Deal terms: $75m upfront, milestones, and royalties

Under the agreement, Esperion will pay $75 million in cash upfront. Corstasis shareholders may also receive up to $180 million in additional payments tied to specific commercial and regulatory milestones. In addition, the structure includes low double-digit royalties on worldwide sales of Enbumyst and follow-on products.

Esperion intends to finance the acquisition using existing credit facilities and by monetizing its Japanese royalty stream, with capital from funds managed by Athyrium Capital Management and HealthCare Royalty.

Market and pipeline considerations

The announcement cites a sizeable U.S. patient population, estimating 6.7 million American adults living with congestive heart failure, with edema described as a common clinical feature. Esperion pegs the U.S. market opportunity at more than $4 billion and points to potential expansion across hepatic and renal indications, including nephrotic syndrome.

Beyond the marketed product, Corstasis is also advancing a subcutaneous pipeline, including a multidose pen injector program.

Advisers and investor update

Jefferies acted as Esperion’s exclusive financial adviser, while PJT Partners advised Corstasis. Legal counsel included Gibson, Dunn & Crutcher for Esperion and Arnold & Porter Kaye Scholer for Corstasis.

Esperion said it will host an investor conference call and webcast on Tuesday, March 3, 2026 at 8:00 a.m. ET to discuss the acquisition.

Safety and prescribing overview

The U.S. prescribing information lists contraindications including anuria, hepatic coma, and hypersensitivity to bumetanide. It also highlights the risk of fluid, electrolyte, and metabolic abnormalities. Reported common adverse reactions include hypovolemia, headache, muscle cramps, dizziness, hypotension, nausea, and encephalopathy in patients with pre-existing liver disease.