US commercial stage biopharmaceutical company Esperion Therapeutics Inc (NASDAQ:ESPR) on Tuesday announced a definitive agreement to acquire privately held Corstasis Therapeutics Inc, adding Enbumyst (bumetanide nasal spray) to its cardiovascular franchise.

The transaction includes a USD75m upfront cash payment, low double-digit royalties on worldwide sales, and up to USD180m in potential regulatory and commercial milestone payments.

Enbumyst is the first and only FDA-approved nasal spray loop diuretic for oedema associated with congestive heart failure, as well as hepatic and renal disease in adults, following its approval in September 2025. The product is designed as a self-administered outpatient therapy intended to bridge the gap between oral and intravenous diuretics.

Esperion said that this acquisition aligns with its Vision 2040 strategy and is expected to leverage its established cardiovascular commercial infrastructure to support double-digit revenue growth. The company estimates a US market opportunity exceeding USD4bn, with approximately 6.7 million American adults living with congestive heart failure, and additional expansion potential across hepatic and renal indications, including nephrotic syndrome.

Esperion will finance the acquisition through existing credit facilities and royalty monetisation of its Japanese royalties with funds managed by Athyrium Capital Management and HealthCare Royalty. Corstasis is also advancing a subcutaneous pipeline, including a multidose pen injector, which may provide further market opportunities.

The transaction is expected to close in the second quarter of 2026.