Esperion to Acquire Corstasis, Expanding Heart Failure Treatment Portfolio

Esperion has announced a definitive agreement to acquire Corstasis Therapeutics in a move aimed at strengthening its cardiovascular portfolio and expanding access to innovative outpatient therapies for patients with fluid retention associated with heart, liver, and kidney diseases.

The acquisition centers on Enbumyst™, a nasal spray formulation of the diuretic bumetanide developed by Corstasis. The therapy, marketed as Enbumyst, received approval from the U.S. Food and Drug Administration in September 2025. It is currently the first and only intranasal diuretic approved to treat edema associated with Congestive Heart Failure as well as edema linked to hepatic and renal disease in adults.

Unlike traditional diuretic therapies that are administered orally or intravenously, Enbumyst offers a self-administered nasal spray option designed for outpatient use. The therapy is intended to bridge the gap between oral diuretics, which may have delayed absorption or reduced effectiveness, and intravenous treatments typically delivered in clinical settings. By enabling patients to manage fluid buildup at home, the therapy could help reduce hospital visits and improve day-to-day management of worsening symptoms.

Esperion’s President and Chief Executive Officer, Sheldon Koenig, described the deal as a strategically aligned opportunity that supports the company’s long-term “Vision 2040” strategy. According to Koenig, Enbumyst’s novel intranasal delivery system and established regulatory approval make it a strong addition to the company’s growing cardiovascular franchise. He noted that integrating the therapy into Esperion’s existing commercial infrastructure could help drive sustained growth while delivering new treatment options to patients with significant unmet medical needs.

For Corstasis, the acquisition represents validation of its development strategy. Ben Esque said the therapy was developed in close collaboration with the cardiology community to address a critical treatment gap. He emphasized that Enbumyst has the potential to allow earlier intervention when heart failure symptoms worsen, enabling patients to manage fluid retention from home rather than requiring hospital care.

Heart failure remains a major health challenge in the United States. Estimates suggest that approximately 6.7 million adults in the country live with congestive heart failure, with edema—fluid buildup in tissues—being one of the most common and debilitating symptoms. As the disease progresses, managing fluid retention becomes increasingly difficult and often leads to hospitalizations.

Clinical experts see potential advantages in the new treatment approach. James Udelson, Chief of Cardiology at Tufts Medical Center, noted that congestion and edema are among the most persistent and burdensome symptoms for heart failure patients. He said that an FDA-approved intranasal diuretic offers a more flexible and patient-friendly option that could help manage symptoms quickly and potentially prevent hospital admissions.

Under the terms of the agreement, Esperion will acquire all outstanding shares of Corstasis for an upfront cash payment of $75 million. Corstasis shareholders could receive up to an additional $180 million tied to regulatory and commercial milestones. They will also be eligible for low double-digit royalties on sales of Enbumyst and any related follow-on products.

Esperion plans to finance the acquisition through its existing credit facilities and by monetizing Japanese royalties in partnership with funds managed by Athyrium Capital Management and HealthCare Royalty.

The transaction is expected to close in the second quarter of 2026, pending customary closing conditions. Financial advisory support for the deal was provided by Jefferies for Esperion and PJT Partners for Corstasis. Legal counsel was provided by Gibson Dunn and Arnold & Porter.

With the acquisition, Esperion aims to expand its presence in cardiovascular medicine while exploring additional opportunities in metabolic, hepatic, and renal disease markets.