Rare disease-focused pharmaceutical firm Immedica Pharma AB said Monday that it has agreed to buy Marinus Pharmaceuticals (MRNS, Financials) for over $151 million. Marinus shares jumped 43% after the disclosure and closed at $0.53. With ZTALMY (ganaxolone), a seizure medicine licensed for cyclin-dependent kinase-like 5 (CDKL5) deficient disease, the transaction will see Immedica increase its footprint in North America and strengthen its rare neurology portfolio.

• Warning! GuruFocus has detected 5 Warning Signs with MRNS.

Under the terms of the agreement, Immedica will make a tender offer to purchase all outstanding shares of Marinus for $0.55 per share in cash, therefore attaining a 48% premium over Marinus's closing price on Dec. 27 and a 97% premium over its 30-day average price. The Marinus board of directors has approved the deal unanimously and advised that owners offer their shares. Additionally committed to helping the sale are key executives and board members.

Approved by regulatory authorities in the United States, European Union, United Kingdom, and China, ZTALMY offers a therapeutic choice for patients two years of age and above with CDKL5 deficient disease. By adding a commercial-stage medicine to its portfolio, the purchase enables Immedica to increase revenue growth and improve its U.S. market presence. Subject to usual conditions, the deal is scheduled to conclude in the first quarter of 2025.

The agreement marks the end of Marinus's strategic assessment started in October designed to maximize shareholder value. To guarantee complete control of Marinus, Immedica intends to do a second-step merger to buy any outstanding shares at the same price.

Introduced in the U.S. in 2022 as the first FDA-approved medication for seizures linked with CDKL5 deficient condition, ZTALMY is a neuroactive steroid regulating GABAA receptor. While Immedica, supported by investment companies KKR and Impilo, concentrates on medications for rare disorders, operating in more than 50 countries, Marinus specializes in creative seizure therapies.