Lantheus Holdings, Inc. disclosed on October 2, 2026, that it is providing supplemental information to its definitive proxy statement following the filing of three lawsuits and sixteen demand letters related to its pending merger with Curium US Holdings LLC.
The company, a Delaware corporation headquartered in Bedford, Massachusetts, entered into a merger agreement on August 3, 2026. Under the terms of the deal, Coco Merger Sub Inc., a subsidiary of Curium US Holdings LLC, will merge with Lantheus, leaving Lantheus as a wholly owned subsidiary of Curium. Lantheus filed its definitive proxy statement with the Securities and Exchange Commission on September 8, 2026, for a special stockholder meeting scheduled for October 14, 2026.
Since the proxy filing, three complaints have been lodged against Lantheus and certain board members. Two were filed in the Supreme Court of the State of New York on September 16, 2026: Hamilton v. Lantheus Holdings, Inc., et al. (Index No. 655291/2026) and McDaniels v. Lantheus Holdings, Inc., et al. (Index No. 655281/2026). A third complaint, Garfield v. Lantheus Holdings, Inc., et al. (Civil Docket No. 2681CV02581), was filed in the Superior Court of the Commonwealth of Massachusetts, Middlesex County, on September 25, 2026.
The complaints allege that the definitive proxy statement omits or misrepresents information regarding the company's financial projections, the financial analyses performed by Morgan Stanley for its fairness opinion, and potential conflicts of interest involving company insiders. The plaintiffs seek to enjoin the merger unless additional information is disclosed. Additionally, as of September 30, 2026, Lantheus received sixteen demand letters from purported stockholders seeking similar disclosures.
Lantheus stated that it is providing these supplemental disclosures solely to avoid the costs and uncertainties of litigation and to allow stockholders to vote on the merger without admitting liability or wrongdoing. The company denies that the definitive proxy statement is deficient and asserts that the complaints and demand letters are without merit. The supplemental disclosures supersede any conflicting information in the original proxy statement.
The first supplemental disclosure replaces a paragraph regarding Morgan Stanley's discounted cash flow analysis. Morgan Stanley calculated the estimated present value of standalone unlevered free cash flows from June 30, 2026, through December 31, 2035. The analysis used a perpetual growth rate of (5.0%) for the Pylarify family of products and perpetual growth rates ranging from 4.0% to 4.5% for other products.