Overview

A class action lawsuit has been filed against Lantheus Holdings, Inc. (“Lantheus” or the “Company”) and certain of the Company’s former senior executive officers alleging violations of the federal securities laws. The Company’s common stock traded on the NASDAQ under the symbol “LNTH.”

The Lantheus class action lawsuit was brought on behalf of all persons and entities who purchased or otherwise acquired Lantheus securities between February 26, 2025, to August 5, 2025, both dates inclusive, (the “Class Period”).

Lantheus is a global company that develops, manufactures, sells, and distributes certain diagnostic and therapeutic products in three categories: Radiopharmaceutical Oncology, Precision Diagnostics, and Strategic Partnerships and Other Revenue. Pertinently, the Company’s key Radiopharmaceutical Oncology product is Pylarify, a PET imaging agent used to assist in both diagnosing and subsequently treating prostate cancer.

The lawsuit alleges that Defendants misled investors about Lantheus’ expected revenue for fiscal year 2025 by repeatedly assuring the market of Pylarify’s growth potential. They highlighted Pylarify’s supposed market leadership and premium pricing, claiming that these advantages positioned the Company to meet its revenue guidance despite competitive pressures. Defendants further instilled confidence by emphasizing their understanding of market dynamics and portraying Pylarify as resilient to external challenges.

In reality, Lantheus was not equipped to accurately assess the pricing and competitive environment for Pylarify. The Company failed to disclose that its early 2025 price increase, issued in the face of prior price erosion, left Pylarify vulnerable to intensified competition. This undisclosed risk directly threatened Pylarify’s revenue and long-term growth potential, rendering Defendants’ positive statements materially false and misleading.

The truth began to emerge on May 7, 2025, when Lantheus reported first quarter results below expectations. The Company revealed that Pylarify sales had declined year-over-year, attributing the shortfall to a “temporal competitive disruption.” Lantheus reduced its full-year growth projections, narrowing guidance to flat or low single-digit growth. Investors reacted swiftly, and the stock price fell more than 23% in a single day.

Despite this disclosure, Defendants continued to reassure investors that competitive pressures were temporary and maintained that Lantheus would recover and grow in line with revised guidance. However, on August 6, 2025, the Company reported another sharp decline, disclosing that Pylarify sales had fallen 8.3% year-over-year and slashing its fiscal 2025 growth projections further. On this news, the stock price dropped nearly 29% in one day, leaving class members to absorb substantial losses tied to Lantheus’ earlier misrepresentations.

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If you purchased or otherwise acquired Lantheus securities between February 26, 2025, to August 5, 2025, both dates inclusive, and you wish to serve as lead plaintiff in this lawsuit, we encourage you to submit your information to DiCello Levitt LLP via the form on this page. 

You can also contact DiCello Levitt partner Brian O’Mara by calling (888) 287-9005 or at investors@dicellolevitt.com. 

The deadline to apply to the Court to serve as lead plaintiff in the Lantheus class action lawsuit is November 10, 2025.