Enigma Biomedical USA (EB USA) today announced that the Food and Drug Administration (FDA) has accepted a New Drug Application (NDA) for MK-6240 (florquinitau F-18), their Tau Positron Emission Tomography (PET) Alzheimer’s disease radiodiaganostic. The FDA previously granted MK-6240 fast track status, which is a recognition of the potential to address an important unmet need. MK-6240 specifically targets a pathological form of tau called tau neurofibrillary tangles (NFTs), a key hallmark in Alzheimer’s disease. In April 2025 Lantheus announced that MK-6240 met its co-primary endpoints in two pivotal studies and has now delivered on its promise to file the MK-6240 NDA in 3Q 2025. The FDA has set a Prescription Drug User Fee Act (PDUFA) target action date of August 13, 2026.

Lantheus acquired the rights to MK-6240 in 2023 and engaged the Enigma Biomedical team to work on the development of MK-6240.

“EB USA is extremely excited about NDA acceptance of the MK-6240 NDA filing and congratulate our partners at Lantheus for this significant accomplishment. This milestone is an important step in our committed journey to address critical unmet needs in neurodegenerative disease as well as providing tools and technologies to support the development of disease modifying therapies,” said Rick Hiatt, President and CEO of EB USA.

“We are pleased the FDA accepted our NDA for MK-6240,” said Brian Markison, CEO, Lantheus. “By enabling early and accurate identification of tau accumulation, MK-6240 has the potential to enhance diagnostic confidence, personalize patient care, and, through ongoing monitoring, transform our understanding of disease progression. We are deeply grateful for the continued support and expertise of the Enigma team, whose contributions have been instrumental to the development of MK-6240.”

About MK-6240 (florquinitau F-18)

MK-6240 is designed to target aggregated tau protein in the form of neurofibrillary tangles (NFTs), a key hallmark of several neurodegenerative diseases, including Alzheimer’s disease. MK-6240 has demonstrated a high affinity for tau and limited off-target binding in both preclinical and clinical studies.^1,2 Acquired by Lantheus in 2023, MK-6240 has received Fast Track designation and is currently being used in nearly 100 active clinical trials. We anticipate that MK-6240 will support earlier disease detection, patient staging, therapy selection, and monitoring, and may help enable tau to serve as a surrogate endpoint for treatment efficacy.

About Enigma Biomedical – USA

Enigma Biomedical USA’s vision is to be the premier provider of imaging biomarkers for neurological pathologies, associated information technology, and related tools to accelerate the development, approval, and adoption of effective therapies to treat neurodegenerative diseases. EB’s neuroimaging biomarkers provide Pharma and Academic researchers with state-of-the-art tools for enabling Disease-Modifying Therapy development with the highest precision and accuracy. In pursuit of this vision, subsidiaries of EB have sold the best-in-class Tau and Amyloid PET imaging biomarkers, MK-6240 and NAV-4694, to our partners to enable their research efforts. EB also recently announced a partnership with AbbVie to explore their novel 4R Tau PET Imaging Biomarkers.

About Lantheus

Lantheus is the leading radiopharmaceutical-focused company, delivering life-changing science to enable clinicians to Find, Fight and Follow disease to deliver better patient outcomes. Headquartered in Massachusetts with offices in New Jersey, Canada, Germany, Switzerland, Sweden and the United Kingdom, Lantheus has been providing radiopharmaceutical solutions for nearly 70 years. For more information, visit www.lantheus.com.

Safe Harbor for Forward-Looking and Cautionary Statements

This press release contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, that are subject to risks and uncertainties and are made pursuant to the safe harbor provisions of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Forward-looking statements may be identified by their use of terms such as "continue,” “expects,” “may,” “moving closer,” “plans,” “poised,” “position,”“potential,” “will,” and other similar terms. Such forward-looking statements are based upon current plans, estimates and expectations that are subject to risks and uncertainties that could cause actual results to materially differ from those described in the forward-looking statements. The inclusion of forward-looking statements should not be regarded as a representation that such plans, estimates and expectations will be achieved. Readers are cautioned not to place undue reliance on the forward-looking statements contained herein, which speak only as of the date hereof. The Company undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future developments or otherwise, except as may be required by law. Risks and uncertainties that could cause our actual results to materially differ from those described in the forward-looking statements include: (i) a delay in obtaining, or failure to obtain, a positive regulatory outcome from the FDA for MK-6240; (ii) our ability to launch MK-6240 as a commercial product; (iii) the market receptivity to MK-6240 as a radiopharmaceutical diagnostic; (iv) the existence, availability and profile of competing products; (v) our ability to obtain and maintain adequate coding, coverage and payment for MK-6240; (vi) the safety and efficacy of MK-6240; (vii) the intellectual property protection of MK-6240; (viii) our ability to successfully develop and scale the manufacturing capabilities to support the launch of MK-6240; and (ix) the risks and uncertainties discussed in our filings with the Securities and Exchange Commission (including those described in the RiskFactors section in our most recently filed Annual Report on Form 10-K and Quarterly Reports on Form 10-Q).

¹ Krishnadas N, Doré V, Robertson JS, Ward L, Fowler C, Masters CL, Bourgeat P, Fripp J, Villemagne VL, Rowe CC. Rates of regional tau accumulation in ageing and across the Alzheimer’s disease continuum: an AIBL 18F-MK-6240 PET study. EBioMedicine. 2023 Feb;88:104450. doi: 10.1016/j.ebiom.2023.104450. Epub 2023 Jan 27. PMID: 36709581; PMCID: PMC9900352.

² Lohith TG, Bennacef I, Vandenberghe R, Vandenbulcke M, Salinas CA, Declercq R, Reynders T, Telan-Choing NF, Riffel K, Celen S, Serdons K, Bormans G, Tsai K, Walji A, Hostetler ED, Evelhoch JL, Van Laere K, Forman M, Stoch A, Sur C, Struyk A. Brain imaging of Alzheimer dementia patients and elderly controls with 18F-MK-6240, a PET tracer targeting neurofibrillary tangles. J Nucl Med. 2019 Jan;60(1):107-114. doi: 10.2967/jnumed.118.208215. Epub 2018 Jun 7. PMID: 29880509.

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