FDA Approves Tauklarify to Identify Tau Pathology in Patients Being Evaluated for Alzheimer Disease

The FDA approved florquinitau F 18 injection (Tauklarify; Enigma Biomedical USA), a radiodiagnostic agent for positron emission tomography (PET) imaging of the brain in adults with cognitive impairment who are being evaluated for Alzheimer disease (AD). The agent, which was previously studied under the name MK-6240, is designed to help identify patients with tau neurofibrillary tangle (NFT) pathology, a hallmark feature of AD.¹

The prescribing information for Tauklarify includes a warning regarding the risk of misdiagnosis. Its performance was assessed primarily in patients expected to have either no tau NFT pathology (cognitively unimpaired and amyloid beta PET-negative) or clinically significant tau NFT pathology associated with AD (cognitively impaired and amyloid beta PET-positive).

The agent’s performance may be lower in patients at earlier stages of the pathological spectrum, and a negative scan does not necessarily exclude tau NFT pathology, nor does a positive scan necessarily confirm histopathologically confirmed disease. Health care professionals are advised to consider additional evaluation when clinical uncertainty remains.¹

“[Tauklarify] imaging will enable improved understanding of the status of [patients with AD] across the spectrum of cognitive impairment, including those in the early stages of the disease,” Samantha Budd Haeberlein, PhD, chief medical officer of Enigma Biomedical USA, said in the news release. “Two large, independent clinical studies demonstrated the efficacy and safety of Tauklarify in assessing the status of NFTs in patients being evaluated for AD. As AD research moves towards an increased focus on early disease detection and treatment, Tauklarify is uniquely suited to address those emerging needs.”¹

Clinical Trial Data

Tauklarify’s approval was supported by 2 clinical studies in which 5 independent blinded readers classified PET scans as positive or negative for tau NFT pathology. Each scan was then compared against a preestablished reference standard based on cognitive status and amyloid beta PET pathology status. Together, the studies included scans from 617 subjects: 152 of whom had mild AD dementia, 157 had mild cognitive impairment, and 308 were considered cognitively unimpaired. Both studies met their prespecified success criteria.²

In Study 1 (n = 279), reader positive percent agreement (PPA) ranged from approximately 80% (95% CI, 72%-86%) to 88% (95% CI, 82%-93%), and negative percent agreement (NPA) ranged from approximately 98% (95% CI, 94-99) to 99% (95% CI, 95-100). Similarly, in Study 2 (n = 338), reader PPA ranged from 68% (95% CI, 61%-75%) to 82% (95% CI, 76%-87%), and NPA ranged from 93% (95% CI, 89%-96%) to 99% (95% CI, 96%-100%). Interreader agreement was high in both studies, with a generalized Fleiss’ kappa of about 0.92 in Study 1 and 0.86 in Study 2.²

Safety was evaluated in 1734 total participants. The most commonly reported adverse events were headache (0.7%), nausea (0.2%), injection site reactions (0.1%), dizziness (0.1%), and abdominal discomfort (0.1%).^1,2

“This approval is an important and critical step forward in the management of patients being evaluated for AD,” Sterling Johnson, PhD, Jean R. Finley professor of geriatrics and dementia and associate director of the Wisconsin Alzheimer’s Disease Research Center, said in the news release release.¹

Indication and Safety Considerations

Tauklarify is indicated for PET imaging of the brain in adults with cognitive impairment being evaluated for AD to identify tau NFT pathology. The safety and effectiveness of the agent have not yet been established for evaluating non-AD tauopathies, the news release cautions. Additionally, health systems and pharmacy teams should ensure safe handling protocols to protect both patients and staff from unintended radiation exposure, and patients should be advised to hydrate before and after administration and void frequently afterward.¹

Pharmacists should also be aware of a notable drug interaction: CYP1A2 inducers—including tobacco smoking—should be avoided for at least 7 days prior to Tauklarify administration. For lactating patients, breastfeeding should be temporarily discontinued, with pumped breast milk discarded for a minimum of 4 hours after administration.¹

“With the approval of Tauklarify, [we have] demonstrate[d] its ongoing commitment to be the premier developer of imaging biomarkers for neurological pathologies to accelerate the development, approval, and adoption of effective therapies to treat neurodegenerative diseases,” Rick Hiatt, president and CEO of Enigma Biomedical USA, said in the news release.¹

REFERENCES

1. Enigma Biomedical USA announces FDA approval of TAUKLARIFY (florquinitau F 18 injection) for use in patients being evaluated for Alzheimer's disease. News release. Enigma Biomedical USA. August 14, 2026. Accessed August 14, 2026. https://www.biospace.com/press-releases/enigma-biomedical-usa-announces-fda-approval-of-tauklarify-florquinitau-f-18-injection-for-use-in-patients-being-evaluated-for-alzheimers-disease

2. Lantheus announces Alzheimer disease radiodiagnostic MK-6240 meets coprimary endpoints in 2 pivotal studies. News release. April 30, 2025. Accessed August 14, 2026. https://lantheusholdings.gcs-web.com/news-releases/news-release-details/lantheus-announces-alzheimers-disease-radiodiagnostic-mk-6240