STAT+: Biogen’s tau-targeting Alzheimer’s drug posts mixed results in mid-stage study

STAT PlusBiotech Biogen’s tau-targeting Alzheimer’s drug posts mixed results in mid-stage study The company said it plans to move the medicine, diranersen, into a pivotal trial Manage alerts for this article Email this article Share this article By Adam FeuersteinMay 14, 2026 Adam Feuerstein, a senior writer and biotech columnist, is the author of Adam’s Biotech Scorecard, a subscriber-only newsletter about the crossroads of drug development, business, Wall Street, and biotechnology. Adam Feuerstein[email protected]Adam Feuerstein is a senior writer and biotech columnist, reporting on the crossroads of drug development, business, Wall Street, and biotechnology. He is also a co-host of the weekly biotech podcast The Readout Loud and author of the newsletter Adam’s Biotech Scorecard.

You can reach Adam on Signal at stataf.54. Biogen reported mixed results Thursday from a mid-stage clinical trial investigating a treatment for Alzheimer’s disease that targets the protein tau that, like the better-known amyloid, is toxic to neurons and is believed to play a role in the cognitive decline of patients with the disease. In the Phase 2 study, the Biogen drug, called diranersen, or BIIB080, reduced levels of tau in the spinal fluid and brains of patients with early-stage Alzheimer’s.

Those tau reductions also correlated to a slowing of cognitive decline, the company said.Advertisement Biogen investigated three escalating dosing regimens in its study, with the lowest dose showing the best results. For that reason, the study failed to achieve its primary efficacy goal, which was a dose response. STAT+ Exclusive Story Already have an account?

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He is also a co-host of the weekly biotech podcast The Readout Loud and author of the newsletter Adam’s Biotech Scorecard. You can reach Adam on Signal at stataf.54. Newsletter Understand how science, health policy, and medicine shape the world every day Recommended Exclusive May 14, 2026 STAT Plus: CREATE Medicines, a biotech company developing CAR-T therapies, raises $122 million Biotech May 14, 2026 STAT Plus: Regenxbio says Duchenne gene therapy succeeded in clinical trial, paving way for FDA submission Advertisement Adam's Biotech Scorecard May 14, 2026 STAT Plus: ‘No drama’ Diamantas should serve biotech well as acting FDA chief Exclusive May 13, 2026 STAT Plus: What the Trump administration wants in its next FDA leader The Readout May 13, 2026 STAT Plus: Gene therapy viruses linked to a boy’s tumor Subscriber Picks