Polku Therapeutics Reports Positive Efficacy for Lead Compound POLK-38 in PS19 Tauopathy Model

Helsinki, Finland – June 19, 2026 – Polku Therapeutics, a biotechnology company developing disease-modifying therapies for neurodegenerative disorders, today announced positive efficacy results from an ongoing preclinical study of POLK-38, its lead PREP-targeting small molecule, in the PS19 tauopathy mouse model.

Following oral administration, POLK-38 produced a significant treatment effect on brain tau pathology and spatial learning, supporting Polku's approach of targeting the PREP–PP2A pathway to counter tau pathology and neurodegeneration.

The PS19 model is among the most widely used translational models of tauopathy and is commonly employed to evaluate potential disease-modifying therapies for Alzheimer's disease and related disorders. Additional analyses, including neuropathological assessments, are ongoing and will further characterize the effects of POLK-38 on disease-relevant biomarkers.

Polku will present new research from its PREP-targeting platform at AAIC 2026 on July 12. The presentation will be delivered by Professor Timo Myöhänen, co-founder of Polku Therapeutics and Professor of Pharmacology at the University of Helsinki.

"Generating positive oral efficacy data for POLK-38 in a rigorous tauopathy model is another important step forward for our program," said Simon Bennett, Chief Executive Officer of Polku Therapeutics. "We believe the PREP–PP2A pathway offers a differentiated approach to restoring neuronal homeostasis and addressing the biology that drives neurodegenerative disease."

"We are encouraged by the results to date and look forward to sharing further scientific insights with the Alzheimer's research community at AAIC," added Professor Myöhänen.

POLK-38 is part of a portfolio of novel small molecules Polku is advancing to modulate prolyl oligopeptidase (PREP) and restore protein homeostasis mechanisms implicated in tauopathies and other neurodegenerative disorders.

About Polku Therapeutics

Polku Therapeutics is a Finnish biotechnology company developing disease-modifying therapies for neurodegenerative diseases. Its lead program targets the PP2A activation via PREP to restore cellular mechanisms involved in tau homeostasis and neuronal function. For more information, visit polkutx.com.

Contact: Sebastian Soidinsalo, Chief Operating Officer, Polku Therapeutics — seb@polkutx.com | +358 40 681 1716