Samus Therapeutics Launches Phase 1 Trial of Tau-targeting Therapy

Following the approval of its investigational new drug (IND) application by the U.S. Food and Drug Administration (FDA), Samus Therapeutics is launching a Phase 1 trial in the United States to evaluate the safety of its investigational therapy PU-AD, an epichaperome inhibitor, for the treatment of Alzheimer’s disease.

The trial, which will be carried out at a center in Texas, is recruiting participants. More information about enrollment can be found here.

Characteristic features of Alzheimer’s, such as disrupted communication between nerve cells, are partly caused by the presence of abnormal aggregates of two proteins — called beta-amyloid and tau — in the brain.

Tau proteins are necessary components of healthy brain nerve cells, but in Alzheimer’s, this protein undergoes chemical modifications — a process called hyperphosphorylation — that make tau stick to other tau proteins, forming a complex known as tau tangles.

Protein complexes known as epichaperomes (or stress chaperomes) prevent the degradation of aberrant proteins such as tau, allowing their aggregation.

PU-AD, developed by Samus Therapeutics, is an oral, brain-permeable investigational therapy for Alzheimer’s that specifically inhibits epichaperomes, thus allowing the removal of tau tangles.

Previous evidence from preclinical studies suggests that epichaperomes contribute to and may even initiate neurodegenerative diseases, such as Alzheimer’s. Inhibiting their activity with PU-AD allowed abnormal tau proteins to be degraded and improved memory in animals.

“In [Alzheimer’s] and tauopathy mouse models, inhibiting the epichaperome with PU-AD effected degradation of mutated hyperphosphorylated and aggregated tau protein,” Barbara Wallner, chief scientific officer of Samus Therapeutics, said in a press release.

“This is supported by a series of memory tests in treated mice, which indicated improved or restored cognitive functions. Acceptance of our IND application and initiation of our clinical program are important steps in validating our approach,” Wallner said.

The Phase 1 trial (NCT03935568) will assess the safety and tolerability of single increasing doses of PU-AD in healthy subjects. The first participant has been dosed. In the future, Samus expects to test multiple ascending doses of PU-AD.

If PU-AD shows good results in the current trial, Samus hopes to initiate a Phase 1b/2a trial to test the therapy in Alzheimer’s patients in the first six months of 2020.

“Testing of an entirely new target deeply implicated in the progression and even initiation of pervasive neurodegenerative diseases is very exciting. I look forward to understanding full potential of new therapies in an area with enormous public health consequences,” said professor Jeffrey Cummings, principal clinical adviser to Samus.

Professor Gabriela Chiosis, co-founder of Samus Therapeutics and a professor at Memorial Sloan Kettering Cancer Center, said: “Targeting epichaperomes represents one of the most novel and exciting new pathways toward finding new treatments for these diseases.”