Axial Biotherapeutics Clinical Research

Parkinson’s Institute and Clinical Center Trials

Axial Biotherapeutics Safety Study on GI Tolerability and Gut Microbiome for Patients with Parkinson’s Disease

Axial Biotherapeutics

Listen to your gut! Contribute to the science of Parkinson’s disease and GI function. A safety and tolerability study of AB-4166: safety assessment in a subset of subjects with Parkinson’s.

Status: Recruiting

Investigator: Dr. Kristin Andruska, MD, PhD

More information: Contact the Parkinson’s Institute and Clinical Center at (650) 770-0205 or email

Trial Description

Axial Biotherapeutics is conducting this study to assess the tolerability, safety, and effects of AB-4166 on gastrointestinal (GI) function and the gut microbiome in subjects with Parkinson’s. AB-4166 is to be taken over a period of 18 weeks with meals. The study assesses the safety of AB-4166 for management of the gut microbiome, which may support gastrointestinal function in individuals who have an elevated level of certain bacteria in their stool.

Who may be eligible to participate?

Subjects 30 to 85 years of age (inclusive) on a stable therapeutic regimen, have prolonged colonic transit time, and diagnosed with mild-to-moderate Parkinson’s may be eligible. Other inclusion/exclusion criteria apply.

What does participation involve?

This study is comprised of screening, consumption of AB-4166 with meals, and follow-up. Study participants to visit the study site up to 11 times over a maximum duration of 32 weeks (including screening and follow-up visits).

There are no costs or insurance requirements for this study.


The study will assess the safety and tolerability of the ingestion of AB-4166 through typical measures (e.g., safety labs), as well as assessments of GI function (e.g., GI transit time), aspects of motor function, physical and neurological exams, and the microbiome of participants.


Local car transportation to and from the clinic will be provided upon request.




Dr. Kristin Andruska, MD, PhD

More information

Ccontact the Parkinson’s Institute and Clinical Center at (650) 770-0205 or email

Questions about making a donation? Please call (650) 770-0201.

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Parkinson's Institute and Clinical Center
2500 Hospital Drive, Building 10, Suite 1 | Mountain View, CA 94040
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