A Study to Evaluate the Safety and Pharmacokinetics of Single and Multiple Doses of Prosetin in Healthy Volunteers and Participants With ALS

A Phase 1, Randomized, Double-Blind, Placebo-Controlled Dose Escalating Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of Single Ascending and Multiple Ascending Doses of Prosetin in Healthy Volunteers and Participants With Amyotrophic Lateral Sclerosis (ALS) With an Optional Open-Label Extended Treatment Period for ALS Participants Who Complete 14 Days of Blinded Treatment

The primary purpose of this study is to evaluate the safety and tolerability of prosetin in healthy volunteers and participants with ALS.

PRO-101 is a four-part study. Parts A and B, which respectively evaluated the safety, tolerability, and PK of single and multiple ascending doses of prosetin in 48 healthy volunteers, have been completed.

Parts C and D, which are ongoing, will evaluate the effects of prosetin on safety, tolerability, PK, and biomarkers in 24 participants with ALS. Part C is a double-blind, placebo-controlled, multiple ascending dose component of the study, and Part D is an optional 52-week open-label extension available to ALS participants who complete 14 days of dosing in Part C.

PRO-101, Parts A and B, were completed in healthy volunteers.

PRO-101, Parts C and D are ongoing in participants with ALS. Key eligibility criteria are summarized below:

Key Inclusion Criteria - Part C

• Adults ≥18 years of age
• Diagnosis of ALS based on the Gold Coast diagnostic criteria
• Slow Vital Capacity (SVC) >50% predicted
• If being concomitantly treated with riluzole and/or locally approved standard of care treatments, the participant must be on a stable dose for at least 30 days prior to screening and throughout the study
• In the opinion of the Investigator, participant is able to swallow liquid in order to ingest the study medication.

Key Exclusion Criteria - Part C

• Active dementia, neurologic diseases other than ALS, or psychiatric illness that in the opinion of the investigator would affect participation in the current study.
• Significant history or clinical manifestation of comorbid disease in any organ system that currently requires active treatment or is likely to require treatment during the study.
• Any episodes of vertigo in the previous 12 months prior to screening.
• Any medical history of seizures, or any clinically significant EEG finding at Screening or at Day -1.
• A diagnosis of cancer or evidence of continued disease within five years before screening. Protocol-specified exceptions may be considered with approval from the Sponsor's Medical Monitor.
• Participation in any other investigational study drug trial in which receipt of an investigational study drug occurred within 30 days prior to the first dose of study medication.
• Prior exposure to any stem cell or gene therapies (investigational or off-label) for the treatment of ALS.

Key Inclusion Criteria- Part D

Participants who meet all of the following criteria may be included in Part D of the study:

• Participants must have completed 14 days of blinded treatment in Part C.
• Participants taking approved ALS standard-of-care medications must remain on stable doses through Day 28 of open-label treatment.
• In the judgment of the Investigator, the participant's participation in the open-label portion of the study is medically appropriate

Key Exclusion Criteria- Part D

• Treatment with any other investigational drug or device throughout the duration of the study is excluded, with the exception of any COVID-19 vaccine or treatment with an emergency use authorization.

NOTE: Other protocol-defined Inclusion/Exclusion Criteria may apply. Please contact trials@projenx.com with any questions about eligibility criteria.