Phase 1 Study of PRX019 in Healthy Adult Volunteers

A Phase 1, Randomized, Double-Blind, Sponsor-Open, Placebo Controlled, First In Human Study to Evaluate the Safety, Tolerability, Immunogenicity, and Pharmacokinetics of Single Ascending and Multiple Doses of PRX019 in Healthy Adults

The purpose of this study is to assess the safety and tolerability of PRX019 in healthy adult participants.

Study Overview

• Status: Completed
• Conditions: Healthy Participants Study
• Intervention / Treatment: Drug: Placebo; Drug: PRX019

• Study Type: Interventional
• Enrollment (Actual): 50
• Phase: Phase 1

Contacts and Locations

Study Locations

• United States
  • California
    • Los Alamitos, California, United States, 90720
      • Local Institution

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Male and female participants who are healthy as determined by the investigator based on review of medical history, physical examination, and clinical laboratory tests obtained during the screening period
• Participant is willing and able to adhere to the study visit schedule and other protocol requirements

Exclusion Criteria:

• Evidence of organ dysfunction or any clinically significant deviation from normal in physical examination, vital signs, or clinical laboratory tests beyond what is consistent with a healthy population in the region in which the study is conducted
• Participant was exposed to an investigational drug (new chemical entity) within 90 days preceding the first dose administration, or within 7 times the elimination half-life, if known (whichever is longer)

NOTE: Other protocol-defined inclusion/exclusion criteria apply

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Sequential Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: PRX019, single dose; Specified dose on specified days	Drug: Placebo; Placebo; Drug: PRX019; Specified dose on specified days
Experimental: PRX019, multiple dose; Specified dose on specified days	Drug: Placebo; Placebo; Drug: PRX019; Specified dose on specified days

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Number of participants with adverse events	Up to 6 months
Number of participants with clinical laboratory assessment abnormalities	Up to 6 months

Secondary Outcome Measures

Outcome Measure	Time Frame
Maximum observed plasma concentration (Cmax)	Up to 6 months
Time to the maximum measured plasma concentration (Tmax)	Up to 6 months
Area under the concentration-time curve from time 0 through the intended dosing interval (AUCͳ)	Up to 6 months
Terminal elimination half-life in plasma (t1/2)	Up to 6 months
Maximum observed plasma concentration at steady state (Cmax,ss)	Up to 6 months
Area under the concentration-time curve from time 0 through the intended dosing interval at steady state (AUCͳ,ss)	Up to 6 months

Collaborators and Investigators

• Sponsor: Prothena Biosciences Ltd.
• Investigators: Study Director: Chad Swanson, Prothena Biosciences

Study record dates

Study Major Dates

• Study Start (Actual): November 8, 2024
• Primary Completion (Actual): January 16, 2026
• Study Completion (Actual): January 16, 2026

Study Registration Dates

• First Submitted: October 28, 2024
• First Submitted That Met QC Criteria: November 19, 2024
• First Posted (Actual): November 21, 2024

Study Record Updates

• Last Update Posted (Actual): May 14, 2026
• Last Update Submitted That Met QC Criteria: May 11, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: PRX019-101

Plan for Individual participant data (IPD)

• IPD Plan Description: Prothena will provide access to individual anonymized participant data upon request from qualified researchers, and subject to certain criteria.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No