ENX-205 SAD/PET Study in Healthy Adults

A Two-Part, Single Ascending Dose and Positron Emission Tomography Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Receptor Occupancy After Single Oral Dose Administration of ENX-205 in Healthy Adult Participants

This is a two-part study designed to evaluate the safety, tolerability, pharmacokinetics (PK), and receptor occupancy (RO) of ENX-205 in healthy adult participants in a double-blind placebo-controlled, single ascending dose (SAD) study (Part 1) and an open-label, single-dose, positron emission tomography (PET) study (Part 2).

Study Overview

• Status: Completed
• Conditions: Healthy Volunteer
• Intervention / Treatment: Drug: Placebo; Drug: ENX-205

• Study Type: Interventional
• Enrollment (Actual): 59
• Phase: Phase 1

Contacts and Locations

Study Locations

• United Kingdom
  • Middlesex
    • London, Middlesex, United Kingdom, HA1 3UJ
      • Parexel London EPCU

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Biologically female participants who are not pregnant, lactating, or breastfeeding

  1. Of non-childbearing potential, defined as either permanently sterilized, and with a negative pregnancy test. OR
  2. Part 1 only: Of childbearing potential and willing to comply with restrictions related to birth control, and with a negative pregnancy test.
• Biologically male participants (defined as assigned male at birth), if fertile must be willing to comply with restrictions related to birth control. Moreover, male participants should refrain from sperm donation.

Exclusion Criteria:

• Unable or unwilling to comply with the requirements of the study or, in the opinion of the Investigator or Sponsor, should not participate in the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo	Drug: Placebo; oral solution
Experimental: ENX-205	Drug: ENX-205; oral solution

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Part 1: Number of Participants with Treatment Emergent Adverse events	From Day 1 up to Day 10

Secondary Outcome Measures

Outcome Measure	Time Frame
Part 2: Number of Participants with Treatment Emergent Adverse events	From Day 1 up to Day 10

Collaborators and Investigators

• Sponsor: Engrail Therapeutics INC
• Investigators: Principal Investigator: David George Steel, MBChB, Parexel

Study record dates

Study Major Dates

• Study Start (Actual): March 23, 2025
• Primary Completion (Actual): May 7, 2026
• Study Completion (Actual): May 7, 2026

Study Registration Dates

• First Submitted: November 19, 2025
• First Submitted That Met QC Criteria: November 19, 2025
• First Posted (Actual): November 28, 2025

Study Record Updates

• Last Update Posted (Actual): May 28, 2026
• Last Update Submitted That Met QC Criteria: May 26, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: ENX-205-001; 1011367 (Other Identifier: IRAS ID)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No