Drug-drug Interaction Study of Clemizole (EPX-100) in Healthy Participants

A Phase 1, 3-Part Study to Evaluate the Effect of CYP3A4 Inhibition and Induction on the Pharmacokinetics of Clemizole and the Effect of Clemizole on the Pharmacokinetics of CYP2C19, CYP3A4, and CYP2B6 Substrates in Healthy Participants

This is a 3-part, drug-drug interaction study in healthy participants. Each part is designed as a 2-period, fixed-sequence and can be conducted concurrently.

Part 1 will assess the effect of itraconazole on the pharmacokinetics (PK) of EPX-100. Part 2 will assess the effect of phenytoin on the PK of EPX-100. Part 3 will assess the effect of EPX-100 on the PK of omeprazole, midazolam, and bupropion.

Study Overview

• Status: Completed
• Conditions: Drug Drug Interaction
• Intervention / Treatment: Drug: Itraconazole; Drug: EPX-100; Drug: Phenytoin; Drug: Omeprazole; Drug: Midazolam; Drug: Bupropion

• Study Type: Interventional
• Enrollment (Actual): 54
• Phase: Phase 1

Contacts and Locations

Study Locations

• United States
  • Arizona
    • Tempe, Arizona, United States, 85283
      • Celerion

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Healthy, adult, male or female, 18-55 years of age, inclusive, at the screening visit
• Continuous non-smoker who has not used nicotine- and tobacco-containing products for at least 3 months prior to the first dosing.
• Body mass index ≥18.0 and ≤32.0 kilograms per square meter(kg/m^2) within 28 days prior to first dosing.

Exclusion Criteria:

• Is mentally or legally incapacitated or has significant emotional problems at the time of the screening visit or expected during the conduct of the study.
• History or presence of clinically significant medical or psychiatric condition or disease in the opinion of the Investigator or designee.
• History of any illness that, in the opinion of the Investigator or designee, might confound the results of the study or poses an additional risk to the participant by their participation in the study.

Note: Additional inclusion/exclusion criteria may apply, per protocol

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Part 1 - Itraconazole; Treatment A (Period 1): EPX-100 on Day 1. Treatment B (Period 2): itraconazole twice daily (BID) on Day 1; then once daily (QD) on Days 2-5, with EPX-100 administered approximately 2 hours after itraconazole dosing on Day 5.	Drug: Itraconazole; Oral solution; Drug: EPX-100; Oral solution; Other Names: Clemizole hydrochloride
Experimental: Part 2 - Phenytoin; Treatment C (Period 1): EPX-100 on Day 1. Treatment D (Period 2): phenytoin three times daily (TID) on Days 1 to Day 14, with EPX-100 coadministered on the morning of Day 14.	Drug: EPX-100; Oral solution; Other Names: Clemizole hydrochloride; Drug: Phenytoin; Phenytoin sodium extended-release capsules
Experimental: Part 3 - Omeprazole, Midazolam, and Bupropion; Treatment E (Period 1): omeprazole on Day 1; midazolam on Day 2; bupropion on Day 3. Treatment F (Period 2): EPX-100 BID on Days 1-18 with omeprazole coadministered on the morning of Day 12; midazolam coadministered on the morning of Day 14; bupropion coadministered on the morning of Day 15.	Drug: EPX-100; Oral solution; Other Names: Clemizole hydrochloride; Drug: Omeprazole; Delayed-release capsule; Drug: Midazolam; Midazolam hydrochloride (HCl) syrup; Drug: Bupropion; Bupropion HCl tablets

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Area Under The Concentration-time Curve (AUC), from Time 0 to the Last Observed Non-zero Concentration (AUC0-t) Of EPX-100	Up to Day 15
AUC From Time 0 extrapolated to infinity (AUC0-inf) of EPX-100	Up to Day 15
Maximum Observed Concentration (Cmax) of EPX-100	Up to Day 15
AUC0-t of Omeprazole	Up to Day 15
AUC0-inf of Omeprazole	Up to Day 15
Cmax of Omeprazole	Up to Day 15
AUC0-t of Midazolam	Up to Day 15
AUC0-inf of Midazolam	Up to Day 15
Cmax of Midazolam	Up to Day 15
AUC0-t of Bupropion	Up to Day 19
AUC0-inf of Bupropion	Up to Day 19
Cmax of Bupropion	Up to Day 19

Secondary Outcome Measures

Outcome Measure	Time Frame
Number of Participants with Treatment Emergent Adverse Events	Up to 12 Weeks

Collaborators and Investigators

• Sponsor: Epygenix
• Collaborators: Harmony Biosciences Management, Inc.
• Investigators: Study Director: Amit Ray, MD, MBA, FAES, FAAN, Epygenix

Study record dates

Study Major Dates

• Study Start (Actual): January 15, 2025
• Primary Completion (Actual): April 3, 2025
• Study Completion (Actual): April 3, 2025

Study Registration Dates

• First Submitted: September 11, 2026
• First Submitted That Met QC Criteria: September 11, 2026
• First Posted (Actual): September 17, 2026

Study Record Updates

• Last Update Posted (Actual): September 17, 2026
• Last Update Submitted That Met QC Criteria: September 11, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Keywords: Healthy Volunteers
• Additional Relevant MeSH Terms: 2-Pyridinylmethylsulfinylbenzimidazoles; Sulfoxides; Sulfur Compounds; Organic Chemicals; Pyridines; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Benzimidazoles; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Azoles; Imidazoles; Benzazepines; Benzodiazepines; Triazoles; Ketones; Piperazines; Propiophenones; Hydantoins; Imidazolidines; Midazolam; Omeprazole; Bupropion; Itraconazole; Phenytoin
• Other Study ID Numbers: EPX-100-CL-101

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