A Single-Dose Study to Evaluate Safety and Efficacy of CS-1103 in Participants Receiving a Single Dose of Methamphetamine

A Phase 2 Single-Dose Study to Evaluate Safety and Efficacy of CS-1103 in Participants With Methamphetamine Use Disorder Not Seeking Treatment Receiving a Single Dose of Methamphetamine

The purpose of the study is to evaluate the safety, efficacy, and pharmacokinetics of four single, increasing doses of CS-1103, given by intravenous (IV) infusion in otherwise healthy, non-treatment seeking participants with methamphetamine use disorder in the presence of a clinically relevant dose of methamphetamine HCl (30 mg IV).

Study Overview

• Status: Recruiting
• Conditions: Methamphetamine Abuse; Methamphetamine Disorders; Methamphetamine Intoxication
• Intervention / Treatment: Drug: Methamphetamine; Drug: Sterile Saline; Drug: CS-1103

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Piercen Oliver, Ph.D.; Phone Number: 617-621-8500; Email: poliver@clearsci.com
• Study Contact Backup: Name: Anna Del Rosario, B.S.; Phone Number: 617-621-8500; Email: adelrosario@clearsci.com

Study Locations

• United States
  • California
    • Glendale, California, United States, 91206
      • Recruiting
      • California Clinical Trials Medical Group
      • Contact: Lev Gertsik, M.D.; Phone Number: 888-228-7425; Email: study.losangeles@parexel.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Major Inclusion Criteria:

1. Healthy participants aged 18 to 55 years, inclusive;
2. Meets DSM-5 criteria for methamphetamine use disorder;
3. Not seeking treatment for methamphetamine use disorder;
4. Primary route of methamphetamine self-administration must be intravenous or smoking;
5. Able to abstain from methamphetamine without experiencing severe withdrawal;
6. A body mass index between 18 to 30 kg/m2, inclusive and a minimum body weight of 50 kg;
7. Females must not be lactating and must have a negative pregnancy test during screening and admission.

Major Exclusion Criteria:

1. Estimated glomerular filtration rate <60 mL/min/1.73 m2;
2. History of cardiovascular disease;
3. Current moderate to severe use disorder for alcohol, cannabis, cocaine, opioids, or benzodiazepines;
4. History of any clinically important disease or disorder which, in the opinion of the Investigator, may interfere with safe study participation.

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
Placebo Comparator: Placebo; Participants receive methamphetamine HCl (30 mg) followed by placebo (saline).	Drug: Methamphetamine; Methamphetamine HCl for intravenous administration; Drug: Sterile Saline; Sterile Saline for intravenous administration
Active Comparator: Active; Participants receive methamphetamine HCl (30 mg) followed by one of four doses of CS-1103	Drug: Methamphetamine; Methamphetamine HCl for intravenous administration; Drug: CS-1103; CS-1103 for intravenous administration

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of participants with CS-1103-related adverse events (AEs) assessed by physical examinations	Physical examinations	3 days plus follow-up on Day 10
Number of participants with CS-1103-related adverse events (AEs) assessed by electrocardiograms (ECGs)	Digital 12-lead electrocardiograms (ECGs). Any correlation between CS-1103 plasma concentrations and changes in QT intervals will be noted.	3 days plus follow-up on Day 10
Number of participants with CS-1103-related adverse events (AEs) assessed by vital signs	Blood pressure, pulse rate, respiratory rate, oxygen saturation, and body temperature	3 days plus follow-up on Day 10
Number of participants with CS-1103-related adverse events (AEs) assessed by laboratory parameters	Clinical chemistry, hematology, coagulation, and urinalysis	3 days plus follow-up on Day 10
Time course and magnitude of urine excretion of methamphetamine	Measurement of concentration of methamphetamine in urine	48 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time course of CS-1103 blood and urine concentrations	Measurement of plasma and urine concentrations of CS-1103	48 hours

Collaborators and Investigators

• Sponsor: Clear Scientific, Inc.
• Collaborators: National Institute on Drug Abuse (NIDA)
• Investigators: Principal Investigator: Xinhua Li, Ph.D., Clear Scientific, Inc.

Study record dates

Study Major Dates

• Study Start (Estimated): February 5, 2026
• Primary Completion (Estimated): September 4, 2026
• Study Completion (Estimated): September 11, 2026

Study Registration Dates

• First Submitted: December 3, 2024
• First Submitted That Met QC Criteria: December 3, 2024
• First Posted (Actual): December 6, 2024

Study Record Updates

• Last Update Posted (Estimated): January 12, 2026
• Last Update Submitted That Met QC Criteria: January 9, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Organic Chemicals; Amines; Phenethylamines; Ethylamines; Amphetamines; Methamphetamine
• Other Study ID Numbers: CS-1103-02; 5U01DA058548-02 (U.S. NIH Grant/Contract)

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