Recruiting
Phase 2

CS-1103 with Fentanyl

Sponsor:

Clear Scientific, Inc.

Code:

NCT07459166

Conditions

Fentanyl Overdose

Fentanyl Poisoning

Eligibility Criteria

Sex: All

Age: 18 - 55

Healthy Volunteers: Accepted

Interventions

Naloxone Hydrochloride

Fentanyl

Sterile Saline

CS-1103

Study Details

Brief summary:

The purpose of the study is to evaluate the safety, tolerability, pharmacokinetics, and efficacy of CS-1103 (1,000 mg), given by intravenous (IV) infusion in healthy participants in the presence of a clinically relevant dose of fentanyl (200 μg, IV), with naloxone blockade (400 μg, IV).

Conditions

Fentanyl Overdose

Fentanyl Poisoning

Study ID

NCT07459166

Start date

May 28, 2026

Status verified date

Aug, 2026

Completion date

Oct, 2026

Anticipated

Primary completion date

Jul 22, 2026

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 55

Healthy Volunteers: Accepted

Major Inclusion Criteria:

1. Healthy participants aged 18 to 55 years, inclusive;
2. Have prior experience with opioids, such as from a dental procedure, chronic pain management, or previous inpatient surgical procedure;
3. A body mass index between 18.0 to 30.0 kg/m2, inclusive, and a minimum body weight of 56 kg;
4. Females must not be lactating and must have a negative pregnancy test during screening and admission.

Major Exclusion Criteria:

1. Estimated glomerular filtration rate <90 mL/min/1.73 m2;
2. History of cardiovascular disease;
3. History of any clinically important disease or disorder which, in the opinion of the Investigator, may interfere with safe study participation.

Study Design

Enrollment

16 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

placebo comparator: Placebo

Participants receive naloxone blockade (400 μg, IV), followed by fentanyl (200 μg, IV), followed by placebo (saline).

active comparator: Active

Participants receive naloxone blockade (400 μg, IV), followed by fentanyl (200 μg, IV), followed by CS-1103 (1,000 mg, IV).

Interventions

Naloxone Hydrochloride

Naloxone for intravenous administration

Fentanyl

Fentanyl for intravenous administration

Sterile Saline

Sterile Saline for intravenous administration

CS-1103

CS-1103 for intravenous administration

Primary outcome measure

  • Number of participants with CS-1103-related adverse events (AEs) assessed by physical examinations [ Time Frame: 3 days plus follow-up on Day 10 ]
  • Number of participants with CS-1103-related adverse events (AEs) assessed by electrocardiograms (ECGs) [ Time Frame: 3 days plus follow-up on Day 10 ]
  • Number of participants with CS-1103-related adverse events (AEs) assessed by vital signs [ Time Frame: 3 days plus follow-up on Day 10 ]
  • Number of participants with CS-1103-related adverse events (AEs) assessed by laboratory parameters [ Time Frame: 3 days plus follow-up on Day 10 ]
  • Time course of CS-1103 blood and urine concentrations [ Time Frame: 48 hours ]
  • Time course and magnitude of urine excretion of fentanyl [ Time Frame: 48 hours ]

Central Contacts and Locations

Central contacts

Anna Del Rosario, B.S.

617-621-8500adelrosario@clearsci.com

Piercen Oliver, Ph.D.

617-621-8500poliver@clearsci.com

Locations

California Clinical Trials Medical Group

Recruiting

Glendale, California, United States, 91206

Contacts

Lev Gertsik, M.D.

888-228-7425study.losangeles@parexel.com

More Information

Sponsor

Clear Scientific, Inc.

Last update posted

Aug 24, 2026

Last verified

Aug, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Clear Scientific, Inc. on 2026-08-24.