CSX-1004 Effects on Fentanyl-Induced Respiratory Depression

Overview

Sponsor-declared trial summary

Key facts

Sponsor

Cessation Therapeutics Inc.

Participant type

Patients, Healthy volunteers

Age range

18-64 years

Gender

Male and Female

Therapeutic area

Analytical, Diagnostic and Therapeutic Techniques and Equipment [E] - Anesthesia and Analgesia [E03]

Trial duration

27 Mar 2026 → ongoing

Decision date (initial)

2026-03-20

Transition trial

No

Low-intervention

No

Rare-disease indication

No

Vulnerable population

No

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Prophylaxis

To evaluate the effect of CSX-1004 Injection on fentanyl-induced respiratory depression in healthy adult participants and participants with OUD, as determined by change in isohypercapnic minute ventilation (MV).

Secondary objectives 4

1. To evaluate the effect of CSX-1004 Injection on fentanyl-induced respiratory depression in healthy adult participants and participants with OUD, as determined by the secondary outcome measures.
2. To assess the effect of CSX-1004 Injection on fentanyl-induced subjective and miotic effects.
3. To assess serum CSX-1004 and plasma fentanyl concentrations in healthy adult participants and participants with OUD.
4. To examine the safety and tolerability of CSX-1004 Injection when co-administered with fentanyl.

Conditions and MedDRA coding

Opioid use disorder

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 7

1. Must provide written informed consent prior to the initiation of any protocol-specific procedures.
2. Male and female adults, between 18 and 55 years of age, inclusive.
3. Body mass index (BMI) within 18.0 to 32.0 kg/m², inclusive (minimum weight of at least 50.0 kg).
4. Must be medically stable, as determined by medical history, physical examination, ECG, and vital signs at Screening
5. Negative urine drug screen for fentanyl at Screening.
6. Is willing and able to comply with the study requirements, including clinic confinement and blood sampling.
7. Part B: Diagnosis of mild or moderate opioid use disorder (DSM-5-TR) and self-reported daily opioid use, defined as daily oral MME doses ≥30 to ≤120 mg for at least 3 months.

Exclusion criteria 5

1. History or presence of any clinically significant psychiatric, endocrine, hematologic, hepatic, immunologic, metabolic, urologic, pulmonary, neurologic, dermatologic, renal, or other major disease or illness at Screening.
2. Part A: History of or currently meets the criteria for a diagnosis of substance use disorder according to DSM-5-TR criteria for any substances (excluding caffeine).
3. Part B: Currently meets the criteria for a diagnosis of substance use disorder according to DSM-5-TR criteria for any substances, excluding opioids, caffeine, or nicotine.
4. Part B: History of or currently meets the criteria for a diagnosis of severe opioid use disorder.
5. Requires concomitant treatment with prohibited medications that cannot be safely discontinued prior to first drug administration.

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 1

1. Peak change in MV (absolute and % [L/min]), calculated based on a 1-minute average of the ventilation data of each individual participant.

Secondary endpoints 8

1. Peak change in respiratory rate [breaths/min], oxygen saturation (SpO2), tidal volume [L]
2. Incidence of apnea (≥20 sec loss of respiratory activity)
3. Incidence of oxygen desaturation (<92%)
4. Pupillometry (maximum pupil diameter)
5. Alertness/Drowsiness visual analog scale (VAS) (minimum effect [Emin])
6. Any Drug Effects VAS (maximum effect [Emax])
7. Drug Liking VAS (Emax)
8. High VAS (Emax)

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 1

Placebo 1

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Cessation Therapeutics Inc.

Sponsor organisation

Cessation Therapeutics Inc.

Address

3031 Tisch Way Ste 505

City

San Jose

Postcode

95128-2531

Country

United States

Scientific contact point

Organisation

Cessation Therapeutics Inc.

Contact name

Cessation Therapeutics, Inc.

Public contact point

Organisation

Cessation Therapeutics Inc.

Contact name

Cessation Therapeutics, Inc.

Locations

1 EU/EEA country · 1 investigational sites

By country

Investigational sites

Country notifications

Trial-start, recruitment-start, end and early-termination notifications submitted per Member State

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 11 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

Application history

1 submissions — initial application plus substantial / non-substantial modifications