Assisting Smokers to Switch to an e-Cigarette by Accelerating Learning of Adaptive Habits Using D-cycloserine

NCT05994703 | Completed Phase 2 FDA Drug

• 1 other identifier: CYCLE
• Study Type: interventional
• Target: 25
• Locations: 1 country
• Sites: 2

Brief Summary

This study will evaluate the effects of a reward devaluation strategy, which has been researched in the past, combined/augmented with the medication d-cycloserine in assisting smokers to switch from combustible cigarette (CC) to Juul.

Conditions

Smoking Cessation; Harm Reduction

Outcome Measures

Primary Outcomes (2)

• Smoking Abstinence based on Self-Report

  Complete switching from combustible cigarette use at each time point will be defined by a self-report of no cigarette smoking (not even a puff) since the prior session.

  During weeks 3-6 and 9-12 post-switching date.

• Smoking Abstinence based on Expired Air Carbon Monoxide (CO)

  Complete switching from combustible cigarette use at each time point will be confirmed by an expired air CO reading of less than 5 ppm.

  End of Week 6, End of Week 12

Secondary Outcomes (3)

• Reduction in Cigarettes Per Day

  Week 6, Week 12, Six-Month Follow-Up

• Reduction in Expired Air Carbon Monoxide (CO)

  End of Week 6, End of Week 12

• Change in rewarding effects for cigarettes and e-cigarettes at 6 weeks post switch

  End of Week 6

Other Outcomes (1)

• Tolerability of daily use of D-cycloserine in conjunction with Juul

  Week 2, Week 6, Week 8, Week 12

Study Arms (1)

DCS with Juul e-cigarette

EXPERIMENTAL

d-cycloserine (DCS) 100 mg taken orally, once a day for six weeks. There will be a 50 mg dose taken the afternoon/evening prior to the first switch date (after enrollment) to ensure serum levels of the medication are available for the first switch to e-cigarette attempt. Participants will be instructed to use the Juul as often as they like during the 12 week period, and to switch completely to the Juul within 1 week. If, however, they do smoke any combustible cigarettes (CC), they will also be instructed to use the Juul immediately before each CC to relieve their craving as much as possible before smoking their usual brand. The Juul will also be the first product that they are instructed to use each morning. Smokers will be told to try to completely substitute Juul for CCs by the end of the first week of use.

Drug: d-cycloserine; Other: Juul e-cigarette

Interventions

d-cycloserine DRUG

d-cycloserine (DCS) 100 mg taken orally, once a day for six weeks.

DCS with Juul e-cigarette

Juul e-cigarette OTHER

Juul use as often as the participant likes for 12 weeks.

DCS with Juul e-cigarette

Eligibility Criteria

• Age: 22 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Has signed the informed consent form (ICF) and is able to understand the information provided in the ICF.
• Is 22 to 65 years of age (inclusive) at screening.
• Smokes ≥ 10 commercially available CCs per day (no brand restrictions), for the last 12 months.
• Expired air CO reading of at least 10 ppm as assessed at the screening session.
• Interested in switching to an electronic cigarette.
• Willing and able to comply with the requirements of the study.
• Owns a smart phone with text message and data capabilities compatible with necessary surveys.

You may not qualify if:

• Is unhealthy or cannot participate in the study for any reason (e.g., medical, psychiatric, and/or social reason) as judged by the Investigator or designated medical staff based on all available assessments from the screening period (e.g., safety laboratory, vital signs, physical examination, ECG, concomitant medications and medical history).
• Patient Health Questionnaire (PHQ-9) score greater than 9, or a score greater than 0 on item #9 ("Thoughts that you would be better off dead, or of hurting yourself in some way") at screening.
• Planned use of an FDA-approved smoking cessation product during the study.
• High Blood Pressure (systolic \>150 mm Hg, diastolic \>95 mm Hg) at screening.
• Body mass index (BMI) less than 15.0 kg/m2 or greater than 40.0 kg/m2.
• Coronary heart disease, structural cardiac disease (including, but not limited to valvular heart disease or cardiac murmurs), cardiac dysrhythmias, syncope, cardiac chest pain, or history of heart attack or heart failure.
• Has received psychotherapy or behavioral treatments within 30 days of screening, or during the study.
• Taking antidepressants or psychoactive medications (e.g., antipsychotics, antidepressants, benzodiazepines, hypnotics).
• Use of any of these products in the past 30 days:
• Illegal drugs (or if the urine drug screen is positive for cocaine, tetrahydrocannabinol (THC), amphetamines, methamphetamines, or opiates);
• Experimental (investigational) drugs that are unknown to participant;
• Chronic opiate use;
• Medications to treat tuberculosis (e.g., isoniazid, ethionamide).
• Use of smokeless tobacco (chewing tobacco, snuff), cigars (except for "Black \& Mild" cigars or Cigarillos), pipes, hookah, e-cigarettes, nicotine replacement therapy or other smoking cessation treatments within 14 days of screening.
• Pregnant or nursing (by self-report) or positive pregnancy test.

Sponsors & Collaborators

• Rose Research Center, LLC: lead
• Foundation for a Smoke Free World INC: collaborator

Study Sites (2)

Rose Research Center

Charlotte, North Carolina, 28262, United States

Location

Rose Research Center

Raleigh, North Carolina, 27617, United States

Location

MeSH Terms

Conditions

Smoking Cessation; Harm Reduction

Interventions

Cycloserine

Condition Hierarchy (Ancestors)

Health Behavior; Behavior

Intervention Hierarchy (Ancestors)

Isoxazoles; Azoles; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Oxazolidinones; Oxazoles; Serine; Amino Acids, Neutral; Amino Acids; Amino Acids, Peptides, and Proteins

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 24, 2023
• First Posted: August 16, 2023
• Study Start: October 20, 2023
• Primary Completion: October 13, 2025
• Study Completion: January 12, 2026
• Last Updated: January 20, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

US (2)