Dronabinol As an Adjunct for Reducing Pain (DARP)-Texas Children's Hospital

NCT06834997 | Withdrawn Phase 2 DMC FDA Drug

• 1 other identifier: H-56181
• Study Type: interventional
• Target: N/A
• Locations: 1 country
• Sites: 2

Brief Summary

This exploratory, proof-of-concept study is a double-blind (participants and investigators will be blinded), placebo-controlled, randomized, two-arm clinical trial of Marinol \[dronabinol, synthetic Δ9-tetrahydrocannabinol (THC)\] for e endometriosis-associated chronic pelvic pain (endo-CPP) with a 2:1 allocation ratio. Up to 75 subjects will be enrolled in this pilot study and randomized to receive doses of THC (up to 30 mg/day), orally, over 8 weeks. This study will be conducted at a single site; it does not include any stratifications, and there is no interim analysis planned. Notably, the goal is to determine whether there is enough evidence of the safety of THC to support the development of later-phase clinical trials. Thus, detailed developmental plans are contingent on the outcomes of this study.

Conditions

Endometriosis; Endometriosis Related Pain; Endometriosis, Pain

Keywords

Endometriosis Related Pain; Endometriosis

Outcome Measures

Primary Outcomes (2)

• Pain Intensity

  For change in pain intensity from baseline to 8-weeks, the investigators will estimate the mean within each arm using the The Endometriosis Health Profile Questionnaire (EHP-30). 30 point scale ranging from 0 (Never) to 5 (Always).

  Baseline to 8-weeks

• Safety Analysis

  AEs will be coded using the most recent version of the Medical Dictionary of Regulatory Activities (MedDRA) preferred terms and will be grouped by system, organ, and class (SOC) designation. The severity, frequency, and relationship of AEs to investigational product will be presented by preferred term by SOC grouping. Listings of each individual AE including start date, stop date, severity, relationship, outcome, and duration will be provided.

  Baseline to 8-weeks

Secondary Outcomes (4)

• Analgesic Use Log

  Baseline to 8-weeks

• Patient-Reported Outcomes Measurement Information System (PROMIS-29)

  Baseline to 8-weeks

• Profile of Mood States (POMS questionnaire)

  Baseline to 8-weeks

• Visual Pain Scale

  Baseline to 8-weeks

Study Arms (2)

Dronabinol

EXPERIMENTAL

Dronabinol capsules, over-encapsulated with filler to match the appearance of the placebo capsule, up to 15 mg, twice per day for 8 weeks.

Drug: Dronabinol Capsules

Placebo

PLACEBO COMPARATOR

Capsules with placebo (i.e., cellulose filler), twice per day for 8 weeks.

Drug: Placebo

Interventions

Dronabinol Capsules DRUG

Eligible subjects will be randomized (2:1) to dronabinol or placebo, administered orally. The dose of dronabinol will be titrated such that on Day 1, subjects will take 2.5 mg, twice. On subsequent days patients may gradually increase the total number of doses, by one dose each day, as needed and tolerated until either the optimal dose is achieved, or the dose reaches 30 mg THC per day.

Also known as: Marinol, delta-9-tetrahydrocannabinol

Dronabinol

Placebo DRUG

Matching placebo will be prepared and administered in the same manner as the active medication. Titration will occur in a masked fashion such that individuals assigned to placebo undergo a similar perceived titration process.

Placebo

Eligibility Criteria

• Age: 18 Years - 64 Years
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Provision of signed and dated informed consent form.
• Stated willingness to comply with all study procedures and availability for the duration of the study.
• Ability to take oral medication per protocol.
• Female, aged 18-64 years.
• Females aged ≥ 18 years clinically diagnosed with endometriosis meeting one of the following criteria: a. Patients with previous surgical confirmation of endometriosis and a high suspicion of recurrence b. Patients with imaging (MRI or ultrasonography) findings highly suggestive of endometriosis and confirmed after surgery.
• Has chronic endometriosis pain that has persisted at least 3 months and has resulted in pain as determined by the Endometriosis Health Profile Questionnaire (EHP-30).
• For females of reproductive potential: currently practicing an effective form of two types of birth control, which are defined as those, alone or in combination, that result in a low failure rate (i.e., less than 1% per year) when used consistently and correctly, for at least 1 month prior to screening and agrees to use such a method during study participation and for an additional 4 weeks after the end of study medication administration unless she is surgically sterile, partner is surgically sterile, or she is postmenopausal (one year): a. contraceptive sponge, b. patch, c. double barrier (diaphragm/spermicidal or condom/spermicidal), d. intrauterine contraceptive system, e etonogestrel implant, f. medroxyprogesterone acetate contraceptive injection, g. complete abstinence from sexual intercourse, and/or hormonal vaginal contraceptive ring.
• Patients using oral contraceptives, vaginal ring for contraception and/or management of endometriosis, can be included if both they and their primary provider agree to stopping their medication and transitioning to dronabinol (THC) as the primary treatment of endometriosis throughout the study period
• Agreement to adhere to Lifestyle Considerations (see section 5.3) throughout study duration.
• On a stable pain treatment (pharmacological or otherwise) for ≥3 months at the time of the screening and agree to refrain from adding new analgesic medications or increasing their current dose of analgesic medications for the duration of the study.
• Due to the inability to translate patient facing documents into various languages the investigators will only recruit English speaking participants

You may not qualify if:

• Current and unwilling to stop use of cannabis/marijuana and any other cannabinoids (CBD), including over the counter CBD products.
• Known allergic reactions to cannabis, CBD, THC, or components of the study interventions.
• Have Blood Urea Nitrogen or Creatinine levels outside the normal range, or other clinically significant laboratory abnormalities
• Current use of automated external defibrillator (AED)
• Chronic daily opioid use and any chronic pain or frequently reoccurring pain condition, other than endometriosis, that is treated with opioids for \> 14 days per month
• Women with a BMI \> 35 kg/m2
• Current use of barbiturates, benzodiazepines, ethanol, lithium, buspirone, muscle relaxants which in the opinion of the P.I. and/or the admitting clinician would preclude the safe and/or successful completion of the study.
• Current use of amphetamines, other sympathomimetic agents, atropine, amoxapine, scopolamine, antihistamines, other anticholinergic agents, amitriptyline, or desipramine, within 3 months of randomization
• Treatment with another investigational drug or other intervention within 3 months of the screening visit.
• Pregnancy, plans to become pregnant, or lactation.
• Any interventional pain procedures within 6 weeks prior to screening or at any point during study enrollment.
• Surgical intervention or introduction/increased dose of an opioid or analgesic regimen at any point during study enrollment
• Implanted spinal cord or dorsal root ganglion stimulator for pain treatment.
• Meets DSM-V criteria for a current major psychiatric illness, such as bipolar disorder, or psychosis which in the opinion of the P.I. and/or the admitting clinician would preclude the safe and/or successful completion of the study.
• Have a history of substance abuse or dependence which in the opinion of the P.I. and/or the admitting clinician would preclude the safe and/or successful completion of the study.

Sponsors & Collaborators

• Baylor College of Medicine: lead

Study Sites (2)

Baylor College of Medicine

Hosuton, Texas, 77030, United States

Location

Michael E DeBakey VA Medical Center

Houston, Texas, 77030, United States

Location

Related Publications (1)

• Fitzcharles MA, Baerwald C, Ablin J, Hauser W. Efficacy, tolerability and safety of cannabinoids in chronic pain associated with rheumatic diseases (fibromyalgia syndrome, back pain, osteoarthritis, rheumatoid arthritis): A systematic review of randomized controlled trials. Schmerz. 2016 Feb;30(1):47-61. doi: 10.1007/s00482-015-0084-3.

  PMID: 26767993 BACKGROUND

MeSH Terms

Conditions

Endometriosis; Pain

Interventions

Dronabinol

Condition Hierarchy (Ancestors)

Genital Diseases, Female; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Genital Diseases; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Cannabinoids; Terpenes; Hydrocarbons; Organic Chemicals

Study Officials

• Christopher Verrico, PhD in Pharmacology

  Baylor College of Medicine

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Model Details: Randomized, Double-Blind, Placebo-Controlled, Parallel Groups

Study Record Dates

• First Submitted: February 10, 2025
• First Posted: February 19, 2025
• Study Start: April 1, 2026
• Primary Completion (Estimated): March 1, 2028
• Study Completion (Estimated): December 30, 2028
• Last Updated: March 13, 2026

Record last verified: 2026-02

Locations

US (2)