NCT06834997

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

A Randomized, Double-Blind, Placebo-Controlled, Parallel Groups Study to Explore The Safety And Therapeutic Potential Of Cannabinoids As An Adjunct For Reducing Pain (Carp)- TCH

• Status: Withdrawn
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 0 (actual)
• Sponsor: Baylor College of Medicine · Academic / Other
• Sex: Female
• Age: 18 Years – 64 Years
• Healthy volunteers: Not accepted

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.

Detailed description

Endometriosis is a progressive, chronic inflammatory disorder that affects approximately 10% of women of reproductive age, with up to 70% to 90% of patients experiencing pelvic pain symptoms, thereby reducing their quality of life, and decreasing labor productivity. Current standard treatments for endometriosis-associated chronic pelvic pain (endo-CPP) include progestin-based hormonal treatments, such as combined oral contraceptive (OC) pills, gonadotropin-releasing hormone (GnRH) analogs, and laparoscopic surgeries. However, endo-CPP often persists even after laparoscopic excision of endometriosis lesions, indicating that controlling disease progression does not necessarily lead to pain relief. As pain is an important factor in endometriosis, optimal analgesia should be sought, which, to date, has primarily been treated with non-steroidal anti-inflammatory drugs (NSAIDs), metamizole, or, in extreme cases, opioids. However, the response to NSAIDs is often ineffective. Additionally, NSAIDs are associated with a higher risk of gastrointestinal bleeding. As for metamizole, agranulocytosis is the most notorious adverse event, along with metamizole-associated hepatotoxicity. Although opioids are generally not recommended for pain relief in women with endometriosis, opioid prescriptions have been identified for women diagnosed with endometriosis within the past year in the United States (As-Sanie S, 2021). Patients undergoing robotic surgery for endometriosis use over two times as many opioids postoperatively as patients without endometriosis and experience higher perceived postoperative pain. Women with endometriosis have a four-fold greater risk of chronic opioid use compared to those without endometriosis. Opioids are highly addictive, and the use of both synthetic and natural opioids can quickly result in dependence, which includes physical and/or psychological dependence, as well as opioid use disorder. Side effects of opioid medications are generally dose-dependent and include constipation, miosis, sedation, and respiratory depression. However, the efficacy of THC in endo-CPP remains uncertain.

Conditions

• Endometriosis
• Endometriosis Related Pain
• Endometriosis, Pain

Interventions

Type	Name	Description
DRUG	Dronabinol Capsules	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.
DRUG	Placebo	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.

Timeline

• Start date: 2026-04-01
• Primary completion: 2028-03-01
• Completion: 2028-12-30
• First posted: 2025-02-19
• Last updated: 2026-03-13

Locations

2 sites across 1 country: United States

Regulatory

• FDA-regulated drug study