Current Clinical Trial Research in Vulvodynia: A Cross-Sectional Study

Objectives: Vulvodynia is an idiopathic, chronic vulvar pain condition that poses a significant challenge to affected women and their partners, resulting in substantial disruptions to the patient’s sexual and psychological well-being. A study by Torres-Cueco, et al., in 2021 estimated that vulvodynia impacts 8-10% of women of all ages in the U.S. Vulvar pain syndromes such as vulvodynia were rarely addressed in the medical literature before the mid-1980s. Developing effective treatments for vulvodynia requires high-quality clinical trials, thus, our primary objective was to examine clinical trials for vulvodynia within the United States National Library of Medicine’s (NLM) clinical trials database (clinicaltrials.gov) to assess the current and upcoming landscape for treatment development.

Methods: A search was performed on 02/15/24 using the National Library of Medicine's clinical trials database to identify interventional trials for vulvodynia that were active or completed after 2014. We then classified the trials based on status, intervention type, trial phase, and trial location. Finally, we reported overall study characteristics from the sample and a more in-depth assessment of trials with reported results within the database.

Results: From the initial 74 trials identified through our search, 28 were excluded due to their lack of relevance to vulvodynia, completion outside of the inclusion criteria date range, or lack of clinical intervention, resulting in a final sample of 46 trials. Of these trials, 25 were completed with only 3 of these trials reporting results on ClinicalTrials.gov. Trials using Behavioral/Cognitive Behavioral Therapy (CBT) interventions accounted for 26.1% of the studies followed by medical devices at 23.9%. Pharmaceutical intervention and alternative therapies each accounted for 21.7%, and 6.5% of studies used a surgical intervention. Of the 16 trials that were ongoing (active or recruiting), 81% were listed as Phase ‘Not Applicable’, 13% were Phase 2, and 6% was Phase 3. Not Applicable describes trials without FDA-defined phases, including trials of devices or behavioral interventions. Finally, trials were predominantly conducted in Canada, with a minority of trials conducted in the US, Europe, and Asia. We found 5 completed trials with results—2 were CBT, 2 were drug trials, and 1 was laser therapy. None of these trials showed a significant change in primary endpoints; though the drug interventions showed high rates of adverse events.

Conclusions: The wide range of trial designs and interventions—which is predominately split between alternative therapy, Behavioral/CBT, and Medical Devices highlights the complex nature of vulvodynia and stresses the importance of considering alternative therapies and behavioral interventions in addition to traditional pharmacologic and procedural treatment methods. This also underscores the difficulty in identifying the physiological cause of vulvodynia, the current lack of efficacious treatment for the condition, and the need for additional research in the area.