(083) Baseline Characteristics of Participants in a Multicenter Randomized Clinical Trial of Vestibulodynia: Understanding Pathophysiology and Determining Appropriate Treatments (Vestibulodynia: UPDATe)
Authors: Cutting H , Farb D , Rapkin A , Carey E , Geller E , Nackley A , Akaninwor J , Stirling C , Borstov A , Mcnultry S , Merrill P , Zakroysky P , Luo S , Delarosa J 
Published: May 2023

Abstract

Introduction
Vestibulodynia (VBD) is a common cause of sexual pain that affects ~14 million women in the United States. Many different therapies are used on a trial-and-error basis which can delay effective care. Two distinct VBD subtypes may benefit from different types of treatment: 1) VBD peripheral (VBD-p) - pain localized to the vulvar vestibule and 2) VBD central (VBD-c) - VBD and &gt;1 chronic overlapping pain condition(s) affecting remote body regions. Thus, we are evaluating the efficacy of peripheral, central, and combined treatments for VBD-p vs VBD-c. We will also evaluate cytokine and microRNA biomarkers to help determine pathophysiology and predict treatment response.

Objective
To describe the design and present baseline participant characteristics of our ongoing RCT for VBD.

Methods
This is a multi-site randomized, double-blind trial that will enroll participants to one of four parallel arms: 1) peripheral treatment with 5% lidocaine/0.5 mg/ml 0.02% estradiol compound cream and placebo pills, 2) central treatment with tricyclic antidepressant nortriptyline pills and placebo cream, 3) lidocaine/estrogen cream and nortriptyline pills, or 4) placebo cream and placebo pills. The treatment phase will last 16 weeks, with clinical outcome measures and biomarkers assessed at 4 time points (0, 8, 16, and 24 weeks). We will enroll 400 women 18-50 years who report tenderness at the vulvar vestibule and report &gt;3/10 pain with tampon insertion on a numeric rating scale (NRS). Primary outcome is pain with tampon test. Secondary outcomes include self-reported pain on the McGill Pain Questionnaire, psychosocial measures, pressure pain thresholds (PPTs) measured at the vaginal vestibule, levator ani muscles, and remote body sites, and levels of cytokines and microRNAs in local vaginal and circulating blood samples using multiplex assays and RNA sequencing to determine the ability of these biomarkers to predict treatment response.

Results
So far 135 subjects have enrolled and 78 of these have completed the study. Enrollment remains open, with 27 subjects active and 30 subjects discontinued. Mean (range) age is 26.9 (18-48) years and body mass index is 23.7 (16-37). Self-disclosed racial identity of subjects is: White (67.4%), Asian (14.1%), Multiracial (9.6%), Black (8.9%), with 14.8% of subjects identifying as Hispanic or Latino. Of the enrolled subjects, 94/135 (69.6%) subjects are categorized VBD-c, and 41/135 (30.4%) are categorized VBD-p. Of those categorized as VBD-c, fibromyalgia syndrome (39.3%), endometriosis (34.1%), back pain (25.20%), irritable bowel syndrome (19.3%), chronic headaches (16.3%), temporomandibular disorder (11.1%), interstitial cystitis (10.4%) and chronic fatigue syndrome (1.5%) have been reported. At baseline visit, subjects report an average tampon test score of 4.2 (□ 2.11) and 93.3% of subjects report pain during vaginal intercourse.

Conclusions
We have launched a multicenter randomized trial to evaluate the efficacy of peripherally and centrally acting medications used for treating unique VBD subtypes based on distinct clinical and biological signatures. We hope to advance our knowledge of the pathophysiologic mechanisms underlying VBD-p and VBD-c, determine the efficacy of peripheral, central, and combined therapies in alleviating pain in women with VBD-p and VBD-c, and identify biomarkers that predict treatment response.

Disclosure
No