A Phase 2 Controlled Study of SB206, a Topical Nitric Oxide-Releasing Drug for Extragenital Wart Treatment

October 2018 | Volume 17 | Issue 10 | Original Article | 1100 | Copyright © October 2018

Stephen K. Tyring MD PhD,a Theodore Rosen MD,b Brian Berman MD PhD,c Nathan Stasko PhD,d Todd Durham PhD,d Tomoko Maeda-Chubachi MD PhD MBAd

aUniversity of Texas Health Science Center, Houston, TX bBaylor College of Medicine, Houston, TX cUniversity of Miami Miller School of Medicine, Miami, FL, and Center for Clinical; Cosmetic Research, Aventura, FL dNovan, Inc., Morrisville, NC

BACKGROUND: Nitric oxide (NO), a free radical gas, is endogenously produced in human cells. In high concentration, NO neutralizes many disease-causing microbes. The topical investigational drug SB206 releases NO and has the potential to treat skin diseases caused by viruses. Genital warts (condyloma acuminata) are primarily caused by human papillomavirus (HPV) types 6 and 11. Available treatments have low tolerability and efficacy rates and are inconvenient for the patient. Genital warts can recur if HPV is incompletely eradicated during treatment. OBJECTIVE: Topical SB206 (berdazimer sodium plus carboxymethyl cellulose hydrogel) was assessed for tolerability, safety, and efficacy for up to12 weeks in patients with external genital and/or perianal warts (EGW/PAW) in a phase 2, double-blind, randomized, dose-escalation study. METHODS: Patients (N=108) were randomly assigned to SB206 or vehicle in a 3:1 ratio: SB206 4% once (QD) or twice daily (BID), 8% QD, 12% QD, or corresponding vehicle. Treatment duration was up to 84 days. The primary efficacy endpoint was complete clearance of baseline EGW/PAW at or before week 12. Pearson’s Chi Square tests compared the efficacy of active vs vehicle treatments. Safety was assessed through adverse event and tolerability reports, physical examination findings, and clinical laboratory test results. RESULTS: In the Intent-to-Treat population, the percentage of patients with complete clearance of baseline EGW/PAW at or before week 12 was higher for SB206 groups than for vehicle groups, with the greatest difference between SB206 12% QD (33.3%; P=0.010) and vehicle QD (4.3%). CONCLUSION: Berdazimer sodium (SB206) plus hydrogel was efficacious and well tolerated in the treatment of EGW/PAW. J Drugs Dermatol. 2018;17(10):1100-1105.


Genital warts (condyloma acuminata), mainly caused by human papillomavirus (HPV) types 6 and 11, affect approximately 1% of sexually active adults in the United States and Europe.1,2 More than 1 million new cases of extragenital warts (EGW) and perianal warts (PAW) are diagnosed annually.3,4,5 Although HPV 6 and 11 have low oncogenic potential,6,7,8 other high-risk HPV types may be present concurrently with HPV 6 and 11 and may initiate the development of squamous cell carcinoma.9,3 Even after the successful removal or elimination of EGW/PAW, residual HPV is still a concern as it can lead to recurrence. Existing treatments for EGW/PAW include physician- and patient-applied topical agents, surgery, cryotherapy, laser ablation, and systemic therapy. Topical treatments for EGW/PAW have low tolerability and efficacy rates, and some are inconvenient because they require frequent clinic visits. Although effectiveness varies among EGW/PAW treatments, patients report feeling distressed, embarrassed, and uncomfortable with some treatment options,10 and prefer products they can apply in privacy.11 Of the patient-applied topical treatments, imiquimod has recurrence rates up to 26%12 and is commonly associated with local adverse reactions in the sensitive skin of the genital area, such as, itching, burning, pain, erosions, and the development of vitiligo-like hypopigmentation. Sinecatechin 15% ointment is similar to imiquimod in terms of efficacy, local side effects, and recurrence rates.13 Podophyllotoxin is often irritating and must be washed off 1 to 4 hours after application to avoid systemic absorption.14,15 Trichloroacetic acid is a topical, clinician-applied treatment requiring