Results of a Phase 2, Randomized,Vehicle-Controlled Study Evaluating the Efficacy,Tolerability, and Safety of Daily or Twice Daily SB204 for the Treatment of Acne Vulgaris
December 2016 | Volume 15 | Issue 12 | Original Article | 1496 | Copyright © December 2016
Lawrence F. Eichenfield MD,a Linda Stein Gold MD,b Walter K. Nahm MD PhD,c Fran E. Cook-Bolden MD,d and David M. Pariser MDe
aUniversity of California, San Diego, CA bHenry Ford Hospital System, Detroit, MI cUniversity of California, San Diego and University Clinical Trials, San Diego, CA dSkin Specialty Dermatology Research Division, New York, NY eDepartment of Dermatology, Eastern Virginia Medical School and Virginia Clinical Research, Inc, Norfolk,VA
OBJECTIVE: This randomized, double-blind, placebo-controlled, Phase 2 study compared efficacy, tolerability, and safety of SB204 once or twice daily to vehicle in the treatment of acne vulgaris.
METHODS: Eligible subjects were to be between 12 and 40 years old, have facial acne vulgaris with 25 to 70 non-inflammatory lesions, 20 to 40 inflammatory lesions, no more than 2 nodules, and a baseline Investigator’s Global Assessment (IGA) score of moderate or severe. The co-primary efficacy endpoints were the absolute change in inflammatory and non-inflammatory lesion counts and IGA success rate (baseline to week 12). Safety assessments included reported adverse events (AEs), physical examinations, and laboratory testing. Tolerability was evaluated by the investigators based on the occurrence and severity of erythema, scaling, dryness, pruritus, and burning/stinging.
RESULTS: A total of 213 subjects were randomized: 27 subjects to vehicle once daily; 29 subjects to vehicle twice daily; 53 subjects to SB204 2% twice daily; 52 subjects to SB204 4% once daily; and 52 subjects to SB204 4% twice daily. When compared to vehicle, treatment with all 3 SB204 regimens significantly reduced the absolute inflammatory lesion count and SB204 4% once daily reduced the absolute non-inflammatory lesion count. Treatment with SB204 4% once daily demonstrated a significant reduction in percent inflammatory lesions by week 4. There were no significant differences in the IGA success rates between groups at the end of treatment. All treatment regimens of SB204 were found to be safe and well tolerated.
CONCLUSIONS: When compared to vehicle, SB204 2% and SB204 4% significantly decreased the absolute inflammatory lesion count and SB204 4% once daily also significantly decreased the absolute non-inflammatory lesion count in subjects with acne vulgaris treated for 12 weeks. Treatment with SB204 2% and 4% was found to be safe and well tolerated.J Drugs Dermatol. 2016;15(12):1496-1502.
Acne vulgaris is a chronic, inflammatory skin disease in which inflammation induced by P. acnes initiates and contributes to lesion formation.1 The binding of P. acnes to the Toll-like receptor 2 (TLR2) initiates a cascade that leads to pro-inflammatory cytokine release, T cell differentiation, and recruitment of lymphocytes and neutrophils in early acne lesions.2-5 Activation of TLR2 also stimulates IL-1α release from keratinocytes, which stimulates keratinocyte proliferation and promotes comedogenesis.6 Nitric oxide, an endogenous rapidly-acting gas, has both immu- noregulatory and anti-microbial activity.7-8 Nitric oxide has been shown to inhibit specific immunoregulatory pathways impor- tant in the pathogenesis of acne, including in ammasomes and caspases.9-11 Secretion of IL-1α and IL-1ß appear to be sensitive to caspase, although the precise mechanism appears to differ for these two cytokines.12-13 Nitric oxide targets bacteria through multiple nitrosative and oxidative mechanisms, leading to a low propensity for the development of resistance.14-15 The innate anti-microbial and immunomodulatory activities of nitric oxide suggest that it may be an attractive candidate for the treatment of acne. SB204 is a topical gel containing the nitric oxide-releasing macromolecule NVN1000 in development for acne vulgaris. NVN1000 is comprised of a polysiloxane backbone with co- valently bound N-diazeniumdiolate nitric oxide donors, and is designed to be co-administered with a hydrogel to enhance nitric oxide release at the time of application.16 In a previous