Efficacy and safety of PAC-14028 cream - a novel, topical, nonsteroidal, selective TRPV1 antagonist in patients with mild-to-moderate atopic dermatitis: a phase IIb randomized trial.

BACKGROUND: Transient receptor potential vanilloid subfamily, member 1 (TRPV1) may play an important role in pruritus and inflammation induction in atopic dermatitis (AD). The treatment effect of TRPV1 antagonist via topical application in patients with AD remains unknown.

OBJECTIVES: To assess the clinical efficacy and safety of PAC-14028, a TRPV1 antagonist, via topical application in patients with AD.

METHODS: In this 8-week, phase IIb, randomized, double-blind, multicentre, vehicle-controlled study, patients with mild-to-moderate AD were randomized to receive PAC-14028 cream 0·1%, 0·3%, 1·0% or vehicle cream twice daily. The primary efficacy end point was the Investigator's Global Assessment (IGA) success rate defined as the percentage of patients with an IGA score of 0 or 1 at week 8. The secondary efficacy end points included the severity Scoring of Atopic Dermatitis (SCORAD) index and Eczema Area and Severity Index (EASI) 75/90.

RESULTS: A total of 194 patients were enrolled. IGA success rates at week 8 were 14·58% for vehicle cream, 42·55% for PAC-14028 cream 0·1% (P = 0·0025 vs. vehicle), 38·30% for PAC-14028 cream 0·3% (P = 0·0087 vs. vehicle) and 57·45% for PAC-14028 cream 1·0% (P < 0·001 vs. vehicle). In particular, statistically significant differences were found between the vehicle and treatment groups in the IGA success rates with two-grade improvement. The SCORAD index, EASI 75/90, sleep disturbance score and pruritus visual analogue scale showed a trend towards improvement. No significant safety issues were reported.

CONCLUSIONS: PAC-14028 cream may be an effective and safe treatment modality for the treatment of patients with mild-to-moderate AD.