Maintenance of remission following successful treatment of papulopustular rosacea with ivermectin 1% cream vs. metronidazole 0.75% cream: 36-week extension of the ATTRACT randomized study.

BACKGROUND: There are a limited number of approved treatments for papulopustular rosacea (PPR) and remission is difficult to maintain after successful treatment.

OBJECTIVES: To investigate remission over a 36-week extension period in patients with moderate to severe PPR successfully treated with 16 weeks' treatment with ivermectin 1% cream once daily (QD) or metronidazole 0.75% cream twice daily (BID) in a randomized, parallel-group Phase III study.

METHODS: Treatment was discontinued in patients initially successfully treated [Investigator's Global Assessment (IGA) score of 0 or 1] with ivermectin 1% cream QD (n = 399) or metronidazole 0.75% cream BID (n = 365; Part A) and patients were followed every 4 weeks for up to 36 weeks (Part B). Treatment with the same study treatment as used in Part A was only re-initiated if patients relapsed (IGA ≥ 2). Efficacy assessments were: time to first relapse; relapse rate; and number of days free of treatment. Safety assessments included incidence of adverse events and local cutaneous signs and symptoms.

RESULTS: The median time to first relapse was significantly longer (115 days vs. 85 days) and relapse rates at the end of the study period significantly lower (62.7% vs. 68.4%) for patients initially successfully treated with ivermectin 1% compared with metronidazole 0.75%; Kaplan-Meier plot demonstrated a statistically significant difference between the two arms (P = 0.0365). The median number of days free of treatment was higher for ivermectin compared with metronidazole (196 days vs. 169.5 days; P = 0.026). The percentage of patients who experienced a related adverse event was equally low in both groups.

CONCLUSION: The results of this relapse study showed that an initial successful treatment with ivermectin 1% cream QD significantly extended remission of rosacea compared with initial treatment with metronidazole 0.75% cream BID following treatment cessation.