A randomized phase 3b/4 study to evaluate concomitant use of topical ivermectin 1% cream and doxycycline 40-mg modified-release capsules, versus topical ivermectin 1% cream and placebo in the treatment of severe rosacea

Abstract

Background: Randomized controlled studies of combination therapies in rosacea are limited.

Objective: Evaluate the efficacy and safety of combining ivermectin 1% cream (IVM) and doxycycline 40-mg modified-release capsules (ie, 30-mg immediate-release and 10-mg delayed-release beads) (DMR) versus IVM and placebo for treatment of severe rosacea.

Methods: This 12-week, multicenter, randomized, investigator-blinded, parallel-group comparative study randomized adult subjects with severe rosacea (Investigator's Global Assessment [IGA] score, 4) to receive either IVM and DMR (combination arm) or IVM and placebo (monotherapy).

Results: A total of 273 subjects participated. IVM and DMR displayed superior efficacy in reduction of inflammatory lesions (-80.3% vs -73.6% for monotherapy [P = .032]) and IGA score (P = .032). Combination therapy had a faster onset of action as of week 4; it significantly increased the number of subjects achieving an IGA score of 0 (11.9% vs 5.1% [P = .043]) and 100% lesion reduction (17.8% vs 7.2% [P = .006]) at week 12. Both treatments reduced the Clinician's Erythema Assessment score, stinging/burning, flushing episodes, Dermatology Life Quality Index score, and ocular signs/symptoms and were well tolerated.

Limitations: The duration of the study prevented evaluation of potential recurrences or further improvements.

Conclusion: Combining IVM and DMR can produce faster responses, improve response rates, and increase patient satisfaction in cases of severe rosacea.

Keywords: clear; combination therapy; concomitant use; doxycycline; individualized treatment; ivermectin; rosacea; rosacea treatment; severe rosacea.