Efficacy, Safety, and Tolerability of Oral DFD-29, a Low-Dose Formulation of Minocycline, in Rosacea: Two Phase 3 Randomized Clinical Trials.

Introduction: A low-dose modified formulation of minocycline hydrochloride, DFD-29, is under evaluation for treating papulopustular rosacea (PPR).

Objective: To determine the efficacy and safety of DFD-29, 40 mg, compared with doxycycline, 40 mg, and placebo for treating PPR.

Design, Setting, And Participants: This study included data from 2 double-blind, placebo-controlled, phase 3 randomized clinical trials (MVOR-1 and MVOR-2) conducted between March 2022 and May 2023 at 61 centers in the US and Germany. Healthy adults 18 years and older with moderate to severe PPR were included.

Interventions: Participants were randomized 3:3:2 to oral DFD-29 (minocycline hydrochloride capsules), 40 mg; doxycycline, 40 mg; or placebo once daily for 16 weeks.

Main Outcomes And Measures: The coprimary efficacy outcomes were (1) proportion of participants with Investigator's Global Assessment (IGA) treatment success with DFD-29 vs placebo and (2) total inflammatory lesion count reductions with DFD-29 vs placebo. Secondary outcomes included comparisons between DFD-29 and doxycycline in coprimary outcomes and between DFD-29 and placebo in erythema reduction.

Results: Of 653 participants enrolled, 323 were randomized in MVOR-1 (247 [76.5%] women; mean [SD] age, 47.2 [13.7] years) and 330 were randomized in MVOR-2 (249 [75.5%] women; mean [SD] age, 51.6 [14.0] years). DFD-29 demonstrated superior efficacy in IGA success rates compared with placebo (MVOR-1: treatment difference [TD], 32.9%; 95% CI, 19.6-46.2; P < .001; MVOR-2: TD, 34.1%; 95% CI, 21.3-46.8; P < .001) and compared with doxycycline (MVOR-1: TD, 18.0%; 95% CI, 5.0-31.1; P = .01; MVOR-2: TD, 28.3%; 95% CI, 17.4-39.3; P < .001). DFD-29 also showed superior efficacy in least-squares mean reductions in total inflammatory lesions vs placebo (MVOR-1: TD, -9.2; 95% CI, -11.5 to -6.9; P < .001; MVOR-2: TD, -6.8; 95% CI, -8.9 to -4.8; P < .001) and doxycycline (MVOR-1: TD, -4.7; 95% CI, -6.7 to -2.8; P < .001; MVOR-2: TD, -3.5; 95% CI, -5.4 to -1.6; P < .001). Adverse events with DFD-29, doxycycline, and placebo were reported in 32 of 121 (26.4%), 25 of 116 (21.6%), and 27 of 76 (35.5%), respectively, in MVOR-1 and 51 of 122 (41.8%), 40 of 121 (33.1%), and 30 of 82 (36.6%), respectively, in MVOR-2. The most common adverse events with DFD-29, doxycycline, and placebo were nasopharyngitis, reported in 4 of 121 (3.3%), 2 of 116 (1.7%), and 3 of 76 (3.9%), respectively, in MVOR-1 and 13 of 122 (10.7%), 10 of 121 (8.3%), and 13 of 82 (15.9%), respectively, in MVOR-2, and COVID-19, reported in 4 of 121 (3.3%), 3 of 116 (2.6%), and 4 of 76 (5.3%) in MVOR-1 and 7 of 122 (5.7%), 8 of 121 (6.6%), and 5 of 82 (6.1%) in MVOR-2.

Conclusions And Relevance: In this study, DFD-29 was superior in efficacy to both doxycycline and placebo and demonstrated a favorable risk-benefit profile in the treatment of PPR.

Trial Registration: ClinicalTrials.gov Identifiers: NCT05296629 and NCT05343455.