week 8 to week 12 in either treatment group (P≥.06). The ER minocycline group experienced a significant week 8 to week 12 decrease in IGA (P=.04), while the ER minocycline + azelaic acid 15% group did not (P=.22).
Neither treatment was superior with respect to reduction in any outcome variable in any time interval. Specifically, 2-sample comparisons of visit-to-visit changes showed that the ER minocycline
and ER minocycline + azelaic acid 15% groups did not significantly differ with respect to visit-to-visit change up to week 12 (P>.31).
After discontinuation of treatment at week 12, there were no significant changes in lesion count, IGA, or CEA in either treatment
group to week 16 (P≥.33), and groups did not differ in changes after week 12 on any study outcome (P≥.32).
Safety Analyses
Twenty-seven subjects experienced a total of 44 AEs. Subjects in the ER minocycline + azelaic acid 15% group were more likely to experience an AE (16 of 30, 53%) than those in the ER minocycline
group (11 of 30, 37%), although this difference was nonsignificant (CMH test, P=.31). The number of AEs also did not significantly differ between groups (Poisson GLMM, P=.15).
Two AEs were classified as possibly related to the study medication—an upset stomach and generalized urticaria in separate patients both receiving ER minocycline + azelaic acid 15%. Four AEs in 3 patients (all receiving ER minocycline + azelaic acid 15%) were severe but not suspected to be related to the study medication (bilateral oophorectomy with dermoid cyst removal,
gastric erosion after lap band surgery, a severe respiratory infection, and cholecystitis).
Sensitivity Analysis of Per-Protocol Population
The PP population was defined at each week of follow-up as those that did not deviate from the study protocol by (1) missing a visit or (2) having a visit outside of the allowable window for the given
