One of these underappreciated findings concerned safety. The rate of treatment-related dermatologic adverse events during the double-blind first 3 months of the study was 2.5% in the ivermectin group compared with 6.3% in vehicle-treated controls.
“That’s pretty impressive. That the active treatment arm of the study had less treatment-related dermatologic adverse events than placebo has never been seen before in any other topical study. It tells you something: The assumption here is that the potent inherent anti-inflammatory activity of ivermectin is overwhelming,” the dermatologist said.
The other particularly noteworthy finding came in the long-term, 40-week extension study that followed the initial 12-week, double-blind stage. What was impressive here was the way the proportion of patients who were IGA clear/almost clear rose steadily throughout, he noted. At the end of the initial 3-month phase of the two studies, 38%-40% of ivermectin-treated patients were clear/almost clear. At 12 months, nearly 70% were.
“In most studies, efficacy sort of plateaus at some point. Here it keeps going up through 12 months. So if somebody comes to your office after 3 months using ivermectin and says, ‘Eh, I’m okay, but I’m not clear or almost clear,’ there’s no reason to switch to another medication, because if they continue you know there’s a high chance they will become clear/almost clear,” Dr. Kircik said.
On the other hand, study participants who were still IGA ‘severe’ after 3 months remained severe after 12 months on the drug. So the message here is if a patient still has severe rosacea after 3 months on ivermectin it’s time to change drugs, he added.