Topical gel quells persistent erythema of rosacea
Louisville, Ky. — Once-daily application of Sansrosa (brimonidine tartrate/BT gel, Galderma) 0.5 percent has proven safe and effective for treating the persistent facial erythema of rosacea, according to the results of a phase 2 trial.
Patients received one of five randomly chosen treatments: BT 0.18 percent once (QD) or twice daily, BT 0.5 percent once daily, or vehicle once or twice daily. BT is a highly selective alpha-2 adrenergic receptor agonist and vasoconstrictor used in glaucoma. Patients used the treatment daily for four weeks, then underwent four weeks' follow-up.
On day 29, patients who used BT 0.5 percent experienced significantly superior improvement over baseline compared to daily use of vehicle (P<0.001), as well as on days one and 15 (P<0.001 for both). Investigators and the Food and Drug Administration defined this primary endpoint as a two-point reduction as rated by both patients and investigators over 12 hours.
Using the same yardstick, success rates for BT 0.5 percent QD at hours three, six, nine and 12 on day 29 were 30.2 percent, 28.3 percent, 32.1 percent and 18.9 percent, respectively. Conversely, success rates for vehicle QD at the same time points ranged between 3.6 and 7.3 percent (Fowler J, Moore A, Meadows K, et al. Poster 4825. Presented at: American Academy of Dermatology Annual Meeting; March 16-20, 2012; San Diego). Also at hour three on day 29, 75.5 percent of patients in the BT 0.5 percent cohort showed a one-point improvement in erythema, versus 30.9 percent for vehicle.
"The study's most significant result was the striking improvement in redness — the treatment really works," says principal investigator Joseph Fowler, M.D. He is a Louisville, Ky., dermatologist in private practice, clinical professor of dermatology at the University of Louisville and assistant clinical professor in the Division of Occupational Medicine at the University of Kentucky.
Also impressive, he says, was the persistence of the improvements. With the 0.5 percent formulation, researchers observed no significant falloff in the percentage of patients who maintained treatment success (an improvement of at least two points) until nine hours post-treatment. This means that someone can apply the product in the morning and not worry about it wearing off in the middle of the day, Dr. Fowler says.
Additionally, he says that it was somewhat surprising that the once-daily 0.5 percent concentration was much more effective than 0.18 percent used twice daily. "Going into the study, it was uncertain" which dose would prove optimal, he says. "Most dermatologists would prefer to have a once-daily product because patient compliance is a lot better."
Dr. Fowler surmises that the twice-daily BT 0.18 percent didn't work as well as 0.5 percent QD because it takes a certain level of the drug to penetrate the stratum corneum and get into the skin. "Therefore, even if you apply a low concentration more frequently, you probably never get enough penetration" to achieve efficacy. At the lower concentration, "There was efficacy — it just wasn't as good and as prolonged. That tells us the higher concentration is necessary to get the drug into the skin to do what it has to do," he explains.
Because the treatment has little residual effect, Dr. Fowler says, "Patients will need to use it on an ongoing basis to maintain the reduction in redness." To date, no published study has evaluated the treatment's safety beyond four months, he says. "However, I don't anticipate any issues. Patients with rosacea tend to have sensitive skin. To me, that would be the biggest concern, although we didn't see much of that with this product.
"That tells us it's probably a very good formulation" for patients with rosacea, Dr. Fowler says. If irritation were to occur, "It's likely to occur early on, not after ongoing use."
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