KAPALUA, HAWAII — A formulation of doxycycline that is anti-inflammatory without being antibiotic significantly reduced rosacea lesions in two phase III trials, according to Dr. James Q. Del Rosso, the principal investigator.
Dr. Del Rosso, a dermatologist in Las Vegas, reported that CollaGenex Pharmaceuticals Inc., in Newtown, Pa., for which he works in several roles, has applied to the Food and Drug Administration for an indication in rosacea based on the outcomes.
He gave a general description of the findings at the Winter Clinical Dermatology Conference, Hawaii, and said that data from the trials would be presented at the American Academy of Dermatology meeting this month. “This therapy provides the anti-inflammatory effect but does not predispose patients to development of antibiotic resistance. That is significant,” he said in an interview.
In his presentation, he suggested that antibiotic resistance was a concern because rosacea is a chronic disease for which patients are often treated for long periods. All tetracyclines have anti-inflammatory activity, he said, but doxycycline is the only one for which investigators have separated anti-inflammatory from antibiotic dosing.
Anti-inflammatory-dose doxycycline is a 40-mg, controlled-release doxycycline monohydrate capsule that is administered once a day, said Dr. Del Rosso. “The advantage of once-daily dosing is obviously better patient compliance,” he added.
All told, 537 patients at 28 sites were enrolled in the two randomized, double-blind, placebo-controlled studies. The investigator said that patients in both trials achieved significant improvements in inflammatory lesion counts and in Investigator's Global Assessment of Improvement scores with anti-inflammatory-dose doxycycline.
“In the two studies, patients receiving anti-inflammatory-dose doxycycline experienced a 61% and 46% mean reduction in inflammatory lesions, compared to 29% and 20%, respectively, in those receiving placebo,” Dr. Del Rosso said. Lesion-count drops in the doxycycline group became statistically significant as early as 3 weeks after treatment began.
Erythema also improved progressively in both trials, with one trial demonstrating a statistically significant difference from placebo, he said at the conference, which was sponsored by the Center for Bio-Medical Communication Inc.
Adverse reactions were similar in the placebo and active groups in both studies.
Neither trial reported phototoxicity or photosensitivity, and no female patients developed oral or vaginal candidiasis during treatment with anti-inflammatory-dose doxycycline, he emphasized.
This therapy is anti-inflammatory but does not predispose patients to antibiotic resistance. DR. DEL ROSSO
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