NEW ORLEANS — A combined formulation of clindamycin (1%) and tretinoin (0.025%) in an aqueous hydrogel improved acne vulgaris significantly faster than did either drug alone or vehicle, James Leyden, M.D., reported in a poster presentation at the annual meeting of the American Academy of Dermatology.
The combination gel targets three factors in acne pathogenesis, according to Dr. Leyden, a consultant for Connetics Corp., which developed Velac gel and sponsored the studies.
Clindamycin targets Propionibacterium acnes and decreases inflammation, while topical tretinoin normalizes follicular keratinization.
Data were pooled from two phase III, randomized, double-blind, multicenter trials that evaluated 2,219 patients with acne vulgaris at 37 U.S. sites.
Patients were randomized to one of four treatment groups: combination gel, clindamycin, tretinoin, or vehicle. Treatments were applied once daily in the evening for 12 weeks.
Of the 2,219 patients enrolled (combination 634, clindamycin 635, tretinoin 635, and vehicle 315), 1,902 (85.7%) patients completed the two trials.
From baseline to week 12, the percentage reduction in total lesions was significantly greater with the combination gel (48.7%) than with either clindamycin (38.3%) or tretinoin (40.3%) alone, or the vehicle (23.3%).
The median time to a 50% reduction in total lesion counts was 8 weeks with the combination gel, which was significantly faster than with clindamycin (12 weeks), tretinoin (12 weeks), or vehicle.
The reduction in inflammatory and noninflammatory lesion counts also was significantly greater with the combination gel than with each agent alone.
At week 12, the number of patients who were “clear” or “almost clear” on the investigator's static global assessment was significantly higher in the combination group than in each of the other three treatment groups.
The combination of clindamycin and tretinoin was well tolerated, with a similar incidence of site reactions as tretinoin monotherapy, reported Dr. Leyden, of the University of Pennsylvania, Philadelphia.
In the combination group, 119 patients (19%) reported 207 incidences of application site reactions including dryness, desquamation, burning, erythema, and pruritus.
In the tretinoin group, 107 (17%) reported 190 incidences of application site reactions.
Velac gel is under review by the Food and Drug Administration and is expected to be available in the third quarter of 2005, according to a company spokesperson.