A multicentre, single-blind, randomized comparison of a fixed clindamycin phosphate/tretinoin gel formulation (Velac (R)) applied once daily and a clindamycin lotion formulation (Dalacin T (R)) applied twice daily in the topical treatment of acne vulgaris

Background A successful phase III pilot study compared the efficacy and saf ety of a fixed clindamycin 1%/tretinoin 0 . 025% gel formulation (CTG; Vela c (R) gel) applied once daily and a clindamycin 1% lotion formulation (CLN, Dalacin T (R) lotion) applied twice daily in the treatment of moderate to severe acne vulgaris. Objectives We aimed to follow up this study. Methods The two treatment regimens were compared in a multicentre, single-b lind, randomized 12-week investigation of patients with moderate to severe acne vulgaris. Results At week 12, the mean percentage reduction in non-inflamed lesions ( open and closed comedones) was greater in the CTG group compared with the C LN group (P = 0 . 05). Absolute reductions in open and closed comedones wer e also greater in the CTG group, consistent with the comedolytic activity o f tretinoin. There was a significantly greater absolute reduction in inflam ed lesions (pustules, papules and nodules) from baseline to bath end-point (last observed efficacy outcome: P = 0 . 043) and week 12 (P = 0 . 018) in the CTG group compared with the CLN group. Evaluation of the calculated ove rall acne severity score, considering all five lesion subtypes, demonstrate d a significantly greater mean percentage reduction in the CTG group compar ed with the CLN group, both at end-point (P = 0 . 01) and at week 12 (P < 0 . 01). The more subjective assessment of overall acne severity according t o the Cook scale also demonstrated a significantly greater mean reduction i n the CTG group than the CLN group after 12 weeks of therapy (P = 0 . 007). CTG had a more rapid effect on the onset of improvement compared with CLN; a 50% reduction in total lesion counts by day 60 was found in 77% of patie nts on CTG compared with 56% receiving CLN (P = 0 . 003). This was largely due to the reduction in open comedone counts (P = 0 . 0006). For all other variables, CTG was at least as effective as CLN. Both treatments were well tolerated. Conclusions A single daily topical application of Velac (R) gel was superio r to Dalacin T (R) lotion applied twice daily in reducing overall acne scor es, and was faster acting, The simpler dosing regimen of Velac (R) gel and its rapid effect are likely to have a positive effect on both patient compl iance and cost.