Cutaneous melasma is a relatively common dermatologic disease, occurring most commonly in Asian and Hispanic women of childbearing years.1-5 Exposure to solar UV radiation is the most important environmental factor in the pathogenesis of melasma.2,3 Therapy for melasma remains a challenge. Pharmacologic treatments are the mainstay.2,6,7 Hydroquinone, azelaic acid, tretinoin, and topical corticosteroids have been used as monotherapy7-11 or in various combinations.12-15 Kligman and Willis15 found that monotherapy with hydroquinone, tretinoin, or the topical corticosteroid dexamethasone did not produce substantial hypopigmentation within a 3-month treatment period. However, they did observe satisfactory results with a combination of tretinoin 0.1%, hydroquinone 5.0%, and dexamethasone 0.1% in a hydrophilic ointment.15 Furthermore, Kligman and Willis,15 as well as other researchers, have noted efficacy and safety benefits with use of hydroquinone, tretinoin, and various topical corticosteroids. In experimental and clinical studies, the use of tretinoin and other retinoids has been found to abrogate the epidermal atrophy that can occur with topical corticosteroids.16,17 This could be due to the ability of tretinoin and other retinoids to induce hyperplasia of epidermal cells and to induce dermal collagen synthesis.16,17 The objective of the 2 well-controlled trials featured in this article was to compare the efficacy and safety of the combination of hydroquinone, tretinoin, and the fluorinated topical corticosteroid fluocinolone acetonide, in a hydrophilic cream formulation, with 3 dual-combination products in the clearing of melasma. back to top
METHODS Study Design—The 2 pivotal trials used similar multicenter, randomized, investigator-blind, active-control, parallel-group protocols. Thirteen centers were involved in these trials. Both studies compared a triple-combination hydrophilic cream vehicle containing tretinoin 0.05%, hydroquinone 4.0%, and fluocinolone acetonide 0.01% (RA+HQ+FA) with the dual-combination products tretinoin plus hydroquinone (RA+HQ), tretinoin plus fluocinolone acetonide (RA+FA), and hydroquinone plus fluocinolone acetonide (HQ+FA). All products involved the same drug concentrations and vehicle. All formulations were used once daily at night. A total of 641 adult patients were randomized to the various treatment groups. Objective evaluation of melasma severity at baseline and at various points after treatment involved investigator assessment of global improvement from baseline using an 8-point scale (0=completely clear to 7=worse) at each follow-up visit. A baseline photograph was used for comparison. Patient Population—Patients enrolled in the study were predominantly white women (aged 21 to 75 years) with Fitzpatrick skin types I through IV. For enrollment into the study, all patients had to demonstrate a stable hyperpigmentation on the face for at least 3 months’ duration, macular lesions that were neither depressed nor atrophic, and melasma severity scores of at least 2 (ie, hyperpigmentation that was at least moderately darker than the surrounding normal skin). There were no significant differences in demographic parameters or skin phototypes among patients in each of the 4 treatment groups. The degree of hyperpigmentation in all patients was moderate to severe. Efficacy and Safety Analysis—The primary efficacy end point involved the investigators’ assessment of the proportion of intent-to-treat patients in each treatment group who achieved complete clearing at week 8. The secondary end point (secondary success) involved the proportion of intent-to-treat patients in each treatment group who achieved complete clearing (score=0) or near-complete clearing (ie, mild residual hyperpigmentation, score=1) by week 8 (Table 1).
| View this table | Table 1. Melasma Severity Rating Scale Used in Primary and Secondary Efficacy Analysis |
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All patients randomized to the various treatment groups were analyzed for adverse events. Statistical analysis involved the Cochran-Mantel-Haenszel test, stratified by center. back to top
RESULTS Efficacy—Significantly more of the patients treated with RA+HQ+FA (26.1%) experienced complete clearing compared with each of the dual-therapy groups at week 8 (9.5% for RA+HQ, 1.9% for RA+FA, and 2.5% for HQ+FA, P