TRI-LUMA Cream Ref.[50486] Active ingredients: Fluocinolone Hydroquinone Tretinoin

Percutaneous absorption of unchanged tretinoin, hydroquinone and fluocinolone acetonide into the systemic circulation of two groups of healthy volunteers (Total N=59) was found to be minimal following 8 weeks of daily application of 1g (Group I, n=45) or 6g (Group II, n=14) of TRI-LUMA Cream.

For tretinoin quantifiable plasma concentrations were obtained in 57.78% (26 out of 45) of Group I and 57.14% (8 out of 14) of Group II subjects. The exposure to tretinoin as reflected by the C_max values ranged from 2.01 to 5.34 ng/mL (Group I) and 2.0 to 4.99 ng/mL (Group II). Thus, daily application of TRI-LUMA Cream resulted in a minimal increase of normal endogenous levels of tretinoin. The circulating tretinoin levels represent only a portion of total tretinoin-associated retinoids, which would include metabolites of tretinoin and that sequestered into peripheral tissues.

For hydroquinone, quantifiable plasma concentrations were obtained in 18% (8 out of 44) Group I subjects. The exposure to hydroquinone, as reflected by the C_max values, ranged from 25.55 to 86.52 ng/mL. All Group II subjects (6g dose) had post-dose plasma hydroquinone concentrations below the quantitation limit. For fluocinolone acetonide, Groups I and II subjects had all post-dose plasma concentrations below quantitation limit.

When fluocinolone acetonide, hydroquinone, and tretinoin in fixed combinations equivalent to 10%, 50%, 100%, and 150% of the concentrations in the clinical formulation of TRI-LUMA Cream were applied topically to male and female CD-1 mice for up to 24 months at dosages approximating up to 50, 19,000, and 250 µg/kg/day, respectively (corresponding to dosages of 150, 57,000, and 750 μg/m²/day, respectively), no statistically significant changes in tumor incidence were observed.

When fluocinolone acetonide, hydroquinone, and tretinoin in fixed combinations equivalent to 10%, 25%, 50%, and 100% of the concentrations in the clinical formulation of TRI-LUMA Cream were applied topically to male and female SD rats for up to 24 months at dosages approximating up to 10, 4000, and 50 µg/kg/day, respectively (corresponding to dosages of 60, 24,000, and 300 μg/m²/day, respectively), statistically significant increases in the incidences of islet cell adenomas and combined islet cell adenomas and carcinomas of the pancreas in both males and females were observed. The clinical relevance of these findings is unknown.

Studies of hydroquinone in animals have demonstrated some evidence of carcinogenicity. The carcinogenic potential of hydroquinone in humans is unknown.

Studies in hairless albino mice suggest that concurrent exposure to tretinoin may enhance the tumorigenic potential of carcinogenic doses of UVB and UVA light from a solar simulator. This effect has been confirmed in a later study in pigmented mice, and dark pigmentation did not overcome the enhancement of photocarcinogenesis by 0.05% tretinoin. Although the significance of these studies to humans is not clear, patients should minimize exposure to sunlight or artificial ultraviolet irradiation sources.

Mutagenicity studies were not conducted with this combination of active ingredients. Published studies have demonstrated that hydroquinone is a mutagen and a clastogen. Treatment with hydroquinone has resulted in positive findings for genetic toxicity in the Ames assay in bacterial strains sensitive to oxidizing mutagens, in in vitro studies in mammalian cells, and in the in vivo mouse micronucleus assay. Tretinoin has been shown to be negative for mutagenesis in the Ames assay. Additional information regarding the genetic toxicity potential of tretinoin and of fluocinolone acetonide is not available.

A dermal reproductive fertility study was conducted in SD rats using a 10-fold dilution of the clinical formulation. No effect was seen on the traditional parameters used to assess fertility, although prolongation of estrus was observed in some females, and there was a trend towards an increase in pre-and post-implantation loss that was not statistically significant. No adequate study of fertility and early embryonic toxicity of the full-strength drug product has been performed. In a six-month study in minipigs, small testes and severe hypospermia were found when males were treated topically with the full strength drug product.

Two adequate and well-controlled efficacy and safety trials were conducted in 641 subjects between the ages of 21 to 75 years, having Fitzpatrick Skin types I-IV and moderate to severe melasma of the face. TRI-LUMA Cream was compared with 3 possible combinations of 2 of the 3 active ingredients [(1) hydroquinone 4% (HQ) + tretinoin 0.05% (RA); (2) fluocinolone acetonide 0.01% (FA) + tretinoin 0.05% (RA); (3) fluocinolone acetonide 0.01% (FA) + hydroquinone 4% (HQ)], contained in the same vehicle as TRI-LUMA Cream. Subjects were instructed to apply their study medication each night, after washing their face with a mild soapless cleanser, for 8 weeks. Instructions were given to apply a thin layer of study medication to the hyperpigmented lesion, making sure to cover the entire lesion including the outside borders extending to the normal pigmented skin. Subjects were provided a mild moisturizer for use as needed. A sunscreen with SPF 30 was also provided with instructions for daily use. Protective clothing and avoidance of sunlight exposure to the face was recommended.

Subjects were evaluated for melasma severity at Baseline and at Weeks 1, 2, 4, and 8 of treatment. Primary efficacy was based on the proportion of subjects who had an investigators' assessment of treatment success, defined as the clearing of melasma at the end of the eight-week treatment period. The majority of subjects enrolled in the two trials were white (approximately 66%) and female (approximately 98%). TRI-LUMA Cream was demonstrated to be significantly more effective than any of the other combinations of the active ingredients.

PRIMARY EFFICACY ANALYSIS:

Table 2. Investigators' Assessment of Treatment Success* At the End of 8 Weeks of Treatment:

^* Treatment success was defined as melasma severity score of zero (melasma lesions cleared of hyperpigmentation)

p-value is from Cochran-Mantel-Haenszel chi-square statistics controlling for pooled investigator and comparing TRI-LUMA Cream to the other treatment groups.

In the Investigators' assessment of melasma severity at Day 56 of treatment, the following table shows the clinical improvement profile for all subjects treated with TRI-LUMA Cream based on severity of their melasma at the start of treatment.

Table 3. Investigators' Assessment of Change in Melasma Severity from Baseline to Day 56 of Treatment (combined results from trials 1 and 2):

^* Assessment based on subjects with severity scores at Day 56. Percentages are bases on the total number in the treatment group population.
^† Does not include subjects who cleared before Day 56 or were missing from the Day 56 Assessment

Assessment Scale: Cleared (melasma lesions approximately equivalent to surrounding normal skin or with minimal residual hyperpigmentation); Mild (slightly darker than the surrounding normal skin); Moderate (moderately darker than the surrounding normal skin); Severe (markedly darker than the surrounding normal skin).

Subjects experienced improvement of their melasma with the use of TRI-LUMA Cream as early as 4 weeks. However, among 7 subjects who had clearing at the end of 4 weeks of treatment with TRI-LUMA Cream, 4 of them did not maintain the remission after an additional 4 weeks of treatment.

After 8 weeks of treatment with the trial drug, subjects entered into an open-label extension period in which TRI-LUMA Cream was given on an as-needed basis for the treatment of melasma. The remission periods appeared to shorten between progressive courses of treatment. Additionally, few subjects maintained complete clearing of melasma (approximately 1 to 2%).