Cost-effectiveness of a fixed combination of hydroquinone/tretinoin/fluocinolone cream compared with hydroquinone alone in the treatment of melasma

Journal of Drugs in Dermatology, Feb, 2007 by Tania Cestari, Lucie Adjadj, Margaret Hux, Maria Regina Shimizu, Vincent Pierre Rives

Results

In the clinical study, 120 patients were randomized in 4 study centers in Brazil. (19) One patient in the HQ group stopped treatment before 8 weeks and the remaining 119 patients were included in the economic analyses. Groups were of a similar age (mean age: 47.2 vs. 45.3 years for TCT and HQ patients, respectively) with more females in the TCT group (98.3% vs. 90% of HQ patients, P<.05). By week 8, primary success was found for 35.0% (95% CI: 22.9% to 47.1%) of TCT patients and 5.1% (95% CI: 1.7% to 13.9%) of HQ patients. TCT offered a 6 times greater chance for successful treatment than HQ with an additional 29.9% chance of complete clearing compared to HQ. The average usage of TCT cream was 17.9 g (95% CI: 11.0 g to 24.8 g) and for hydroquinone was 36.9 g (95% CI: 22.8 g to 49.2 g), which was attributable to the difference in number of daily applications of the 2 treatments, once daily and twice daily, respectively. The number of complaints regarding tolerability was similar for both groups by the end of therapy; the most frequently reported systemic adverse event was headache, with a similar number in both groups (11 events for TCT vs. 9 for HQ) and these events were not considered related to study treatment. Only 2 potentially related adverse events associated with melasma treatment were found to be statistically different between the 2 groups: pruritus was increased with HQ (0% vs. 15.3%, P=.002) and desquamation was increased with TCT (11.7% vs. 1.7%, P=.03).

In the base case economic analysis, considering a choice to treat melasma compared to not treating (Table 1), the cost per successful treatment was found to be lower for TCT in every country (37% to 93% lower depending on country). Comparing active treatments, TCT was found to be both less costly and more effective than HQ in the US. Therefore, from a pharmacoeconomic perspective, TCT is said to be the dominant treatment in the US. In the other countries, there was an additional cost for better effectiveness, and the incremental cost per additional primary success (complete clearing of melasma) with TCT for each country is shown in Table 1. In the other studied countries the incremental cost per additional primary success with TCT varied depending on the price of the 2 treatments.

Sensitivity of results to varying effectiveness of TCT was assessed using the lower and upper 95% CI of the success rate while retaining the base case estimate for HQ. The cost per treatment success compared to not treating remains lower for TCT than HQ for all countries (ranging from 4% to 89% lower, depending on country), assuming the lower 95% CI (22.9% chance of treatment success). Comparing active treatments, TCT remained dominant in the US (better effectiveness and lower cost). However, the incremental cost per additional primary success in each of the other countries expressed in their currency was increased (Table 2).

A sensitivity analysis using the acquisition cost for the most frequently purchased product was conducted for countries where the comparator used in the clinical trial was not the most frequently purchased HQ 4% (US and Argentina). Results were similar to those presented in the base case (Table 2). In the US, if generic HQ use is assumed, compared to not treating TCT cost per primary success was 85% lower than using HQ; comparing active treatments, the incremental cost was $10 for each additional patient with complete clearing of melasma. In Argentina, although the most frequently sold HQ 4% is half the price of the HQ used in the base case, the cost per primary success for TCT compared to not treating is lower than with HQ; there is an incremental cost of 610 pesos for each additional patient with complete clearing of melasma.