Abstract: 【Abstract】 Objective To evaluate the efficacy and safety of tazarotene/betamethasone dipropionate cream at different concentration ratios in the treatment of psoriasis vulgaris, and to determine the optimal drug concentration ratio for clinical use. Methods A multicenter, randomized, double-blinded, multi-dose controlled study was conducted. From December 2008 to April 2009, a total of 180 patients with psoriasis vulgaris were enrolled from 7 research centers, such as Hospital for Skin Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College. These patients were randomly and equally divided into 5 groups: treatment groups 1, 2, 3, 4 treated with tazarotene/betamethasone dipropionate cream at concentration ratios of 0.025%/0.025%, 0.05%/0.025%, 0.025%/0.05% and 0.05%/0.05% respectively once a day, and control group treated with the cream vehicle once a day. The treatment lasted 4 weeks. Efficacy and safety were evaluated after 1, 2 and 4 weeks of treatment. One-way analysis of variance and least significant difference (LSD)-t test were used to compare measurement data among several groups, chi-square test and Fisher′s exact test to compare categorical data among groups, and Cochran-Mantel-Haenszel （CMH） test to compare psoriasis area severity index （PASI） response rates between groups. Results After 4 weeks of treatment, 11 patients （30.56%）, 12 （33.33%）, 12 （33.33%）, 19 （52.78%） and 2 （5.56%） in the treatment groups 1, 2, 3, 4 and control group respectively achieved a 75% reduction in PASI （PASI75）, and the proportions of patients achieving PASI75 were significantly higher in the treatment groups than in the control group （all P < 0.012 7）. Additionally, the proportions of patients achieving PASI90 were also significantly higher in the treatment groups 1, 2 and 4 than in the control group （all P < 0.012 7）. After 4 weeks of treatment, the rates of reduction in PASI scores were 59.52% ± 26.79%, 57.19% ± 31.98%, 56.85% ± 30.46% and 68.21% ± 37.20% in treatment groups 1, 2, 3, and 4 respectively, which were all significantly higher than the rate of reduction in the control group （20.07% ± 28.55%; LSD-t = 5.36, 5.05, 5.00, 6.55, all P < 0.001）. The treatment group 4 showed marked comprehensive efficacy. All the tested drugs were well tolerated in the patients, and adverse reactions occurred in 11 （30.56%）, 8 （22.22%）, 2 （5.56%）, 4 （11.11%） and 2 （5.56%） cases in the treatment groups 1, 2, 3, 4 and control group respectively. The incidence rate of adverse reactions was significantly higher in the treatment group 1 than in the control group （P = 0.012）, and there was no significant difference among the treatment groups 2, 3, 4 and control group （all P > 0.05）. Conclusion The tazarotene 0.05%/betamethasone dipropionate 0.05% cream can be recommended for subsequent clinical trials in psoriasis vulgaris.

Key words: Psoriasis, Tretinoin, Betamethasone, Randomized controlled trial, Tazarotene/betamethasone dipropionate cream