Halobetasol and Tazarotene: Further Defining the Role of a Unique Fixed Combination Topical Lotion in Moderate-to-Severe Plaque Psoriasis

December 2018 | Volume 17 | Issue 12 | Original Article | 1290 | Copyright © December 2018

Linda Stein Gold MD,a Jerry Bagel MD,b Mark G. Lebwohl MD,c Tina Lin PharmD,d Gina Martin MOT,e Radhakrishnan Pillai PhD

aHenry Ford Hospital, Detroit, MI bPsoriasis Treatment Center of Central New Jersey, East Windsor, NJ cIcahn School of Medicine at Mount Sinai, New York, NY dOrtho Dermatologics, Bridgewater, NJ eDow Pharmaceutical Sciences Inc., Petaluma, CA

BACKGROUND: A unique fixed combination halobetasol propionate 0.01% and tazarotene 0.045% (HP/TAZ) lotion has been shown to be effective in psoriasis using Investigator Global Assessment (IGA) tools to assess erythema, plaque elevation, and scaling. However, these do not consider changes in Body Surface Area (BSA). The IGAxBSA composite tool is a simple, effective, validated alternative for measuring improvement in psoriasis severity. It correlates well with the Psoriasis Area and Severity Index (PASI) and demonstrates sensitivity to changes from baseline in patients with both mild and moderately severe disease. OBJECTIVE: To further define the role of a fixed combination halobetasol propionate 0.01% and tazarotene 0.045% (HP/TAZ) lotion in moderate-to-severe plaque psoriasis using the IGAxBSA composite tool. METHODS: Post hoc analysis of 212 patients with moderate-to-severe plaque psoriasis randomized (2:2:2:1) to HP/TAZ lotion, HP, TAZ, or vehicle once-daily for 8 weeks, with a 4-week posttreatment follow-up. Efficacy assessments using the validated IGAxBSA composite tool. RESULTS: HP/TAZ lotion demonstrated statistically significant superiority at week 8 (versus TAZ and vehicle) and week 12 (versus HP, TAZ, and vehicle). By week 8, HP/TAZ lotion achieved a 63.5% reduction in mean IGAxBSA composite score (P less than 0.001 versus TAZ and vehicle), that was sustained four weeks posttreatment (P less than 0.001 versus TAZ and vehicle and P equals 0.003 versus HP). A 25% and 50% improvement in IGAxBSA was achieved within 1.9 and 4.6 weeks, respectively, and 47.5% of patients achieved IGAxBSA-75 by week 8. LIMITATIONS: This post hoc analysis was limited to patients with moderate-to-severe plaque psoriasis with IGA ≥3 and BSA involvement (3%-12%). CONCLUSION: HP/TAZ lotion was associated with significant and rapid reductions in disease severity as assessed by the IGAxBSA composite tool. The addition of tazarotene affords sustained benefits posttreatment. J Drugs Dermatol. 2018;17(12):1290-1296.


Psoriasis is a common chronic inflammatory disease as- sociated with numerous comorbidities, with a profound impact on patients’ quality of life. Assessing disease severity without biomarkers has led to the development of more than 50 clinical assessment tools to measure disease severity and treatment response1; but no instrument meets all validity criteria.2 The most common instrument, the Psoriasis Area Severity Index (PASI) was first used some 40 years ago and is widely considered the gold standard measure of disease severity.3,4 However, PASI has several limitations and has been criticized for being cumbersome and difficult to interpret; lacking sensitivity to detecting changes in disease severity in mild-to-moderate disease; and low in accuracy and having a non-linear scale.5The final score is not meaningful to most physicians.6 Investigator Global Assessment (IGA) tools assess erythema, plaque elevation and scaling using 5- to 8- point scales and are less complex than PASI2. However, most do not take into account Body Surface Area (BSA) involvement, a key aspect of disease severity and management.1,7 A patient with extensive BSA involvement, for example, could have the same IGA score as one with limited involvement if the degrees of lesion erythema, plaque elevation, and scaling were equivalent. To address the limitations of both PASI, IGA and BSA, alternative instruments have been developed.The product of IGA and BSA involvement (IGAxBSA) is a simple, validated alternative for assessing response to therapy that has been consistently shown to be highly correlated with PASI, despite some differ- ences in the scales used to assess erythema, plaque elevation or scaling.5,6,8,9-12