SAN FRANCISCO — A novel over-the-counter topical leave-on coal tar solution achieved significantly greater and more persistent improvement compared to prescription calcipotriol cream in patients with moderate chronic plaque psoriasis in a randomized trial.
Equally noteworthy was participants' rating of the coal tar solution as comparable to calcipotriol cream in terms of cosmetic acceptability, convenience, and aesthetics, Dr. Maria Beatrice Alora-Palli said at the annual meeting of the American Academy of Dermatology.
Topical coal tar has been used for centuries to control the symptoms of plaque psoriasis. In recent decades, however, it has come to be viewed as unacceptably messy and inconvenient.
The novel coal tar solution, marketed as Psorent by NeoStrata Co., is engineered to circumvent those shortcomings. It contains 15% liquor carbonis distillate, equivalent to 2.3% coal tar.
Dr. Alora-Palli of Massachusetts General Hospital, Boston, presented an 18-week investigator-blinded randomized trial involving 55 adults with chronic plaque psoriasis over 3%–15% of their body surface area. They applied either the topical coal tar solution or calcipotriol cream 0.005% (Dovonex) twice daily for 12 weeks, followed by a 6-week follow-up assessment of regression of improvement, during which the coal tar solution clearly outperformed the calcipotriol cream.
Twelve weeks of therapy resulted in a Psoriasis Area and Severity Index (PASI) 50—that is, at least a 50% improvement over baseline in PASI scores—in 67% of the coal tar group, compared with 36% of those on calcipotriol cream. A PASI 75 was attained by 37% of the coal tar group and no one in the calcipotriol cream study arm. Moreover, PASI scores improved by a mean of 58% in the coal tar group, compared with 37% in the calcipotriol cream group.
Physician Global Assessment scores improved in the coal tar group from a mean of 3.1 at baseline to 1.3 at week 12 and 1.6 at week 18. This was significantly better than the scores in the calcipotriol group, which went from 2.9 at baseline to 2.0 at 12 weeks and then rebounded significantly to 2.6 at 18 weeks, Dr. Alora-Pilli continued.
A total of 70% of the coal tar group reported having good control of the overall discomfort and appearance of their psoriatic lesions, compared with about half as many calcipotriol patients.
Dr. Alora-Pilli received a research grant to conduct the NeoStrata-funded study.