A proactive long-term strategy of maintenance therapy involving twice-weekly application of combined calcipotriene and betamethasone dipropionate spray foam was safe and effective in patients with moderate plaque psoriasis in the international, randomized PSO-LONG clinical trial, Mark Lebwohl, MD, reported at the virtual annual meeting of the American Academy of Dermatology.
Dr. Mark Lebwohl
The median time to first relapse – the primary study endpoint – was 56 days in patients randomized to the twice-weekly fixed-dose combination calcipotriene 0.005% and betamethasone dipropionate 0.064% foam (Enstilar), a significantly better outcome than the median 30 days for controls assigned to foam vehicle. Moreover, it took 169 days for 75% of patients on the combination foam to experience their first relapse: three times longer than in controls, added Dr. Lebwohl, principal investigator for PSO-LONG and professor and chair of the department of dermatology at the Icahn School of Medicine at Mount Sinai, New York.
The positive results “could have been predicted,” he said in an interview. “But what really distinguishes this study from others is that no one before has ever done a placebo-controlled, double-blind trial with a topical steroid that lasted a year. This is a first, and we’ve shown that if you limit treatment to twice a week you get dramatic improvements in efficacy at no cost in terms of safety.”
The combination spray foam is approved by the Food and Drug Administration as once-daily therapy in psoriasis patients aged 12 years and older, but only for up to 4 weeks because of safety concerns regarding longer use of the potent topical steroid. However, psoriasis is a chronic disease. The PSO-LONG trial was designed to study the impact of a for-now still-investigational long-term maintenance treatment strategy.
The open-label run-in period of the study included 640 adults with plaque psoriasis, 82% of whom had moderate disease at baseline as rated by Physician Global Assessment (PGA). Participants applied the combination foam once daily for 4 weeks. At that point, 80% of them had achieved a PGA rating of clear or almost clear with at least a two-grade improvement from baseline; these 521 responders were then randomized to 52 weeks of double-blind treatment with the combination foam or vehicle foam. Anyone who relapsed went on 4 weeks of once-daily active treatment with the combination foam, then returned to their original treatment arm.
The risk of a first relapse during the course of 1 year was 43% lower with the combination foam than in controls. The relapse rate over the year was 46% lower. Patients in the active treatment arm spent an average of 256.5 days in remission during the year, compared with 222 days in controls.
“That’s more than 1 month more time in remission during the year with active treatment. And remember, if patients flared, they went on daily therapy for a month,” the dermatologist noted.
The rate of treatment-related adverse events was similar in the two groups at 2.8 events per 100 patient-years in the combination foam arm and 4.5 per 100 patient-years in controls. The twice-weekly active treatment group had no increase in stretch marks, telangiectasias, skin atrophy, serum calcium, or abnormalities of the hypothalamic-pituitary-adrenal axis.
Although the combination foam is approved for daily use for a maximum of 1 month in adolescents and adults, PSO-LONG was restricted to adults.
“I think that what will happen in the marketplace is that the data obtained from this adult study will likely be applied to younger patients,” Dr. Lebwohl predicted.
He reported receiving an institutional research grant to conduct the trial from LEO Pharma, the study sponsor, as well as serving as a consultant to and researcher for the company.