LAS VEGAS – Many patients taking adalimumab for psoriasis over the long term can expect a high rate of response that persists, but there is some real but small loss of effect, Dr. Kenneth B. Gordon said at a dermatology seminar sponsored by Skin Disease Education Foundation.
Adalimumab (Humira) is approved for the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylosis, and Crohn's disease. The best published long-term data for adalimumab in psoriasis is from the double-blind, placebo-controlled REVEAL trial, which evaluated the PASI 75 response rates between weeks 4 and 24 of treatment in 1,212 patients (J. Am. Acad. Dermatol. 2008;58:106-15). Data from the trial showed that the PASI 75 response rates among patients on adalimumab were 19% at week 4, 54% at week 8, 68% at week 12, 71% at week 16, and 70% at week 24.
A second component of the trial evaluated the sustained responsiveness from weeks 16-33 in adalimumab-treated patients. The researchers found that the mean percentage of PASI improvement in this cohort was 92% at week 16, 92% at week 24, and 89% at week 33.
The great majority, but not all, of patients on adalimumab maintain responses, said Dr. Gordon, who heads the division of dermatology at NorthShore University HealthSystem, Evanston, Ill. "We do lose patients with treatment over time."
A cohort of 233 patients from the trial who received continuous adalimumab therapy up to 100 weeks showed that 100% of patients achieved a PASI 75 at week 33. But the percentage who sustained a PASI 75 dropped over time, from 85% at week 52 to 87% at week 76, and 83% at week 100.
"This tells me that of the patients who are doing well after about 8 months, the great majority are going to maintain response, but there are going to be a few that lose," he said. "It's the patients that are having marginal responses that you lose."
As for safety, the side effect profile seems to be relatively consistent with adalimumab. "It does not seem to increase over time," he emphasized. Data from the REVEAL trial found that the rate of serious adverse events was similar to the placebo group, about 1.8%.
According to pooled data from integrated studies, the top five most common adverse reactions are nasopharyngitis, followed by upper respiratory infection, headache, arthralgia, and injection site reaction.
If loss of efficacy with long-term use of adalimumab occurs in patients with psoriasis, it tends to happen in the first year.
"We think about treatment for psoriasis in 12- or 16-week blocks because that's what the primary end points of the clinical trials are," he said. "But psoriasis is a long-term disease. People have it for 20, 30, or 40 years, so we need to think beyond the realm of short-term."
Dr. Gordon disclosed that he has received research support or honoraria from Abbott, which manufactures adalimumab as Humira, as well as Amgen, Astellas, Centocor, and Genentech.