AMSTERDAM – Certolizumab pegol maintained significant improvement in dermatologic outcomes in psoriatic arthritis patients through 96 weeks of treatment in the phase III RAPID-PsA trial.
Moreover, the safety profile of this tumor necrosis factor (TNF) inhibitor was in line with findings from shorter-term studies, including the week 24 report from RAPID-PsA. Treatment-emergent adverse events were similar in type and frequency to those in placebo-treated controls, with the exception of an increased rate of minor upper respiratory tract infections. No cases of tuberculosis occurred.
“There were no new safety issues despite the increased exposure time out to 96 weeks,” Dr. Owen Davies reported at the annual congress of the European Academy of Dermatology and Venereology.
RAPID-PsA is an ongoing 216-week phase III study. It was double-blind and placebo-controlled through the first 24 weeks. The study started out with 409 psoriatic arthritis patients, half of whom had previously failed to response to one nonbiologic disease-modifying antirheumatic drug (DMARD), while the other half had been nonresponders to two or more. Of the 273 patients placed on certolizumab, 80% completed both 48 and 96 weeks of the study, explained Dr. Davies of UCB Pharma in Slough, England.
He focused on the dermatologic outcomes because the arthritis outcomes have previously been reported and served to support certolizumab’s regulatory approval for the treatment of psoriatic arthritis. The biologic is also approved for treatment of rheumatoid arthritis, ankylosing spondylitis, and Crohn’s disease. However, certolizumab’s durability of effect on the psoriatic skin manifestations of psoriatic arthritis hasn’t previously been addressed.
Briefly, at week 12 – the primary endpoint for the joint-related outcomes – 55% of patients achieved an ACR 20 response, compared with 24% on placebo. Moreover, 35% of certolizumab-treated patients had an ACR 50 response at that point, and 20% had an ACR 70 response. The ACR response rate in certolizumab-treated patients was similar regardless of whether or not they had previously been on another anti-TNF biologic.
Dr. Davies addressed in detail the dermatologic outcomes in the 166 psoriatic arthritis patients with at least 3% psoriasis body surface area involvement at baseline. They had an average 10-year disease duration, 24% body surface area involvement, and a baseline Psoriasis Area Severity Index (PASI) score of 12.0.
Dermatologic responses to certolizumab were comparable regardless of whether patients had been randomized to the biologic at 200 mg subcutaneously every 2 weeks or 400 mg once every 4 weeks. As was true for the joint-related responses to certolizumab, the skin responses were similar both in anti-TNF–naive and anti-TNF–experienced patients, he noted.
The PASI 75 response rate in this group of psoriatic arthritis patients with significant skin involvement was 61% at week 24, 65% at week 48, and 53% at week 96. The improvement was even greater in the 71 patients with more severe skin involvement as defined by a baseline PASI score of 10 or more. Certolizumab-treated patients also showed important improvements on the Physician Global Assessment and Dermatology Life Quality Index.
Certolizumab is a pegylated Fab’ fragment of a humanized TNF inhibitor monoclonal antibody.
“Certolizumab is structurally different from other currently available anti-TNF agents, which are either IgG1 monoclonal antibodies or, in the case of etanercept, a receptor fusion protein. Whether or not these structural differences will translate into clinical differences is a question being addressed in ongoing clinical trials,” Dr. Davies said.
The RAPID-PsA study is sponsored by UCB Pharma, where Dr. Davies is employed.