WASHINGTON – The oral Janus kinase inhibitor tofacitinib is safe and effective in patients with active psoriatic arthritis and an inadequate response to tumor necrosis factor inhibitors, according to findings from the phase III OPAL Beyond trial.
Both the American College of Rheumatology 20% improvement criteria (ACR20) response rate and change from baseline in Health Assessment Questionnaire Disability Index (HAQ-DI) scores at month 3 – the primary endpoints of the study – were superior with tofacitinib (Xeljanz) versus placebo in the 6-month, double-blind, randomized, multicenter trial, Dafna D. Gladman, MD, reported in a late-breaking poster at the annual meeting of the American College of Rheumatology.
Dr. Dafna D. Gladman
The superiority of tofacitinib over placebo in achieving an ACR20 response was evident as early as 2 weeks when the response rates were 13% in 131 patients who received placebo, 26.7% in 131 patients who received 5 mg of tofacitinib twice daily, and 28.8% in 132 patients who received 10 mg of tofacitinib twice daily, Dr. Gladman said. Later on at 3 months, the ACR20 response rates were 23.7% for placebo, 49.6% for 5 mg of tofacitinib twice daily, and 47% for 10 mg of tofacitinib twice daily.
The change from baseline in HAQ-DI scores was –0.14 with placebo, –0.39 with 5 mg tofacitinib, and –0.35 with 10 mg tofacitinib.
Study subjects had a 6-month or greater psoriatic arthritis diagnosis, fulfilled classification criteria for psoriatic arthritis, had active arthritis at screening and baseline and active plaque psoriasis at screening, and inadequate response to TNF inhibitors, which was defined as discontinuation for inadequate efficacy or due to an adverse event. All had ongoing treatment with a conventional synthetic disease-modifying antirheumatic agent, and those in the placebo group were advanced after 3 months to receive either 5 mg or 10 mg of tofacitinib twice daily (66 and 65 patients, respectively).
The effects of treatment on secondary efficacy endpoints were generally consistent with the findings with respect to the primary endpoints, Dr. Gladman said.
As for safety endpoints, serious adverse events and drug discontinuations due to adverse events were rare. Serious adverse event rates at 6 months were 3% in the placebo group who advanced to 5 mg tofacitinib, 1.5% in those who advanced to 10 mg tofacitinib, 3.8% in the original 5 mg tofacitinib group, and 6.1% in the original 10 mg tofacitinib group. Corresponding rates for all adverse events were 60.6%, 58.5%, 71%, and 72.7%. The most common adverse events were upper respiratory tract infections, nasopharyngitis, and headache.
OPAL Beyond was sponsored by Pfizer. Dr. Gladman disclosed financial relationships with AbbVie, Amgen, Bristol-Myers Squibb, Celgene, Janssen, Novartis, Pfizer, and UCB. Several other authors disclosed financial relationships with pharmaceutical companies, including Pfizer. Five of the 11 authors were employees of Pfizer.