The Food and Drug Administration has approved abatacept, a selective T-cell costimulation modulator, for treating adults with active psoriatic arthritis (PsA), the manufacturer, Bristol-Myers Squibb, has announced.
Approval of abatacept (Orencia) was based on two randomized, double-blind, placebo-controlled studies (PsA-I and PsA-II) in 594 adults with PsA for more than 7 years, according to the July 6 announcement . Patients had active PsA (at least three swollen joints and at least three tender joints), despite previous disease-modifying antirheumatic drug (DMARD) therapy and had one qualifying psoriatic skin lesion measuring at least 2 cm in diameter. The studies included patients treated with TNF inhibitors (TNFi) previously.
In the PsA-I trial, 170 patients received abatacept administered intravenously (IV) at days 1, 15, 29, and then every 28 days for 24 weeks, followed by open-label abatacept every 28 days. Patients were then randomized to placebo or treatment with abatacept 3 mg/kg, 10 mg/kg, or two doses of 30 mg/kg followed by weight range–based dosing of 10 mg/kg without escape for 24 weeks.
In the PsA-II trial, 424 patients received weekly doses of placebo or abatacept 25 mg administered subcutaneously (SC) without a loading dose for 24 weeks, followed by open-label abatacept at a dose of 125 mg SC weekly.
Compared with those on placebo, more patients treated with abatacept 10 mg/kg IV or 125 mg SC achieved an ACR 20 (American College of Rheumatology 20) response at 24 weeks: 47.5% vs. 19.0% and 39.4% vs. 22.3%, respectively (P less than .05).
Other results included a greater proportion of abatacept SC patients with at least a 0.35 decrease from baseline on the Health Assessment Questionnaire-Disability Index: 31% vs. 24% on placebo at 24 weeks. Responses were seen regardless of prior anti-TNFi treatment and regardless of concomitant non-biologic DMARD treatment. In addition, patients on abatacept IV and SC had improvements in enthesitis and dactylitis at 24 weeks.
The safety profile of abatacept in the two studies was “consistent with the safety profile” in rheumatoid arthritis, according to the company release.
Abatacept, initially approved in 2005, was previously approved for RA in adults and for juvenile idiopathic arthritis
Find the updated prescribing information for abatacept here .