SAT0288 ABATACEPT IN PATIENTS WITH PSORIATIC ARTHRITIS: RESULTS OF A PHASE II STUDY

P. Mease ^1,*M. Genovese ²C. Ritchlin ³J. Wollenhaupt ⁴P.-P. Tak ⁵A. Kivitz ⁶G. Gladstein ⁷O. Bahary ⁸S. Kelly ⁸J. Teng ⁸J.-C. Becker ⁸D. Gladman ⁹

¹UNIVERSITY OF WASHINGTON, Seattle, ²Stanford University, Palo Alto, ³University of Rochester, Rochester, United States, ⁴University of Klinische Immunologie, Hamburg, Germany, ⁵University of Amsterdam, Amsterdam, Netherlands, ⁶Altoona Center for Clinical Research, Duncansville, ⁷New England Research Associates, LLC, Trumbull, ⁸Bristol-Myers Squibb, Princeton, United States, ⁹University of Toronto, Toronto, Canada

Background: Abatacept (ABA) is a selective co-stimulation modulator approved for the treatment of rheumatoid arthritis (RA) and juvenile idiopathic arthritis (JIA).

Objectives: Here, we assess the efficacy of ABA in patients (pts) with psoriatic arthritis (PsA) in a phase II study.

Methods: In this double-blind, placebo-controlled study, 170 pts with a psoriasis target lesion (TL) ≥ 2 cm previously exposed to DMARDs including anti-TNF therapies were randomized (1:1:1:1) to receive either placebo or abatacept at 3, 10, or 30/10 mg/kg (two initial doses of 30 mg/kg, followed by 10 mg/kg) on Days 1, 15, 29, and once every 28 days thereafter. The primary endpoint was ACR20 at Day 169.  Key secondary endpoints were Health Assessment Questionnaire (HAQ), Short Form-36 (SF-36), investigator global assessment (IGA) of psoriasis, and TL scores at Day 169. Magnetic resonance imaging (MRI) scores for joint damage and Psoriasis Area and Severity Index (PASI) at Day 169 were exploratory.

Results: Baseline characteristics were similar among groups except for more pts being previously exposed to anti-TNF therapies in the 30/10 mpk arm (51%) than other arms (29-36%). Of 170 pts treated, 147 completed first 6 months of treatment; 23 pts discontinued (7 for AEs and 10 for lack of efficacy). Proportions of patients achieving ACR20 were significantly higher (p < 0.05) for abatacept 10 mg/kg and 30/10 mg/kg compared to placebo (Table). All abatacept regimens resulted in improved MRI, HAQ and SF-36 physical component summary (PCS) scores, with 10 mg/kg showing the greatest improvements. Improvements of ≥ 50% in TL and PASI were observed in all abatacept arms, with 3 mg/kg being numerically better than 10 mg/kg; an IGA response was seen only with 3 mg/kg. Improvements in ACR20 and TL were greater in anti-TNF-naive pts than in pts pre-exposed to anti-TNF therapies. The safety profiles were similar among arms.

 *30 mpk followed by 10 mpk; †% pts with 95% CI; ‡Adjusted mean (± SE) change from baseline; §Improvement of ≥ 0.3 unit from baseline

Conclusion: ABA improved signs and symptoms of arthritis and psoriasis, and physical function in PsA pts. ABA treatment also resulted in less joint damage by MRI evaluation. These results suggest that ABA 10 mg/kg, the currently approved ABA regimen for RA and JIA, may be an effective treatment option for PsA.

Disclosure of Interest: P. Mease Grant / Research Support from: BMS Consultant for: BMS Speakers Bureau: BMSM. Genovese Grant / Research Support from: BMS Consultant for: BMS Speakers Bureau: BMSC. Ritchlin Grant / Research Support from: Centocor Consultant for: Amgen, BMS, Roche, Sanofi, Wyeth, CentocorJ. Wollenhaupt: None DeclaredP.-P. Tak Grant / Research Support from: BMSA. Kivitz Speakers Bureau: Amgen, Novartis, Takeda, RocheG. Gladstein Grant / Research Support from: Pfizer, Genentech, BMS, Roche, Forest, Cephalon, Regeneron, Centocor Speakers Bureau: BMSO. Bahary Shareholder of: BMS Employee of: BMSS. Kelly Shareholder of: BMS Employee of: BMSJ. Teng Shareholder of: BMS Employee of: BMSJ.-C. Becker Shareholder of: BMS Employee of: BMSD. Gladman Consultant for: Abbott, Amgen, Centocor, Schering, Wyeth, Roche, UCB