Arthritis & Rheumatism, Volume 60,
October 2009 Abstract Supplement

The 2009 ACR/ARHP Annual Scientific Meeting
Philadelphia October 16-21, 2009.


Abatacept in Psoriatic Arthritis: Results of a Phase II Study

Mease1,  P., Genovese2,  M., Ritchlin3,  C., Wollenhaupt4,  J., Tak5,  Paul P., Kivitz6,  A., Gladstein7,  G.

Swedish Medical Ctr/Univ. of Washington, Seattle, WA,
Stanford Univ., Palo Alto, CA,
Univ. of Rochester, Rochester, NY,
Klinikum Eilbek, Hamburg, Germany,
Academic Medical Center/University of Amsterdam, Amsterdam, Netherlands,
Altoona Center for Clinical Research, Duncansville, PA,
New England Research Assoc, Trumbull, CT,
Bristol-Myers Squibb, Princeton, NJ,
Univ. of Toronto, Toronto, ON

Purpose:

Abatacept (ABA) is a selective co-stimulation modulator approved for the treatment of RA and juvenile idiopathic arthritis. Here we assess the efficacy of ABA in patients (pts) with psoriatic arthritis (PsA) previously exposed to DMARDs in a phase II study.

Method:

In this double-blind study, PsA pts with a target lesion (TL) >= 2 cm were randomized (1:1:1:1) to placebo (PBO) and ABA at 3, 10, and 30/10 (30 × 2 followed by 10) mg/kg (mpk). Treatments were administered on Days 1, 15, 29, and then once every 28 days. The primary endpoint was ACR20 at Day 169. Secondary endpoints were Health Assessment Questionnaire (HAQ), Short Form-36 (SF-36), investigator global assessment (IGA), TL score at Day 169, and safety. Psoriasis area and severity index (PASI) and magnetic resonance imaging (MRI) score of the joints 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). Significant number of pts achieved ACR20 with ABA (10 and 30/10 mpk) compared to PBO (table). Improvements in HAQ, physical component summary (PCS) and MRI score were also seen with ABA compared to PBO. The skin response in terms of TL and PASI showed a separation between PBO and ABA arms, with the 3 mpk dose showing the most separation; an improved IGA response was seen only with 3 mpk. 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.

ABA
Response30/10 mpk* n = 4310 mpk n = 403 mpk N = 45PBO n = 42
Joint    
ACR20†42 (27, 57)48 (32, 63)33 (20, 47)19 (7, 31)
p vs. PBO0.0220.0060.121NA
Pre-exposed to anti-TNF therapy    
No, n21272930
ACR20†48 (26, 69)56 (37, 74)35 (17, 52)20 (6, 34)
Yes, n22131612
ACR20†36 (16, 57)31 (6, 56)31 (9, 54)17 (-4, 38)
MRI of joints‡    
Erosion0.3 (3.5)-0.6 (4.2)0.5 (2.4)1.5 (7.4)
Synovitis-0.8 (3.1)-1.4 (3.0)-0.2 (2.9)0.8 (4.3)
Edema-0.5 (1.9)-1.1 (2.6)-0.3 (1.7)0.4 (3.3)
Skin    
TL50†30 (17, 44)33 (18, 47)36 (22, 50)17 (5, 28)
TL75†16 (5, 27)10 (1, 19)29 (16, 42)10 (1, 18)
Patient-reported outcomes    
HAQ§†35 (21, 49)45 (30, 60)36 (22, 50)19 (7, 31)
PCS‡7.3 (1.9)9.3 (1.9)6.3 (1.8)0.2 (1.9)
*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 at 10 mpk significantly improved ACR20 and physical function in PsA pts, consistent with previous trials in RA. ABA treatment also resulted in less joint damage by MRI evaluation. All doses showed improvement in TL score with the 3 mpk dose showing the most.

To cite this abstract, please use the following information:
Mease, P., Genovese, M., Ritchlin, C., Wollenhaupt, J., Tak, Paul P., Kivitz, A., et al; Abatacept in Psoriatic Arthritis: Results of a Phase II Study [abstract]. Arthritis Rheum 2009;60 Suppl 10 :1260
DOI: 10.1002/art.26334

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