Two-year efficacy and safety of infliximab treatment in patients with active psoriatic arthritis: findings of the Infliximab Multinational Psoriatic Arthritis Controlled Trial (IMPACT).
OBJECTIVE
To investigate longterm efficacy/safety of infliximab over 2 years in patients with active psoriatic arthritis (PsA).


METHODS
Initially, 104 patients were randomized to receive blinded infusions of infliximab 5 mg/kg or placebo at Weeks 0, 2, 6, and 14. At Week 16, all patients received infliximab 5 mg/kg every 8 weeks through Week 46. Seventy-eight of the 87 patients completing the first year continued into the open-label longterm extension and received infliximab 5 mg/kg at Weeks 54, 62, 70, 78, 86, and 94. The primary efficacy endpoint for the study extension was the proportion of patients with at least 20% improvement in the American College of Rheumatology response criteria (ACR20) at Week 98. Radiographic progression was assessed by the PsA-modified van der Heijde-Sharp score in patients with radiographs available at baseline and Week 98 (n = 43).


RESULTS
At Week 98, 62% (48/78) of infliximab-treated patients achieved an ACR20 response; 45% (35/78) and 35% (27/78) of patients achieved ACR50 and ACR70 responses, respectively. Among patients with baseline Psoriasis Area and Severity Index scores >or= 2.5, 64% (16/25) achieved > 75% improvement from baseline to Week 98. The average estimated annual radiographic progression with infliximab treatment was significantly reduced versus the estimated baseline rate of progression. No new safety issues were observed during the second year of the study.


CONCLUSIONS
Therapy with infliximab 5 mg/kg through Week 94 produced sustained improvement in joint and skin symptoms, inhibited radiographic progression, and continued to exhibit a favorable benefit-risk ratio in this population with treatment-refractory PsA.
Antoni
Christian E
CE
Clinical Immunology, Schering-Plough Corporation, Kenilworth, New Jersey 07033-0530, USA. christian.antoni@spcorp.com
Kavanaugh
Arthur
A
van der Heijde
Désirée
D
Beutler
Anna
A
Keenan
Gregory
G
Zhou
Bei
B
Kirkham
Bruce
B
Tutuncu
Zuhre
Z
Burmester
Gerd R
GR
Schneider
Udo
U
Furst
Daniel E
DE
Molitor
Jerry
J
Keystone
Edward
E
Gladman
Dafna D
DD
Manger
Bernhard
B
Wassenberg
Siegfried
S
Weier
Ralf
R
Wallace
Daniel J
DJ
Weisman
Michael H
MH
Kalden
Joachim R
JR
Smolen
Josef S
JS
D000328:Adult; D000911:Antibodies, Monoclonal / Q000009:adverse effects / Q000627:therapeutic use*; D018501:Antirheumatic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D015535:Arthritis, Psoriatic / Q000000981:diagnostic imaging / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D000069285:Infliximab; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012720:Severity of Illness Index; D016037:Single-Blind Method; D016896:Treatment Outcome
D000911:Antibodies, Monoclonal; D018501:Antirheumatic Agents; D000069285:Infliximab