Anakinra for rheumatoid arthritis

Platelets amplify inflammation in arthritis via collagen-dependent microparticle production

In addition to their pivotal role in thrombosis and wound repair, platelets participate in inflammatory responses. We investigated the role of platelets in the autoimmune disease rheumatoid arthritis. We identified platelet microparticles--submicrometer vesicles elaborated by activated platelets--in joint fluid from patients with rheumatoid arthritis and other forms of inflammatory arthritis, but not in joint fluid from patients with osteoarthritis. Platelet microparticles were proinflammatory, eliciting cytokine responses from synovial fibroblasts via interleukin-1. Consistent with these findings, depletion of platelets attenuated murine inflammatory arthritis. Using both pharmacologic and genetic approaches, we identified the collagen receptor glycoprotein VI as a key trigger for platelet microparticle generation in arthritis pathophysiology. Thus, these findings demonstrate a previously unappreciated role for platelets and their activation-induced microparticles in inflammatory joint diseases.

IL-1B polymorphism in association with initial intravenous immunoglobulin treatment failure in Taiwanese children with Kawasaki disease

BACKGROUND

Approximately 8-38% of children with Kawasaki disease (KD) will have persistent or recrudescent fever after initial intravenous immunoglobulin (IVIG) treatment and are at increased risk for development of coronary artery abnormalities. Using genetic markers may be helpful to identify the high-risk group of IVIG-resistant patients for aggressive treatment. The aim of this study was to evaluate the associations between 4 potential polymorphisms in the interleukin (IL)-1 family of genes and initial IVIG treatment failure in KD children.

METHODS AND RESULTS

A total of 156 KD children (136 with and 20 without a response to IVIG treatment) who were treated with high-dose IVIG (2 g/kg) within 10 days of fever onset were recruited. Polymerase chain reaction and Taqman assays were used for genotyping. A significant increase in IVIG resistance risk was observed for IL-1B -511 TT and IL-1B -31 CC genotypes (adjusted odds ratio (AOR) 5.27, 95% confidence interval (CI) 1.69-16.38, P=0.004; AOR 3.95, 95%CI 1.26-12.41, P=0.019, separately). The diplotype TC/TC (at IL-1B -511 and -31) also showed a significantly increased risk of IVIG resistance (AOR 4.32, 95%CI 1.36-13.71, P=0.013).

CONCLUSIONS

The IL-1B -511 TT and IL-1B -31 CC genotypes or the TC/TC diplotype may be associated with initial IVIG treatment failure in Taiwanese children with KD.

Efficacy and safety of anakinra for the treatment of rheumatoid arthritis: an update of the Oregon Drug Effectiveness Review Project

OBJECTIVE

To systematically review the general and comparative efficacy and safety of anakinra for rheumatoid arthritis.

METHODS

We searched MEDLINE((R)), Embase, The Cochrane Library, and the International Pharmaceutical Abstracts from 1980 to April 2009. We manually searched reference lists of pertinent review articles and explored the Center for Drug Evaluation and Research database. For efficacy we included randomized controlled trials (RCTs) comparing anakinra with placebo or other biologics. For safety both experimental and observational studies were eligible. Two persons independently reviewed abstracts and full text articles and extracted relevant data.

RESULTS

We included data from 3 RCTs comparing anakinra with placebo for rheumatoid arthritis (RA). The pooled relative risk (RR) of an ACR50 (American College of Rheumatology) response for anakinra compared with placebo is 2.28 (95% CI 1.41 to 3.67). Adjusted indirect comparisons of ACR50 response rates of anakinra and anti-TNF agents showed a RR of 0.67 (95% CI 0.38 to 1.17) favoring the anti-TNF drugs. This result did not reach statistical significance. For safety, we included 9 experimental and observational studies of 24 weeks to 3 years duration. Up to 30% of patients withdrew from the studies due to adverse events. 67.2% (95% CI 38.7 to 95.7) of patients experienced an injection site reaction.

CONCLUSIONS

Anakinra is an effective drug for treating RA. Indirect comparisons with adalimumab, etanercept and infliximab, however, showed a trend towards greater efficacy for the anti-TNF drugs. Anakinra also seems to be associated with comparably high rates of injection site reactions. These results should be taken into account when considering biologic therapy for patients with RA.

A network meta-analysis of randomized controlled trials of biologics for rheumatoid arthritis: a Cochrane overview

BACKGROUND

We sought to compare the benefits and safety of 6 biologics (abatacept, adalimumab, anakinra, etanercept, infliximab and rituximab) in patients with rheumatoid arthritis.

METHODS

In this network meta-analysis, we included all completed and updated Cochrane reviews on biologics for rheumatoid arthritis. We included data from all placebo-controlled trials that used standard dosing regimens. The major outcomes were benefit (defined as a 50% improvement in patient- and physician-reported criteria of the American College of Rheumatology [ACR50]) and safety (determined by the number of withdrawals related to adverse events). We used mixed-effects logistic regression to carry out an indirect comparison of the treatment effects between biologics.

RESULTS

Compared with placebo, biologics were associated with a clinically important higher ACR50 rate (odds ratio [OR] 3.35, 95% confidence interval [CI] 2.62-4.29) and a number needed to treat for benefit of 4 (95% CI 4-6). However, biologics were associated with more withdrawals related to adverse events (OR 1.39, 95% CI 1.13-1.71), with a number needed to treat for harm of 52 (95% CI 29-152). Anakinra was less effective than all of the other biologics, although this difference was statistically significant only for the comparison with adalimumab (OR 0.45, 95% CI 0.21-0.99) and etanercept (OR 0.34, 95% CI 0.14-0.81). Adalimumab, anakinra and infliximab were more likely than etanercept to lead to withdrawals related to adverse events (adalimumab OR 1.89, 95% CI 1.18-3.04; anakinra OR 2.05, 95% CI 1.27-3.29; and infliximab OR 2.70, 95% CI 1.43-5.26).

INTERPRETATION

Given the limitations of indirect comparisons, anakinra was less effective than adalimumab and etanercept, and etanercept was safer than adalimumab, anakinra and infliximab. This summary of the evidence will help physicians and patients to make evidence-based choices about biologics for the treatment of rheumatoid arthritis.

Efficacy, safety, and tolerability of abatacept in the management of rheumatoid arthritis

The management of rheumatoid arthritis (RA) has undergone an impressive transformation over the past few decades. Further understanding of the pathophysiology of the disease process has resulted in the development of biologic agents that target proinflammatory cytokines and both B and T lymphocytes. By blocking an important costimulatory pathway, abatacept leads to a dramatic reduction in T cell stimulation and proliferation. Multiple clinical trials have revealed consistent benefit with regards to clinical and radiographic efficacy, quality of life, and disability in patients suffering from RA who have had inadequate responses to methotrexate or tumor necrosis factor inhibitors. The possibility of remission when used early in the disease course has also been demonstrated. Importantly, abatacept has been very well tolerated with a low rate of serious infections and no apparent increase in malignancies to date. Continued surveillance of the benefits and risks will help to better define its place amongst the other biologic agents in the treatment of RA.