Comparative Immunogenicity of TNF Inhibitors: Impact on Clinical Efficacy and Tolerability in the Management of Autoimmune Diseases. A Systematic Review and Meta-Analysis.

BACKGROUND: Tumor necrosis factor (TNF) inhibitors are a mainstay in the treatment of rheumatoid arthritis (RA), as well as in the management of spondyloarthritis (SpA) and inflammatory bowel diseases (IBD). Unfortunately, a portion of patients taking these drugs require escalating doses within the approved label to achieve response, while others lose response altogether. This may be due to the development of antibodies against TNFi agents. OBJECTIVES: Our objective was to examine the immunogenicity of TNF inhibitors (adalimumab, infliximab, etanercept, golimumab, and certolizumab) in RA, SpA, and IBD, and to examine the potential effect of anti-drug antibodies (ADABs) on the loss of clinical response through a systematic literature review and meta-analysis. METHODS: We conducted a comprehensive literature search using three databases (PubMed, Web of Science, and the Cochrane library) to identify studies examining the immunogenicity of TNF inhibitors in autoimmune diseases between 1966 and 31 December 2013. Inclusion criteria required that studies be in English, be randomized controlled trials, observational studies, or case reports involving more than five patients, and that the patients be aged 18 years or older. Studies were excluded if they were strictly genetic with no clinical correlate, if the patients had concomitant cancer within 5 years of the study, or if the patients had a renal disease requiring dialysis. Double extraction was followed by a third extraction if needed. Consensus was reached by discussion when disagreements occurred. Random-effect models were generated for the meta-analysis of 68 studies to estimate the odds ratio (OR) of the ADAB effects on TNF inhibitor response. Regression analysis was used to compare among the drugs and diseases. RESULTS: A total of 68 studies (14,651 patients) matched the inclusion/exclusion criteria. Overall, the cumulative incidence of ADABs was 12.7 % [95 % confidence interval (CI) 9.5-16.7]. Of the patients using infliximab, 25.3 % (95 % CI 19.5-32.3) developed ADABs compared with 14.1 % (95 % CI 8.6-22.3) using adalimumab, 6.9 % (95 % CI 3.4-13.5) for certolizumab, 3.8 % (95 % CI 2.1-6.6) for golimumab, and 1.2 % (95 % CI 0.4-3.8) for etanercept. ADABs reduced the odds of clinical response by 67 % overall, although most of the data were derived from articles involving infliximab (nine) and adalimumab (eight). The summary effect for infliximab yielded an estimated OR (with ADABs vs. without) of 0.42 (95 % CI 0.30-0.58); the summary effect for adalimumab yielded an estimated OR (as above) of 0.13 (95 % CI 0.08-0.22); and the OR (as above) for golimumab was 0.42 (95 % CI 0.22-0.81). All figures were statistically significant. ADABS decreased response by 27 % in RA and 18 % in SpA, both of which were statistically significant. However, the effect of ADABS on response was not statistically significant for IBD when we only included the studies that reported the duration of exposure in the regression analysis. The use of concomitant immunosuppressives (methotrexate, 6-mercaptopurine, azathioprine, and others) reduced the odds of ADAB formation in all patients by 74 %. The OR for risk with immunosuppressives versus without was 0.26 (95 % CI 0.21-0.32). CONCLUSION: ADABs developed in 13 % of patients. All five TNF inhibitors were associated with ADABs, but to varying degrees depending on the specific TNF inhibitor and the disease. ADABs are associated with reduced clinical response and an increased incidence of infusion reactions and injection site reactions. Concomitant use of immunosuppressives can reduce ADAB formation.

Tocilizumab in rheumatoid arthritis: a meta-analysis of efficacy and selected clinical conundrums.

INTRODUCTION: Tocilizumab (TCZ) is a biological agent used for the treatment of moderate to severe rheumatoid arthritis (RA). In the present systematic literature review and meta-analysis, we provide an update on the efficacy and safety of TCZ and our clinical comments for the treatment of RA. METHODS: We searched PubMed for randomized, double-blind, placebo-controlled clinical trials investigating the effects of TCZ on RA. The initial search included articles from 1966 to December 2011. The search was subsequently updated in April 2013. Studies had to report clinical efficacy using American College of Rheumatology (ACR) 20, 50, and 70 disease measures. The studies included participants who were 18 years of age and who met the ACR 1987 revised criteria for RA for 6 months or longer. Two reviewers independently abstracted the data, and disagreement was resolved by discussion with a third reviewer. Outcome measures were analyzed as odds ratio using the Mantel-Haenszel estimator under a random effects model to account for heterogeneity in intervention effects between trials. Descriptive statistics were used to compare adverse events. RESULTS: After reviewing and culling, 8 randomized, controlled, double-blind studies were included in the efficacy meta-analysis. TCZ 8mg/kg was statistically favored over TCZ 4mg/kg or placebo regarding ACR responses. Clinically significant adverse events that occurred with TCZ treatment included infections, lipid and liver function test abnormalities, and gastrointestinal side effects, all of which were more common with TCZ. CONCLUSIONS: This meta-analysis supports the use of TCZ as an appropriate treatment for moderate to severe RA as monotherapy and combination therapy. Close monitoring for significant adverse events is required when treating patients with TCZ. Future long-term trials should focus further on safety of this agent.

Management of coccidioidomycosis in patients receiving biologic response modifiers or disease-modifying antirheumatic drugs.

OBJECTIVE: Coccidioidomycosis (valley fever) is an endemic fungal infection of the American Southwest, an area with a large population of patients with rheumatic diseases. There are currently no guidelines for management of patients who develop coccidioidomycosis while under treatment with biologic response modifiers (BRMs) or disease-modifying antirheumatic drugs (DMARDs). We conducted a retrospective study of how both concurrent diseases were managed and the patient outcomes at 2 centers in Tucson, Arizona. METHODS: A retrospective chart review identified patients who developed coccidioidomycosis during treatment with DMARDs or BRMs. Patients were seen at least once in a university-affiliated or Veterans Affairs outpatient rheumatology clinic in Tucson, Arizona, between 2007 and 2009. RESULTS: Forty-four patients were identified. Rheumatologic treatment included a BRM alone (n = 11), a DMARD alone (n = 8), or combination therapy (n = 25). Manifestations of coccidioidomycosis included pulmonary infection (n = 29), disseminated disease (n = 9), and asymptomatic positive coccidioidal serologies (n = 6). After the diagnosis of coccidioidomycosis, 26 patients had BRMs and DMARDs stopped, 8 patients had BRMs stopped but DMARD therapy continued, and 10 patients had no change in their immunosuppressive therapy. Forty-one patients had antifungal therapy initiated for 1 month or longer. Followup data were available for 38 patients. BRM and/or DMARD therapy was continued or resumed in 33 patients, only 16 of whom continued concurrent antifungal therapy. None of the patients have had subsequent dissemination or complications of coccidioidomycosis. CONCLUSION: Re-treating rheumatic disease patients with a BRM and/or a DMARD after coccidioidomycosis appears to be safe in some patients. We propose a management strategy based on coccidioidomycosis disease activity.