Malignancy outcomes in patients with rheumatoid arthritis treated with abatacept and other disease-modifying antirheumatic drugs: Results from a 10-year international post-marketing study.

OBJECTIVE: To evaluate the risk of malignancy (overall, breast, lung, and lymphoma) in patients with rheumatoid arthritis treated with abatacept, conventional synthetic (cs) disease-modifying antirheumatic drugs (DMARDs), and other biologic/targeted synthetic (b/ts)DMARDs in clinical practice. METHODS: Four international observational data sources were included: ARTIS (Sweden), RABBIT (Germany), FORWARD (USA), and BC (Canada). Crude incidence rates (IRs) per 1000 patient-years of exposure with 95% confidence intervals (CIs) for a malignancy event were calculated; rate ratios (RRs) were estimated and adjusted for demographics, comorbidities, and other potential confounders. RRs were then pooled in a random-effects model. RESULTS: Across data sources, mean follow-up for patients treated with abatacept (n = 5182), csDMARDs (n = 73,755), and other b/tsDMARDs (n = 37,195) was 3.0-3.7, 2.9-6.2, and 3.1-4.7 years, respectively. IRs per 1000 patient-years for overall malignancy ranged from 7.6-11.4 (abatacept), 8.6-13.2 (csDMARDs), and 5.0-11.8 (other b/tsDMARDs). IRs ranged from: 0-4.4, 0-3.3, and 0-2.5 (breast cancer); 0.1-2.8, 0-3.7, and 0.2-2.9 (lung cancer); and 0-1.1, 0-0.9, and 0-0.6 (lymphoma), respectively, for the three treatment groups. The numbers of individual cancers (breast, lung, and lymphoma) in some registries were low; RRs were not available. There were a few cases of lymphoma in some of the registries; ARTIS observed an RR of 2.8 (95% CI 1.1-6.8) with abatacept versus csDMARDs. The pooled RRs (95% CIs) for overall malignancy with abatacept were 1.1 (0.8-1.5) versus csDMARDs and 1.0 (0.8-1.3) versus b/tsDMARDs. CONCLUSIONS: This international, post-marketing observational safety study did not find any statistically significant increase in the risk of overall malignancies in pooled data in patients treated with abatacept compared with csDMARDs or with other b/tsDMARDs. Assessment of larger populations is needed to further evaluate the risks for individual cancers, especially lymphoma.

Incidence of non-Hodgkin's lymphoma among individuals with chronic hepatitis B virus infection.

UNLABELLED: Although hepatitis C virus (HCV) infection has been shown to be associated with development of non-Hodgkin's lymphoma (NHL), few studies have investigated the association between chronic HBV infection and NHL. The purpose of this study was to compare the incidence of NHL between patients with and without chronic hepatitis B virus (HBV) infection. Using automated laboratory result and clinical data from two United States health systems, we identified individuals with chronic HBV infection from January 1, 1995 through December 31, 2001. Using each health system's population-based tumor registry, we identified all cases of NHL diagnosed through December 31, 2002. We excluded any individual with a history of NHL or human immunodeficiency virus (HIV). We fit Cox proportional hazards models to calculate hazard ratios comparing the incidence of NHL between chronic HBV-infected patients (N = 3,888) and patients without HBV (N = 205,203) drawn from the source populations. We identified 8 NHL cases in the chronic HBV infection cohort and 111 cases in the comparison cohort. Patients with chronic HBV infection were 2.8 times more likely to develop NHL than matched comparison patients (adjusted hazard ratio = 2.80, 95% confidence interval = 1.16-6.75), after controlling for age, race, sex, income, Charlson comorbidity index, study site, and HCV infection. CONCLUSION: chronic HBV-infected patients were nearly 3 times more likely to develop NHL than comparison patients.