TB risk varies between anti-TNFs

Infliximab and adalimumab are associated with a three- to four-fold higher rate of tuberculosis compared to etanercept, data from the British Society for Rheumatology Biologics Register shows. The data also shows a six and a half-fold increased risk for tuberculosis diagnosis in non-white patients compared to white patients. Published in the Annals of the Rheumatic Diseases, the study examined data from over 10,700 patients with active RA who were prescribed anti-TNFs and over 3,200 patients who were prescribed DMARDs between 2001 and 2008. It identified 40 reported cases of tuberculosis (TB), all of which were in the anti-TNF cohort. After adjustment, the incidence rate ratio compared to patients treated with etanercept was 3.1 for infliximab and 4.2 for adalimumab. The study authors said the data indicated that the increased risk of TB was confined to anti-TNFs because if the DMARD cohort had the same risk of developing TB they would have expected to see ten cases. “The magnitude of difference between the observed and expected cases strongly suggests that anti-TNF therapy is associated with significant risk of tuberculosis above and beyond the risk conferred by RA alone,” they said. They pointed out that the rate of TB seen in the anti-TNF cohort was eight times higher than that seen in the general population. However, they said that it was important for clinicians to be aware that, although the rates of TB in patients taking infliximab and adalimumab were high, the overall number of cases was low. They also noted that while the rate of TB seen in patients taking etanercept was lower, “clinicians should still be aware that etanercept still confers an increased risk”. Lastly, they said that many patients had contracted the disease after they had stopped taking their medication. “This should remind clinicians to remain vigilant… even after discontinuing anti-TNF therapy,” they said. Annals of the Rheumatic Diseases; Online First...