Can biologic treatments influence the occurrence of infections in patients with rheumatoid arthritis?

This study compared the occurrence of infections and identified their risk factors in patients with rheumatoid arthritis (RA) that were treated with tofacitinib (Xeljanz) against those given a tumor necrosis factor inhibitor (TNFi). The data showed that serious and non-serious infections were higher in patients that received tofacitinib compared to a TNFi.

Patients with RA have a higher risk of developing serious and non-serious infections. Reasons for this include the disease activity of RA, age of patients, lifestyle, having other conditions along with RA, and RA treatments.

Several treatment options exist for patients with RA. Patients’ risk of infections can vary depending on treatment type. Tofacitinib is a Janus kinase (JAK) inhibitor. It works by blocking the immune system. This reduces inflammation associated with RA. Etanercept (Enbrel) and adalimumab (Humira) are TNFis. These drugs also reduce inflammation by blocking TNF, an inflammatory protein.

It has been shown that patients with RA are more prone to infections compared to the general population. Etanercept has been shown to reduce the risk of infections in contrast to other TNFis and tofacitinib. Based on these observations, it is necessary to assess the safety of tofacitinib against TNFis in patients with RA and to identify significant risk factors for infections.

This study included 4362 patients with RA, aged 50 years or older with at least one risk factor for cardiovascular disease. Patients were treated with oral tofacitinib or a TNFi (adalimumab or etanercerpt). 1455 patients received oral tofacitinib at a dose of 5 mg, twice daily. 1456 patients were given 10 mg of oral tofacitinib, twice-daily. 1451 patients received a TNFi. Patients were assessed on all infections, serious or non-serious infections, herpes zoster (HZ), and tuberculosis (TB). Patients were followed for 4 years.

Overall, all infections, serious and non-serious infections were higher in patients that received 5 mg and 10 mg of tofacitinib compared to those that were given a TNFi. Patients that were 65 years or older had an increased risk of all infections and serious infections compared to patients between 50 years to 65 years. Predictive risk factors for serious infections were age, opioid use, chronic lung disease, and time-dependent use of corticosteroids.

The data showed that tofacitinib resulted in increased infections compared to adalimumab and etanercept in patients older with RA.

The study design was not designed for direct comparisons between treatment groups. This means that definitive conclusions cannot be drawn about serious infections. More studies are needed. This study was funded by Pfizer, the manufacturer of tofacitinib.