Patients with axial spondyloarthritis have a significantly lower likelihood of achieving improvement in disease activity or remission when their dose of tumor necrosis factor inhibitor therapy is reduced, based on a systematic review and meta-analysis of six trials that included 747 adults.

Tumor necrosis factor inhibitors (TNFi) “have shown significant sustained clinical improvement in axSpA and are introduced in patients with axial disease or as the next line of treatment after inadequate response to nonsteroidal anti-inflammatory drugs,” but this improvement comes with a degree of immunosuppression that can increase infection risk, wrote Daeria O. Lawson of Toronto Western Hospital and colleagues. However, the impact of reducing or discontinuing TNFi therapy, compared with standard dosing, has not been well examined, they said.

In a study published in Arthritis Care & Research, the investigators identified six randomized, controlled trials with a total of 747 adults. Overall, patients on a reduced dose had a lower likelihood of achieving 40% improvement in Assessment of SpondyloArthritis international Society response criteria (ASAS40) or ASAS partial remission, compared with those on a standard TNFi dose (risk ratios, 0.62 and 0.17, respectively).

In addition, the mean increase in the Bath Ankylosing Spondylitis Disease Activity Index score was 0.35 for patients on reduced TNFi therapy, and no differences were seen in C-reactive protein levels, infection rates, or injection/infusion reactions in patients on a reduced dose, compared with those on the standard dose.

Patients on the reduced TNFi dose also had more disease flares and/or relapses, compared with the standard group (risk ratio, 1.73).

The study findings were limited by several factors including the inability to compare subgroups based on dosing regimens, potential blinding and selection bias, and inadequate data to assess certain patient outcomes, including maintenance of disease remission and quality of life, the researchers noted. The results confirm findings from previous studies and support the benefit of standard dosing for maintaining stable disease, they said.

However, more research is needed to identify patients who may be more responsive to TNFi reduction, they wrote. “Although treatment recommendations for the best dose reduction strategies cannot be made at this time given the heterogeneity in tapering strategies reported in the literature, this decision should be an individualized one between the patient and their physician,” the researchers emphasized.

The study received no outside funding. Dr. Lawson is supported in part by the Ontario Drug Policy Research Network Student Training Program.

SOURCE: Lawson DO et al. Arthritis Care Res. 2020 Mar 12. doi: 10.1002/ACR.24184.