Abatacept, rituximab and tocilizumab and infection risk in rheumatoid arthritis

Takeaway

• Patients with rheumatoid arthritis (RA) treated with non-TNF-inhibitor (non-TNFi) biologic disease-modifying antirheumatic drugs were at a higher risk for overall infections.
• The risk appeared higher with rituximab vs abatacept and tocilizumab during the first and second year of treatment.

Why this matters

• Only a few studies have investigated the overall risk for infection (prescription of antibiotics or hospitalisation due to infection) in patients initiating non-TNF-inhibitor therapy.

Study design

• An observational cohort study identified 3696 treatment episodes among 2716 patients with RA (abatacept, n=1115; rituximab, n=1017; tocilizumab, n=1564).
• Main outcome: occurrence of the first infection at 12 and 24 months.
• Funding: AbbVie and others.

Key results

• Adjusted incidence rate (aIR) per 100 person-years (PY) was as follows:
  • at first 12 months: abatacept (aIR, 76; 95% CI, 69-84); rituximab (aIR, 87; 95% CI, 79-96); tocilizumab (aIR, 77; 95% CI, 71-84).
  • at first 24 months: abatacept (aIR, 66; 95% CI, 61-72); rituximab (aIR, 76; 95% CI, 70-80); tocilizumab (aIR, 69; 95% CI, 65-75).
• After 12 months, the overall risk for infections was lower with:
  • abatacept vs rituximab (RR, 0.94; 95% CI, 0.81-1.08) and
  • tocilizumab vs rituximab (RR, 0.94; 95% CI, 0.81-1.03).
• After 24 months, the overall risk for infections reduced with:
  • abatacept vs rituximab (RR, 0.95; 95% CI, 0.83-1.10),
  • tocilizumab vs rituximab (RR, 0.98; 95% CI, 0.86-1.12) and
  • abatacept vs tocilizumab (RR, 0.98; 95% CI, 0.86-1.10).
• The risk for infections was higher for all combined drugs among:
  • switchers vs biologics-naïve (RR, 1.27; 95% CI, 1.13-1.44) and
  • smokers vs never smokers (RR, 1.13; 95% CI, 1.00-1.27).

Limitations

• Risk for information bias and residual confounding.