Association Between Abatacept Exposure Levels and Infection Occurrence in Patients With Rheumatoid Arthritis: Post...

Area of Science:

• Rheumatology
• Pharmacokinetics
• Infectious Disease Epidemiology

Background:

• Rheumatoid arthritis (RA) is a chronic autoimmune disease.
• Subcutaneous abatacept (SC ABA) is a biologic therapy used for RA treatment.
• Understanding the relationship between drug exposure and adverse events like infections is crucial for patient safety.

Purpose of the Study:

• To investigate the association between serum exposure levels of subcutaneous abatacept (SC ABA) and the risk of infection in adult patients with early rheumatoid arthritis (RA).
• To evaluate the impact of concomitant medications and patient factors on this relationship.

Main Methods:

• Analysis of data from the randomized, placebo-controlled AVERT2 study.
• Population pharmacokinetic (PPK) analysis to model SC ABA pharmacokinetics.
• Evaluation of the association between steady-state ABA concentrations and first infection using Kaplan-Meier plots and Cox proportional hazards models.

Main Results:

• Higher body weight was the only significant covariate in the PPK model.
• Infection rates were similar between SC ABA + methotrexate (MTX) and placebo + MTX groups (47.6% vs 44.5%).
• No increased risk of first infection was observed based on ABA exposure, MTX/glucocorticoid (GC) use, baseline GC use, or higher body weight.

Conclusions:

• Subcutaneous abatacept (SC ABA) treatment in early RA patients is not associated with an increased risk of infection, irrespective of serum exposure levels.
• Concomitant use of MTX and GCs with SC ABA does not elevate the risk of infection in RA patients.