Remission Rates Similar Among Patients with RA Receiving Adalimumab, Other Biologics

Enriqueta Vallejo-Yagüe, PhD

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In patients with rheumatoid arthritis (RA), no differences in the 28-joint Disease Activity Score (DAS28)-remission were observed between those receiving adalimumab as the first biologic and those receiving other biologics, such as etanercept, infliximab, and abatacept, according to a study published in BMJ Open.¹ Although obesity is linked to lower treatment response in this patient population, results were independent of body mass index (BMI).

“Despite the advances in the treatment of RA and the availability of several biologic/targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs), up to 60% of patients will either not respond or lose response to therapy over time,” wrote a team of investigators led by Enriqueta Vallejo-Yagüe, PhD, associated with the Pharmacoepidemiology Group, Institute of Pharmaceutical Sciences, ETH Zurich, Switzerland, and the Institute of Primary Health Care (BIHAM), University of Bern, Switzerland. “Thus, evidence-based decision on the optimal b/tsDMARD for each patient remains challenging.”

As previous research has linked obesity with worse disease activity and management in this patient population, optimal decision-making is particularly important for patients with high BMI. Theories behind this reduced therapeutic response include the effect on body weight for the drug’s volume of distribution and the increased probability of developing antidrug antibodies observed in patients with higher BMI. Additionally, obesity is a low-grade systemic inflammatory condition and may also be affected by social factors which could impact clinical management, such as weight stigma leading to less exercise.²

Adult patients with RA from the Swiss Clinical Quality Management in Rheumatic Diseases (SCQM) registry who received infliximab, abatacept, etanercept, or adalimumab as their first b/tsDMARD were in the observational cohort study. These patients were then categorized based on their BMI—normal weight, overweight, and obese—at baseline.

During the study period, the primary endpoint was remission within 12 months, defined as a DAS28 < 2.6. The effectiveness of adalimumab compared with the other study drugs was assessed using logistic regression. The BMI groups were analyzed separately.

In total, the study included 1243 (49.4%) normal weight, 829 (33.0%) overweight, and 443 (17.6%) obese patients with RA. Regardless of BMI category, no statistically significant differences in the odds of DAS28-remission at ≤12 months were observed. However, etanercept was linked to a reduced odds of achieving Rheumatoid Arthritis Disease Activity Index-Five (RADAI-5) remission in overweight patients (ORadj .44, 95% confidence interval [CI] .22 — .90).

There was no evidence that being treated with abatacept increased the likelihood of remission among obese patients with RA when compared with adalimumab and Kaplan-Meier curves demonstrated no differences in drug survival across study drugs.

Investigators mentioned the sample size as a limitation of the study, as they were unable to further stratify the BMI cohorts by sex due to low statistical power. Further, they could not obtain an adequate sample size of underweight patients. Lastly, investigators chose to focus the analysis on only 4 biologics due to a combination of former Swiss clinical guidelines for the treatment of RA and the varying times of drug approvals.

“The number of head-to-head trials in RA is increasing, and while studies on the comparative effectiveness of b/tsDMARDs in real-world setting are rising, they remain limited,” investigators noted. “To our knowledge, this is the first real-world comparative effectiveness observational cohort study on biologics in patients with RA stratified by BMI category.”

References

1. ^{Vallejo-Yagüe E, Burkard T, Finckh A, Burden AM; clinicians and patients of the Swiss Clinical Quality Management Program. Comparative effectiveness of biologics in patients with rheumatoid arthritis stratified by body mass index: a cohort study in a Swiss registry. BMJ Open. 2024;14(2):e074864. Published 2024 Feb 8. doi:10.1136/bmjopen-2023-074864}
2. ^{Wu Y-K, Berry DC. Impact of weight stigma on physiological and psychological health outcomes for overweight and obese adults: A systematic review. J Adv Nurs 2018;74:1030–42. doi:10.1111/jan.13511}