Body Mass Index Not a Factor in Clinical Response to Abatacept

Baseline body mass index (BMI) had no effect on the efficacy or retention of intravenous abatacept in patients with rheumatoid arthritis (RA), according to a 6-month analysis of a 2-year noninterventional prospective study. Results were published ahead of print on December 30, 2016, in Joint Bone Spine.¹

High BMI is frequently present in patients with RA. More than 60% of patients with RA have a BMI greater than 25 kg/m², the same prevalence as seen in the general population. High BMI has previously been found to have an adverse impact on patients’ responses to both methotrexate, the cornerstone of RA treatment, and tumor necrosis factor-ɑ (TNF-ɑ) inhibitors, the most frequently employed class of biological drugs in the treatment of RA. 

Abatacept is a biologic with a novel mechanism of action: it inhibits the CD80/CD86:CD28 co-stimulatory signal, thus preventing T cells from becoming fully activated. Prior clinical trials and real-world studies had already demonstrated that BMI did not influence the efficacy of abatacept in patients who had previously been unresponsive to treatment with a biologic. This study was the first to show that BMI likewise did not influence the efficacy of abatacept when used as a first-line biologic.

For the study, lead investigator Xavier Mariette, MD, PhD, of Paris-Sud University, Paris, France, and colleagues analyzed data from the Long Term Experience With Abatacept in Routine Clinical Practice (ACTION) noninterventional, 2-year international prospective cohort of patients with RA who had an inadequate response to methotrexate or anti-TNF therapy and who had initiated treatment with abatacept from May 2008 to December 2013.

Patients included in the present analysis were those with an established diagnosis of moderate to severe disease according to the 1987 American College of Rheumatology Revised Classification Criteria for RA for whom BMI data were available and who had not previously received a biologic. 

Patients were classified into baseline BMI subgroups: underweight/normal(<25 kg/m²), overweight (25 to <30 kg/m²), and obese (≥30 kg/m²). 

  Results showed that at 6 months, clinical response to abatacept, as assessed by European League Against Rheumatism (EULAR) response criteria based on the 28-joint Disease Activity Score (DAS28), did not significantly vary by BMI subgroup. 

A moderate or good treatment response was achieved in 80.7% of underweight/normal patients, 86.1% of overweight patients, and 77% of obese patients. No response occurred in 19.3% of underweight/normal patients, 13.9% of overweight patients, and 23% of obese patients (P =.178.) Retention, defined as consecutive time on treatment, also did not vary by subgroup. Crude retention rates were 89% for underweight/normal patients, 92% for overweight patients, and 89% for obese patients (P=.382).

Summary and Clinical Applicability

The investigators stated that abatacept may be an effective treatment option in biologic-naive patients with RA, irrespective of BMI. “In this analysis of the real-world ACTION study, baseline BMI did not impact clinical response or retention rates with abatacept in a population of patients with RA who were naive to biologic therapy,” they wrote. 

“These findings suggest that abatacept is an effective first-line biologic agent for the treatment of the signs and symptoms of RA in patients with prior [conventional synthetic disease-modifying antirheumatic drugs] csDMARD failure, regardless of patient BMI at treatment initiation.” 

Disclosures

Xavier Mariette is on speaker bureaus for Bristol-Myers Squibb, Glaxo-SmithKline, Pfizer, and UCB. Rieke Alten has received research grants and is on a speaker bureau for Bristol-Myers Squibb. Hubert Nüßlein is a consultant for and is on speaker bureaus for Bristol-Myers Squibb, AbbVie, MSD, UCB, Novartis, Celgene, Roche, Pfizer, and Janssen. Hanns-Martin Lorenz is a consultant for and is on a speaker bureau for Bristol-Myers Squibb. Alain Cantagrel  has received research grants from UCB and Pfizer, and consulting fees from AbbVie, Bristol-Myers Squibb, Lilly, MSD, Novartis, Pfizer, and Roche. Melanie Chartier and Coralie Poncet are consultants for Bristol-Myers Squibb. Christiane Rauch and Manuela Le Bars are employees and shareholders of Bristol-Myers Squibb.

Reference

Mariette X, Alten R, Nüßlein HG, et al. The effect of body mass index on clinical response to abatacept as a first-line biologic for rheumatoid arthritis: 6-month results from the 2-year, observational, prospective ACTION study [published online December 30,2016]. Joint Bone Spine.doi:10.1016/j.jbspin.2016.10.011

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