Background Studies have shown an influence of BMI on clinical outcomes in patients with RA treated by anti-TNF agents.¹ The efficacy of abatacept does not seem to be impacted by weight; baseline weight was not identified as a predictive factor of efficacy (DAS28 [CRP] <2.6) in a post hoc analysis of the AVERT trial² and, in real-world analyses, BMI did not impact the retention rate on drug or effectiveness.^3,4 Clinical evaluation of RA in obese patients can be difficult, but power Doppler ultrasound (PDUS) is a method for evaluating joints that can differentiate joint effusion from synovitis and identify real disease activity due to RA. APPRAISE was the first prospective, multinational study to use the composite greyscale/PDUS synovitis score, developed by the OMERACT-EULAR Ultrasound Task Force, to measure early signs of response to treatment with IV abatacept plus MTX.^5-7

Objectives To explore the effect of BMI on the efficacy of IV abatacept plus MTX using PDUS.

Methods PDUS was assessed over 6 months in underweight/normal (<25 kg/m²), overweight (25–<30 kg/m²) and obese (≥30 kg/m²) patients receiving IV abatacept plus MTX. Efficacy was assessed by the percentage of patients achieving DAS28 (CRP) <2.6, low disease activity (DAS28 [CRP] ≤3.2) or clinically meaningful improvement (change in DAS28 [CRP] of ≥1.2).

Results Of the 96/104 patients evaluable for PDUS, 46 (47.9%) had a BMI <25 kg/m², 28 (29.2%) were overweight and 22 (22.9%) were obese. Baseline demographics and disease characteristics were comparable between the BMI subgroups; however, differences were noted at baseline between global PDUS joint effusion scores within each BMI subgroup: mean (SD) score was 15.7 (15.2) for the underweight/normal group, 19.6 (16.1) for the overweight group and 23.0 (16.4) for the obese group. Mean changes from baseline in PDUS and DAS28 (CRP) scores over 6 months for each BMI subgroup are presented; no differences between the BMI subgroups were detected (Figure). Note that when using more stringent criteria such as the percentage of patients reaching DAS28 (CRP) <2.6 over time, a greater response within the first month was seen in the underweight/normal group versus overweight and obese groups, influenced mainly by high-sensitivity CRP and patient global assessment; responses were otherwise similar over 6 months.

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Conclusions This post hoc analysis of the APPRAISE study confirms that BMI does not affect clinical response to IV abatacept plus MTX nor does it influence the magnitude in changes of PDUS-detected inflammation over time.

References

1. Gremese E, et al. Arthritis Care Res 2013;65:94–100.

2. Emery P, et al. Arthritis Rheum 2014;66(Suppl 11):S1084. Poster 2485.

3. Nüsslein H, et al. Arthritis Rheum 2014;66(Suppl 11):S1088. Poster 2492.

4. Iannone F, et al. Ann Rheum Dis 2014;73(Suppl 2):498–9. Poster FRI0313.

5. D'Agostino MA et al. Ann Rheum Dis 2012;71(Suppl 3):186. Poster THU0095.

6. D'Agostino MA, et al. Arthritis Rheum 2012;64(Suppl 10):S352. Poster 810.

7. D'Agostino MA, et al. Arthritis Rheum 2012;64(Suppl 10):S353. Poster 811.

Disclosure of Interest M. A. D'Agostino Speakers bureau: Bristol-Myers Squibb, Abbvie, UCB, M. Le Bars Shareholder of: Bristol-Myers Squibb, Employee of: Bristol-Myers Squibb, M. Taylor: None declared, B. Chou: None declared, J. Zhu Employee of: Bristol-Myers Squibb, V. K. Ranganath Grant/research support from: Bristol-Myers Squibb, Genentech