Body mass index and treatment response to subcutaneous abatacept in patients with psoriatic arthritis: a post hoc analysis of a phase III trial

Abstract

Objective: This post hoc analysis of the phase III Active PSoriaTic Arthritis RAndomizEd TriAl (ASTRAEA) evaluated the effect of baseline body mass index (BMI) on subsequent response to subcutaneous (SC) abatacept in patients with psoriatic arthritis (PsA).

Methods: In ASTRAEA, patients with active PsA were randomised (1:1) to receive blinded weekly SC abatacept 125 mg or placebo for 24 weeks. Treatment response at week 24 was assessed by the proportions of patients achieving American College of Rheumatology 20% improvement response, Disease Activity Score in 28 joints (DAS28 (C reactive protein (CRP))) ≤3.6 and <2.6, Health Assessment Questionnaire-Disability Index reduction from baseline ≥0.35 and radiographic non-progression (defined as change from baseline ≤0 in PsA-modified total Sharp/van der Heijde score). Responses were stratified by baseline BMI (underweight/normal, <25 kg/m2; overweight, 25-30 kg/m2; obese, >30 kg/m2) and compared in univariate and multivariate models.

Results: Of 212/213 and 210/211 patients with baseline BMI data in the abatacept and placebo groups, respectively, 15% and 19% were underweight/normal, 36% and 27% were overweight, and 49% and 54% were obese. After adjusting for baseline characteristics, there were no significant differences for any outcome measure at week 24 with abatacept in the overweight or obese versus underweight/normal subgroup. In the placebo group, patients in the obese versus underweight/normal subgroup were significantly less likely to achieve DAS28 (CRP) <2.6 at week 24 (OR 0.26; 95% CI 0.08 to 0.87; p=0.03).

Conclusion: BMI does not impact clinical or radiographic response to SC abatacept in patients with PsA.

Trial registration number: NCT01860976.

Keywords: DMARDs (biologic); disease activity; psoriatic arthritis.

Conflict of interest statement

Competing interests: IBM has received grant/research support from Bristol-Myers Squibb, Celgene, Janssen and UCB, and has acted as a consultant to Bristol-Myers Squibb (<US$10 000), AbbVie (<US$10 000), Celgene (<US$10 000), Janssen (<US$10 000), Lilly (<US$10 000), Novartis (<US$10 000), Pfizer (<US$10 000) and UCB (<US$10 000). GF has received grant/research support from Roche, Bristol-Myers Squibb and Pfizer, and has received speaking fees from MSD (<US$10 000), UCB (<US$10 000), Pfizer (<US$10 000), AbbVie (<US$10 000), Lilly (<US$10 000), Celgene (<US$10 000), Novartis (<US$10 000) and Roche (<US$10 000). MAD has received speaking fees from Bristol-Myers Squibb (<US$10 000), AbbVie (<US$10 000), Novartis (<US$10 000) and Celgene (<US$10 000). MLB was a shareholder and employee/consultant of Bristol-Myers Squibb (<US$10 000) at the time the study was conducted. SB and HAA are shareholders and employees/consultants of Bristol-Myers Squibb (<US$10 000). YE is a consultant to Bristol-Myers Squibb (<US$10 000). PJM received grant/research support from AbbVie, Amgen, Bristol-Myers Squibb, Celgene, Janssen, Lilly, Novartis, Pfizer, Sun and UCB; acted as a consultant to AbbVie (>US$10 000), Amgen (>US$10 000), Bristol-Myers Squibb (<US$10 000), Celgene (<US$10 000), Corrona (<US$10 000), Galapagos (<US$10 000), Janssen (>US$10 000), Lilly (>US$10 000), Novartis (>US$10 000), Pfizer (>US$10 000), Sun (<US$10 000), UCB (<US$10 000) and Zynerba (<US$10 000); and received speaking fees from AbbVie (>US$10 000), Amgen (>US$10 000), Bristol-Myers Squibb (<US$10 000), Celgene (<US$10 000), Genentech (<US$10 000), Janssen (>US$10 000), Novartis (>US$10 000), Pfizer (>US$10 000) and UCB (<US$10 000).

Figures

Figure 1

Univariate model of adjusted* comparisons of treatment response at week 24 between BMI subgroups in patients receiving (A) abatacept and (B) placebo. An OR >1 indicates a higher likelihood of response, while an OR

Figure 2

Multivariable model of adjusted* comparisons of treatment response at week 24 between BMI subgroups in patients receiving (A) abatacept and (B) placebo. An OR >1 indicates a higher likelihood of response, while an OR

Figure 3

Multivariable model of adjusted* comparisons of treatment response at week 24 between BMI subgroups in patients receiving abatacept (A) without any non-biologic DMARD and (B) in combination with a non-biologic DMARD. An OR >1 indicates a higher likelihood of response, while an OR