title: 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.
abstract: OBJECTIVE
  To assess the impact of baseline body mass index (BMI) on the efficacy and retention of intravenous abatacept at 6 months in biologic-naïve patients with rheumatoid arthritis (RA).
  
  
  METHODS
  This was a 6-month analysis of a 2-year, non-interventional, international, prospective study. Baseline characteristics, clinical response and retention rates were compared by BMI subgroup: underweight/normal, overweight and obese (<25, 25 to <30 and ≥30kg/m2, respectively).
  
  
  RESULTS
  BMI was reported in 643/672 (96%) patients: 264 (41%) were underweight/normal, 224 (35%) overweight and 155 (24%) obese. At baseline, the obese group had more active disease (mean [95% confidence intervals] 28-joint Disease Activity Score [C-reactive protein; derived] 4.6 [4.5, 4.7], 4.8 [4.7, 5.0] and 5.1 [4.9, 5.2] for underweight/normal, overweight and obese groups, respectively), a higher prevalence of metabolic disorders, a greater proportion of women and a lower proportion of patients with rheumatoid factor positivity. There were no significant differences in the percentages of patients achieving a good/moderate European League Against Rheumatism response by BMI group (80.7, 86.1 and 77.0% for underweight/normal, overweight and obese groups, respectively; P=0.178). Overall retention rates at 6 months did not differ across groups (89, 92 and 89% for underweight/normal, overweight and obese groups, respectively; log-rank P=0.382). After adjustment for baseline characteristics, BMI was not significantly associated with risk of discontinuation (reference BMI<25kg/m2; hazard ratio [95% confidence intervals] 0.46 [0.22, 0.99] and 0.69 [0.34, 1.41] for overweight and obese patients, respectively).
  
  
  CONCLUSIONS
  BMI does not impact abatacept clinical response or retention in biologic-naïve patients with RA.
authors.affiliation: Université Paris-Sud, Hôpitaux Universitaires Paris-Sud, INSERM U1184, 63, rue Gabriel-Péri, 94270 Le Kremlin-Bicêtre, France. Electronic address: xavier.mariette@bct.aphp.fr.
authors.forename: Xavier
authors.initials: X
authors.lastname: Mariette
authors.affiliation: Schlosspark-Klinik University Medicine, 14059 Berlin, Germany.
authors.forename: Rieke
authors.initials: R
authors.lastname: Alten
authors.affiliation: University of Erlangen-Nuremberg, 91054 Erlangen, Germany.
authors.forename: Hubert G
authors.initials: HG
authors.lastname: Nüßlein
authors.affiliation: University of Siena, 53100 Siena, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Galeazzi
authors.affiliation: University Hospital, 69120 Heidelberg, Germany.
authors.forename: Hanns-Martin
authors.initials: HM
authors.lastname: Lorenz
authors.affiliation: Hôpital Purpan, 31000 Toulouse, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Cantagrel
authors.affiliation: Chiltern International, 92200 Neuilly, France.
authors.forename: Melanie
authors.initials: M
authors.lastname: Chartier
authors.affiliation: DOCS International, 92000 Nanterre, France.
authors.forename: Coralie
authors.initials: C
authors.lastname: Poncet
authors.affiliation: Bristol-Myers Squibb, 80636 Munich, Germany.
authors.forename: Christiane
authors.initials: C
authors.lastname: Rauch
authors.affiliation: Bristol-Myers Squibb, 92500 Rueil-Malmaison, France.
authors.forename: Manuela
authors.initials: M
authors.lastname: Le Bars
mesh_terms: D000069594:Abatacept / Q000008:administration & dosage*; D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000188:drug therapy*; D001688:Biological Products / Q000008:administration & dosage*; D015992:Body Mass Index; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage; D038622:Internationality; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D001688:Biological Products; D007166:Immunosuppressive Agents; D000069594:Abatacept
keywords: Abatacept; Body mass index; EULAR response; Real-world study; Retention rate; Rheumatoid arthritis