title: Ten years with biologics: to whom do data on effectiveness and safety apply?
abstract: OBJECTIVE
  During the past decade, the position of biologics in the therapeutic armamentarium, the number of approved indications and the number of available biologics have changed. Available data on (long-term) safety might thus pertain to patient populations not comparable with contemporary patients. The aim of this study was to assess the extent to which contemporary patients who start or switch biologic therapies are comparable with those patients who gave rise to the currently available data on effectiveness and safety.
  
  
  METHODS
  We identified all adult patients with RA (n=9612), PsA (n=1417) and other SpA (n=1652) initiating a first biologic therapy between 1 January 1999 and 31 December 2008, registered in the Swedish Biologics Register (ARTIS), including information on demographics, disease characteristics and 1-year risk of first-line treatment discontinuation.
  
  
  RESULTS
  Over calendar time, measures of disease activity at start declined substantially for all indications, and diminished between first-, second- and third-line therapy starts. One-year risks of first-line therapy discontinuation increased. Switchers to anti-TNF and non-TNF biologics had different comorbidities. Despite <50% drug retention at 5 years, most patients remained exposed to some biologic.
  
  
  CONCLUSIONS
  The trends in baseline characteristics and drug retention underscores that any effects of biologics, including comparison between different biologics, must be interpreted in light of the characteristics of the population treated. The observed differences further call for continued vigilance to properly evaluate the safety profiles of biologic treatments as they are currently used. Exposure to multiple biologics presents a challenge for attribution of long-term effects.
authors.affiliation: Department of Medicine, Clinical Epidemiology Unit, T2, Karolinska Institutet, Karolinska University Hospital, 171 76 Stockholm, Sweden. julia.simard@post.harvard.edu
authors.forename: Julia F
authors.initials: JF
authors.lastname: Simard
authors.forename: Elizabeth V
authors.initials: EV
authors.lastname: Arkema
authors.forename: Anders
authors.initials: A
authors.lastname: Sundström
authors.forename: Pierre
authors.initials: P
authors.lastname: Geborek
authors.forename: Tore
authors.initials: T
authors.lastname: Saxne
authors.forename: Eva
authors.initials: E
authors.lastname: Baecklund
authors.forename: Lars
authors.initials: L
authors.lastname: Coster
authors.forename: Christina
authors.initials: C
authors.lastname: Dackhammar
authors.forename: Lennart
authors.initials: L
authors.lastname: Jacobsson
authors.forename: Nils
authors.initials: N
authors.lastname: Feltelius
authors.forename: Staffan
authors.initials: S
authors.lastname: Lindblad
authors.forename: Solbritt
authors.initials: S
authors.lastname: Rantapää-Dahlqvist
authors.forename: Lars
authors.initials: L
authors.lastname: Klareskog
authors.forename: Ronald F
authors.initials: RF
authors.lastname: van Vollenhoven
authors.forename: Martin
authors.initials: M
authors.lastname: Neovius
authors.forename: Johan
authors.initials: J
authors.lastname: Askling
mesh_terms: D000328:Adult; D018501:Antirheumatic Agents / Q000009:adverse effects; D015535:Arthritis, Psoriatic / Q000188:drug therapy*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy*; D001688:Biological Products / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D012720:Severity of Illness Index; D025241:Spondylarthritis / Q000188:drug therapy*; D013548:Sweden; D013997:Time Factors; D016896:Treatment Outcome; D000079424:Tumor Necrosis Factor Inhibitors; D048069:Tumor Necrosis Factors / Q000009:adverse effects
chemical_list: D018501:Antirheumatic Agents; D001688:Biological Products; D000079424:Tumor Necrosis Factor Inhibitors; D048069:Tumor Necrosis Factors