title: Persistence of low disease activity after tumour necrosis factor inhibitor (TNFi) discontinuation in patients with psoriatic arthritis.
abstract: OBJECTIVE
  To determine the duration of clinical benefit among patients with psoriatic arthritis (PsA) discontinuing tumour necrosis factor inhibitor (TNFi) therapy while in low disease activity (LDA), and to identify patient characteristics associated with prolonged clinical benefit.
  
  
  METHODS
  We performed an observational cohort study assessing patients with PsA from the Consortium of Rheumatology Researchers of North America (CORRONA) registry who had discontinued TNFi after achieving LDA, defined as clinical disease activity index (CDAI) score ≤10 and physician's global assessment (PGA) of skin psoriasis ≤20/100. Kaplan-Meier method was used to estimate the duration of clinical benefit.
  
  
  RESULTS
  Of the 5945 patients with PsA in CORRONA, 302 patients had discontinued TNFi (n=325) while in LDA and had follow-up data available. At time of discontinuation, mean PsA duration was 9.8 years, mean CDAI was 3.9, and mean duration of TNFi use was 1.5 years; 52.6% of patients had discontinued their first TNFi. Median time to loss of benefit was 29.2 months. 179 (55.1%) patients had persistent benefit at their previous clinic visit. An increased risk of losing clinical benefit was seen among patients with higher disease activity at discontinuation (CDAI≥3.2 vs <3.2; HR 1.43 (p=0.32)) and among smokers (HR 1.78 (p=0.027)).
  
  
  CONCLUSIONS
  Patients with PsA who achieve LDA may maintain clinical benefit after discontinuation of TNFi therapy.
authors.affiliation: Allergy and Rheumatology Clinic , La Jolla, California , USA.
authors.forename: D H
authors.initials: DH
authors.lastname: Huynh
authors.affiliation: Division of Rheumatology, Department of Medicine , Western University , London, Ontario , Canada.
authors.forename: T A
authors.initials: TA
authors.lastname: Boyd
authors.affiliation: Corrona LLC , Southborough, Massachusetts , USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: Etzel
authors.affiliation: Corrona LLC , Southborough, Massachusetts , USA.
authors.forename: V
authors.initials: V
authors.lastname: Cox
authors.affiliation: Corrona LLC , Southborough, Massachusetts , USA.
authors.forename: J
authors.initials: J
authors.lastname: Kremer
authors.affiliation: Swedish Medical Center and University of Washington , Seattle, Washington , USA.
authors.forename: P
authors.initials: P
authors.lastname: Mease
authors.affiliation: Division of Rheumatology, Allergy and Immunology, University of California, San Diego, California, USA; School of Medicine, La Jolla, California, USA.
authors.forename: A
authors.initials: A
authors.lastname: Kavanaugh
keywords: Anti-TNF; Disease Activity; Psoriatic Arthritis; Treatment