Ann Rheum Dis doi:10.1136/annrheumdis-2012-201933
  • Clinical and epidemiological research
  • Extended report

Clinical response, drug survival and predictors thereof in 432 ankylosing spondylitis patients after switching tumour necrosis factor α inhibitor therapy: results from the Danish nationwide DANBIO registry

  1. Merete Lund Hetland2,3
  1. 1Department of Rheumatology, Gentofte University Hospital, Copenhagen, Denmark
  2. 2The Danish Rheumatologic Database (DANBIO), Glostrup, Denmark
  3. 3Department of Rheumatology, Copenhagen University Hospital Glostrup, Glostrup, Denmark
  4. 4Zitelab Aps, Copenhagen, Denmark
  5. 5Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark
  6. 6Department of Rheumatology, Frederiksberg Hospital, Copenhagen, Denmark
  7. 7Department of Rheumatology, Vejle Sygehus, Sygehus Lillebælt, Vejle, Denmark
  8. 8Department of Rheumatology, Aalborg Hospital, Aalborg, Denmark
  9. 9Department of Rheumatology, Køge Hospital, Køge, Denmark
  10. 10Department of Rheumatology, Odense University Hospital, Odense, Denmark
  11. 11Department of Infectious Diseases and Rheumatology, Rigshospitalet, Copenhagen, Denmark
  12. 12Department of Rheumatology, Vendsyssel Hospital, Hjørring, Denmark
  13. 13Department of Rheumatology, Esbjerg Hospital, Esbjerg, Denmark
  14. 14Department of Rheumatology, Helsingør Hospital, Helsingør, Denmark
  15. 15Department of Rheumatology, Regionshospital Randers, Randers, Denmark
  1. Correspondence to Dr Bente Glintborg, Department of Rheumatology, Gentofte University Hospital, Niels Andersensvej 65, Hellerup 2900, Denmark; glintborg{at}
  • Received 26 April 2012
  • Accepted 19 July 2012
  • Published Online First 31 August 2012


Objective To investigate frequencies and reasons for switching, treatment responses and drug survival in patients with ankylosing spondylitis (AS) switching tumour-necrosis-factor-α inhibitor (TNFi) treatment in routine clinical care.

Methods AS patients were identified in the Danish nationwide DANBIO registry. Disease activity, treatment responses (50% or 20 mm reduction in Bath AS Disease Activity Index (BASDAI)), duration and rates of drug survival and predictors thereof were studied in patients receiving ≥2 different biological drugs.

Results Of 1436 AS patients starting TNFi treatment, 432 patients (30%) switched to a second and 137 (10%) to a third biological drug. Compared with non-switchers, switchers were more frequently women (33%/22%), had shorter disease duration (3 years/5 years) and higher BASDAI (62(52–76) mm/56(43–69) mm (median(interquartile-range))), Bath AS Functional Index (BASFI) (54(39–71) mm/47(31–65) mm) and visual-analogue-scale (VAS) global, pain and fatigue scores when they started the first TNFi (all p<0.01). Main reason for switching was lack of response (56%). During the first, second and third treatment BAS- and VAS scores had decreased after 6 months' treatment (all p<0.05). Median drug survivals were 3.1, 1.6 and 1.8 years respectively (p<0.001). After 2 years of treatment 52% of switchers and 63% of non-switchers had achieved response (number needed to treat 1.9 and 1.6, respectively, p=0.01). Drug survivals were similar regardless of the reason for switching. Male gender and low BASFI predicted drug survival of the second TNFi.

Conclusions Nearly one-third of AS patients in clinical practice switched biological treatment. Response rates and drug survivals were lower among switchers, however, half of switchers achieved treatment response.