Ankylosing%20spondylitis Treatment

• Maximize long-term quality of life by:
  • Controlling occurrence and severity of symptoms
  • Reducing functional limitations
  • Maintaining flexibility and posture of the vertebral column
  • Preventing continuous structural damage and disease complications
  • Improving social interaction/quality of life
  • Normalizing everyday activities
• Disease management involves the combination of non-pharmacological and pharmacological strategies
• Treatment approach should be individualized based on the disease activity, presence of comorbidities, structural changes, functional impairment, extra-articular manifestations, side effects of treatments, and psychosocial factors
• Shared decision making between the patient and rheumatologist is encouraged

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)

• First-line agents for AS patients with pain and stiffness
• Continuous long-term therapy is preferred for AS patients with active and symptomatic AS
• On-demand therapy is preferred for patients with stable AS 
• Studies show that continuous use of NSAIDs has the potential to reduce the radiographic progression of AS

Corticosteroids

• Direct injection of glucocorticoids to the local site (eg musculoskeletal inflammation) may be considered in AS patients with stable axial disease and active enthesitis or active peripheral arthritis who are unresponsive to NSAID therapy
• Intravenous/oral corticosteroids should only be considered as short-term therapy (not >2 weeks) in patients with flares during pregnancy, peripheral arthritis, or inflammatory bowel disease

Tumor Necrosis Factor (TNF) Inhibitors

• Eg Adalimumab, Certolizumab pegol, Etanercept, Golimumab, Infliximab 
• Indicated in AS patients with persistently high disease activity despite NSAIDs treatment
• Requirements before initiation of anti-TNF therapy:
  • Confirmed diagnosis of AS based on the modified New York criteria for AS (grade ≥2 bilaterally or ≥3 unilaterally)
  • Sustained active disease (a BASDAI of ≥4 units on a 0–10 scale, ASDAS-CRP ≥2.1, ≥4 cm on 0–10 cm spinal pain VAS and expert opinion based on clinical findings) of ≥4 weeks
  • Negative for tuberculosis, human immunodeficiency virus (HIV) (in high-risk populations) or viral hepatitis B and C
  • Elevated CRP, inflammation on MRI sacroiliac joints or radiographic sacroiliitis are also indications for TNF inhibitor use
  • Presence of refractory disease
    • Treatment failure with ≥2 NSAIDs for four weeks with predominantly axial SpA
    • Failure of intra-articular steroids
    • Treatment failure with Sulfasalazine for four months in patients with predominantly peripheral arthritis
  • Using precautions and observing contraindications when using biological treatments
• Monitoring of ASAS core set, laboratory tests, imaging, and BASDAI is recommended after initiation of treatment
• Adequate response to TNF inhibitors:
  • BASDAI reduced to 50% or ≥2 units of pretreatment value
  • ≥2 cm spinal pain VAS after 12 weeks of treatment
• Switching to another TNF inhibitor is recommended when response is no longer seen for at least 12 weeks with initial TNF inhibitor
• Elevated CRP was identified as the strongest predictor of good response

Interleukin (IL) Inhibitors

• Eg Ixekizumab, Secukinumab
• Human selective inhibitor of IL-17A used in the treatment of moderate-to-severe AS
• Can be considered in patients if initial TNF inhibitor treatment fails or if with contraindications to TNF inhibitors
  • History of recurrent uveitis, active IBD, or psoriasis 
• Indicated for patients with ASDAS ≥2.1, failure to respond to ≥2 NSAIDs and have either elevated CRP, MRI inflammation of sacroiliac joints or radiographic sacroiliitis

Janus Kinase (JAK) Inhibitors 

• Eg Tofacitinib, Upadacitinib
• Selective and reversible JAK inhibitors that preferentially inhibits signalling by JAK1 or JAK1/3 with functional selectivity over cytokine receptors that signal via pairs of JAK2 in human cellular assays
• Indicated for the treatment of active AS in adult patients who have inadequate response to conventional therapy, ASDAS ≥2.1, failure to respond to ≥2 NSAIDs and have either elevated CRP, MRI inflammation of sacroiliac joints or radiographic sacroiliitis

Alternative Treatments

Analgesics

• Eg Paracetamol, opioids
• May be prescribed to patients with residual pain after treatment failure with other drugs

Conventional Synthetic Disease-Modifying Anti-Rheumatic Drugs (DMARDs)

• Eg Methotrexate, Sulfasalazine
• Therapeutic option for patients unresponsive to NSAIDs, intolerant of TNF inhibitors or when TNF inhibitors are not available
• May be considered in patients with peripheral SpA or extra-articular manifestations
  • Treatment with Sulfasalazine may be considered in patients with peripheral SpA
• Further studies are needed to prove the efficacy of Methotrexate and other DMARDs for the treatment of AS
• Concomitant use with TNF inhibitors or NSAIDs is not recommended as it increases the risk for adverse effects

Pamidronic acid (Pamidronate)

• Treatment option for active AS patients with contraindications to TNF inhibitor therapy
• Further studies are needed to prove the use of Pamidronate for the management of active AS

Management of Comorbidities

• Eg IBD, psoriasis, uveitis should be managed accordingly
• Please refer to the respective disease management charts for further information
• Infliximab or Adalimumab and topical corticosteroids may be prescribed to AS patient with recurrent uveitis
• AS patients with inflammatory bowel disease may benefit from TNF inhibitor monoclonal antibodies