What are the treatment options for ankylosing spondylitis?

Treatment Options for Ankylosing Spondylitis

Start all patients with active ankylosing spondylitis on NSAIDs at maximum tolerated doses combined with regular physical therapy, and escalate to TNF inhibitors if disease activity remains high after an adequate NSAID trial. 1

First-Line Treatment: NSAIDs and Physical Therapy

NSAIDs as Primary Pharmacologic Therapy

• NSAIDs are strongly recommended as first-line drug treatment for all patients with AS presenting with pain and stiffness. 1
• Approximately 75% of AS patients demonstrate good or very good response to full-dose NSAIDs within 48 hours, compared to only 15% of patients with mechanical back pain. 1
• Continuous daily NSAID therapy is preferred over on-demand use for patients with persistently active symptomatic disease. 1
• For patients with increased gastrointestinal risk, use either non-selective NSAIDs plus gastroprotective agents (PPIs or H2 blockers) or selective COX-2 inhibitors. 1

Physical Therapy (Strongly Recommended)

• Physical therapy and regular exercise are strongly recommended as foundational non-pharmacological treatment and should be initiated concurrently with NSAIDs. 1
• Both individual and group physical therapy sessions should be considered. 1
• Patient education programs and self-help groups provide additional benefit. 1

Second-Line Treatment: TNF Inhibitors

When to Escalate to Biologics

• TNF inhibitors are strongly recommended for patients with persistently high disease activity despite adequate NSAID therapy and physical therapy. 1
• An "adequate NSAID trial" means testing at least one NSAID at maximum tolerated dose for sufficient duration (typically 4 weeks minimum) before declaring treatment failure. 1

TNF Inhibitor Selection

• No specific TNF inhibitor is preferred for most patients—all are equally effective (infliximab, etanercept, adalimumab, certolizumab, golimumab). 1
• Exception: For patients with concomitant inflammatory bowel disease or recurrent iritis, TNF inhibitor monoclonal antibodies (infliximab, adalimumab, certolizumab, golimumab) are strongly recommended over etanercept. 1
• Standard dosing: Etanercept 50 mg weekly, adalimumab 40 mg every other week. 2, 3, 2

Important Caveats for TNF Inhibitors

• Do NOT require patients to fail conventional DMARDs (sulfasalazine, methotrexate) before starting TNF inhibitors for axial disease—there is no evidence these drugs work for spinal involvement. 1
• Screen all patients for latent tuberculosis before initiating TNF inhibitor therapy and treat latent TB if detected. 2, 3
• Monitor closely for serious infections during treatment, as TNF inhibitors increase infection risk including reactivation of latent tuberculosis and invasive fungal infections. 2, 3

Third-Line Treatment: IL-17 Inhibitors

• For patients who fail to respond to TNF inhibitors (primary non-responders) or have contraindications to TNF inhibitors, use IL-17 inhibitors (secukinumab or ixekizumab). 1
• These agents are conditionally recommended as alternatives when TNF inhibitors are inappropriate. 1

Treatments NOT Recommended for Axial Disease

Conventional DMARDs (No Benefit for Spine)

• Sulfasalazine, methotrexate, and leflunomide have NO proven efficacy for axial/spinal manifestations of AS. 1
• Sulfasalazine may be considered only for patients with peripheral arthritis (not axial disease). 1

Systemic Corticosteroids (Strong Recommendation Against)

• Do NOT use systemic corticosteroids for axial disease—there is no evidence of benefit. 1
• Local corticosteroid injections directed at specific sites of musculoskeletal inflammation (enthesitis, peripheral joints) may be considered. 1

Adjunctive Pain Management

• Simple analgesics (acetaminophen) and opioids may be considered for pain control when NSAIDs are insufficient, contraindicated, or poorly tolerated. 1
• These are symptomatic treatments only and do not address inflammation. 1

Surgical Interventions

• Total hip arthroplasty is strongly recommended for patients with advanced hip arthritis causing refractory pain or disability with radiographic structural damage, regardless of age. 1
• Spinal corrective osteotomy and stabilization procedures may benefit selected patients with severe deformities. 1

Disease Monitoring Strategy

• Monitor disease activity using patient history, clinical parameters (spinal mobility, enthesitis), laboratory tests (ESR, CRP), and imaging according to the ASAS core set. 1, 4
• Reassess at 4-6 week intervals when initiating or changing therapy. 4
• HLA-B27 testing is useful for diagnosis but does not need repeating—it is a one-time genetic test. 5

Common Pitfalls to Avoid

• Do not delay TNF inhibitor therapy waiting for patients to "fail" sulfasalazine or methotrexate—these drugs don't work for axial disease. 1
• Do not use on-demand NSAIDs in patients with persistently active disease—continuous therapy is more effective. 1
• Do not rule out AS based on normal CRP/ESR—inflammatory markers can be normal even in active disease. 5
• Do not switch from an effective originator TNF inhibitor to a biosimilar in stable patients—continue the working regimen. 1