Early Disease Activity or Clinical Response as Predictors of Long‐Term Outcomes With Certolizumab Pegol in Axial Spondyloarthritis or Psoriatic Arthritis

OBJECTIVE: Early identification of patients unlikely to achieve good long‐term disease control with anti–tumor necrosis factor therapy in axial spondyloarthritis (SpA) and psoriatic arthritis (PsA) is important for physicians following treat‐to‐target recommendations. Here we assess associations between disease activity or clinical response during the first 12 weeks of treatment and attainment of treatment targets at week 48 in axial SpA and PsA patients receiving certolizumab pegol. METHODS: The relationship between disease activity or clinical response during the first 12 weeks of treatment and achievement of week‐48 targets (for axial SpA: inactive disease based on Ankylosing Spondylitis Disease Activity Score [ASDAS] using the C‐reactive protein [CRP] level, or Bath Ankylosing Spondylitis Disease Activity Index <2 with normal CRP level; and for PsA: minimal disease activity) was assessed post hoc using RAPID‐axSpA and RAPID‐PsA trial data. RESULTS: A clear relationship between disease activity from week 2 to 12 and achievement of week‐48 treatment targets was observed in both axial SpA and PsA populations. In axial SpA, week‐48 ASDAS inactive disease was achieved by 0% of patients (0 of 21) with ASDAS very high disease activity at week 12, compared to 68% of patients (34 of 50) with week‐12 ASDAS inactive disease. For PsA, week‐48 minimal disease activity was achieved by 0% of patients (0 of 26) with Disease Activity Score in 28 joints (DAS28) using the CRP level >5.1 at week 12, compared to 73% of patients (57 of 78) with DAS28‐CRP <2.6. Similar results were observed regardless of the disease activity measure used. Clinical response at week 12 also predicted week‐48 outcomes, though to a lesser extent than disease activity. CONCLUSION: Using disease activity and the clinical response state during the first 12 weeks of certolizumab pegol treatment, it was possible to identify a subset of axial SpA and PsA patients unlikely to achieve long‐term treatment goals.