Background/Purpose:

Adalimumab (ADA) has been previously shown to be effective for the treatment of non-radiographic axial spondyloarthritis (nr-axSpA) patients (pts) in the ABILITY-1 trial.¹ Week (wk) 12 results were further supported by sustained clinical response and remission data through Year 2 of the study.² We evaluate the final Year 3 long-term response/remission and durability of response with ADA in pts with nr-axSpA. 

Methods:

ABILITY-1 was a phase 3, double blind (DB), randomized, controlled trial in pts with nr-axSpA who had an inadequate response, intolerance, or contraindication to NSAIDs. A 12-wk DB period of ADA 40 mg every other week (eow) or placebo was followed by an open-label period in which pts could receive ADA 40 mg eow for up to an additional 144 wks. This post hoc analysis evaluated the final Year 3 (wk 156) efficacy and safety results for both the overall population and the MRI+/elevated CRP sub-population defined as those with a positive MRI at baseline (BL) (SPARCC score ≥2 for either the SI joints or spine) or an elevated CRP at BL. ASAS, BASDAI and ASDAS responses were calculated. Clinical remission was defined by ASDAS inactive disease (ASDAS ID, ASDAS <1.3) or by ASAS partial remission (ASAS PR).

Results:

Of the 185 pts enrolled in ABILITY-1, 122 (66%) had data available at wk 156 and 97 of 142 (68%) from the MRI+/elevated CRP sub-population. Clinical responses and remission rates were generally sustained between Year 2 and Year 3 of the study (Table). Through 412.2 patient-years (PYs) of exposure to ADA, the serious infection rate observed was 2.4 events/100 PYs, including 1 case of disseminated TB. There were 2 deaths – 1 due to suicide and another due to opiate toxicity. There were no malignancies reported.

Table. Long-term clinical response and remission at Years 2 and 3

^aN=135; ^bN=131; ^cN=136; ^dN=120; ^eN=118; ^fN=104; ^gN=103; ^hN=105; ⁱN=96; ^jN=93; ^kN=95.

ASAS, Assessment of SpondyloArthritis international Society; ASDAS, Ankylosing Spondylitis Disease Activity Score; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; CII, clinically important improvement; ID, inactive disease; MI, major improvement; NRI, non-responder imputation; PR, partial remission. 

Conclusion:

Almost half of the pts who remained on long-term ADA therapy in ABILITY-1 were in remission at the end of the study (Year 3), whether measured by ASAS PR or ASDAS ID. Results were similar between the overall population and the MRI+/elevated CRP sub-population.

References:

1. Sieper J et al. Ann Rheum Dis 2013;72:815–22.
2. Sieper J et al. Ann Rheum Dis 2013;72(Suppl3):88.

---

« Back to 2014 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/clinical-response-and-remission-in-patients-with-non-radiographic-axial-spondyloarthritis-after-three-years-of-adalimumab-therapy/