Background Adalimumab (ADA) is currently approved in the EU for the treatment of severe non-radiographic axial spondyloarthritis (nr-axSpA), in patients (pts) with an elevated CRP and/or positive MRI who have had an inadequate response to, or are intolerant to NSAIDs. Reduction of sacroiliac joint (SIJ) and spine inflammation on MRI has been previously reported after 12 wks of ADA compared to placebo in the ABILITY-1 study.
Objectives To determine the efficacy of ADA in improving inflammation on MRI in pts with nr-axSpA and the relationship between MRI and clinical remission.
Methods ABILITY-1 is an ongoing phase 3, randomized, controlled trial in pts with nr-axSpA who had an inadequate response, intolerance, or contraindication to NSAIDs. A 12-wk double-blind period of ADA 40 mg every other week (eow) or placebo (PBO) was followed by an open-label period in which pts could receive ADA 40 mg eow for up to an additional 144 wks. MRI of the SIJ and spine were done at baseline (BL), wks 12, 52 and 104, and were read using the SPARCC scoring system (6 discovertebral unit method for the spine) by 2 independent readers who were blinded to time sequence. Mean reader scores were used. This post hoc analysis evaluated the efficacy of ADA in improving MRI inflammation at wks 52 and 104 in the overall population and in the MRI+/CRP+ subpopulation (pts who had positive BL MRI [SPARCC score ≥2 for either the SIJ or spine] or elevated BL CRP). Clinical remission was defined by ASDAS inactive disease (ASDAS ID, ASDAS <1.3) and MRI remission by SPARCC score <2.
Results 142 (69 ADA, 73 PBO) of the total efficacy population (N=185) were in the MRI+/CRP+ subpopulation. MRI obtained at wks 52 and 104 showed sustained mean improvements with long-term ADA therapy in SPARCC SIJ and spine scores for the overall population (wk 52 n=149, –3.7 and n=148, –1.2; wk 104 n=131, –3.8 and n=130, –1.4) and for the MRI+/CRP+ subpopulation (wk 52 n=116, –4.6 and n=115, –1.7; wk 104 n=102, –4.8 and n=101, –2.0). AmongMRI+/CRP+ pts with SIJ score <2 or spine score <2 at wk 104 and available BL values, 45% and 43% had BL score ≥2 for SIJ or spine, respectively. The table presents MRI and clinical remission rates in MRI+/CRP+ pts with ASDAS and MRI data available at wks 52 or 104. Of the 50 pts in ASDAS ID at wk 104, 74%, 76% and 58% had MRI remission of the SIJ, spine or both SIJ and spine.
Conclusions In ABILITY-1, ADA therapy of up to 2 yrs in nr-axSpA pts resulted in reduction of inflammation on MRI. The majority of pts in clinical remission were noted to also have MRI remission. However, resolution or absence of inflammation on MRI did not always correspond to clinical remission.
Acknowledgements AbbVie Inc funded the study (NCT00939003). AbbVie was responsible for the study design, research, analysis, data collection, interpretation of data, and writing, review, and approval of the publication. Medical writing support was provided by Kathleen V. Kastenholz, PharmD, MS, of AbbVie.
Disclosure of Interest D. van der Heijde Grant/research support from: AbbVie, Amgen, AstraZeneca, BMS, Centocor, Chugai, Daiichi, Eli Lilly, GSK, Janssen Biologics, Merck, Novartis, Novo-Nordisk, Otsuka, Pfizer, Roche, Sanofi-Aventis, Schering-Plough, UCB, Vertex, Consultant for: AbbVie, Amgen, AstraZeneca, BMS, Centocor, Chugai, Daiichi, Eli Lilly, GSK, Janssen Biologics, Merck, Novartis, Novo-Nordisk, Otsuka, Pfizer, Roche, Sanofi-Aventis, Schering-Plough, UCB, Vertex; Director of Imaging Rheumatology BV, W. Maksymowych Grant/research support from: AbbVie, Amgen, BMS, Eli-Lilly, Janssen, Merck, Pfizer, Consultant for: AbbVie, Amgen, BMS, Eli-Lilly, Janssen, Merck, Pfizer, J. Sieper Grant/research support from: AbbVie, Merck, Pfizer, UCB, Consultant for: AbbVie, Merck, Pfizer, UCB, Speakers bureau: AbbVie, Merck, Pfizer, UCB, R. Lambert Grant/research support from: AbbVie, Consultant for: Perceptive Imaging and Synarc, M. Brown Consultant for: AbbVie, S. Rathmann Shareholder of: AbbVie, Employee of: AbbVie Inc, J. Anderson Shareholder of: AbbVie, Employee of: AbbVie Inc, A. Pangan Shareholder of: AbbVie, Employee of: AbbVie Inc