Humira of Benefit Over Long Term to Nonradiographic Axial Spondyloarthritis Patients, Study Reports

Long-term treatment with Abbvie‘s adalimumab, sold as Humira, led to sustained clinical remission accompanied by better physical abilities in patients with nonradiographic axial spondyloarthritis (nr-axSpA).

“Clinical and MRI remission in patients with nonradiographic axial spondyloarthritis who received long-term open-label adalimumab treatment: 3-year results of the ABILITY-1 trial” was published in the journal Arthritis Research & Therapy.

Nonradiographic axial spondyloarthritis (nr-axSpA) is a form of axial spondyloarthritis in which lesions in the sacroiliac joint – the link between your lower spine and pelvis – are only detected through magnetic resonance imaging (MRI) and clinical criteria, and cannot be seen a standard X-ray.

Adalimumab, a medication for ankylosingspondylitis, plaque psoriasis, rheumatoid arthritis, Crohn’s disease, and other conditions, is an antibody that targets the pro-inflammatory molecule tumor necrosis factor-alpha.

The double-blind phase of the ABILITY-1 study (NCT00939003), a Phase 3 trial, showed that patients with nr-axSpA randomized to 12 weeks of treatment with 40 mg of adalimumab delivered every other week had significant improvements in disease activity, physical function, and health-related quality of life relative to placebo controls. Treated patients also had lesser inflammation in the spine and lower sacroiliac joint.

Following the double-blind phase, all patients could enter an open-label phase of the study in which they were randomized to receive adalimumab at 40 mg for up to three years (144 weeks).

Overall, 185 patients were included in the total population and 142 in the MRI/CRP-positive subpopulation — identified by positive magnetic resonance imaging (MRI) and/or high C-reactive protein (MRI/CRP-positive), an inflammation marker. Of these, 65% and 68%, respectively, stayed with the study for three years.

Clinical response and safety along with MRI data were analyzed after three and two years of treatment, respectively.

Clinical and MRI remission were defined as Ankylosing Spondylitis Disease Activity Score (ASDAS) inactive disease (score below 1.3), and a Spondyloarthritis Research Consortium of Canada (SPARCC) MRI score below 2 for sacroiliac joints, spine, or both. Physical function was assessed using the Bath Ankylosing Spondylitis Functional Index.

Clinical, functional, and MRI improvements were similar and equally sustainable in both patients populations.

Specifically, in both populations, treatment with adalimumab led to sustained improvements in physical function, and MRI scans taken at year one and two showed a significant and sustained suppression of inflammation in both the sacroiliac joint and spine.

Twenty-four percent of patients in the inflammation subgroup achieved a sustained clinical remission in year two, and 23% at year three. These patients also exhibited normal physical abilities.

Adalimumab’s safety profile was in agreement with that observed in other immune-mediated inflammatory diseases.

Overall, “treatment of patients with nr-axSpA with adalimumab over 3 years demonstrated sustained clinical remission in a substantial proportion of patients, which was associated with the achievement or maintenance of normal physical function,” the researchers wrote.

“Together with the safety data from the ABILITY-1 study, our findings support the favorable benefit-risk profile of long-term adalimumab therapy in patients with nr-axSpA,” they concluded.