BOSTON -- Persistent benefits lasting up to 3 years have been seen with adalimumab (Humira) treatment among patients who have axial spondyloarthritis without apparent x-ray changes in the sacroiliac joints, researchers reported here.
Among patients who remained in the long-term extension phase of a study known as ABILITY-1, two-thirds of patients maintained a 40% improvement according to the criteria of the Assessment of Spondyloarthritis International Society (ASAS40) at year 3, reported , of Leiden University Medical Center in the Netherlands in a poster session at the .
Action Points
- Note that these studies were published abstracts and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
Axial spondyloarthritis is a category of spinal inflammatory diseases that includes both ankylosing spondylitis, in which sacroiliitis is visible on radiographs, and so-called nonradiograpic axial spondyloarthritis, in which changes can only be detected by MRI.
First-line treatment for both conditions is with nonsteroidal anti-inflammatory drugs (NSAIDs), and tumor necrosis factor (TNF) inhibitors also are approved for ankylosing spondylitis.
However, it's been less clear whether TNF inhibitors are also safe and effective for nonradiographic disease, so van der Heijde and colleagues conducted a phase III multicenter study, in which the first 3 months consisted of a double-blind comparison of adalimumab, 40 mg every other week, or placebo. This was followed by an open-label phase in which patients could continue on the active treatment for another 144 weeks.
For inclusion in the study, patients had to have a disease activity index score of 4 or higher (out of 10), and an inadequate response to at least one NSAID.
Treatment responses were measured on several assessment tools, including the ASAS20 and 40, the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the Ankylosing Spondylitis Disease Activity Score (ASDAS).
Efficacy analyses also were performed on both the overall population plus a subpopulation of 142 patients whose baseline MRI had a score of 2 or higher on the Spondyloarthritis Research Consortium of Canada tool for either the sacroiliac joints or spine, and/or whose baseline C-reactive protein was elevated.
Slightly more than half of the patients were female, and mean age was 38. Baseline BASDAI was 6.5, patient global assessment of disease activity was 6.8, and total back pain score on a 10-point visual analog scale was 6.8.
Of the 185 patients initially enrolled in ABILITY, 66% were still in the study at week 156.
In the double-blind phase of the study, more patients in the adalimumab group than in the placebo group had an ASAS40 response at 12 weeks, (36% versus 15%, P<0.001).
Then, within a month of the beginning of the open-label phase, the entire study population had responses similar to those of the active treatment group in the blinded phase, the investigators found.
"Week 12 results were further supported by sustained clinical response and remission data through year two of the study," they observed.
By year three, 70% of patients had a 50% improvement on the BASDAI, increasing from 63% at year one and 65% at year two.
At all three time points, 69% of patients achieved the rating of ASDAS clinically important improvement, and at year three, 40% had ASDAS major improvement and 46% had ASDAS inactive disease.
On the ASAS criteria for partial remission, rates rose from 34% at year 1 to 43% at year three.
A total of 17.4% of patients had any serious adverse event during the 3 years of the study, for a rate of 10.9 per 100 patient-years.
One patient developed a lupus-like reaction, and two reported hepatic-related events. Another patient, a woman with a history of deep venous thrombosis who was on hormonal birth control, developed a pulmonary embolism.
There was one case of disseminated tuberculosis, but there were no opportunistic infections, malignancies, cardiovascular-related events, or cases of vasculitis or demyelinating disease.
Two patients died, one from suicide and the other from opiate toxicity.
"The safety profile of adalimumab in nonradiographic axial spondyloarthritis is comparable to what has been observed in other disease indications," including , the investigators noted.
Disclosures
The study was funded by AbbVie. van der Heijde and colleagues disclosed financial relationships with the company.
Primary Source
American College of Rheumatology
Source Reference: van der Heijde D, et al "Clinical response and remission in patients with nonradiographic axial spondyloarthritis after thee years of adalimumab therapy" ACR 2014; Abstract 562.