Study results in the context of previous findings
Commenting on their findings, first author Tamara Rusman, of the Amsterdam University Medical Center, and coauthors wrote that the results suggested early treatment with etanercept in patients without a positive MRI and raised CRP levels was not effective.
However, they acknowledged that two previous placebo-controlled studies had specifically included patients with nr-axSpA and found a significantly better treatment response to TNF inhibitors than to placebo. One of these studies included a significant number of patients with MRI-detected active inflammatory SIJ lesions at baseline, which is a known predictor of treatment response.
“The relatively low number of patients with either a positive MRI-SIJ (23%) and/or elevated CRP level (13%) at baseline in our study could be an explanation for the absence of a treatment effect in favor of etanercept,” they wrote.
They also raised the possibility that their choice of study population didn’t truly capture patients with nr-axSpA, and that it was not powered to compare patients with or without a positive MRI or raised CRP level at baseline.
“It would be interesting to know whether our study results will be replicated by others in comparable study populations with equal numbers of patients with and without a positive MRI-SIJ and raised CRP in the future,” they wrote.
The study was supported by an unrestricted financial grant from Pfizer and ReumaNederland. No conflicts of interest were declared.
SOURCE: Rusman T et al. Arthritis Rheumatol. 2020 Dec 5. doi: 10.1002/art.41607.