“Central pain was actually associated with having residual symptoms,” Dr. Ruderman said at the RWCS. Higher WPI scores were significantly associated with higher ASDAS-CRP scores, and a high WPI was also associated with higher odds of having high or very high disease activity (ASDAS > 2.1), independent of other factors including elevated CRP, the investigators reported in their abstract.
Arthur Kavanaugh, MD, professor of medicine at the University of California, San Diego, commented that “we don’t have great [non-opioid] treatments for pain,” prompting Dr. Ruderman to emphasize the importance of “resisting the urge to [automatically] switch to another biologic” without trying to discern whether residual pain is inflammatory or noninflammatory in nature.
“I’m really comfortable with this,” Dr. Ruderman said, noting that he prescribes drugs like duloxetine or pregabalin for suspected central pain. “For the statin (for cardiovascular disease prevention), I’m more likely to turn back to the primary care physician and work with them, but here it’s part of what we’re treating — it becomes part of our tool kits.”
The central pain issue, Dr. Ruderman said after the meeting, is one of recognition and nomenclature. In the last few years, “there’s been a tendency to get away from secondary fibromyalgia as a label. There’s a lot of baggage with the diagnosis, unfortunately,” he said in the interview. “And it’s all connected. … It’s very likely that the [central] pain signaling is triggered by the inflammatory pain in the first place.”
A New Look at Sex-Specific Incidence of AS
The study on AS in a retrospective cohort of 729,000 working-age US military service members “flew under the radar,” but its finding of a similar incidence in men and women who underwent screening for chronic back pain is “fascinating,” Dr. Ruderman said. Compared with females, men were not significantly more likely to have a diagnosis of AS (adjusted odds ratio [OR], 0.79; 95% CI, 0.61-1.02; P = .072), the researchers reported.
“We’ve always assumed that AS is a male disease, and that, as we got into nonradiographic axSpA, we would see more women. This study calls that into question,” he said.
More Light on bDMARD Dosage Extension and Withdrawal
The GO-BACK study of the TNF inhibitor golimumab (Simponi) randomized 188 patients with inactive nonradiographic axSpA after 6 months of 50 mg golimumab monthly to treatment withdrawal/monthly placebo, continued monthly treatment, or treatment every 2 months. The take-home message, Dr. Ruderman said, is that “withdrawal, but not reduction in dose, led to a higher risk of flare.”
Also notable in this study published in 2023 is that “almost 100% of those who flared were recaptured with the reinitiation of monthly dosing,” he said. “So you don’t lose if you try to stop … [although] I don’t think that will ever be a successful strategy.” (The proportion of patients without a disease flare over 12 months was 34% in the withdrawal group, 68% in the extended dosing group, and 84% in the continued monthly treatment group.)
Dosing extensions have been shown to be potentially viable with other biologics, “but with this one, it looks like you can spread it out almost with impunity because it doesn’t look like there’s much difference” between continuing monthly and extending, Dr. Kavanaugh commented.
Another study from 2023 of the IL-17A inhibitor ixekizumab in axSpA similarly showed a high recapture rate for patients who withdrew from therapy and then flared. In this phase 3 extension study in which 155 patients with inactive or low-level disease were randomized at week 24 to continued ixekizumab or placebo, 53% of placebo patients flared by 2 years, compared with 13% in the ixekizumab arm. Of those who flared, 96% recaptured low disease activity with re-initiation of therapy.
“It’s the same story. You might get away with [stopping the therapy] because it’s not 100% who flared. But is it worth it?” Dr. Ruderman said.