A Danish study showing that about half of patients with newly diagnosed inflammatory bowel disease (IBD) had findings consistent with spondyloarthritis (SpA) was highlighted as one of last year’s more actionable studies on SpA and axial SpA (axSpA) at the Rheumatology Winter Clinical Symposium (RWCS) 2024.
“There’s a lesson here,” said Eric M. Ruderman, MD, professor of medicine and associate chief of clinical affairs in the Division of Rheumatology at Northwestern University Feinberg School of Medicine, Chicago, Illinois. “We’ve spent a lot of time working with the dermatologists in the last 10 years to try to coordinate what we’re doing [for psoriatic disease]. It’s time to start working with the gastroenterologists more.”
The findings offer “more evidence” for an increasingly documented overlap of IBD with SpA — whether axial or peripheral — and suggest there is underdiagnosis of SpA among patients with IBD. “It’s important,” he said at the meeting, “because if there are meaningful joint symptoms, this should be considered when making treatment choices [for IBD],” just as rheumatologists must be aware of the potential for IBD in choosing therapies.
Dr Ruderman also urged rheumatologists making treatment decisions for axSpA to more carefully consider the role of central pain in driving residual symptoms in patients on biologic disease-modifying antirheumatic drugs (bDMARDs). He pointed to a 2023 study of patients with radiographic axSpA (r-axSpA) receiving bDMARDs that showed significant associations between high central pain and a greater odds of having higher disease activity, independent of elevated C-reactive protein (CRP) levels.
“I’ve come to the conclusion that there’s a huge amount of central pain in our patients — that it [affects] 20%-30% of our patients, no matter what rheumatologic disease they have,” he said, “and if you don’t acknowledge and consider that, you’ll keep churning through medications that aren’t going to work because you’re not addressing a fundamental issue.”
Among other key studies of 2023 highlighted by Dr Ruderman was a large retrospective cohort study showing a similar incidence of ankylosing spondylitis (AS) in US military men and women screened for chronic back pain and the GO-BACK withdrawal and retreatment trial of golimumab suggesting that dosing can be extended.
Meanwhile, last year brought more bad news for interleukin (IL)-23 inhibition in axSpA, with the termination of a phase 2 study of tildrakizumab (Ilumya). Good news came with the US Food and Drug Administration approval in 2023 of an intravenous formulation of the IL-17 inhibitor secukinumab (Cosentyx), which will be helpful for some Medicare patients. And moving forward, the biologic pipeline is SpA is “almost all about new pathways in the IL-17 arena,” Dr Ruderman said.
Making Good Drug Choices for the Gut and the Joints
In the study of SpA among patients with IBD, reported at the EULAR 2023 meeting in Milan, Italy, rheumatologists assessed 110 consecutive patients — 34% of whom were diagnosed with Crohn’s disease and 59% of whom had ulcerative colitis — from a Danish IBD inception cohort. The patients, about 40% of whom were male, had a mean age of 42.
At the time of IBD diagnosis, 49% had arthralgias/musculoskeletal symptoms, 52% fulfilled Assessment of SpondyloArthritis International Society (ASAS) classification criteria for peripheral SpA, and 49% had synovitis and/or enthesitis verified by ultrasound, Dr Ruderman said.
Gastroenterologists like the integrin antagonist vedolizumab (Entyvio) for some patients with IBD because “it’s a very gut-specific drug and doesn’t have as much impact on the systemic immune system as other drugs, but because it’s gut specific, it does nothing for peripheral or axial joint symptoms,” Dr Ruderman said in an interview after the meeting. “We’ve seen patients switched to this drug from Humira [or other biologics] and suddenly they have joint pains they never had before.”
The IL-12/23 inhibitor ustekinumab (Stelara) and the IL-23 inhibitor risankizumab (Skyrizi) are also sometimes selected for IBD, but “neither work well for patients with confirmed axSpA or inflammatory axial spine pain and arthritis,” he said. “Maybe these patients belong on a TNF [tumor necrosis factor] inhibitor or a JAK [Janus kinase] inhibitor, which will manage both the joints and the gut.”
“It’s not that we don’t talk to one another, but as we get more and more drugs in this space — both us and the gastroenterologists — it behooves us to communicate better to make sure we’re making the right choices for patients,” Dr Ruderman said in the interview.
On the flip side, there’s a clear link between patients with axSpA who have or later develop IBD, as was further documented in 2023 by a multicenter Spanish study that evaluated patients with SpA (including both radiographic and nonradiographic axSpA) for the prevalence of undiagnosed IBD, Dr Ruderman said at the RWCS.
The study, reported at the American College of Rheumatology (ACR) 2023 annual meeting, included only patients who were bDAMRD-naive and off of steroids for at least 30 days. The researchers used elevated fecal calprotectin levels (≥ 80 mcg/g) followed by colonoscopy — and an endoscopic capsule study or MRI if colonoscopy was normal — to confirm a diagnosis of IBD. Of 559 patients, 4.4% had such a confirmed diagnosis (95% with Crohn’s disease), and interestingly, only 30% of these patients had clinical IBD symptoms.
“These are people who had no suspicion,” Dr Ruderman said at the meeting. “You could say that maybe not having symptoms is not a big deal, but over time, maybe there will be consequences.”
The IL-17 inhibitors ixekizumab (Taltz), secukinumab, and bimekizumab (Bimzelx) are generally felt to be contraindicated in patients who have confirmed IBD, Dr Ruderman noted in the interview. “While we don’t want to necessarily avoid those drugs, we need to be aware of the potential [for IBD],” he said, “and we need to have a low threshold of suspicion if our patients develop any GI symptoms.”
Considering Noninflammatory Residual Pain
The 2023 central pain study that caught Dr Ruderman’s attention — research reported at the EULAR 2023 meeting — looked at 70 patients with r-axSpA receiving bDMARD treatment (mostly TNF inhibitors) who were being followed in an extension of the German Spondyloarthritis Inception Cohort. Investigators used the Widespread Pain Index (WPI) to help quantify central pain/central sensitization and the Ankylosing Spondylitis Disease Activity Score using C-reactive protein (ASDAS-CRP) to measure disease activity.
“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.
IL-23 Inhibition in Axial Disease and the Pipeline
Is the chapter on IL-23 inhibitors closed for axSpA? Aside from a possible role for axial disease in psoriatic arthritis (PsA), it likely is, Dr Ruderman said, pointing to the phase 2 randomized, double-blind, placebo-controlled study of tildrakizumab in patients with AS that was terminated at week 24 after the drug showed no difference in efficacy from placebo.
Dr Kavanaugh agreed. “This adds to the data on risankizumab and ustekinumab in studies done properly in AS,” he said. “There’s no benefit.”
The “real issue” still to be determined, said Dr Ruderman, “is what is the role of IL-23 inhibitors in patients with axial PsA?”
A post-hoc analysis of data from the SELECT PsA 1 and 2 trials, published in 2023, showed greater improvement in the overall Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score in patients with axial disease who received 15 mg upadacitinib (Rinvoq), compared with placebo.
“It suggests there’s improvement in the patients with axial PsA as defined [by a high BASDAI score], but they didn’t compare this with patients without axial disease…it’s muddy,” Dr Ruderman said. Other research that’s underway should provide clarity, Dr Kavanaugh said.
The pipeline for new treatments for SpA, including axSpA, is focused on new biologics targeting the IL-17 pathways, as well as a fair number of targeted synthetics, Dr Ruderman said. “What will be interesting to me is what happens with the TYK2 inhibitors…because one of the postulated mechanisms is that the IL-23 signals through TYK-2,” he said. “So if that’s the mechanism, will they really help our patients with axial disease? We need the trials to find out.”
The intravenous formulation of secukinumab, approved in 2023 for AS, nr-axSpA, and PsA, is a “nice addition to our armamentarium,” Dr Ruderman noted in his 2023 review. “For years, a patient doing well on an IL-17 inhibitor for their axial disease or their psoriatic disease would hit Medicare age and suddenly couldn’t afford subcutaneous administration, and we had to switch them over to an IV-TNF inhibitor,” he said. “Now we have an IV IL-17 inhibitor.”