An IL-17 Inhibitor for a Patient Whose Colitis Has Been Quiet for Eighteen Years
A guideline update means her remote ulcerative colitis no longer rules out an IL-17 inhibitor by itself. It does not mean every drug in the class carries the same risk, or that the class is automatically safer to reach for than the alternative it was excluding.
Marguerite T. retired from the postal service four years ago and has since turned a spare bedroom into what she calls her "watercolor studio," a hobby that gave her an unusually precise vocabulary for describing when her hands started failing her: not the fine tremor she expected from age, but a stiffness through her low back and hips each morning that took nearly two hours and a hot shower to loosen, long enough that she'd sometimes miss the best light for painting. An HLA-B27- positive workup eventually explained it as ankylosing spondylitis, active enough on exam and imaging to clear the threshold for a first biologic after NSAIDs alone kept her BASDAI parked at 6.8.
The complicating detail sits eighteen years back in her history: a bout of ulcerative colitis in forty, treated to remission with mesalamine and steroids, with no flare and no medication for it since — eighteen quiet years, the last six of them anchored by a surveillance endoscopy that came back clean. Until 2025, that history alone would have closed off an entire drug class for her — IL-17 inhibitors carried an absolute contraindication in anyone with IBD, active or not, on the theory that IL-17A itself helps maintain the gut's mucosal barrier and its inhibition could reawaken quiescent disease. The 2025 BSR axSpA guideline changed that specific rule, treating inactive, distant IBD as a relative rather than absolute concern. What the guideline update does not settle, and what her own chart can't answer for her, is whether the real-world safety data behind that change looks the same for every drug carrying the IL-17 label, or whether "the class is no longer forbidden" is quietly being read as "the class is now interchangeable." Her own gastroenterologist, looped in before this visit, offered no objection to reconsidering the class in principle. The uncomfortable detail sits underneath the reassurance rather than in it: the safety data that softened the rule was generated overwhelmingly in patients who had never had inflammatory bowel disease, where the outcome counted was new-onset colitis. Marguerite is not that patient. Her colon has already proved it can do this once, and nothing in the evidence that reopened the class for her was measured on anyone whose colon had.
Reopening a drug class her chart used to close
The 2025 BSR guideline didn't just remove a blanket rule, it opened a real choice within the IL-17 class, and the evidence behind that choice already points somewhere specific. Alsakarneh and colleagues, matching over thirteen thousand IL-17A initiators against apremilast initiators, found secukinumab carried a significantly increased risk of incident IBD — adjusted hazard ratio 2.82 — while ixekizumab in the same analysis did not reach significance. Her disease responds well to IL-17 inhibition as a mechanism; the guideline change means we don't have to give up that mechanism, we just have to pick the right drug inside it — ixekizumab, not secukinumab.
I hear the drug-specific argument, and it's a real distinction, not a hand-wave — but she isn't a population-level data point, she's a woman with an actual colon that's been quiet for the better part of two decades and that I'd like to keep that way. IL-17A itself participates in maintaining the gut's mucosal barrier; that biological mechanism doesn't become safer because one claims analysis found a particular molecule's confidence interval crossed one instead of the other.
A TNF monoclonal antibody has decades of use in patients with exactly her history, with a well-characterized, generally favorable relationship to IBD specifically — that's a lower-uncertainty starting point than "the newer study on this specific IL-17 drug looks better than the older one."
Both of you are reading one study as more settled than the literature actually is. A 2020 secukinumab-specific cohort found no elevated IBD signal at all — the opposite direction from the 2025 claims analysis driving today's ixekizumab argument. That inconsistency doesn't resolve to "ixekizumab is proven safer"; it resolves to "we genuinely don't have a stable answer for either drug yet." Given that, and given her own quiet history, I'd rather start where the mechanism itself isn't in question at all and revisit IL-17 inhibition later if adalimumab doesn't control her spine.
Agreed: start adalimumab, continue routine GI surveillance per her existing schedule, and treat any new GI symptoms as reason for immediate rheumatology/GI co-management rather than waiting for the next scheduled visit.
Not agreed: whether ixekizumab should be the second-line choice if adalimumab fails to control her axial disease, or whether that decision should wait for more mature, less internally contradictory IL-17/IBD data. The rheumatologist would move to ixekizumab specifically, citing the same claims analysis; the gastroenterologist would want a second TNF inhibitor tried first, given how recently and incompletely this exact question has been studied.