Autoinflammatory Diseases Beyond IL-1: VEXAS and More

Clinical Deep DivesGenerated November 2026 · Clinical Deep Dive0 CommentsVEXAS May Be More Common Than You Think. Not One Randomized Trial Has Reported on How to Treat It.Transplant or azacitidine? Does clone size predict death? The field has strong opinions and weak evidence.You have a man in his 60s with macrocytic anemia, a rash that keeps changing shape, and an ear “infection” that turned out to be chondritis. Steroids work. Every taper fails. Now what?For VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome, the honest answer is that nobody knows the best next step. The American College of Rheumatology (ACR)-backed guidance panel (published online August 2025) voted 52 of 52 that future clinical trials are needed to identify the best treatment (Arthritis & Rheumatology). No agent carries an FDA or European Medicines Agency (EMA) indication for VEXAS in the sources reviewed. Every drug below is off-label.Unlike interleukin 1 (IL-1) blockade, which comes with proven, regulator-approved pull, this territory has no such anchor. Genetic discovery has outrun the evidence. Here is where the field is split, and what to do while it sorts itself out.This Isn’t a Rare-Disease FootnoteA genomic screen of 163,096 unselected Geisinger patients found 11 carriers of likely pathogenic UBA1 variants. Including one highly suspicious variant, the estimated prevalence was 1 in 13,591 unrelated individuals. Among men over 50, the figure was 1 in 4269 (JAMA). That puts VEXAS in the range of Behçet disease and above granulomatosis with polyangiitis and polyarteritis nodosa (JAMA).All 11 carriers had anemia. Five of 11 didn’t meet criteria for any rheumatologic or hematologic diagnosis historically tied to VEXAS (JAMA). The disease is broader and milder at the edges than case series suggested.It’s Two Tracks, Not a LadderForget the steroid-to-biologic-to-azacitidine-to-transplant staircase. The ACR guidance splits management in two (Arthritis & Rheumatology):Inflammatory Track: Glucocorticoids first. For patients needing a prednisone-equivalent dose of 10 mg/day or more, the panel favored cytokine-directed agents over conventional disease-modifying antirheumatic drugs (DMARDs) or rituximab (48 of 52 agreed). Options are interleukin 6 (IL-6) inhibitors, Janus kinase (JAK) inhibitors (ruxolitinib preferred), and IL-1 inhibitors.Hematologic Track: Moderate-to-severe cytopenia, myelodysplastic syndrome (MDS), myeloma, or a lymphoproliferative disorder goes straight to hematology. Allogeneic hematopoietic stem cell transplantation (HSCT) is weighed on its own merits (50 of 52 agreed), not as a last resort.Safety flags matter here. JAK inhibitors raise viral infection, thrombosis, and cardiovascular risk. Anakinra has caused severe injection-site reactions in VEXAS (Arthritis & Rheumatology).Where the Field Is SplitAzacitidine First, or Transplant First?Camp 1: Clone-directed drug therapy works, with limits. The FRENVEX registry followed 88 azacitidine-treated patients. Inflammatory response was 41% at 6 months and 54% at 12 months. Molecular response (at least a 25% drop in UBA1 variant allele fraction, or VAF) hit 65% of evaluable patients (Blood).The catch is durability and toxicity. Of 12 responders who stopped, 9 (75%) relapsed. Grade 3 or higher adverse events occurred in 60% of all patients, mostly infections and cytopenias (Blood).Camp 2: If you’re going to hit the clone, hit it hard. A 2026 multicenter comparison of 66 patients pitted hypomethylating agents (HMA; n = 35) against allogeneic HSCT (n = 31). After adjustment, transplant carried a survival advantage (hazard ratio [HR], 0.20; 95% CI, 0.05-0.81; P =.024). Molecular remission was 100% (24/24) with transplant versus 22% (5/23) with HMA. Steroid discontinuation was 58% versus 6% (Am J Hematol).The Caveat Both Camps Share: It’s retrospective, and the authors say it establishes equipoise for a randomized trial, not an answer (Am J Hematol). The result held across four sensitivity analyses, including 1:1 matching and propensity weighting (Am J Hematol).The ACR Position: It sits in the middle. Azacitidine “can be an effective treatment in some patients” (51 of 52 agreed), and transplant is a potentially curative option for select patients (Arthritis & Rheumatology).Voices From Each Camp: “Azacitidine works in three dimensions,” said Thibault Comont, MD, of Toulouse University Hospital in France, a study author on FRENVEX (ASH Clinical News). On the transplant side, Ajoy L. Dias and colleagues at the National Institutes of Health wrote in 2024, “we recommend allo-HCT [allogeneic HSCT] early in the disease course.” They also advise a hypomethylating agent or other disease-modifying therapy as a bridge, and say prospective trials are needed to define transplant’s role (Ann Hematol).Does Clone Size Predict Death?This is one of the few places where two well-run studies flatly disagree.Japan’s nationwide prospective registry (n = 60) found higher baseline VAF independently predicted death or transfusion dependence (HR, 1.036 per 1% VAF increase; 95% CI, 1.005-1.069; P =.023), or about 1.43-fold per 10 points. It was replicated in a 34-patient cohort (Ann Rheum Dis). A retrospective NIH/Mayo analysis (n = 80) found no VAF-mortality association (Blood).Study design doesn’t fully explain the gap. Genotype adds confusion. Retrospective series linked p.Met41Leu to better survival (Br J Dermatol). The Japanese cohort didn’t reproduce that when measuring from enrollment. It reappeared only when survival was counted from symptom onset (Ann Rheum Dis).What to Do Now: Treat VAF as one input, not a stand-alone prognostic number.Randomized Data Are Finally ComingPAXIS (NCT06782373): A randomized, double-blind, placebo-controlled phase 2 trial of pacritinib in 78 patients on stable steroids, testing flare prevention during taper (J Clin Med). The FDA granted Fast Track designation, announced September 9, 2026 (BioSpace), because VEXAS has no approved therapies. Topline data are expected in 2027 (RARE Daily).ATLAS (NCT07569081): GSK’s momelotinib, another JAK inhibitor, is being tested in a randomized phase 2/3 trial. The registry listed it as not yet recruiting (ClinicalTrials.gov).Neither has reported results. Until they do, every treatment hierarchy rests on retrospective and single-arm data.You Can’t Treat What Your Panel Doesn’t TestAs of 2023, UBA1 still wasn’t routinely offered on standard myeloid or immune-dysregulation panels (JAMA). Sanger sequencing of exon 3 catches canonical hotspot variants at VAFs above roughly 15%-20% and misses smaller clones. Full-gene next-generation sequencing (NGS) is more sensitive. Marrow vacuoles are suggestive but not diagnostic (Arthritis & Rheumatology).Bedside clues help, though none is diagnostic alone. Macrocytic anemia is easily mistaken for vitamin B12 deficiency or alcohol-related anemia in an older patient. Unilateral periorbital swelling and a rash that recurs, changes character each time, and comes with fever should raise suspicion (Medscape Medical News). The disease spans internal medicine, hematology, dermatology, and pulmonology, so no single specialist sees the whole picture (Medscape Medical News).Two edges of the VEXAS spectrum are worth knowing:About 5% of cases carry non-canonical UBA1 variants. They are linked to fewer classic inflammatory features and more isolated hematologic disease (Leukemia).Female VEXAS is rare but real. Population screening found pathogenic UBA1 variants in 74 of 245,368 All of Us participants, a disproportionate share of them women (Lancet).What Your Peers Are SayingWithout UBA1 on the sequencing panel, VEXAS “would be very challenging to diagnose,” said Gena Foster, MD, assistant professor of medicine in hematology at Yale School of Medicine, in 2025 comments to Medscape Medical News (Medscape Medical News).A rash that recurs and “looks different every time,” especially with fever, is a clue, said Christine Ko, MD, professor of dermatology and pathology at Yale School of Medicine, in 2025 comments to Medscape Medical News (Medscape Medical News).Managing VEXAS, “for the moment, is really for experts,” said Arsène Mekinian, MD, of Saint-Antoine Hospital, Greater Paris University Hospitals–Sorbonne University, first author of the ACR guidance, in 2025 comments to Medscape Medical News (Medscape Medical News). Mekinian added that people with VEXAS are dying mainly from infection (Medscape Medical News). The guidance treats infection prophylaxis and thromboprophylaxis as core management (Arthritis & Rheumatology).Disclosures: Mekinian reports investigator roles and consulting or travel fees from Celgene, Roche, Chugai, LFB, Sanofi, Shire, Takeda, and Novartis. Foster reports consulting for Sanofi. Ko reports none.What to Do NowTest for It. Persistent inflammatory markers plus skin, ocular, lung, or cartilage involvement and/or cytopenia should prompt UBA1 testing, especially in men over 50 (Arthritis & Rheumatology).Check Your Panel. Confirm UBA1 is on it. If Sanger is negative and suspicion stays high, send full-gene NGS, from marrow if blood is uninformative (Arthritis & Rheumatology).Don’t Rely on Marrow Vacuoles. Genetic confirmation is mandatory.Bring Hematology in Early. Do it for cytopenias or suspected MDS.Plan Prophylaxis. Cover infection and thromboembolism from day one.Be Honest About the Evidence. Tell patients the hierarchy rests on retrospective data, and discuss trial enrollment where available.The Bottom LineVEXAS is likely more common than most vasculitides and still under-tested.No approved drug and no reported randomized trial exist. PAXIS data are expected in 2027.Transplant versus azacitidine is unresolved. The best comparison is retrospective, and its authors call for a trial.Whether VAF predicts mortality is contested between a prospective and a retrospective study.Across the pathway map, treat confidently on consensus and mechanism, and keep the missing randomized evidence in view.DEEP DIVE:Autoinflammatory Diseases Beyond IL-1: Diagnosis and Treatment of VEXAS, Interferonopathies, HA20, and DADA2Medscape Medical News © 2026 WebMD, LLCSend comments and news tips to news@medscape.net. Cite this: Autoinflammatory Diseases Beyond IL-1: Diagnosis and Treatment of VEXAS, Interferonopathies, HA20, and DADA2 - Medscape- November 13, 2026.