Behçet’s Disease

Overview

Behçet’s disease is a chronic, relapsing inflammatory disorder in which blood-vessel inflammation can affect many parts of the body. Recurrent mouth and genital ulcers, skin lesions, painful joints, and eye inflammation are common; some people develop potentially life-threatening vascular, neurologic, or gastrointestinal disease. It is uncommon in the United States, more prevalent across the Middle East and Asia, and often begins in people’s 20s or 30s. Behçet’s Syndrome overview

Outcomes vary widely by organ involvement. Many people achieve symptom control, but recurrent inflammation can cause irreversible damage such as vision loss, thrombosis, aneurysms, or neurologic disability. There is no established cure. Current care is individualized and aims to suppress flares and prevent organ damage: topical corticosteroids and colchicine are commonly used for mucocutaneous disease, while systemic corticosteroids, conventional immunosuppressants, anti-tumor necrosis factor (anti-TNF) biologics, interferon-alpha, and other targeted drugs are selected for more severe or organ-threatening disease. Behçet’s Syndrome overview UK living guideline

Scope of Recent Research (2020–present)

Research since 2020 has been active but remains centered on better disease control rather than proven disease eradication: researchers are testing whether targeted immune therapies can reduce inflammation more safely, identify which patients will respond, and restore immune regulation rather than broadly suppress immunity. A 2025 systematic review informing updated EULAR recommendations found only 69 eligible studies of major-organ treatment and only five randomized trials, underscoring both progress and the rarity-driven evidence gap. EULAR evidence review No curative gene, RNA, or regenerative therapy has yet demonstrated durable, treatment-free remission in Behçet’s disease. Behçet’s Syndrome overview

Major Breakthroughs and Emerging Therapies

The clearest recent advance is stronger comparative evidence for TNF blockade, which neutralizes the inflammatory signaling protein TNF. In a 2024 phase 2 randomized trial of 52 people with severe vascular or neurologic Behçet’s disease, infliximab plus a common steroid regimen produced complete clinical, laboratory, and imaging response at week 22 in 81% of participants, versus 56% with cyclophosphamide; adverse events occurred in 29.6% and 64.0%, respectively. This is a meaningful shift toward a more effective induction strategy for severe disease, but it is remission while receiving treatment—not a cure. Infliximab vs. cyclophosphamide

Recent trials also refined choices within established biologics. A 2024 multicenter randomized study in 40 people with refractory mucocutaneous disease found response in 64% of infliximab-treated and 94% of adalimumab-treated participants over six months, with improved quality of life in both groups. Separately, the UK BIO-BEHÇET’S randomized trial found infliximab and interferon-alpha similarly effective in refractory active disease, while exploratory metabolomics and interferon-lambda genetic analyses sought markers that could personalize treatment selection. Infliximab vs. adalimumab BIO-BEHÇET’S RCT

The most conceptually “cure-oriented” clinical approach is immune rebalancing with low-dose interleukin-2 (IL-2). Unlike high-dose IL-2 used in some cancers, low-dose IL-2 preferentially expands regulatory T cells—immune cells that restrain excessive inflammation. In a randomized, double-blind phase 2 trial, 60 participants with active oral ulcers received low-dose IL-2 or placebo; at week 12, the IL-2 group had fewer oral ulcers, less pain and disease activity, and improved quality of life, alongside expansion of regulatory T cells and a lower ratio of inflammatory effector T cells to regulatory T cells. Low-dose IL-2 phase 2 trial This is an encouraging tolerance-restoration signal, but its size, duration, and focus on mucosal outcomes do not yet establish durable immune reset. Low-dose IL-2 phase 2 trial

Other experimental strategies target cytokine and intracellular signaling pathways. A phase 2b trial has been designed to compare tocilizumab, which blocks interleukin-6 signaling, and tofacitinib, a Janus kinase (JAK) inhibitor that interrupts multiple cytokine signals, against cyclophosphamide for vascular Behçet’s disease. Tocilizumab and tofacitinib trial A broader refractory-autoimmune trial also lists Behçet’s disease among eligible conditions for BCMA-CD19 CAR-T-cell therapy, an intensive cell therapy intended to deplete B cells and plasma cells; however, no Behçet-specific outcomes were available in the registry record reviewed. BCMA-CD19 CAR-T trial These efforts are exploratory, and CAR-T should not be interpreted as an established Behçet’s treatment.

Clinical Trials and Experimental Approaches

The completed low-dose IL-2 trial, NCT04065672, was a single-center, randomized, double-blind phase 2 study sponsored by HeJing/Peking University People’s Hospital. It enrolled 60 participants, used 1 million IU subcutaneous IL-2 every other day for 12 weeks followed by 12 weeks of observation, and reported improved oral-ulcer outcomes without infections or severe adverse events in the published report. NCT04065672 registry record Low-dose IL-2 phase 2 trial

For severe disease, the French Ministry of Health–funded infliximab-versus-cyclophosphamide phase 2 trial provides the strongest recent head-to-head evidence, favoring infliximab at 22 weeks. Infliximab vs. cyclophosphamide The NIHR-funded BIO-BEHÇET’S trial enrolled 79 UK patients with active disease inadequately controlled by first-line therapy and found no meaningful efficacy difference between infliximab and interferon-alpha, with a trend favoring infliximab for treatment persistence and tolerability. BIO-BEHÇET’S RCT

Additional registered studies illustrate the pipeline’s limitations. NCT05845723 is a planned 81-participant, randomized phase 2b vascular-disease study of tocilizumab or tofacitinib plus glucocorticoids versus cyclophosphamide plus glucocorticoids. Tocilizumab and tofacitinib trial NCT05449548 lists a 42-participant study of lenalidomide for refractory mucosal Behçet’s syndrome; its registry record displayed recruiting status even though its listed estimated completion date had passed, so results and current operational status require confirmation before clinical interpretation. Lenalidomide trial

Methodologies and Scientific Approaches

Investigators increasingly combine clinical trials with precision-medicine measurements. BIO-BEHÇET’S analyzed interferon-lambda gene variants and urine metabolomics—the measurement of small molecules in urine—to identify predictors or signatures of response to interferon-alpha and infliximab. BIO-BEHÇET’S RCT The IL-2 study used flow cytometry, a technique that counts and characterizes immune-cell types, to measure regulatory and inflammatory T-cell populations before and after treatment. NCT04065672 registry record

Single-cell RNA sequencing is also helping map disease mechanisms cell by cell. Blood studies have identified inflammatory C1q-high monocytes linked to interferon-gamma signaling and reduced after tofacitinib exposure, while recent intestinal-tissue profiling identified endothelial–neutrophil signaling and stromal activation as possible drivers of intestinal Behçet’s disease. C1q-high monocyte study Intestinal single-cell atlas These platforms can generate drug targets and biomarkers, but they remain hypothesis-generating until validated in larger, prospective cohorts.

Leading Institutions and Funding

Major recent clinical research has come from Peking University People’s Hospital in China, which conducted the low-dose IL-2 trial; French academic hospital networks led by Assistance Publique–Hôpitaux de Paris, which ran the severe vascular/neurologic infliximab trial; and the UK’s national Behçet’s centers and partner universities, which delivered BIO-BEHÇET’S. NCT04065672 registry record Infliximab vs. cyclophosphamide BIO-BEHÇET’S RCT

Funding has included the French Ministry of Health for the infliximab-versus-cyclophosphamide trial and the UK National Institute for Health and Care Research (NIHR) Efficacy and Mechanism Evaluation program for BIO-BEHÇET’S. The latter award, “Optimal utilization of biologic drugs in Behçet’s Disease,” was reported at £601,396 and supported a stratified-medicine approach to biologic selection. Infliximab vs. cyclophosphamide NIHR BIO-BEHÇET’S funding record

Strengths, Limitations, and Challenges

The field is beginning to produce the kind of comparative trials needed for clinical progress. Infliximab’s advantage over cyclophosphamide in severe disease is especially important because it pairs a higher short-term complete-response rate with fewer overall adverse events. Infliximab vs. cyclophosphamide Low-dose IL-2 is notable because it attempts to correct an immune-regulatory imbalance rather than only block inflammation. Low-dose IL-2 phase 2 trial

However, Behçet’s disease is clinically diverse, rare, and prone to waxing and waning, which makes trials small, slow to recruit, and difficult to compare across organ-specific subgroups. The major-organ evidence review found only five randomized trials among 69 included studies, and the BIO-BEHÇET’S investigators noted that reduced recruitment limited secondary and mechanistic analyses. EULAR evidence review BIO-BEHÇET’S RCT Current drugs can produce remission but generally require ongoing treatment, may not work across all manifestations, and do not establish whether the underlying disease process has been permanently eliminated. UK living guideline

Outlook and Future Directions

As of September 10, 2026, a true cure for Behçet’s disease is not close enough to forecast on a timeline. The most important milestones to watch are replication of low-dose IL-2 in larger and longer trials with treatment-withdrawal follow-up; results of vascular studies testing tocilizumab and JAK inhibition; validation of molecular response markers; and carefully reported, Behçet-specific outcomes from immune-reset cell-therapy studies. Low-dose IL-2 phase 2 trial Tocilizumab and tofacitinib trial BCMA-CD19 CAR-T trial Until then, the realistic goal is earlier diagnosis, organ-protective remission, fewer toxic treatments, and eventually personalized strategies that can sustain remission without continuous immunosuppression. Behçet’s Syndrome overview

References

• Behçet’s Syndrome overview — MedlinePlus, 2026.
• UK living guideline — British Association of Dermatologists and British Society for Rheumatology, 2025.
• EULAR evidence review — European Alliance of Associations for Rheumatology, 2026.
• Infliximab vs. cyclophosphamide — Saadoun et al., 2024.
• Infliximab vs. adalimumab — Talarico et al., 2024.
• BIO-BEHÇET’S RCT — Moots et al., NIHR, 2024.
• Low-dose IL-2 phase 2 trial — Li et al., 2026.
• Tocilizumab and tofacitinib trial — ClinicalTrials.gov, 2026.
• BCMA-CD19 CAR-T trial — ClinicalTrials.gov, 2026.
• NCT04065672 registry record — ClinicalTrials.gov, 2024.
• Lenalidomide trial — ClinicalTrials.gov, 2026.
• C1q-high monocyte study — Zhou et al., 2022.
• Intestinal single-cell atlas — Zhang et al., 2026.
• NIHR BIO-BEHÇET’S funding record — Research Excellence Framework, 2021.