Mapping the future of rheumatology: Owkin’s top takeaways from EULAR 2025

From June 11–14, the annual European Alliance of Associations For Rheumatology (EULAR) Congress brought together the latest advances in rheumatology and immune-mediated inflammatory diseases (IMIDs) in vibrant Barcelona. Here’s what caught our eye:

Deciphering disease complexity at the cellular level

The rapid adoption of single-cell and spatial transcriptomics (ST) is revolutionizing disease understanding. Take the example of SLE, a highly heterogenous and complex disease where it’s not all about Type I IFN and B cells!

Virginia Pascual showed how erythrocyte mitochondrial components activate monocytes via IL-1β in a distinct IFN/myeloid-driven lupus subgroup, questioning the possibility of combo-therapies.
Cross-species SLE transcriptomics (mouse/human) now inform which models best match human endotypes, crucial for predicting drug response.
The Accelerating Medicines Partnership in SLE/RA continues to deliver. Andrea Fava’s group identifies new kidney myeloid populations linked to histology severity.
Spatial transcriptomics in lupus nephritis uncovered new critical players such as macrophage subtypes (Mac3/4) and a potential macrophage-fibroblast crosstalk, especially in Class III/IV nephritis. Congrats to the French Axis Brest-Marseille.

Patient stratification & precision medicine

Emerging tools and modalities are improving patient stratification:

Metabolomics remains an informative modality for certain diseases such as SSc, RA, SLE and PSA, but the accuracy of signatures is very disease and sample-dependent (e:g. urine performs better than blood in SLE).
Predicting drug response remains a challenge. The IMID Consortium presents the DoCTIS platform: a large-scale drug-response atlas; covering 180 IMIDs, a landmark toward personalized therapies.
Biomarker (BM) discovery advances and clinical trials: “Tissue is the issue “ but thanks to the efforts led by Pr C. Pitzalis (UK) and S. Alivernini (Italy), new Clinical trials integrating BMs derived from synovial biopsies (ScRNA and ST) and AI driven treatment recommendation, aim to change this.

Therapeutic developments

B Cell depleting therapy: A new era

A decade ago, treatment options were limited to rituximab (anti-CD20) and belimumab (anti-BAFF/BLyS), each approved for select indications and with varying efficacy across diseases. Today, we’re witnessing new momentum, with several therapies now demonstrating promising results in Phase II and III trials.

Obinutuzumab (a new anti-CD20) yields ~69% renal responses with sustained depletion in Lupus nephritis.
BAFF/APRIL inhibitors: watch for Phase III readouts from telitacicept, atacicept and ianalumab.
T cell engagers: (CD19/CD3, BCMA/CD3) show potent plasma cell targeting; new trispecific CD3/CD28/CD19 completed Phase I in SLE. More potent T cell depleting without safety issues.
CAR-T Cells: early RESET SLE and REST SSc data shows immune reset and B cell repertoire renewal with minimal CRS. Long-term efficacy and safety remains to be established before the celebration.

Novel mechanisms of action (MOAs) to watch

In SLE, TLR7/8 inhibition with Enpatoran (WILLOW study) suppresses IFN signatures within 2 weeks with overall great efficacy and few adverse events in CLE/SLE. Better than Anifrolumab? Inhibition of CD40L with Dapirolizumab is also exciting.
Should we target myeloid cells? IW-601 is a first in class anti MOSPD2 mAb that blocks monocyte migration. Phase I showed enthusiastic results with an overall good safety profile and long half-life (4 weeks SC).
FcRn inhibitors (e.g., efgartigimod) for Sjögren’s disease showed promising Phase II results.
Complement inhibition: Promising in large vessel vasculitis (GCA)—a potential new option beyond the recent success of JAK inhibitors.

Recommendation updates

The 2025 update to EULAR recommendations supports quadruple therapy early on in lupus nephritis management: glucocorticoids, hydroxychloroquine, an immunosuppressant (MMF or low‑dose cyclophosphamide), and either a calcineurin inhibitor or biologics such as belimumab or obinutuzumab.

Our conclusions

EULAR 2025 reinforced the momentum toward data generation with transformative technologies like scRNA-seq and spatial transcriptomics to decipher complex biology and the use of tissue derived biomarker-driven clinical trials.
Novel, exciting therapies are emerging and we will soon need good-quality data to position each therapy (sequential therapy vs combo) along the patient journey.
The time is ripe for data generation of a new kind: Owkin will soon contribute with miidas (Multimodal Immunology & Inflammation Data Atlas, with Spatial omics). This landmark initiative is building a comprehensive, multi-dimensional atlas of I&I diseases, integrating scRNA-seq, spatial transcriptomics, genomics, proteomics, and detailed clinical data from thousands of patients. Stay tuned in the coming months.
Miidas will power Owkin K for I&I applications, starting with biomarker discovery in IBD.