Dr Maxime Raffray
JAK inhibitors are associated with nearly double the risk of venous thromboembolism of TNF inhibitors in rheumatoid arthritis, according to a large Swedish registry study presented at EULAR 2026 in London. The authors estimated that switching 250 patients from a TNF inhibitor to a JAK inhibitor for one year would produce approximately one additional VTE event.
Dr Maxime Raffray of the Karolinska Institute presented data from more than 25,000 RA patients in the Swedish Rheumatology Quality Register treated with JAK inhibitors, TNF inhibitors, or other biologic therapies. A total of 347 VTE events were recorded.
The age- and sex-standardised incidence rate per 1000 person-years was:
- JAK inhibitors: 8.3
- IL-6 inhibitors: 7.3
- Rituximab: 5.9
- TNF inhibitors: 4.3
- Abatacept: 4.0
- General population: 2.9
The fully adjusted hazard ratio for VTE with JAK inhibitors versus TNF inhibitors was 1.89.
Dr Raffray said the findings confirmed earlier evidence linking JAK inhibitors to an elevated VTE risk, but noted the increased risk did not appear to be unique to this drug class. He said the size of the risk should be weighed against the clinical benefits of JAK inhibitor therapy.
Further work investigating the potential effects of individual JAK inhibitors is underway, he added.