Comparison of drug retention of TNF inhibitors, other biologics and JAK inhibitors in RA patients who discontinued JAK inhibitor therapy.

OBJECTIVES: JAK Inhibitors (JAKi) are recommended DMARDs for patients with moderate-to-severe RA who failed first-line therapy with methotrexate. There is a lack of data allowing an evidence-based choice of subsequent DMARD therapy for patients who had discontinued JAKi treatment. We aimed to compare the effectiveness of TNF inhibitor (TNFi) therapy vs JAKi vs other mode of action (OMA) biologic DMARD (bDMARD) in RA patients who were previously treated with a JAKi. METHODS: RA patients who discontinued JAKi treatment within the Swiss RA registry SCQM were included for this observational prospective cohort study. The primary outcome was drug retention for either TNFi, OMA bDMARD or JAKi. The hazard ratio for treatment discontinuation was calculated adjusting for potential confounders. A descriptive analysis of the reasons for discontinuation was performed. RESULTS: Four hundred treatment courses of JAKi were included, with a subsequent switch to either JAKi, TNFi or OMA bDMARD. The crude overall drug retention was higher in patients switching to another JAKi as compared with TNFi and comparable to OMA. A significant difference of JAKi vs TNFi persisted after adjusting for potential confounders. CONCLUSION: In a real-world population of RA patients who discontinued treatment with a JAKi, switching to another JAKi resulted in a higher drug retention than switching to a TNFi. A switch to a second JAKi seems an effective therapeutic option.

Prox-1 promotes invasion of kaposiform hemangioendotheliomas.

Kaposi's sarcoma (KS) is the most frequently occurring malignant tumor in patients infected with HIV. Recent studies have revealed that infection of vascular endothelial cells with KS-associated herpes virus in vitro results in a lymphatic reprogramming of these cells, with potent induction of the lymphatic marker genes podoplanin and vascular endothelial growth factor receptor-3, which is mediated by upregulation of the transcription factor Prox1. However, the potential effects of Prox1 expression on the biology of KS and, in particular, on the aggressive and invasive behavior of KS tumors in vivo have remained unknown. We stably expressed Prox1 cDNA in the two mouse hemangioendothelioma cell lines EOMA and Py-4-1, well-established murine models for kaposiform hemangioendothelioma. Surprisingly, we found that expression of Prox1 was sufficient to induce a more aggressive behavior of tumors growing in syngenic mice, leading to enhanced local invasion into the muscular layer and to cellular anaplasia in vivo, and increased migration rate in vitro. This enhanced malignant phenotype was associated with upregulation of several genes involved in proteolysis, cell adhesion, and migration. Together, these results indicate that Prox1 plays an important, previously unanticipated role in mediating the aggressive behavior of vascular neoplasms such as KS.