Study protocol for a randomised, phase II, double-blind, experimental medicine study of obinutuzumab versus rituximab in ANCA-associated vasculitis: ObiVas.

INTRODUCTION: Relapses in ANCA-associated vasculitis (AAV) increase the incidence of end-organ damage and their prevention requires prolonged immunosuppressive therapy. Rituximab, a type I anti-CD20 B cell depleting monoclonal antibody, is the current standard of care for induction of disease remission. Rituximab is not always effective and is associated with a high subsequent relapse risk. Obinutuzumab is a type II anti-CD20 humanised monoclonal antibody with the potential to obtain greater tissue B cell depletion than rituximab and reduce relapse risk in AAV. METHODS AND ANALYSIS: ObiVas is a randomised, phase II, double-blind controlled trial that will compare the mechanistic effects of rituximab and obinutuzumab in the induction treatment of patients with AAV positive for proteinase 3 ANCA (PR3-ANCA). 26 patients, either newly diagnosed or relapsing, will be recruited from a single centre and randomised in a 1:1 ratio to receive 1000 mg rituximab or obinutuzumab as induction therapy on days 1 and 15, alongside a tapering glucocorticoid regimen. The primary end point is CD19+ B cell depletion in nasal-associated lymphoid tissue (NALT), assessed as change from baseline to week 26. Secondary outcomes will compare the safety and clinical efficacy of rituximab and obinutuzumab and their impact on immune biomarkers, including tissue and peripheral blood lymphocyte subsets and PR3-ANCA binding levels. Patients are followed through to week 78. The trial opened for recruitment in January 2023 and is forecasted to complete recruitment by the end of 2024. ETHICS AND DISSEMINATION: For all patients, informed written consent will be obtained in keeping with Good Clinical Practice. Trial results will be disseminated to the relevant scientific, clinical and patient communities on trial closure. NALT data analysis will start before trial completion. Other analyses will be reported after trial completion. This trial was given ethical approval by Edgbaston (West Midlands) Research Ethics Committee (approval reference 22/WM/0174). TRIAL REGISTRATION NUMBER: ISRCTN13069630.

Transcriptional analysis identifies potential novel biomarkers associated with successful ex-vivo perfusion of human donor lungs.

BACKGROUND: Transplantation is an effective treatment for end-stage lung disease, but the donor organ shortage is a major problem. Ex-vivo lung perfusion (EVLP) of extended criteria organs enables functional assessment to facilitate clinical decision-making around utilization, but the molecular processes occurring during EVLP, and how they differ between more or less viable lungs, remain to be determined. METHODS: We used RNA sequencing of lung tissue to delineate changes in gene expression occurring in 10 donor lungs undergoing EVLP and compare lungs that were deemed non-transplantable (n = 4) to those deemed transplantable (n = 6) following perfusion. RESULTS: We found that lungs deemed unsuitable for transplantation had increased induction of innate immune pathways and lower expression of oxidative phosphorylation related genes. Furthermore, the expression of SCGB1A1, a gene encoding an anti-inflammatory secretoglobin CC10, and other club cell genes was significantly decreased in non-transplantable lungs, while CHIT-1 was increased. Using a larger validation cohort (n = 17), we confirmed that the ratio of CHIT1 and SCGB1A1 protein levels in lung perfusate have potential utility to distinguish transplantable from non-transplantable lungs (AUC .81). CONCLUSIONS: Together, our data identify novel biomarkers that may assist with pre-transplant lung assessment, as well as pathways that may be amenable to therapeutic intervention during EVLPAQ6.