Controlling Hyperactive Immunity With Long-lived Lymphocytes

This is a single-arm, open label, multicentre, Phase 1/2, first in human study of QEL005 in adult participants with diffuse cutaneous systemic sclerosis (dcSSc) or difficult to treat rheumatoid arthritis (D2TRA). QEL005 is an autologous chimeric antigen receptor regulatory T-cell (CAR-Treg) therapy directed against the CD19 marker found on B cells. The primary objective of this study is to evaluate the safety and tolerability of single IV infusions of QEL005 across different dose levels in participants with dcSSc or D2TRA. Secondary and exploratory objectives include assessment of preliminary clinical efficacy (for example, changes in disease activity scores, skin involvement, or joint symptoms, as appropriate for each disease) and evaluation of biological activity (including effects on B cell populations, immune biomarkers, and other laboratory measures). The study uses a dose escalation phase then a dose expansion phase. In the dose escalation phase, sequential cohorts of participants receive increasing doses of QEL005 under close safety monitoring. Safety assessments include recording of adverse events, vital signs and laboratory abnormalities. QEL005 is manufactured from autologous leukapheresis material obtained at baseline. Participants undergo leukapheresis for collection of peripheral blood mononuclear cells, which are then genetically modified ex vivo to express a CD19directed CAR-T regulatory cell. Over the course of the trial, participants will attend scheduled visits for clinical evaluations, laboratory tests, imaging studies, and patient reported outcome questionnaires, as well as tissue biopsies, to characterize the safety profile and to explore pharmacodynamic and immunologic effects of QEL005. There are detailed assessments over the first year following QEL-005 infusion, and then additional long-term follow up for 15 years, standard for cell therapy trials. Data from this Phase 1/2 trial will inform the recommended dose, regimen, and patient population for subsequent studies of QEL005 in autoimmune diseases.