Trial of Regulatory T-cells Plus Low-Dose Interleukin-2 for Steroid-Refractory Chronic Graft-versus-Host-Disease

Treg-enriched Cell Dose: Participants will be targeted to a defined dose of donor Treg-enriched total nucleated cells. Initial enrollment will be at target dose-level A. Subsequent cohorts will be dose escalated/de-escalated per the schema

Interleukin-2: Starting the day of Treg-enriched cell infusion, each participant will receive daily subcutaneous IL-2 for self-administration for 8 weeks, followed by a 4-week hiatus. IL-2 will be administered on an outpatient basis. Expected toxicities and potential risks as well as dose modifications are described in Section 6 (Expected Toxicities and Dosing Delays/Dose Modification).