Facilitating Resolution of Life-Threatening Acute Graft-vs-Host Disease with Human Chorionic Gonadotropin and Epidermal Growth Factor

Background: Acute graft-versus-host disease (aGVHD) is a potentially fatal complication of allogeneic hematopoietic cell transplantation that fails to improve with intense immunosuppression in some patients. We hypothesized that urinary-derived human chorionic gonadotropin [uhCG] could help facilitate resolution of life-threatening aGVHD when added as supportive care via two potential mechanisms: immunomodulation (akin to its role in pregnancy) and supplementation of epidermal growth factor (EGF, to aid in epithelial repair). Methods: In phase I, 26 participants received subcutaneous injections of uhCG in addition to standard immunosuppression (13 initial therapy for Minnesota high risk aGVHD and 13 receiving 2nd line therapy). Participants underwent serial blood testing for biomarkers of hormone response, immune modulation, and aGVHD activity on study. Findings: UhCG was well tolerated, with no dose-limiting toxicities. Sixty-two percent of patients in the high-risk cohort and 54% of patients in the 2nd line cohort had a complete response at study day 28. Plasma EGF was elevated 6-fold (from 4 to 24 pg/ml, p=0.02) at 6 hours post-dose in the high risk cohort, in contrast to no peak in plasma EGF in the more severe 2nd line cohort. After 1 week of uhCG, patients demonstrated a 2-fold increase in regulatory T cell to conventional T cell ratio, suggesting immune modulation despite high dose steroids. Responding patients showed significantly lower plasma amphiregulin and higher plasma butyrate at study completion, suggesting improvement in mucosal damage over time. Interpretation: hCG is a novel, safe supportive therapy, proceeding to phase II testing at 2,000 units/m2 in high-risk aGVHD. Trial Registration: This study is registered at ClinicalTrials.gov (NCT02525029). Funding Statement: This study was funded by the BMT Fund for the Future (SGH), a Regenerative Medicine Minnesota clinical trial award (SGH), and R01 HL11879, R01 HL56067 and R37 AI34495 (BRB). SGH is a University of Minnesota Women’s Early Research Career (WERC) award recipient and conducted this study during her time as a WERC scholar. Declaration of Interests: The authors have no relevant financial conflicts of interest to disclose. SGH has provided consulting services for Incyte, Bristol Myers Squibb, Janssen, and CSL Behring. BRB receives remuneration as an advisor to Kadmon Pharmaceuticals, Inc, Five Prime Therapeutics Inc, Regeneron Pharmaceuticals, Magenta Therapeutics, BlueRock Therapeuetics and consulting services for Bristol-Myers-Squibb, Incyte, Equillium, Regimmune, Dr. Reddy, GT Biopharma and Incyte Corp; research support from Fate Therapeutics, RXi Pharmaceuticals, Alpine Immune Sciences, Inc, Abbvie Inc., Leukemia and Lymphoma Society, Childrens' Cancer Research Fund, and KidsFirst Fund, and is a co-founder of Tmunity. Ethics Approval Statement: This study was approved by the University of Minnesota Institutional Review Board, and all participants signed written, informed consent.