Cellular Therapy Long-Term Follow-Up of a Pilot Study Using Placenta-Derived Decidua Stromal Cells for Severe Acute Graft-versus-Host Disease Behnam Sadeghi 1, *, Mats Remberger 6 , Britt Gustafsson 3 , Jacek Winiarski 3 , Gianluca Moretti 1 , Bita Khoein 1 , Lena Klingspor 4 , Magnus Westgren 5 , Jonas Mattsson 2,7 , Olle Ringd  en 1 1 Translational Cell Therapy Research, Department of Clinical Science, Intervention and Technology, CLINTEC, Karolinska Institute, Huddinge, Sweden 2 Department of Oncology and Pathology, Karolinska Institute, Stockholm, Sweden 3 Division of Pediatrics, CLINTEC, Karolinska Institute, Astrid Lindgren Children’s Hospital, Karolinska University Hospital, Huddinge, Sweden 4 Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institute, Karolinska University Hospital, Huddinge, Stockholm, Sweden 5 Division of Obstetrics and Gynecology, CLINTEC, Karolinska Institute, Karolinska University Hospital, Huddinge, Stockholm, Sweden 6 Kliniska Forsknings- och Utvecklingsenheten, Verksamhetsomra  de Blod- och Tum€ orsjukdomar, Uppsala University Hospital, and Department of Medical Sciences, Uppsala University, Uppsala, Sweden 7 Division of Medical Oncology and Hematology, Princess Margaret Cancer Center, University of Toronto, Toronto, Ontario, Canada Article history: Received 10 January 2019 Accepted 29 May 2019 ABSTRACT There is a need for effective therapy with few side effects for severe acute graft-versus-host disease (GVHD). The placenta protects the fetus from the mother’s haploidentical immune system during pregnancy. We found that maternal stromal cells from the fetal membrane, so-called decidua stromal cells (DSCs), are more immunosup- pressive than other sources of stromal cells. We prospectively treated 21 patients (median age, 49 years; range, 1.6 to 72 years) for grade II-IV acute GVHD. All 21 patients had biopsy-proven gastrointestinal GVHD. The majority of patients were either steroid-refractory or had progressive GVHD, 11 patients after >7 days or with progression after 3 days, and 10 were refractory to steroids after >3 days. We used an improved protocol in which DSCs were thawed and infused in a buffer with 5% human albumin. DSCs were given at a median dose of 1.2 (range, 0.9 to 2.9) £ 10 6 cells/kg body weight with a median of 2 (range, 1 to 6) doses, given 1 week apart. The median viability of thawed DSCs was 93% (range, 69% to 100%), and the median cell passage number was 4 (range, 2 to 4). Complete resolution of GVHD was seen in 11 patients, with a partial response in the other 10. The cumulative incidence of chronic GVHD was 52%. GVHD was mild in 6 patients, moderate in 4 patients, and severe in 1 patient based on National Institutes of Health chronic GVHD severity scoring. Nine patients died, including 3 from relapse and 1 each from acute GVHD and septicemia, Zygomycetes infection, liver insufficiency, cerebral hemorrhage, multiple organ failure, and chronic GVHD with obstructive bronchiolitis. Four-year transplantation-related mortality was 28.6%, and overall survival was 57%. Survival was similar (P = .33) to that for all 293 patients who underwent allo- geneic hematopoietic cell transplantation during the same period (2012 to 2015), with 66% overall survival. DSC infusion is a novel therapy for acute GVHD grade II-IV, and a randomized trial is currently underway (Clinical- Trials.gov NCT 02172937). © 2019 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. Key Words: Decidua stromal cells Graft-versus-host disease Long-term follow-up Steroid-resistant GVHD Survival INTRODUCTION Graft-versus-host disease (GVHD) remains a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT) [14]. Steroids are the first-line therapy for acute GVHD, but the outcome is poor in patients with steroid-refractory acute GVHD [3,4]. There is a need for effective therapy for severe acute GVHD. Several novel immunosuppressive therapies have emerged in recent years [5]. Anti-CD52, anti-TNFa, mycophenolate mofetil, sirolimus, pentostatin, and extracorporeal photopheresis have been tried in several pilot studies, with varying response rates and no dramatic improvement in survival. The most recently introduced innovative drug to treat steroid-refractory acute GVHD is vedolizumab, an anti-a4b7 integrin [6]. However, the results from a phase II trial were not encouraging, owing to limited efficacy (personal communication, Yngvar Floisand and Jonas Mattsson). In another study, the selective adhesion mole- cule inhibitor natalizumab (Tysabri) was administered to 18 patients with acute gastrointestinal GVHD grade II-IV [7]. The Financial disclosure: See Acknowledgments on page 1969. * Correspondence and reprint requests: Behnam Sadeghi, MD, PhD, Transla- tional Cell Therapy Research (TCR) Group, Department of CLINTEC, Karolinska Institutet, Kliniskt Forskningscentrum KFC, NOVUM, Plan 6, H€ alsov€ agen 7-9, SE-141 57 Huddinge, Sweden. E-mail addresses: behnam.sadeghi@ki.se, behnamsg@yahoo.com (B. Sadeghi). https://doi.org/10.1016/j.bbmt.2019.05.034 1083-8791/© 2019 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. Biol Blood Marrow Transplant 25 (2019) 19651969 Biology of Blood and Marrow Transplantation journal homepage: www.bbmt.org