Treatment Of Steroid-Refractory Acute Graft-versus-host Disease With Mesenchymal Stromal Cells Versus Best Available Therapy

A Randomised, Open-label, Multicentre, Phase 3 Trial of First-line Treatment With Mesenchymal Stromal Cells MC0518 Versus Best Available Therapy in Adult and Adolescent Subjects With Steroid-refractory Acute Graft-versus-host Disease After Allogeneic Haematopoietic Stem Cell Transplantation (IDUNN Trial)

The primary purpose of this trial is to demonstrate the superiority of MC0518 compared to the first used best available therapy (BAT) with respect to overall response rate (ORR) at Day 28 and/or overall survival (OS) until Visit Month 24 in adult and adolescent subjects with steroid-refractory acute graft-versus-host disease (SR-aGvHD).

Inclusion Criteria:

• Participant had a previous allogeneic HSCT as indicated for non-malignant (including inborn errors of metabolism, primary immunodeficiencies, haemoglobinopathies, and bone marrow failure syndromes) or haematological malignant disease, irrespective of human leukocyte antigen match
• Participant has been clinically diagnosed with Grade II to IV aGvHD at the Screening Visit
• Participant has experienced failure of previous first-line aGvHD treatment (ie, SR-aGvHD), defined as: a) aGvHD progression within 3 to 5 days of therapy onset with >= 2 mg/kg/day of prednisone equivalent or b) failure to improve within 5 to 7 days of treatment initiation with >= 2 mg/kg/day of prednisone equivalent or c) incomplete response after > 28 days of immunosuppressive treatment including at least 5 days with >= 2 mg/kg/day of prednisone equivalent
• Participant has an estimated life expectancy > 28 days at the Screening Visit
• Male or female participant who is >= 12 years of age at the Screening Visit

Exclusion Criteria:

• Participant has overt relapse or progression or persistence of the underlying disease at the Screening Visit
• Participant has received the last HSCT for a solid tumour disease
• Participant has GvHD overlap syndrome at the Screening Visit
• Participant has received systemic first line treatment for aGvHD other than steroids and a prophylaxis with other than calcineurin inhibitors, mammalian target of rapamycin (mTOR) inhibitors, anti-thymocyte globulin (ATG), mycophenolate mofetil (MMF), methotrexate (MTX), and / or cyclophosphamide before the Screening Visit
• Participant has a known pregnancy (as confirmed by a positive pregnancy test at the Screening Visit) and or is breastfeeding at the Screening Visit
• Participant has received treatment with any other investigational agent within 30 days or 5 half-lives (whichever is longer) before the Screening Visit (compliance to be confirmed for the period between the Screening Visit and the Baseline Visit at the Baseline Visit).