Repair of Acute Respiratory Distress Syndrome in COVID-19 by Stromal Cells (REALIST-COVID Trial): A Multicentre, Randomised, Controlled Trial.

ABSTRACT

RATIONALE Mesenchymal stromal cells (MSCs) may modulate inflammation, promoting repair in COVID-19-related Acute Respiratory Distress Syndrome (ARDS). OBJECTIVES: We investigated safety and efficacy of ORBCEL-C (CD362-enriched, umbilical cord-derived MSCs) in COVID-related ARDS. METHODS: This multicentre, randomised, double-blind, allocation concealed, placebo-controlled trial (NCT03042143) randomised patients with moderate-to-severe COVID-related ARDS to receive ORBCEL-C (400million cells) or placebo (Plasma-Lyte148). MEASUREMENTS The primary safety and efficacy outcomes were incidence of serious adverse events and oxygenation index at day 7 respectively. Secondary outcomes included respiratory compliance, driving pressure, PaO2/FiO2 ratio and SOFA score. Clinical outcomes relating to duration of ventilation, length of intensive care unit and hospital stays, and mortality were collected. Long-term follow up included diagnosis of interstitial lung disease at 1 year, and significant medical events and mortality at 2 years. Transcriptomic analysis was performed on whole blood at day 0, 4 and 7. MAIN RESULTS: 60 participants were recruited (final analysis n=30 ORBCEL-C, n=29 placebo 1 in placebo group withdrew consent). 6 serious adverse events occurred in the ORBCEL-C and 3 in the placebo group, RR 2.9(0.6-13.2)p=0.25. Day 7 mean[SD] oxygenation index did not differ (ORBCEL-C 98.357.2], placebo 96.667.3). There were no differences in secondary surrogate outcomes, nor mortality at day 28, day 90, 1 or 2 years. There was no difference in prevalence of interstitial lung disease at 1year nor significant medical events up to 2 years. ORBCEL-C modulated the peripheral blood transcriptome. CONCLUSION: ORBCEL-C MSCs were safe in moderate-to-severe COVID-related ARDS, but did not improve surrogates of pulmonary organ dysfunction. Clinical trial registration available at www. CLINICALTRIALS gov, ID NCT03042143. This article is open access and distributed under the terms of the Creative Commons Attribution 4.0 International License (https//creativecommons.org/licenses/by/4.0/).