Remestemcel-L Reduces Inflammatory Biomarkers Predictive of High Mortality in Acute Graft Versus Host Disease

NEW YORK, Dec. 07, 2020 (GLOBE NEWSWIRE) -- Mesoblast Limited (Nasdaq:MESO; ASX:MSB), global leader in allogeneic cellular medicines for inflammatory diseases, today announced results presented at the 62^nd annual meeting American Society of Hematology (ASH), which provide in vivo biomarker evidence linking remestemcel-L’s immunomodulatory activity to survival outcomes in children with steroid-refractory acute graft versus host disease (SR-aGVHD). The results were presented on December 6, 2020 by the Phase 3 trial’s lead investigator and pediatric transplant physician, Dr Joanne Kurtzberg, the Jerome Harris Distinguished Professor of Pediatrics and Professor of Pathology, and Director, Pediatric Blood and Marrow Transplant Program at Duke University Medical Center.

Key conclusions were:

• Clinically meaningful overall responses and survival in children with SR-aGVHD treated with remestemcel-L were associated with significant reductions in certain biomarkers of inflammation which have been validated as predictors of mortality risk
• These biomarkers provide evidence of in vivo bioactivity of remestemcel-L in pediatric SR-aGVHD, where children under 12 are at high-risk for mortality, with no approved therapies in the United States
• The durable reductions in blood levels of certain biomarkers associated with inflammatory diseases of the gut suggest that these could be more generally reflective of remestemcel-L activity in vivo in other inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis      

Blood levels of soluble suppression of tumorigenicity 2 (ST2)^1,2 and MAGIC Biomarker Score (MBS)^3,4, validated biomarkers that predict high mortality in SR-aGVHD and active gut inflammation more broadly, were measured at baseline and sequentially over 180 days in 40 of the 54 children with SR-aGVHD who received at least four weeks of remestemcel-L treatment in the single-arm Phase 3 trial. Both the elevated baseline levels of ST2 and MBS were significantly reduced after remestemcel-L treatment at Days 100, 160 and 180 (all timepoints p<0.001 for both markers). This was accompanied by significant reductions in activated circulating T cells. Day 100 survival was 74% in the 54 remestemcel-L children with SR-aGVHD (89% with Grade C/D disease), which compares very favourably with a mortality approaching 70-90% in children of similar severity treated with other therapies.    

Dr Kurtzberg said: “These results support the bioactivity of remestemcel-L in treating the severe inflammation in children with acute graft versus host disease refractory to steroids and provide evidence linking the immunomodulatory properties of remestemcel-L with the excellent responses and survival we see when treating these desperately ill children.”

About Remestemcel-L

Remestemcel-L is an investigational therapy comprising culture-expanded mesenchymal stromal cells derived from the bone marrow of an unrelated donor. Remestemcel-L is thought to have immunomodulatory properties to counteract the cytokine storms that are implicated in various inflammatory conditions by downregulating the production of pro-inflammatory cytokines, increasing production of anti-inflammatory cytokines, and enabling recruitment of naturally occurring anti-inflammatory cells to involved tissues.

About Mesoblast

Mesoblast Limited (Nasdaq:MESO; ASX:MSB) is a world leader in developing allogeneic (off-the-shelf) cellular medicines. The Company has leveraged its proprietary mesenchymal lineage cell therapy technology platform to establish a broad portfolio of commercial products and late-stage product candidates. Mesoblast has a strong and extensive global intellectual property portfolio with protection extending through to at least 2040 in all major markets. The Company’s proprietary manufacturing processes yield industrial-scale, cryopreserved, off-the-shelf, cellular medicines. These cell therapies, with defined pharmaceutical release criteria, are planned to be readily available to patients worldwide. For more information, please see , LinkedIn: Mesoblast Limited and Twitter: @Mesoblast

References

1. Reichenbach DK et al. Bloo`d. 2015 May 14;125(20):3183-92.

2. Vander Lugt MT et al.  New Engl J Med. 2013 Aug 8 369:529-39.

3. Hartwell MJ et al. JCI Insight. 2017;2(3):e89798.

4. Major-Monfried H et al. Blood. 2018;131(25):2846‐2855.

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