Mesoblast Files for Orphan Drug and Pediatric Rare Disease Designations for Rexlemestrocel-L as Treatment for Severe Congenital Heart Disease

NEW YORK, Nov. 26, 2023 (GLOBE NEWSWIRE) -- Mesoblast Limited (Nasdaq:MESO; ASX:MSB), global leader in allogeneic cellular medicines for inflammatory diseases, today announced that it has filed for orphan drug designation (ODD) and rare pediatric disease designation (RPDD) with the United States Food and Drug Administration (FDA) for its allogeneic cell therapy Revascor (rexlemestrocel-L) in the treatment of the congenital heart disease hypoplastic left heart syndrome (HLHS). The filings were based on results from a blinded, randomized, controlled prospective trial of REVASCOR conducted at a single center in the US in 19 children with HLHS and accepted for publication in an upcoming issue of the peer reviewed The Journal of Thoracic and Cardiovascular Surgery Open (JTCVS Open).¹

HLHS is a severe congenital heart disease in which the left side of the heart does not fully develop and effective pumping of oxygenated blood by the left ventricle to the rest of the body is reduced. Without immediate surgery after birth, the prognosis is dismal with HLHS overall being responsible for 25% to 40% of all neonatal cardiac mortality.² In the longer term, surgery that creates a two-ventricle series circulation with the left ventricle (LV) pumping blood to the body and the right ventricle pumping blood to the lungs is the ideal anatomic repair. Unfortunately, achievement of this objective is limited by the inability in most patients for the left ventricle to grow sufficiently to support the circulation to the body.

REVASCOR is an allogeneic preparation of immunoselected and culture-expanded mesenchymal precursor cells which have been shown previously to have multiple mechanisms-of-action that may be beneficial to children with HLHS including neovascularization, anti-fibrosis, anti-apoptosis, immunomodulation, reduction in inflammation, and reversal of endothelial dysfunction. In the DREAM-HF randomized sham-placebo controlled prospective trial of REVASCOR in 565 adult patients with heart failure with low ejection fraction (HFrEF), a single intramyocardial administration of REVASCOR into the left ventricle resulted in significant improvement in LV ejection fraction at 12 months,³ indicative of strengthened overall LV systolic function.