Mesoblast Limited (Nasdaq:MESO; ASX:MSB), global leader in allogeneic cellular medicines for inflammatory diseases, today announced that the United States Food and Drug Administration (FDA) has granted its allogeneic cell therapy Revascor® (rexlemestrocel-L) a Rare Pediatric Disease (RPD) Designation following submission of results from the randomized controlled trial in children with hypoplastic left heart syndrome (HLHS), a potentially life threatening congenital heart condition.

RPD Designation is granted by the FDA for certain serious or life-threatening diseases which primarily affect children. On FDA approval of a Biologics Licensing Application (BLA) for REVASCOR for the treatment of HLHS, Mesoblast may be eligible to receive a Priority Review Voucher (PRV) that can be redeemed for any subsequent marketing application or may be sold or transferred to a third party.

Results from a blinded, randomized, placebo-controlled prospective trial of REVASCOR conducted in the United States in children with HLHS were published in the December 2023 issue of the peer reviewed The Journal of Thoracic and Cardiovascular Surgery Open (JTCVS Open).1

In the HLHS trial conducted in 19 children, a single intramyocardial administration of REVASCOR at the time of staged surgery resulted in the desired outcome of significantly larger increases in left ventricular (LV) end-systolic and end-diastolic volumes over 12 months compared with controls as measured by 3D echocardiography, (p=0.009 & p=0.020 respectively).

These changes are indicative of clinically important growth of the small left ventricle, facilitating the ability to have a successful surgical correction, known as full biventricular (BiV) conversion, which allows for a normal two ventricle circulation with the surgically repaired left ventricle taking over circulatory support to the body. Without full BiV conversion the right heart chamber is under excessive strain with increased risk of heart failure and death.

As noted in our recent publication, “The fact that 100% of REVASCOR-treated children compared with 57% of controls had large enough LVs to accommodate the full BiV conversion suggests that REVASCOR treatment may help increase the ability to ‘better grow’ the HLHS LV after LV recruitment surgery.”

Mesoblast Chief Executive Silviu Itescu said: “Given the impressive enlargement of the left chamber we have seen in these children treated with REVASCOR in the randomized controlled trial and the increased ability to successfully accomplish life-saving surgery, we plan to meet with FDA to discuss the potential for this trial to support accelerated approval in this indication.”