Mesoblast (ASX:MSB) has announced that the US Food and Drug Administration (FDA) has granted Regenerative Medicine Advanced Therapy designation to its Revascor (rexlemestrocel-L) drug for children with hypoplastic left heart syndrome (HLHS).
This builds on earlier FDA designations of Rare Pediatric Disease (RPD) and Orphan-Drug (OD) status for the therapy.
Mesoblast develops allogeneic (off-the-shelf) cellular medicines for treating severe and life-threatening inflammatory conditions. These therapies target diseases by modulating immune system responses and reducing damaging inflammation.
Hypoplastic left heart syndrome
HLHS is a severe heart defect where a child is born with an underdeveloped left side of the heart, including the left ventricle, aorta, and mitral valve. This prevents the heart from pumping oxygenated blood effectively to the body. Without immediate surgery, the defect is usually fatal.
The syndrome affects about 2 to 3 infants per 10,000 live births. It accounts for 2-9% of all congenital heart defects and is responsible for approximately 25-40% of neonatal cardiac deaths.
Revascor has demonstrated promising results in a randomised controlled trial involving 19 children with HLHS. Its effects include:
- promoting the formation of new blood vessels in the underdeveloped left ventricle (“neovascularisation”);
- reducing inflammation and preventing the immune system from attacking healthy tissues, creating a favourable environment for tissue growth (“immunomodulation”).
Regenerative Medicine Advanced Therapy (RMAT) status
The FDA’s RMAT designation accelerates development for therapies addressing life-threatening conditions.
Benefits include rolling review, eligibility for priority review and expedited regulatory pathways for a Biologics License Application (BLA). Mesoblast plans to collaborate with the FDA on an approval strategy.
Chief Executive Silviu Itescu commented: “FDA’s support acknowledges Revascor’s potential impact on the long-term outcomes for critically ill children. We look forward to advancing this therapy to address their unmet needs.”
Shares in Mesoblast have surprisingly fallen following the announcement. They’re currently 7.1% lower at $1.64.