Italy’s Leadiant Biosciences has claimed FDA approval for a new drug for adenosine deaminase severe combined immune deficiency (ADA-SCID) – also known as bubble boy disease.
Revcovi (elapegademase; previously EZN-2279) is a long-acting drug that replaces the missing ADA enzyme in patients with ADA-SCID with an engineered, recombinant form. It provides an alternative to Leadiant’s current animal-derived enzyme replacement therapy Adagen (pegademase bovine) which comes from cows.
ADA-SCID is an ultra-rare, inherited genetic disorder that compromises patients’ immune systems and leaves patients unprotected from infections, and is fatal if untreated. The disease is typically diagnosed within the first few months of life, and undiagnosed babies with ADA-SCID usually die before they reach age two due to infections.
Adagen’s launch in 1990 transformed the treatment of the disease, providing the first alternative to bone marrow transplants for patients. Without treatment, patients with ADA-SCID have to live their lives in carefully-controlled environments to prevent exposure to microorganisms.
Approval of Revcovi is based on two open-label trials which showed that that it increases ADA activity, reduces concentrations of toxic metabolites and improves total lymphocyte counts in ADA-SCID patients.
Since 2016, ADA-SCID patients in Europe have been able to get access to a one-shot gene therapy that can replace the defective gene coding for ADA – GlaxoSmithKline’s Strimvelis – ownership of which was transferred to Orchard Therapeutics earlier this year.
Strimvelis is currently only delivered at a single facility in Italy and has had limited uptake since launch, although Orchard says it is planning to build a manufacturing plant for the therapy and expand the roll-out of the drug to other clinical centres in Europe. Meanwhile, it is also developing another gene therapy – OTL-101 – for ADA-SCID, in development for both the European and US markets.
News of the approval is a boost to Leadiant, which is currently facing fierce criticism over alleged price-gouging for another of its rare disease therapies.
A non-profit health advocacy group in the Netherlands has launched legal action against the Italian drugmaker (formerly Sigma-Tau), accusing it of hiking the price of chenodeoxycholic acid (CDCA) 500-fold.
CDCA is used for the treatment of children and adults with cerebrotendinous xanthomatosis (CTX), a rare genetic metabolic disease that affects around 60 people in the Netherlands. According to an article in the Financial Times, Leadiant has raised the price of CDCA from €300 per patient per year to €140 per capsule – equivalent to a whopping €153,300 per patient per year.