- The FDA approved on Tuesday Alexion's Kanuma for use in patients with lysosomal acid lipase deficiency (LAL-D), a progressive metabolic disease which often leads to liver failure, multi-organ failure, and premature death.
- Lysosomal acid lipase (LAL) deficiency often presents in infants around two to four months, usually leading to death before age one.
- Alexion acquired Kanuma during late-stage development when it bought Synageva Biopharma for $8.4 billion in May.
The extremely rare LAL deficiency can manifest in two forms—Wolman disease, which presents during infancy, or cholesteryl ester storage disease (CESD). Patients with CESD may live longer and have varying degrees of disease severity. Lack of LAL leads to fat build-up within cells and various tissues, which in turn cases liver and cardiovascular issues. For this reason, the ability to intravenously introduce enzyme replacement in these patients represents a major breakthrough.
In an open-label, historically controlled trial involving nine infants with rapidly progressive Wolman disease and 21 controls, six of the infants (67%) were alive at 12 months, compared with none of the untreated infants. Likewise, a double-blind trial of 66 CESD patients showed a statistically significant improvement in LDL-cholesterol levels and other disease parameters in Kanuma-treated patients.
The approval process was two-fold. As Kanuma is produced by genetically engineered chickens, FDA's Center for Veterinary Medicine had to approve the safety of the methodology. The Center needed to ensure the stability of the genome in treated chickens over several generations. The chickens are genetically engineered to produce a replacement LAL protein in their egg whites, which is then extracted and refined to manufacture Kanuma.
The FDA's Center for Drug and Evaluation Research then had to approve Kanuma for use in humans.