The U.S. Food and Drug Administration (FDA) has approved a new treatment for a rare genetic disorder known as alpha-mannosidosis. The intravenous drug, Lamzede (velmanase alfa) manufactured by Chiesi USA provides the first enzyme replacement therapy for this rare condition.

Lamzede is designed to treat alpha-mannosidosis occurrences outside of the central nervous system. Alpha-mannosidosis is a rare genetic condition occurring in 1 in every 500,000 people. It is characterized by the lack of a functional alpha-mannosidase enzyme in the body due to a mutated MAN2B1 gene. The alpha-mannosidase enzyme helps the body by breaking down complex sugar molecules known as oligosaccharides. When the alpha-mannosidase enzyme is absent or dysfunctional due to mutation of the MAN2B1 gene, symptoms of alpha-mannosidosis can occur. According to the FDA, these symptoms include:

  • Mild to moderate intellectual disability
  • Hearing loss
  • Large head
  • Prominent forehead
  • Protruding jaw
  • Skeletal abnormalities
  • Muscle weakness

Lamzede acts as an enzyme replacement that supplements the body's missing or dysfunctional alpha-mannosidase enzymes. By receiving weekly, 10mg infusions, patients can restore typical cell function and improve the quality of their lives.

In clinical trials, Lamzede was compared to a placebo treatment over the course of 52 weeks. During the clinical trial, Lamzede was administered intravenously at 1 mg per kg of a patient’s body weight. After 52 weeks, there was a double-blind examination that consisted of 4 parts: a 3-minute stair climbing exercise, a 6-minute walking test, a forced vital capacity test, and an examination of oligosaccharide levels in patients’ blood. In all three physical tests, patients on Lamzede outperformed placebo patients. Additionally, patients taking Lamzede showed a reduction in their serum oligosaccharide concentration.

While this was enough evidence for the FDA to approve Lamzede, the agency did include some warnings about potential side effects. Most notable was that some patients displayed hypersensitivity to the drug that caused anaphylaxis. This life-threatening side effect warranted the requirement that “medical support measures, including resuscitation equipment, should be readily available during Lamzede administration.”