Orfadin Generic Approved
September 4, 2019 – The U.S. FDA has approved a Novitium Pharma’s generic version of Sobi’s Orfadin® (nitisinone) capsules. Nitisinone capsules are indicated for use in combination with dietary restriction of tyrosine and phenylalanine to treat adult and pediatric patients who have hereditary tyrosinemia type 1 (HT-1).
Hereditary tyrosinemia (HT) is a rare genetic disorder that leads to an excessive buildup of tyrosine, an amino acid, in the blood. Excessive tyrosine is converted into toxins by an enzyme in the body, which leads to organ damage. Type 1 is the most severe form of HT, and begins in the first few months of life. The effects of HT-1 include food intolerance, rickets (softened and weak bones), liver and kidney failure, repeated neurological crises, abdominal pain, respiratory failure, and an increased risk of liver cancer. Without treatment, children diagnosed with HT-1 often do not survive beyond 10 years of age.
First FDA-approved in 2002, nitisinone blocks the enzyme that converts tyrosine into toxins. This slows the effects of HT-1 and creates the potential for increased life expectancy. The recommended starting dose is 0.5mg/kg of body weight taken by mouth twice daily. The daily dosage should be titrated based on biochemical and/or clinical response, up to a maximum of 2mg/kg per day. For patients five years old and up who have undetectable serum and urine succinylacetone concentrations after a minimum of four weeks on a stable dosage, the total daily dose can be given once per day rather than split across two daily doses.
Nitisinone is also available in an Orfadin® oral suspension and under the brand name Nityr™ (nitisinone tablets – Cycle Pharmaceuticals), neither of which has an available generic at this time. Novitium’s generic is available at a wholesale acquisition cost (WAC) of $4,359.51 per 60 capsules, compared to $5,449.39 for brand name Orfadin capsules.