The FDA is busy today. Earlier today, we reported on the FDA approving an at-home infusion option of Glassia for patients with AAT-deficiency. Today, the FDA also approved a higher dose of Orfadin (nitisinone; 20 mg) for the treatment of Hereditary Tyrosinemia type-1 (HT-1).
Due to improvements in our understanding of HT-1 and how to treat this rare condition, children with HT-1 can now lead long and relatively healthy lives and as such, they need additional treatment options as they grow. The 20 mg dose allows adolescents and adults with HT-1 to take fewer capsules per day.
Hereditary Tyrosinemia Type 1 (HT-1)
Tyrosinemia type I is caused by a deficiency of the enzyme fumarylacetoacetate hydrolase (FAH). The absence of FAH leads to an accumulation of toxic metabolic products in various body tissues, which in turn results in progressive damage to the liver and kidneys. Tyrosinemia type I affects males and females in equal numbers.
Treatment for HT-1 consists of a low phenylalanine and tyrosine diet plus Orfadin.
Orfadin inhibits 4-hydroxyphenylpyruvate dioxygenase so that toxic by-products of tyrosine do not accumulate in the the body.
Orfadin is provided in 5 dosing alternatives: 2mg, 5mg, 10mg, 20mg capsules and 4mg/ml oral suspension.
In the video clips below, Jon Miller, founder of NOTA and Geore Diaz, MD of Mount Sinai Hospital talk about the condition from both a parent's and clinician's perspective.