FDA Approves New Formulation for Orfadin to Treat Tyrosinemia
James Radke, PhD
The FDA has approved a new oral liquid formulation for Orfadin (nitisinone) to treat hereditary tyrosinemia type 1 (HT-1).
Orfadin is indicated for use in combination with dietary restriction of tyrosine and phenylalanine for people with HT-1. Orfadin capsules have been available for several years and the new liquid formaluation will an additional option for babies and infants with HT-1.
The oral suspension comes in a 4 mg/mL dose and is expected to be available in August 2016, according to its manufacturer, SOBI.
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.
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.