Dive Brief:
- Orphan diseases specialist Swedish Orphan Biovitrum (Sobi) has gained approval from the Food and Drug Administration for a new dosing frequency of Orfadin (nitisinone), cutting the regimen from two doses a day to just one for patients with hereditary tyrosinaemia type 1 (HT-1) aged five years and older.
- The change in regimen is based on the results of a clinical study in 16 people with HT-1, comparing a four week once-daily and four week twice daily dosing regimen. The results showed similar levels of nitisinone in the blood, and comparable safety and efficacy.
- Orfadin has been approved at the lower dosing frequency in Europe since March 2017.
Dive Insight:
There are around a thousand people worldwide with the rare genetic disorder hereditary tyrosinaemia type 1. Affected individuals cannot break down the amino acid tyrosine, and without dietary restriction and drug treatment may die before the age of two years. The introduction of Orfadin has improved the survival rate from 29% after two years for children who developed symptoms before two months of age, to 93% after two years in patients with treatment initiation before two months of age.
The combination of drug treatment and a low protein diet has improved the health and quality of life of people with the rare genetic disorder, meaning that they are living longer than ever before. However, because Orfadin is dosed according to body weight, the number of capsules required increases as affected children reach adolescence and adulthood. By approving the new treatment regimen, the FDA and the European Medicines Agency have significantly simplified the dosage regimen for patients and their caregivers.
"We are very happy to receive the approval by the FDA of the new dosing frequency for Orfadin. Orfadin is the first nitisinone product approved for once daily use in the U.S. This is an important step towards reducing the treatment burden of people with HT-1 and it follows Sobi’s introduction of Orfadin 20 mg capsules and Orfadin oral suspension," says Milan Zdravkovic, SVP, CMO, and head of R&D at Sobi.