Swedish Orphan Biovitrum has the worldwide rights to this product.
What is Orfadin?
Orfadin is a hard white capsule for oral use. Treatment with Orfadin should be started and monitoredby doctors who are experienced in the treatment of hereditary tyrosinemia type 1 (HT-1) patients.Orfadin contains the active substance nitisinone.
What is Orfadin used for?
Orfadin is used to treat hereditary tyrosinemia type 1 (HT-1), a rare childhood disease. In this diseasethe body is unable to completely break down the amino acid tyrosine. Harmful substances will beformed and accumulate in the body, causing progressive liver failure and liver cancer in youngchildren. It is used with a diet that restricts the amino acids tyrosine and phenylalanine.
Because hereditary tyrosinemia type 1 is a rare disease Orfadin was designated an ‘orphan medicine’ (a medicine used in rare diseases) on 29 December 2000.
The medicine can only be obtained with a prescription.
How is Orfadin used?
Orfadin should be started as early as possible and the dose of Orfadin adjusted to the patient. The recommended starting dose is 1 mg/kg body weight/day divided in 2 doses administered orally. The capsules may be opened and their contents mixed in a small amount of water or formula diet just before swallowing. Orfadin is intended for long-term use.
How does Orfadin work?
Tyrosine is broken down in the body by a number of enzymes. Patients with HT-1 lack one of these enzymes, and the tyrosine in their body is not properly eliminated, but is transformed instead into harmful substances. Nitisinone, the active substance in Orfadin, blocks the breakdown of tyrosinebefore it can be transformed into harmful substances. However, tyrosine will remain in the body andtherefore a special diet (with low tyrosine and phenylalanine content) must be followed when takingOrfadin.
How has Orfadin been studied?
The largest study of Orfadin has been in 257 patients in 87 different hospitals in 25 countries, as part of a ‘compassionate use’ programme (this is a programme through which doctors can request a medicine for one of their patients before the medicine is fully authorised). The effect of Orfadin on survival was studied, and compared to historical records (report of patient survival with diet only as published in medical journals).
What benefit has Orfadin shown during the studies?
The main benefit is that Orfadin has been shown to greatly extend life. For example, a baby less than 2 months old with HT-1 would normally have only a 28% chance of surviving 5 years using diet alone. With additional Orfadin treatment, the survival rate increases to 82%. The sooner treatment is started, the better the rate of survival.
What is the risk associated with Orfadin?
The most common side effects of Orfadin are the result of high tyrosine levels caused by patients not eating the right foods as well as rare cases of a decrease in platelet and white blood cell counts. For the full description of the side effects reported with Orfadin, please see the package leaflet. Orfadin should not be used in people who may be hypersensitive (allergic) to nitisinone or any of the other ingredients.
Why has Orfadin been approved?
The Committee for Medicinal products for Human Use (CHMP) decided that Orfadin seems to be an effective treatment of HT-1, particularly if started early before the patient’s liver is too damaged, and it provides a better outcome for patients than that reported in literature with diet alone. The CHMP decided that Orfadin’s benefits are greater than its risks and recommended that Orfadin be given marketing authorisation.
What information is still awaited for Orfadin?
The company that makes Orfadin has established a post-marketing surveillance program to monitor the use and safety of the medicine in the treatment of HT-1.
Other information about Orfadin:
The European Commission granted a marketing authorisation valid throughout the European Union for Orfadin to Swedish Orphan International AB on 21 February 2005.