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Sobi Receives Approval From the FDA for Once-Daily Dosing Frequency of Orfadin® (nitisinone) for the Treatment of HT-1
[September 05, 2017]

Sobi Receives Approval From the FDA for Once-Daily Dosing Frequency of Orfadin® (nitisinone) for the Treatment of HT-1


Sobi, a pioneering global biopharmaceutical company dedicated to rare and difficult-to-treat diseases, has received approval from the U.S. Food and Drug Administration (FDA) for a reduced dosing frequency for Orfadin® (nitisinone) from twice daily to once daily in patients 5 years of age and older.

Orfadin is approved in combination with dietary restriction of tyrosine and phenylalanine for people with hereditary tyrosinemia type 1 (HT-1), a rare genetic disorder that can cause liver, renal and neurological complications. The reduced dosing frequency is approved for use in patients 5 years of age and older who have undetectable serum and urine succinylacetone concentrations after a minimum of 4 weeks on a stable dosage of nitisinone. A once-daily dosing option was also approved by the European Commission in the beginning of 2017.

"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 20mg capsules and Orfadin oral suspension," says Milan Zdravkovic, Senior Vice President, Chief Medical Officer, and Head of Research & Development at Sobi.

Orfadin is the first nitisinone product approved in the U.S. and Europe. The U.S. approval of the once-daily formulation was based on the results of a clinical study in 16 HT-1 patients, comparing a 4-week once-daily and 4-week twice daily dosing regimen. The study showed comparable blood-levels of nitisinone for these two regimens. The original approval in the U.S. in 2002 was based on an open-label study of 207 HT-1 patients, in which patients younger than 2 months of age who were treated with dietary restrictions and Orfadin experienced 2- and 4-year survival probabilities of 88% and 88%, respectively. Data from historical controls showed that patients treated with dietary restriction alone had 2- and 4-year survival probabilities of 29% and 29%, respectively. For patients presenting between 2 and 6 months of age who were treated with dietary restrictions and Orfadin, 2- and 4-year survival probabilities were 94% and 94%, respectively. Data for historical controls showed that patients treated with dietary restriction alone had 2- and 4-year survival probabilities of 74% and 60%, respectively. The most common adverse reactions (incidence >2%) seen with Orfadin use are hepatic neoplasm, liver failure, thrombocytopenia, leucopenia, visual system complaints including conjunctivitis, corneal opacity, keratitis, and photophobia. Please see important safety information below.

"Between dietary restrictions and pharmaceutical treatment, HT-1 patients andtheir families have a lot to deal with every day, and I applaud Sobi for recognizing that and for introducing new dosing options like once-daily Orfadin for patients 5 years of age and older," said Jon Miller, President of the Network of Tyrosinemia Advocates (NOTA). "My son has HT-1, and Sobi has been a partner to our family through the years, providing many forms of support including multiple dosing alternatives, access to nurses, educational materials and assistance with navigating insurance issues."



"Although HT-1 is a very rare disorder, affecting only an estimated 150 patients in the United States, it is potentially fatal without nitisinone treatment," said Can Ficicioglu, M.D., Ph.D., Director of the Newborn Metabolic Screening Program and the Lysosomal Storage Diseases Program at Children's Hospital of Philadelphia. "Before the introduction of Orfadin, fewer than one-third of infants diagnosed with HT-1 before two months of age lived past their second birthday. Today, many HT-1 patients have entered adolescence or even adulthood, requiring increasing doses, so I appreciate that Sobi is providing new dosing options like once-daily Orfadin."

About Orfadin®


People with hereditary tyrosinemia type 1 (HT-1) have problems breaking down an amino acid called tyrosine. Toxic by-products are formed and accumulate in the body, which can cause liver, renal and neurological complications. Approximately 1,000 persons worldwide are identified as living with HT-1 today.

Orfadin® (nitisinone) blocks the breakdown of tyrosine, thereby reducing the amount of toxic tyrosine by-products in the body. Patients must maintain a special diet in combination with Orfadin treatment as tyrosine is not adequately broken down. Orfadin is a proprietary product and is developed and made available globally by Sobi.

For full U.S. prescribing information, please visit www.orfadin.com.

Indication and Usage

Orfadin is a synthetic reversible inhibitor of 4-hydroxyphenylpyruvate dioxygenase indicated for use as an adjunct to dietary restriction of tyrosine and phenylalanine in the treatment of hereditary tyrosinemia type 1 (HT-1).

Important Safety Information

  • Tyrosine levels can increase in the blood if you do not restrict tyrosine and phenylalanine in your diet while taking Orfadin. Too much tyrosine in the blood can cause serious eye problems or other complications
  • Do not adjust your Orfadin dosage in order to lower the tyrosine levels in the blood.
  • A reduction in the number of white cells and platelets in the blood have been observed during treatment with Orfadin. Your platelet and white blood cell counts should be monitored regularly during Orfadin treatment.
  • The most common adverse reactions to taking Orfadin are liver cancer, liver failure, low platelets or white cells in the blood, and complaints related to the eyes, including conjunctivitis, corneal opacity, inflammation of the cornea, and extreme sensitivity to light.
  • Tell your physician promptly if you have unexplained eye symptoms, rash, jaundice (yellowing of the skin or whites of the eyes) or excessive bleeding.
  • Use Orfadin during pregnancy only if the potential benefit justifies the potential risk to the fetus.
  • Nursing women should discontinue either Orfadin or breast-feeding based on the recommendation of your healthcare professional.

For full prescribing information, please visit www.orfadin.com

About Sobi™

Sobi is an international specialty healthcare company dedicated to rare diseases. Sobi's mission is to develop and deliver innovative therapies and services to improve the lives of patients. The product portfolio is primarily focused on Haemophilia, Inflammation and Genetic diseases. Sobi also markets a portfolio of specialty and rare disease products across Europe, the Middle East, North Africa and Russia for partner companies. Sobi is a pioneer in biotechnology with world-class capabilities in protein biochemistry and biologics manufacturing. In 2016, Sobi had total revenues of SEK 5.2 billion (USD 608 M) and about 760 employees. The share (STO: SOBI) is listed on Nasdaq Stockholm. More information is available at www.sobi.com.


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