The US FDA has given the green light for Jazz Pharma’s Defitelio, adding another product to the company’s stable of rare disease therapies.
The US regulator has approved Defitelio (defibrotide sodium) to treat adults and children who develop hepatic veno-occlusive disease (VOD) as a complication of a haematological stem cell transplant (HSCT).
This is the first FDA-approved therapy for treatment of severe hepatic VOD, a rare and life-threatening condition that is seen in some patients who undergo high-dose chemotherapy and an HSCT to treat other diseases such as haematological cancers.
In VOD, some of the veins in the liver become blocked, causing swelling and a decrease in blood flow inside the liver, which may lead to liver damage and can also affect the kidneys and lungs. Around 2% of HSCT patients develop the complication and in 80% of them it is fatal.
The Health Resources and Services Administration (HRSA) Blood Cell Transplant unit suggests that around 18,000 bone marrow or umbilical cord blood transplants were performed in the US in 2013.
In trials involving 528 patients, 38-45% of Defitelio-treated VOD patients were still alive 100 days after the HSCT procedure, a higher proportion than the expected 21-31% survival rate at that point in patients who received supportive care alone.
Jazz – which is also planning trials this year of Defitelio in the prevention of VOD in high-risk hSCT patients – has been adding to its salesforce in anticipation of approval and said it plans to start shipping the drug “within a week”.
Defitelio has been launched for this indication since 2014 in Europe, where it has an acquisition cost of around £33,000 (around $47,000) per patient, according to NHS figures, which suggests that a large chunk of the cost can be offset by reduced time in intensive care units.
The drug made $71m in European sales last year, down slightly on 2014. Jazz acquired Defitelio as part of its $1bn purchase of Italy’s Gentium in 2013.
Jazz acknowledges that it will take time for Defitelio sales to ramp up in the US as VOD is chronically under-diagnosed, but has suggested in the past that it could make $100m-125m from the drug this year. The company is planning a programme of medical education to try to tackle the under-diagnosis issue.
Meanwhile, Jazz already sells two other rare disease therapies – narcolepsy treatment Xyrem (sodium oxybate) and Erwinaze (asparaginase Erwinia chrysanthemi) for acute lymphoblastic leukaemia (ALL) patients who have developed hypersensitivity to asparaginase produced in Escherichia coli bacteria.
The company has the opportunity to promote both Erwinaze and Defitelio via its haematology/oncology salesforce, it noted.