Active Substance: defibrotide
Common Name: defibrotide
ATC Code: B01AX01
Marketing Authorisation Holder: Gentium S.r.l.
Active Substance: defibrotide
Authorisation Date: 2013-10-18
Therapeutic Area: Hepatic Veno-Occlusive Disease
Pharmacotherapeutic Group: Antithrombotic agents
Defitelio is indicated for the treatment of severe hepatic veno-occlusive disease (VOD) also known as sinusoidal obstructive syndrome (SOS) in haematopoietic stem-cell transplantation (HSCT) therapy.
It is indicated in adults and in adolescents, children and infants over 1 month of age.
What is Defitelio and what is it used for?
Defitelio is a medicine containing the active substance defibrotide. It is used to treat severe veno-occlusive disease (VOD) in patients undergoing haematopoietic (blood) stem-cell transplantation. VOD is a condition in which the veins in the liver become blocked, leading to liver dysfunction. Defitelio is used in adults and in children from one month of age.
Because the number of patients with VOD is low, the disease is considered ‘rare’, and Defitelio was designated an ‘orphan medicine’ (a medicine used in rare diseases) on 29 July 2004.
How is Defitelio used?
Defitelio can only be obtained with a prescription and must be prescribed and given by a doctor experienced in the management of complications of haematopoietic stem cell transplantation. It is available as a concentrate to be made into a solution for infusion (drip) into a vein. Defitelio is given four times a day at a dose of 6.25 mg per kg body-weight. Treatment should last for at least for 3 weeks and continue until the patient’s symptoms resolve.
How does Defitelio work?
VOD is usually a complication resulting from a treatment, known as ‘myeloablative chemotherapy’, that is given to patients before blood stem-cell transplantation. Myeloablative chemotherapy is used to clear the patient’s bone marrow of cells before receiving healthy stem cells from a donor. The medicines used for this treatment can damage the lining of the blood vessels in the liver, leading to the formation of clots and obstruction of the vessels seen in VOD.
The active substance in Defitelio, defibrotide, works by increasing the breakdown of clots in the blood. In addition, there is experimental evidence that Defibrotide may protect the cells lining blood vessels.
What benefits of Defitelio have been shown in studies?
Severe VOD is known to have a high mortality rate, ranging between 75 and 85% and in some patient registries exceeding 85%. In one main study involving 102 patients with severe VOD following blood stem-cell transplantation, Defitelio was compared with a historical control group of patients who had received standard supportive care. Defitelio was shown to lower the mortality rate to 62% at 100days after transplantation, and in 24% of patients the symptoms of severe VOD were completely resolved after 100days.
Benefits of Defitelio were also seen in data from a patient registry in the United States, where patients with severe VOD following blood stem-cell transplantation who received Defitelio plus standard care had better outcomes than those given standard care alone, including a higher 100-day survival rate (39% versus 31%) and a higher proportion of patients whose VOD resolved (51% versus 29%).
What are the risks associated with Defitelio?
The most common side effects with Defitelio (which may affect up to 1 in 10 people) are bleeding, hypotension (low blood pressure) and coagulopathy (problems with blood clotting). For the full list of all side effects reported with Defitelio, see the package leaflet.
Defitelio must also not be used together with other medicines that break down blood clots. For the full list of restrictions, see the package leaflet.
Why is Defitelio approved?
The Agency’s Committee for Medicinal Products for Human Use (CHMP) concluded that Defitelio’s benefits are greater than its risks and recommended that it be approved for use in the EU. The CHMP considered that Defitelio had been shown to improve survival in patients with severe VOD. Although it was not possible to conduct a study directly comparing Defitelio with placebo (dummy treatment), the company had provided sufficient data to show that patients treated with the medicine had improved chances of survival. The side effects seen, such as bleeding, were considered manageable and it was not possible to determine with certainty whether they were caused by Defitelio.
Defitelio has been authorised under ‘exceptional circumstances’. This is because it has not been possible to obtain complete information about Defitelio due to the rarity of the disease. Every year, the European Medicines Agency will review any new information that becomes available and this summary will be updated as necessary.
What information is still awaited for Defitelio?
Since Defitelio has been approved under exceptional circumstances, the company that markets the medicine is required to set up a patient registry to provide further data on long-term safety, health outcomes, and the way the medicine is used in practice. The company will ensure that all healthcare professionals who are expected to use the medicine are provided with information on how to enter their patients in the registry.
What measures are being taken to ensure the safe and effective use of Defitelio?
A risk management plan has been developed to ensure that Defitelio is used as safely as possible. Based on this plan, safety information has been included in the summary of product characteristics and the package leaflet for Defitelio, including the appropriate precautions to be followed by healthcare professionals and patients.
Other information about Defitelio
The European Commission granted a marketing authorisation valid throughout the European Union for Defitelio on 18 October 2013.
Source: European Medicines Agency
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