Inrebic® has been developed to support patients with myelofibrosis and is a type of medicine known as a protein kinase inhibitor. This drug is used to treat adults with myelofibrosis, (a rare form of blood cancer) who have an enlarged spleen and/or other symptoms related to myelofibrosis. By blocking the action of certain enzymes (called Janus Associated Kinases), Inrebic® can reduce the abnormal production of blood cells and reduce the size of the spleen.
The brand name is Inrebic® and the active substance is fedratinib.
How it works
Inrebic® can be used in three types of myelofibrosis:
- Primary myelofibrosis (where there was no pre-existing bone marrow disease);
- Post-polycythaemia vera myelofibrosis (where the disease is linked to an overproduction of red blood cells and prior diagnosis of polycythaemia vera (PV)) and;
- Post-essential thrombocythaemia myelofibrosis (where the disease is linked to an overproduction of platelets and prior diagnosis of essential thrombocythaemia).
It can reduce the size of the spleen in patients with myelofibrosis and relieve symptoms such as fever, night sweats, bone pain and weight loss and itching in patients with myelofibrosis. You may not experience all or any of these symptoms, and there may also be others.
Are there any side effects?
Like all medicines, this one can cause side effects, although not everybody gets them.
The most frequent adverse reactions in Inrebic® treated patients are gastro-intestinal issues. During the first few weeks of treatment, you will be prescribed anti-diarrhoea and anti-sickness medication to help control these symptoms. These issues tend to improve over time and anti-sickness and anti-diarrhoeal medication can be stopped. In some patients these gastro-intestinal side effects can be more severe and not respond to standard supportive medicines. In these cases the dose of Inrebic® may be stopped by your doctor until your symptoms have recovered. The dose of Inrebic® may be reduced upon restarting by your doctor to control these side effects.
Other side effects are listed below:
Very common side effects (may affect more than 1 in 10 people)
- Low levels of red blood cells which may cause tiredness, shortness of breath, pale skin or a fast heartbeat (anaemia).
- Reduction in blood platelets, which can make you bleed or bruise easily (thrombocytopenia). • Reduction in white blood cells (neutropenia), sometimes with fever. Low level of white blood cells can reduce your ability to fight off infections.
- Feeling sick (nausea) or being sick (vomiting).
- Diarrhoea.
- Constipation.
- Bleeding.
- Urinary tract infection.
- Headache.
- Muscle spasms.
- Tiredness (fatigue) or weakness (asthenia).
- Changes in blood test results (alanine amino transferase increased, aspartate aminotransferase increased, increase in blood creatinine, increase in amylase and lipase levels). These may be signs of liver, kidney or pancreas problems.
Other common side effects (may affect 1 in 10 people)
- Dizziness.
- Increase in blood pressure (hypertension).
- Indigestion (dyspepsia).
- Bone pain.
- Pain in limbs, hands or feet (pain in extremity).
- Weight gain.
- Painful passing of urine.
Inrebic® and Encephalopathy
It is important that you inform your doctor or nurse if you notice any of the following symptoms which could be a sign of a serious condition which affects the brain called encephalopathy (including Wernicke’s encephalopathy):
- Confusion, memory loss or difficulty thinking.
- Loss of balance or difficulty walking.
- Eye problems such as double-vision, blurred vision loss of vision or random eye movements.
Frequently asked questions
Will taking Inrebic® cause Encephalopathy? Although not a common side effect, occurring in less than 1% of patients, it is important to contact your hospital consultant immediately if you get any of these signs or symptoms listed above.
Can I eat and drink normally? Other than the need to avoid grapefruit and grapefruit juice, we recommend that you eat a normal, healthy diet and drink plenty of water.
Can I drink alcohol? While it is safe to drink alcohol in moderation whilst taking Inrebic®, we recommend you do not exceed the recommended weekly limit of 14 units for both men and women. Alcohol can cause dehydration, and it is important to avoid becoming dehydrated if you have an MPN. Please ask your doctor or nurse if you require more information regarding alcohol consumption.
What if I want to have a child? If you are considering having a child, or may already be pregnant, it’s important to ask your consultant or doctor before taking this medication. We strongly recommend that you use contraception whilst taking Inrebic®, and avoid becoming pregnant for at least one month after the last dose. • When planning to conceive or to father a child, you should only stop taking Inrebic® AFTER discussion with your doctor.
It is imperative to discuss your plans together with your haematologist prior to becoming pregnant or fathering a child. Your doctor can recommend treatment options for you that will not cause harm to your developing baby and will increase your chance of a successful pregnancy • If you or your partner becomes pregnant while taking this drug, please contact your doctor immediately for further advice
Can I breastfeed while taking Inrebic®? Breastfeeding while taking Inrebic® is not recommended as it is not known if this medicine passes into breast milk.
Who will prescribe Inrebic® for me? Your doctor, specially trained nurse or hospital pharmacist will prescribe your medication.
Can I drive? If you feel dizzy from taking the medication, it is advisable to stop driving until the symptoms stop.
Do I need to take any special precautions? It is important not to stop taking Inrebic® suddenly as this can cause a withdrawal type syndrome which consists of a return of symptoms and growth of your spleen which may be very sudden and has sometimes made patients very unwell.
Can I have vaccinations such as the flu jab while taking Inrebic®? Yes, you can have most vaccinations including the flu vaccine whilst taking Inrebic®. Some vaccinations are live vaccines e.g the shingles vaccine and these should not be taken with Inrebic®. There is now a non-live shingles vaccine available called Shingrix which is suitable to be taken by patients with MPN. Remember to tell the person giving you the vaccine that you are taking Inrebic® and we recommend consulting with your local haematology team.
More Information
If you’d like more information about Inrebic® you can download further information here.
