Besremi

Besremi can only be obtained with a prescription and treatment should only be started under the supervision of a doctor experienced in managing polycythaemia vera.

Besremi is available for injection under the skin in pre-filled pens. The usual starting dose is 100 micrograms every two weeks, which can be increased gradually until the levels of red blood cells are sufficiently low and stable. The maximum dose is 500 micrograms every two weeks. If side effects occur, the doctor can reduce the dose or stop treatment temporarily.

For more information about using Besremi, see the package leaflet or contact your doctor or pharmacist.

The active substance in Besremi, ropeginterferon alfa-2b, works by attaching to receptors (targets) on body cells called interferon alfa/beta receptors (IFNAR). This starts several reactions that cause the bone marrow to produce fewer red blood cells.

Ropeginterferon alfa-2b is a type of 'interferon', a natural substance produced by the body. In Besremi, the interferon has been 'pegylated' (attached to a chemical called polyethylene glycol) so that it can stay longer in the body and be given less often.

A main study of 257 patients showed that Besremi is effective at reducing levels of red blood cells in patients with polycythaemia vera. In this study, 43% of patients receiving Besremi had normal red blood cell counts after one year of treatment; 46% of patients receiving another medicine, hydroxycarbamide, had similar improvements.

An extension of this study showed that continuing treatment with Besremi for longer increased the number of patients whose blood counts reduced to normal.

The most common side effects with Besremi (which may affect more than 1 in 10 people) are low levels of white blood cells and platelets (blood components that help the blood to clot), muscle and joint pain, tiredness, flu-like symptoms and increased blood levels of gamma-glutamyl transferase (a sign of liver problems). For the full list of side effects of Besremi, see the package leaflet.

Besremi must not be used together with telbivudine (a medicine for treating hepatitis B). It must not be used in patients with thyroid disease which is not controlled by standard treatment, patients who have had psychiatric illnesses such as severe depression, patients with severe problems affecting the heart and the blood vessels, patients who have recently had a heart attack or stroke, patients suffering from autoimmune diseases, patients who have had a transplant, and patients with very severe liver or kidney disease. For the full list of restrictions, see the package leaflet.

Besremi is effective at reducing the excessive number of blood cells in patients with polycythaemia vera, and the proportion of patients improving increased with longer treatment. Although Besremi may be less effective than hydroxycarbamide in the first months of treatment, phlebotomy (a procedure to remove excess blood from the body) can help to control the condition in the short term.

As for its safety, the side effects of Besremi are considered manageable. In addition, the fact that Besremi does not have the potential to cause gene mutations was considered an important benefit. The European Medicines Agency therefore decided that Besremi’s benefits are greater than its risks and it can be authorised for use in the EU.

Recommendations and precautions to be followed by healthcare professionals and patients for the safe and effective use of Besremi have been included in the summary of product characteristics and the package leaflet.

As for all medicines, data on the use of Besremi are continuously monitored. Side effects reported with Besremi are carefully evaluated and any necessary action taken to protect patients.

Besremi received a marketing authorisation valid throughout the EU on 15 February 2019.