This page is intended as reference information for the general public in Great Britain.
Safety notice
Pfizer Limited has informed the Medicines & Healthcare products Regulatory Agency (MHRA) that all batches of Oxbryta 500 mg Tablets are being withdrawn due to emerging data from clinical trials and registry-based studies that now indicate the overall benefit of voxelotor no longer outweighs the risk in the approved sickle cell patient population. The data suggest an unfavourable imbalance in vaso-occlusive crises (acute painful crises) and fatal events (deaths).
Information for patients
Your healthcare professional responsible for your care and treatment will contact you to advise you, or the child under your care being treated, to stop taking Oxbryta 500 mg Tablets, and where appropriate, discuss alternative treatment options. They will also advise how to return any remaining packs of Oxbryta 500mg Tablets that you have in your possession. If you have not already been contacted by your healthcare professional, please contact them.
If you experience adverse reactions, have a sudden worsening of clinical condition, or have any questions about your medication, you should seek medical attention. If you have any concerns about your health or the health of somebody else, consult with your healthcare professional. Any suspected adverse reactions should also be reported via the MHRA Yellow Card scheme and by contacting Pfizer Medical information on 01304 616161.
What is Oxbryta and what is it used for?
Oxbryta, alone or together with hydroxycarbamide (also known as hydroxyurea), is used to treat haemolytic anaemia in adults and children from 12 years with sickle cell disease.
Oxbryta contains the active substance voxelotor. Voxelotor works on a protein in red blood cells called haemoglobin to help it take up oxygen that red blood cells can deliver throughout the body.
Patients with the condition called sickle cell disease have an altered form of haemoglobin called sickle haemoglobin which is different from the normal haemoglobin. When the sickle haemoglobin gives up oxygen to the tissues, it sticks together to form long rods and causes red blood cells to alter their shape to that of a crescent moon making these cells rigid and sickled shape. Sickle red blood cells cannot deliver oxygen as well as healthy red blood cells and are also broken down more quickly, leading to lowered levels of red blood cells (haemolytic anaemia). By improving the way the altered haemoglobin holds onto oxygen, Oxbryta improves the function of red blood cells and prolongs their lifespan.
Reference Information
Medicines in Northern Ireland fall under the remit of the European Medicines Agency (EMA) whilst medicines in Great Britain (England, Scotland and Wales) fall under the remit of the Medicines and Healthcare products Regulatory Agency (MHRA) following the UK leaving the European Union. These agencies are responsible for the scientific evaluation, supervision and safety monitoring of medicines developed by pharmaceutical companies.
If you would like to see the Great Britain Patient Information Leaflet (PIL) or Summary of Product Characteristics (SPC) for Oxbryta these can be found at the electronic Medicines Compendium (eMC).
▼ This medicine is subject to additional monitoring. This will allow quick identification of new safety information.
Side effects can be reported directly via the Yellow Card Scheme at https://yellowcard.mhra.gov.uk or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side effects, you can help provide more information on the safety of this medicine