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Providing support to anyone affected by blood cancer
In the last fifteen years treatment for patients with chronic myeloid leukaemia (CML) has been transformed by the development of tyrosine kinase inhibitors, or TKIs. CML is a blood cancer that affects the white blood cells known as myeloid cells. If someone has CML, their body produces too many white blood cells that are not fully developed. This fills up their bone marrow with cells that do not work properly causing symptoms such as anaemia, fatigue, repeat and severe infections, fever and bruising and bleeding.
Before the creation of TKIs, patients with CML had few treatment options and average survival was around seven years. Approved for patient use by the National Institute for Health and Care Excellence (NICE) in the UK in 2003, the introduction of imatinib meant that patients diagnosed with this chronic disease could now expect to have a normal, or near-normal, life-expectancy.
At the end of this year, imatinib, manufactured and marketed by Novartis in Europe as Glivec®, is due to become a “generic medicine”. A generic medicine is a version of a branded medicine, made by a different company (usually at a cheaper price). Pharmaceutical companies normally patent each new drug that they make which means only they can make and market that drug. In the UK, a patent usually lasts for twenty years. When it runs out, other companies can make a treatment containing the same active ingredient to sell.
Whilst it can be a concern that these “copycat drugs” would not be as effective as the branded, original version, a generic drug must contain the same key ingredients; be identical in strength, dosage form, and route of administration; be bioequivalent; and be manufactured under the same strict standards as the brand-name drug. Essentially, for a generic drug to be produced in Europe, it has to be as safe and effective as its branded equivalent.
Generic medicines are a useful way of reducing costs for the NHS, saving it over £13 billion each year. Treating patients with generic medicines can free up NHS funds that can then be directed to other areas of healthcare, where needed.
But for some, the quality of some generic medicines can be a concern. Companies add different “bulking agents” to the key ingredient (in this case, imatinib) to help the drug work. These agents could potentially cause different side effects to that of the original, branded version of the drug. The effectiveness of generic imatinib for CML patients who have been switched from Glivec® to generic imatinib (in countries outside of North America and the European Union (EU) has been topic of discussion, with accounts that some versions of the drug do not achieve a haematological response.
As such, concerns about the effectiveness and safety of generic versions of imatinib have (anecdotally) been raised within the worldwide CML community. Within the EU and North America, however, there are rigorous requirements that make sure that generic drugs work in the same way as the original, branded drug. In the UK, the European Medicines Agency (EMA) assess whether a generic drug should be used and laws have been introduced to regulate the safety of such medicines. Recently, a study has demonstrated that “they did not find any difference in response or toxicity” between the branded and generic version of imatinib. With this in mind, many consultants and practitioners in the UK believe that generic imatinib is as effective as its branded counterpart.
Around a third of CML patients do not respond or stop responding to Glivec®, this is usually because they have developed cell mutations which means that the drug can no longer do its job effectively. There are more TKIs available to patients should they need them, with nilotinib and bosutinib available for patients throughout the UK and dasatinib routinely available in Scotland (and currently funded via the Cancer Drugs Fund for patients in England whilst it is being assessed for use). Although this has considerably improved the outlook for CML patients, these drugs are expensive to develop and manufacture, which is inevitably reflected in their price. By using the generic version of imatinib, NHS funds can potentially be freed up for other treatments to be financed.
For some patients, changing to a generic medicine can understandably lead to confusion and concern. The packaging or the tablet itself can look different, for instance. If you are prescribed a generic medicine, instead of the branded version, your consultant should tell you that they have made the change, and made it clear that the ingredient remains the same. It is important that you tell your consultant if you notice any changes in how you feel so that they can monitor your response.