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Doctors warn against using Avastin for macular degeneration

BMJ 2010; 340 doi: https://doi.org/10.1136/bmj.c2483 (Published 07 May 2010) Cite this as: BMJ 2010;340:c2483
  1. Zosia Kmietowicz
  1. 1London

    Ophthalmologists are warning that it is too soon to use an unlicensed and cheaper drug than the one recommended by the UK National Institute for Health and Clinical Excellence to treat wet age related macular degeneration (AMD) because the risks are unknown.

    Winfried Amoaku, vice president of the Royal College of Ophthalmologists and chairman of its scientific committee, said that while bevacizumab (Avastin) costs much less than ranibizumab (Lucentis), the effects of splitting the doses of bevacizumab, which is not packaged for intravitreal administration, may prove a false economy.

    Some primary care trusts have been telling doctors to use bevacizumab, which is licensed in the United Kingdom for treating colorectal cancer, instead of ranibizumab. Bevacizumab costs £243 (€280; $360) for a 100 mg vial, whereas ranibizumab costs £761 for 0.23 ml.

    “If there is no licensed product then it is reasonable to use a drug off label,” Dr Amoaku told the BMJ. But in the case of wet AMD there is a licensed drug, ranibizumab, whose efficacy has been proved and which has been recommended by NICE.

    Although bevacizumab and ranibizumab are related they are not the same compound, and the effects of bevacizumab in wet AMD are still being investigated. Another uncertainty is that when vials of bevacizumab are split to obtain the smaller dose needed to treat wet AMD the amount of protein administered to patients is unknown, which could lead to problems later on—either through side effects or reduced effectiveness, said Dr Amoaku.

    However, Usha Chakravarthy, professor of ophthalmology and vision sciences at Queen’s University in Belfast, said she thought that the amount of bevacizumab being injected into patients’ eyes would be similar to that of ranibizumab, as pharmacists were preparing injections of bevacizumab specifically for use in wet AMD. When they were administering ranibizumab, doctors themselves had to measure the required dose from the vial, so doses between administrations would also vary slightly.

    In March the Department of Health in England asked NICE to look into the possibility of recommending bevacizumab outside its licensed indication to cut the cost of treating wet AMD.

    NICE normally appraises drugs only within their licensed indications but can look at off-label uses of drugs if the health department requests it. The department has also asked the NHS’s health technology assessment programme to look at the evidence on the use of bevacizumab in the eye.

    The cost of treating wet AMD has escalated since NICE recommended ranibizumab in August 2008. Under an agreement with Novartis, the company that markets ranibizumab in the UK, the NHS pays for the first 14 treatments at a cost of £10 700 per patient, and Novartis pays for any further treatments needed.

    However, even with the cost sharing agreement with Novartis, it has been estimated that treating the condition with ranibizumab costs the NHS more than £300m a year (BMJ 2008;337:a1532; doi:10.1136/bmj.a1532).

    Two clinical trials currently comparing the effects of bevacizumab and ranibizumab are expected to report in late 2011 and early 2012, respectively. Dr Amoaku believes that NICE should wait until the results are available before assessing bevacizumab for wet AMD.

    “We don’t have the evidence at the moment that bevacizumab can work as well as ranibizumab,” he said. “Because there is NICE guidance on this then primary care trusts should be making Lucentis available to patients, because we know it works and we know its risk profile.”

    Professor Chakravarthy added that although more patients around the world had been treated with bevacizumab than with ranibizumab, there was still uncertainty about which drug was better—a question that would be answered only by the results of the ongoing trials.

    Notes

    Cite this as: BMJ 2010;340:c2483