This patient-friendly article is about chemotherapy drug, Bevacizumab (commonly called Avastin) which is used to treat advanced bowel, breast, kidney, brain and non-small cell lung cancer; it is a monoclonal antibody that tackles VEGF but results have been very mixed. It has been turned down in the UK for use with breast and brain tumours.
It is a monoclonal antibody usually given with another drug or chemotherapy and has the ability to lock onto proteins found on the surface of the cancer cell. Bevacizumab targets a protein on the cells called Vascular Endothelial Growth Factor (VEGF) and can stop some cancers from developing new blood vessels (anti-angiogenesis). This reduces the cancer’s supply of oxygen and nutrient and so causes the tumour to shrink or stop growing. It is given intravenously. The drug is made by Roche.
A biosimilar drug, Zirabev, has been launched by Pfizer.
Side-effects: can include: high blood pressure, allergic reactions, increased risk of blood clots, constipation, lowered resistance to infection, bleeding, kidney damage.
Monoclonal Antibodies
The problem with all mono-clonal antibodies is that they work well for a few people (perhaps 20 per cent of the total with the disease). This is because they are linked to a genetic issue that only occurs in certain patients; and there should be a genetic test to see which patients would benefit. (The classic situation is for Herceptin and the HER-2 protein gene).
This makes judging the drug across all patients somewhat misleading. However, that is exactly what health bodies do. For example, NICE is saying that Avastin is ’not worth the money’ for colorectal cancer patients, according to the British Press in August 2010, because it only extends survival by 6 weeks on average. Yes, but what did it do for the group that were genetically positive. The drugs companies only have themselves to blame. With each monoclonal antibody there should be a genetic test (as there is for Herceptin) to show who would benefit, and for whom the drug really is a waste of money.
With that in mind users should read this July 2010 report from America, covered in Cancer Watch. The FDA report is also highly illuminating on the risks and side-effects.
Avastin ’not for breast cancer’
A Food and DRUG Administration (FDA) panel of cancer experts in the USA has voted 12-1 in favour of removing the approval for use of Avastin with breast cancer. ’Their study showed that there is very little benefit to patients with significant toxicity risks and no clear survival benefit’, said Natalie Potis, the panel patients’ representative. Worse, the panelists also worried that the drug did more harm than good because of ’serious side effect, including high blood pressure, fatigue and abnormal levels of white blood cells’. Dr Wyndham Wilson of the NCI added ’We have definitive evidence that Avastin causes harmful side effects and we’ve now seen a number of well done studies that show no advantage to lifespan’.
Avastin, was heralded as the ’blockbuster, wonder drug’ when launched it is a genetically engineered protein grown from hamster ovary cells and supposedly stops nutrients feeding a cancer tumour. Roche sales of Avastin last year were $5.9 billion; Roche acquired the drug when it bought the American company Genentech last year..
The drug is also approved for use with colon, lung, kidney and brain tumours, not just breast cancer. However, this new study does not report on these other cancers.
In 2008 the FDA approved the drug for use based on a trial showing that it extended the time before the cancer worsened by more than five months. At the time many cancer experts said that the drug had not been shown to extend survival times.
As a condition of the approval, Roche had to submit further studies and these did not show the same degree of delay when used with chemotherapy, nor did they show any significant survival time increases.
Brain tumours - Avastin is often the drug of choice for brain tumours in the USA. In the UK, it is not even approved for use because the research evidence 'is not that clear' and seems poor.
Colorectal cancer - Avastin on the drug Website has been 'shown to extend the lives of people with metastatic colorectal cancer when used with 5FU'. However 'Studies have shown that there are some serious side-effects associated with Avastin'. I quote "Although some people may have a life-threatening side effect, most do not".
Whatever happened to this new world of safer targeted drugs rather than those nasty old chemotherapy drugs?
Go to: 10 ways to improve your chemotherapy success and reduce side-effects
Other articles that you may find interesting are:
- A diet for Chemotherapy
- Immunotherapy overview
- A to Z Guide to Complementary Therapies
Go to: Return to the CANCERactive drug list