It's been just a few short months since Avastin (bevacizumab) was being hailed as the great new breakthrough drug for cancer therapy. It is the first drug designed to stop angiogenesis, the development of new blood vessels to carry vital nutrients to a tumour. In other words, the drug starves the tumour.
The US drugs agency, the Food and Drug Administration (FDA), approved it in February as part of the treatment for cancer of the colon or rectum. But, after just five months, doctors have discovered that the drug can cause stroke, heart attacks and angina, doubling the risk of a fatal bloodclot.
Not that the drug was ever a day at the beach. When it was approved, the FDA already knew it could cause fatal stomach perforations, fatal haemorrhage, hypertension and congestive heart failure.
These new concerns should make Avastin one of the untouchables, but they also raise concerns as to the reliability of prelicensing clinical trials, which all too often miss adverse reactions that can even kill the patient.
It's not for the first time, when faced with these deadly therapies, that we've said we'd rather take our chances with the disease (www.fda.gov/opacom/7alerts.html; August 2004).