It's been just a few short months since Avastin (bevacizumab) was being hailed as the great new breakthrough drug for cancer therapy. It's the first drug designed to inhibit angiogenesis, the process by which new blood vessels develop and carry vital nutrients to a tumour. In other words, the drug starves the tumour.
The American drug agency, the Food and Drug Administration (FDA), approved it in February as part of the treatment for cancer of the colon or rectum.
But in just five months of use, doctors have discovered the drug can cause stroke, heart attacks and angina, and can also double the risk of a fatal thrombosis.
Not that the drug was ever a day at the beach. When it was approved the FDA knew the drug could cause fatal stomach perforations, fatal hemorrhage, hypertension and congestive heart failure.
These new concerns must make Avastin one of the untouchables, but the new discoveries raise concerns about the efficacy and reliability of the pre-licensing clinical trials that too often miss adverse reactions that could 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 cancer.