WASHINGTON: Drug maker Genentech Inc. has added warnings at the insistence of federal health officials about a rare brain condition called reversible posterior leukoencephalopathy syndrome, or RPLS, and damage of nasal tissue in patients using its cancer drug Avastin.
The U.S. Food and Drug Administration said Monday Avastin can possibly cause the rare brain capillary leak syndrome that leads to headache, seizure, blindness and other visual and neurological problems. Besides, there are instances of patients using the drug developing perforations on the septum that separates the nasal cavities.
South San Francisco, California-based Genentech started reviewing data on Avastin after letters were published in the New England Journal of Medicine by two women who developed RPLS while on the drug.
The company has posted a letter on the FDA's website saying it has updated the labels to include warnings on RPLS as well as the perforations on the nasal septum.
The company had also sent letters to doctors earlier in September, saying it had received reports of confirmed and possible RPLS in patients using Avastin and participating in clinical studies at a rate of less than 0.1 per cent.
Genentech is now undertaking a study on the use of the drug for 25 types of tumors in 130 clinical trials.
Avastin, which had contributed $1.1 billion to Genentech's revenue in fiscal 2005, is used along with chemotherapy to treat colorectal cancer. The company has sought FDA clearance for use of the drug in breast cancer and advanced lung cancer.
Avastin inhibits a protein that causes growth of tumors.
Swiss drug maker Roche Holding AG is the majority owner of Genentech and markets Avastin outside the United States.
