There were recent news stories about a possible problem for cancer
patients taking Avastin systemically. Dr. Phlip Rosenfeld, the first
ophthalmologist to use this drug "off label" to treat age-related
macular degeneration, addressed this question in today's issue of
Ocular Surgery News Online edition:

OSN SuperSite Top Story 9/29/2006

FDA warning on Avastin has few implications for ophthalmic use,
investigator says

The Food and Drug Administration has added a new label warning to
bevacizumab after reports of cases of reversible posterior
leukoencephalopathy syndrome in cancer patients taking the drug
systemically.

But the warning should have little bearing on ophthalmologic uses,
according to Philip J. Rosenfeld, MD, PhD, of the Bascom Palmer Eye
Institute, one of the pioneer investigators of the off-label use of
bevacizumab for treating exudative age-related macular degeneration.

According to a letter issued by Genentech, the maker of Avastin
(bevacizumab), the brain-capillary leak syndrome was reported in less
than 0.1% of cancer patients using the drug for its approved
indications.

Dr. Rosenfeld explained to Ocular Surgery News that ophthalmologic uses
of Avastin involve markedly lower dosing regimens and local rather than
systemic delivery of the drug as in oncologic uses. Cancer patients
receive high intravenous doses of the drug every 2 weeks, while AMD
patients receive small monthly doses via intravitreal injection. Thus,
he said, the risk of reversible posterior leukoencephalopathy syndrome
(RPLS) in AMD patients is "probably quite remote."
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Additionally, he noted, in oncologic uses, Avastin is used with
adjuvant chemotherapy, which dramatically weakens patients' immune
systems.

All patients who developed RPLS had weakened immune systems, Dr.
Rosenfeld said.

Other common side effects related to Avastin use in cancer patients,
such as hypertension, have not been seen in AMD patients treated with
the drug, which suggests that RLPS is not likely for ophthalmic
patients, he added.

"If you look at the many other drugs that we inject into the eye
off-label, almost all of them have the possibility of serious systemic
adverse events ... at their usual high dose systemically," Dr.
Rosenfeld said. "[But] we don't see [these adverse events] when
injected in small doses into the eye. So the issue with Avastin is not
new."

Irv Arons