Bevacizumab (AVASTIN) ‚off-label use’ in the therapy
of neovascular ocular disorders
Salvatore Grisanti for The Bevacizumab Study Group (Tübingen)
An extensive number of experimental studies have established that vascular endothelial growth
factor (VEGF) plays a central role in the development of several ocular pathologies characterized
by neovascularization and increased vascular permeability. In contrast, (VEGF) plays also
a pivotal role for embryo- and organogesis, regulating haemodynamics, (lymphoid-) vessel
architecture, haematopoiesis and immune system, endocrinology and reparative processes in
adults. Therefore, inhibited VEGF can cause multiple adverse events. Although the intravitreal
administration of smaller doses results in a low systemic exposure, possible local side effects
on retinal perfusion and survival of neuronal tissue must be taken into consideration. Before
the gain in experience with VEGF-inhibitors continues for longer than several years, individual
discussion before the use, extended informed consent and careful follow-up are necessary. From the ethical point of view,
the available drugs should not be used unhesitatingly despite of the clear benefit. First experimental and clinical experiences
with bevacizumab (Avastin®), the first available (off label) drug in Germany, are reported. Bevacizumab (Avastin™), a humanized
monoclonal anti-VEGF antibody originally developed for intravenous therapy of metastatic cancer, is now being used as
off-label therapy in subtypes of age-related macular degeneration. The drug promises not only anti-angiogenic capabilities
in neovascular eye disease, but has also anti-exsudative effects by lowering trans-endothelial permeability of blood vessels.
In future, direct comparison of the different available drugs has to assess possible differences in the risk-benefit profile.