Ranibizumab launched for macular degeneration
A second inhibitor of vascular endothelial growth factor (VEGF) has been launched for the treatment of neovascular (wet) age-related macular degeneration (AMD) — a condition that results in loss of central vision. Ranibizumab (Lucentis; Novartis), a monoclonal antibody which
binds to all isoforms of VEGF-A, is administered by intravitreal injection
like last year’s newcomer, pegaptanib sodium (Macugen), licensed
for the same condition.
Writing in this week’s BMJ, Usha Chakravarthy, professor of ophthalmology
and vision sciences, Queen’s University Belfast, and Jennifer Lim,
associate professor of ophthalmology, University of Southern California,
compare treatments for wet AMD (2007;334:269). They say: “Different
isoforms of the growth factor probably contribute to leakiness, abnormal
morphology, and fragility of the neovascular complex [features of the
disease]. Thus, ranibizumab has better outcomes than pegaptanib sodium,
which inhibits VEGF165 alone.”
They add: “Low dropout rates in the vascular endothelial growth
factor inhibition trials suggest that patients accept the potential long-term
risks associated with such treatment so that they can maintain vision
in the short term.”
The authors add that another monoclonal antibody, bevacizumab, currently
only licensed for treatment of metastatic colorectal cancer, is reported
to provide visual outcomes similar to ranibizumab, but would cost much
less. They suggest that “a controlled clinical trial of bevacizumab
versus ranibizumab should be a priority for health services already struggling
to meet the demands of ever aging populations”.
Ranibizumab is administered monthly for three consecutive months. Patients
are reviewed monthly thereafter for further visual deterioration, and
treated with further monthly injections as needed.
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