Monday 2 January 2012
Definition: Ranibizumab (trade name Lucentis) is a monoclonal antibody fragment (Fab) derived from the same parent mouse antibody as bevacizumab (Avastin).
Ranibizumab-Lucentis is much smaller than the parent molecule and has been affinity matured to provide stronger binding to VEGF-A (VEGFA).
Ranibizumab-Lucentis is an anti-angiogenic that has been approved to treat the "wet" type of age-related macular degeneration (ARMD), a common form of age-related vision loss.
Some investigators believe that bevacizumab at an average cost of $42 a dose (in the U.S.) is as effective as ranibizumab at an average cost of $1,593 a dose.
Ranibizumab was developed by Genentech and is marketed in the United States by Genentech and elsewhere by Novartis, under the brand name Lucentis.
Mechanism of action
Ranibizumab binds to and inhibits a number of subtypes of vascular endothelial growth factor A (VEGF-A).
By blocking VEGF-A in the eye, ranibizumab may prevent and reverse vision loss caused by wet macular degeneration. VEGF may trigger the growth of new vessels, which may leak blood and fluid into the eye. These leaky blood vessels may contribute to macular edema and choroidal neovascularization, resulting in the wet type of ARMD. The drug is injected intravitreally (into the vitreous humour of the eye) once a month. If monthly injections are not feasible, the regimen may be reduced to 1 injection every 3 months after the first 4 months.