Ranibizumab (Lucentis) differs from bevacizumab (Avastin) in which of the following pharmacological characteristics?
- A Ranibizumab binds only VEGF-A while bevacizumab binds all VEGF isoforms
- B Ranibizumab is a monoclonal antibody fragment (Fab) with higher intraocular penetration, while bevacizumab is a full-length humanized monoclonal antibody ✓
- C Ranibizumab has a longer intravitreal half-life than bevacizumab
- D Bevacizumab is FDA approved for intravitreal use while ranibizumab is used off-label
Explanation
Ranibizumab is a Fab fragment (antibody binding fragment) derived from the same parent antibody as bevacizumab, specifically engineered for intravitreal use. Its smaller molecular weight (~48 kDa vs ~148 kDa) allows superior penetration through retinal layers to reach subretinal neovascularization. Bevacizumab (full-length IgG) was developed for systemic colorectal cancer treatment and is used intravitreally off-label. Both bind VEGF-A; neither has superior binding specificity for all isoforms. Ranibizumab actually has a shorter intravitreal half-life (~9 days vs ~20 days for bevacizumab).
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.