Aflibercept differs from ranibizumab in its mechanism of action in the following way:
- A Aflibercept is a full humanized IgG1 antibody; ranibizumab is a Fab fragment
- B Aflibercept is a recombinant fusion protein (VEGF trap) that binds VEGF-A, VEGF-B, and PlGF; ranibizumab binds only VEGF-A ✓
- C Aflibercept inhibits VEGFR-2 kinase directly; ranibizumab is a receptor antagonist
- D Aflibercept binds VEGF-C and D only; ranibizumab targets VEGF-A 165 isoform
Correct answer: B. Aflibercept is a recombinant fusion protein (VEGF trap) that binds VEGF-A, VEGF-B, and PlGF; ranibizumab binds only VEGF-A
Explanation
Aflibercept (EYLEA) is a recombinant fusion protein — the VEGF-binding domains of VEGFR-1 and VEGFR-2 fused to the Fc region of IgG1 — that acts as a 'VEGF trap,' binding VEGF-A, VEGF-B, and placental growth factor (PlGF) with very high affinity. Ranibizumab is a humanized anti-VEGF Fab fragment that binds all isoforms of VEGF-A. Bevacizumab is a full-length humanized IgG antibody against VEGF-A. The broader binding of aflibercept may be relevant in conditions where PlGF plays a role.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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