Patients may respond differently to anti-vascular endothelial growth factor (VEGF) treatments for neovascular age-related macular degeneration (nAMD) depending on their genotypes, researchers say.
A meta-analysis of studies on polymorphisms in the VEGF-A gene and its receptor (VEGFR-2) showed that people with the polymorphism rs833061 were more likely to benefit from anti-VEGF treatment, particularly when the treatment is ranibizumab (Lucentis, Roche) and when the patients are of Asian heritage.
The study by Mingxing Wu and colleagues at the Chongqing Medical University in Changqing, China, appears in the British Journal of Ophthalmology.
There is a significant amount of evidence that the gene VEGF-A is a major mediator of angiogenesis and vascular leakage in nAMD, the researchers wrote. Because VEGF-A binds to VEGFR-2 to stimulate angiogenesis within tissues, SNPS within VEGFR-2 could predict responses to anti-VEGF therapy.
Previous studies on the influence of genetic factors in anti-VEGF treatments have had mixed results, with some showing an association and others not.
Since these have been small studies, Wu and colleagues provided what they believe is the first systematic review. They found 8 studies investigating 9 genetic variations in VEGF-related genes. They also found 7 studies with data on ethnicity. Most of the studies included ranibizumab as the anti-VEGF agent and follow-up ranged from 4 to 12 months.
Wu and colleagues used both best-corrected visual acuity (BCVA) and central subfield retinal thickness as measures of treatment success.
They performed a meta-analysis on 8 single-nucleotide polymorphisms (SNPs) in VEGF-A and 1 in VEGFR-2. They “unexpectedly” only identified 1 SNP with even a marginally significant association with response to anti-VEGF treatment, they wrote.