title: Clinical correlation to differences in ranibizumab and aflibercept vascular endothelial growth factor suppression times.
abstract: OBJECTIVE
  To determine clinical correlations to intraocular vascular endothelial growth factor A (VEGF-A) suppression times (VSTs) on the treatment of neovascular age-related macular degeneration (nAMD) with ranibizumab (Lucentis) or aflibercept (Eylea).
  
  
  METHODS
  Seven of 89 treatment-naïve nAMD eyes showed persistent choroidal neovascular membrane (CNV) activity throughout a spectral domain optical coherence tomography (SD-OCT)-driven pro re nata (PRN) regimen of intravitreal ranibizumab injections over 28±4 months. The treatment was switched to PRN aflibercept injections and patients were followed for another 15±2 months. A total of 160 aqueous humour specimens were collected before the intravitreal injections, and their VEGF-A concentrations were assayed by Luminex multiplex bead analysis (Luminex, Austin, Texas, USA). Intraocular VEGF-A concentrations were correlated to CNV activity shown by SD-OCT.
  
  
  RESULTS
  The mean duration of suppression of VEGF-A concentrations in aqueous humour below the lower limit of quantification of our assay was 34±5 (26-69) days for ranibizumab and 67±14 (49-89) days for aflibercept (p<0.001). The percentual reduction of central retinal volume (CRV) 6 weeks after injection was higher for aflibercept compared with ranibizumab (p=0.009). The time point of clinical re-activity occurred about 50% earlier than the respective VST for each ranibizumab and aflibercept.
  
  
  CONCLUSIONS
  The VST under aflibercept treatment exceeded that under ranibizumab treatment by a factor of 2. This difference correlated with differential clinical CRV reduction 6 weeks after the respective injection. For both medications, clinical activity was found at a time point as early as 50% of the individual VST.
  
  
  BACKGROUND
  NCT01213667, post-results.
authors.affiliation: Department of Ophthalmology, University Hospital of Cologne, Cologne, Germany.
authors.forename: Sascha
authors.initials: S
authors.lastname: Fauser
authors.affiliation: Department of Ophthalmology, University Hospital of Cologne, Cologne, Germany.
authors.forename: Philipp S
authors.initials: PS
authors.lastname: Muether
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D020533:Angiogenesis Inhibitors / Q000008:administration & dosage; D001082:Aqueous Humor / Q000378:metabolism*; D020256:Choroidal Neovascularization / Q000175:diagnosis / Q000188:drug therapy* / Q000378:metabolism; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D058449:Intravitreal Injections; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D000069579:Ranibizumab / Q000008:administration & dosage*; D040262:Receptors, Vascular Endothelial Growth Factor / Q000008:administration & dosage*; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage*; D013997:Time Factors; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014792:Visual Acuity
chemical_list: D020533:Angiogenesis Inhibitors; D011993:Recombinant Fusion Proteins; D042461:Vascular Endothelial Growth Factor A; C533178:aflibercept; D040262:Receptors, Vascular Endothelial Growth Factor; D000069579:Ranibizumab
keywords: Macula; Neovascularisation; Pharmacology; Retina; Treatment Medical