April 2011
Volume 52, Issue 14
Free
ARVO Annual Meeting Abstract  |   April 2011
In Situ Determination of Intravitreal Concentrations of a Biotherapeutic Labeled with a Near-Infrared Fluorescent Ligand Using Confocal Scanning Laser Ophthalmoscopy
Author Affiliations & Notes
  • Anthony S. Basile
    Clinical Pharmacology, Pfizer, Inc, San Diego, California
  • G Glazier
    Charles River, Montreal, Quebec, Canada
  • A Lee
    Clinical Pharmacology, Pfizer, Inc, San Diego, California
  • L Y. Jiang
    Clinical Pharmacology, Pfizer, Inc, San Diego, California
  • T R. Johnson
    Clinical Pharmacology, Pfizer, Inc, San Diego, California
  • M J. Shields
    Clinical Pharmacology, Pfizer, Inc, San Diego, California
  • M Vezina
    Charles River, Montreal, Quebec, Canada
  • V Doppalapudi
    Clinical Pharmacology, Pfizer, Inc, San Diego, California
  • Footnotes
    Commercial Relationships  Anthony S. Basile, Pfizer (E); G. Glazier, None; A. Lee, Pfizer (E); L. Y. Jiang, Pfizer (E); T. R. Johnson, Pfizer (E); M. J. Shields, Pfizer (E); M. Vezina, None; V. Doppalapudi, Pfizer (E)
  • Footnotes
    Support  Research supported by Pfizer Inc.
Investigative Ophthalmology & Visual Science April 2011, Vol.52, 2907. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Anthony S. Basile, G Glazier, A Lee, L Y. Jiang, T R. Johnson, M J. Shields, M Vezina, V Doppalapudi; In Situ Determination of Intravitreal Concentrations of a Biotherapeutic Labeled with a Near-Infrared Fluorescent Ligand Using Confocal Scanning Laser Ophthalmoscopy. Invest. Ophthalmol. Vis. Sci. 2011;52(14):2907.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose: : The pharmacokinetics (PK) of ophthalmic biotherapeutics are difficult to directly determine in human vitreous humor. Because of the high transparency of living tissue to near-infrared (NIR) light, the temporal changes in vitreous concentrations of a biomolecule labeled with a NIR fluorescent probe (NIRF) were monitored in situ using a scanning laser ophthalmoscope (SLO).

Methods: : A humanized IgG was labeled with the NIRF probe IRDye-800 CW (CVX-4164). NZW rabbits were intravitreally administered CVX-4164 and NIRF intensity measured in the center of the vitreous humor using a SLO. Scans were repeatedly taken from 1 to 240 hours after administration. Intensity gray scale values were converted to concentrations using standard curves. PK data were analyzed by non-compartmental and compartmental analysis using WinNonlin. The care and use of the animals in this study were conducted in accordance with the guidelines of the NRC USA and the Canadian Council on Animal Care.

Results: : There was little background fluorescence and the minimum detectable concentration of CVX-4164 was < 10 nM. Vitreal CVX-4164 concentrations determined in situ declined according to a single compartment, 1st order kinetics model, with Cmax ≈1 µM, and t1/2 = 145 hr, consistent with the rabbit vitreal t1/2 of other mAbs (eg, bevacizumab) as measured by ELISA. Vitreal CVX-4164 concentrations were 2.6 to 4.4 times higher than those determined by ex vivo NIRF or ELISA in homogenized vitreous humor, reflecting the superior spatial resolution of in situ imaging. Vitreal CVX-4164 concentrations determined in situ were >3 orders of magnitude greater than plasma concentrations determined by ELISA, and showed a different PK profile.

Conclusions: : This study demonstrates the feasibility of determining the PK of intraocular biotherapeutics labeled with NIRF probes by in situ monitoring. This concept may be extended to the imaging of NIRF-labeled biologicals with either SLO and/or optical coherence tomography for monitoring biomarkers in the cornea and retina, or for diagnosing ocular diseases.

Keywords: imaging/image analysis: non-clinical • clinical research methodology • vitreous 
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×