Avid Bioservices Inc (CDMO)

[freethemice]

New paper published on PGN650-NIR imaging. This is similar to the poster presented at the recent AACR meeting
and available from Peregrine, but with more info.
Molecular Imaging June 2013
Measuring Response to Therapy By Near-infrared Imaging of Tumors Using A Phosphatidylserine-targeting Antibody Fragment.
Gong J, Archer R, Brown M, Fisher S, Chang C, Peacock M, Hughes C, Freimark B.
Abstract
Imaging tumors and their response to treatment could be a valuable biomarker toward early assessment of therapy in patients with cancer. Phosphatidylserine (PS) is confined to the inner leaflet of the plasma membrane in normal cells but is externalized on tumor vascular endothelial cells (ECs) and tumor cells, and PS exposure is further enhanced in response to radiation and chemotherapy. In the present study, we evaluated the potential of a PS-targeting human F(ab')2 antibody fragment, PGN650, to detect exposure of PS in tumor-bearing mice. Tumor uptake of PGN650 was measured by near-infrared optical imaging in human tumor xenografts in immunodeficient mice. PGN650 specifically targeted tumors and was shown to target CD31-positive ECs and tumor cells. Tumor uptake of PGN650 was significantly higher in animals pretreated with docetaxel. The peak tumor to normal tissue (T/N) ratio of probe was observed at 24 hours postinjection of probe, and tumor binding was detected for at least 120 hours. In repeat dose studies, PGN650 uptake in tumors was significantly higher following pretreatment with docetaxel compared to baseline uptake prior to treatment. PGN650 may be a useful probe to detect PS exposed in tumors and to monitor enhanced PS exposure to optimize therapeutic agents to treat tumors.
The paper is here:
http://mi.deckerpublishing.com/index.php/article/measuring-response-to-therapy-by-near-infrared-imaging-of-tumors-using-a-phosphatidylserine-targeting-antibody-fragment
The poster is here:
http://www.peregrineinc.com/images/stories/pdfs/jian_2013.pdf

Note that the imaging trial uses PGN650 bound to Iodine-124 for PET imaging, whereas in this paper,
and the poster, PGN650 is bound to 800CW, which is a probe for Near InfraRed (NIR) imaging.
http://www.clinicaltrials.gov/ct2/show/NCT01632696?term=Bavituximab+OR+Peregrine&recr=Open&rank=5