Bispecific Antibodies Target Disease Cells.(Brief Article)

2001 AUG 8 - (NewsRx.com & NewsRx.net) --

Immunomedics, Inc. (IMMU) announced three trials, two preclinical and one human, involving use of a pretargeting method which can deliver higher doses of radioactive isotope to cancerous tissue.

The pretargeting method uses bispecific antibodies for cancer radioimmunotherapy, and results of the trials were presented at the 48th Annual Meeting of the Society of Nuclear Medicine, in Toronto, Canada. The methodology was developed and patented by IBC Pharmaceuticals, LLC, an affiliated company of Immunomedics.

In a presentation given by Dr. Kraeber-Bodere and associates of the Rene Gauducheau Cancer Center in Nantes, France, in collaboration with clinical scientists at Rennes, France, the Garden State Cancer Center, Belleville, New Jersey, and IBC Pharmaceuticals, LLC, Morris Plains, New Jersey, interim results of a Phase I/II clinical trial in patients with diverse cancers producing carcinoembryonic antigen (CEA) were studied by this two-step procedure. The patients first received the bispecific antibody, composed of half of an anti-CEA antibody linked to half of another antibody that targets a carrier with a therapeutic isotope attached to it.

After waiting a few days for the bispecific antibody that is not bound to the tumor to be eliminated from the body, the clinicians injected the carrier molecule and isotope, which then attached to the other antibody arm at the tumor. Any nontargeted carrier/isotope was then eliminated in the urine. The investigators showed selected uptake of the carrier/isotope in the tumor using a camera that revealed the "hot" tumor sites by detecting the radioactivity. No patients showed toxicity after the therapeutic isotope was given but much higher tumor doses, compared with directly labeled antibodies, were calculated.

"The ...