Alkermes Inc. said it has received a patent on its technologyfor transporting drug molecules into the brain. The U.S. patent,No. 5,154,924, covers methods for using certain antibodies andantibody fragments to deliver therapeutics across the blood-brain barrier.

According to Richard Pops, Alkermes' president and chiefexecutive officer, the broad patent covers "the use of anti-transferrin monoclonals or antibody fragments to takemolecules into the brain."

The patented carriers bind to transferrin receptors, which areused to transport iron from the blood stream to the brain.

Alkermes researchers chose this transport system because it isrobust and has a high throughput, which is important for anytherapeutic application, Pops said.

Also, the "piggyback" technology "appears to have generalapplicability. It's not just idiosyncratic for one or twomolecules," Pops said.

For delivering different therapeutic entities, the receptor-binding portion of the molecule remains the same; but each"requires new chemistry for hooking it up" to a new drug, Popstold BioWorld.

Nor may the full-length antibody molecule be necessary tocarry a drug. "We would like to get it down to a smallercomplex -- either a fusion protein or an antibody fragmentlinked to NGF or the protein of interest," Pops said.

Scientists at the Cambridge, Mass., neuropharmaceuticalcompany (NASDAQ:ALKS) have been studying the carriermolecules' ability to transport nerve growth factor (NGF) intothe brain. Because NGF and other neurotrophic factors areimportant to neuronal survival in animal studies, they couldbecome valuable therapeutics for treating neurodegenerativediseases.

University of Colorado researchers Barry Hoffer and AnnCharlotte Granholm reported Tuesday at the 22nd AnnualMeeting of the Society for Neuroscience that "piggybacked" NGFactually does get into the brain.

Working with Alkermes' Phil Friden, the Colorado researchersshowed that cholinergic neuron-containing forebrain tissuetransplants in rats survived significantly better when treatedwith NGF-conjugated anti-transferrin antibody than did thecontrol groups.

There is some indication that damaged cholinergic nerve cellsof the forebrain in humans lead to cognitive disorders such asmemory loss. "We next plan to test this NGF conjugate onadditional animal models that are more closely related to actualhuman disease states," Hoffer said.

-- Jennifer Van Brunt Senior Editor

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