Companies start human testing of PEG-Intron drug. (Enzon/Schering Corp.)

Enzon/Schering Corp.

Enzon Inc., South Plainfield, New Jersey, and Schering Corp., Madison, New Jersey, a subsidiary of Schering-Plough Corp., announced that Phase I human clinical trials have begun on a longer-lasting version of Intron A, (interferon alpha 2b), Schering's genetically-engineered anticancer and antiviral drug.

Intron A has been conjugated to polyethylene glycol (PEG) through a process called Pegnology, Enzon's proprietary drug delivery technology which extends the time therapeutic proteins stay in the blood.

As a result, PEG-Intron A is expected to last longer in the body, allowing physicians to administer fewer and possibly …