Enzon, Inc. announced Monday that the FDA has grantedorphan drug status for its compound PEG-glucocerebrosidase, amodified form of the enzyme glucocerebrosidase (GC), for thetreatment of Gaucher disease.

The orphan status covers the company's proprietorypolyethylene glycol (PEG) technology to modify the GC enzyme,developed by the National Institute of Mental Health (NIMH).

Gaucher disease results from a deficiency of the enzyme beta-glucocerebrosidase, a deficiency which leaves the body unableto break down and dispose of fatty substances in thebloodstream. The genetic order affects about 15,000 people inthe U.S., 2,000 to 3,000 of whom require medical attention.

The core of Enzon's technology utilizes polyethylene glycol tocoat the surface of the GC enzyme, shielding it from theantibodies generated by the body's natural defense system,explained Donna Chappina, company spokeswoman.

PEG-coated GC enzymes can circulate in the blood for asignificantly longer period of time than unmodified GCenzymes, said Chappina. By increasing the useful life of theenzymes in the body, PEG technology allows for fewer, lowerdose administrations, resulting in fewer side effects.

Enzon has been working on the compound with the NIMHunder a Cooperative Research and Development Agreementsince November 1991 and signed a co-exclusive patent licenseagreement with the National Institutes of Health in Octobercovering its modified recombinant glucocerebrosidase.

Enzon will fund clinical trials of PEG-glucocerebrosidase due tobegin shortly, said Chappina, and the trials will be managed bythe NIMH. She added that Enzon has scaled-up production andNIMH has established a patient database for the trials.

Enzon's PEG-glucocerebrosidase is a "longer-lived" version ofCeredase, a chemically remodeled-carbohydrate replacementfor GC, developed by Framingham, Mass.-based Genzyme Corp.as a treatment for Gaucher disease.

Genzyme's Ceredase received orphan drug status in April andthe company has been under fire since due to the drug's highprice. Industry sources put the cost of treatment with Ceredaseat "$71,000 at least, and as much as half a million dollars peryear per patient."

Chappina said that Piscataway, N.J.-based Enzon has not madeany pricing decisions for its Gaucher disease product. The drugwill be available on an investigational basis through NIMH.Enzon closed Monday at $9.13, up 38 cents a share.

-- Michelle Slade Associate Editor

(c) 1997 American Health Consultants. All rights reserved.