Two biotechnology companies dedicated to gene therapy areabout to acquire exclusive rights to novel cloning vehiclesdeveloped at the National Institutes of Health.

The Federal Register recently announced that Theragen Inc. ofAnn Arbor, Mich., would obtain from the NIH Office ofTechnology Transfer (OTT) a royalty-bearing license to U.S.Patent No. 4,797,368, "Adeno-Associated Virus as EukaryoticExpression Vector."

The company will limit the vector's use to "gene therapytreatments for metabolic disease, joint and connective tissuedisorders, and nervous system diseases," according to theFederal Register.

Thomas S. Porter, Theragen's president, explained that mosthuman gene therapy experiments to date use retroviral vectors.His company, he told BioWorld, "is strongly committed todeveloping AAV (adeno-associated virus vectors) as a safer,more promising gene transfer delivery system for genetherapy." Adeno-associated virus vectors have advantages anddisadvantages vis-a-vis retrovirals, he said.

"The use of many previously available virus-based eukaryoticexpression vectors has been limited," the Federal Registersaid, "because they do not integrate foreign DNA into the hostgenome at high frequency and are not readily rescued fromtheir host."

Genetic Therapy Inc. (GTI) of Gaithersburg, Md., will obtain therights to two U.S. patent applications, "Vector With MultipleTarget Response Elements Affecting Gene Expression" and"Eukaryotic Expression Vectors With Regulation of RNAProcessing." GTI plans to use this genetic-engineering know-how for AIDS therapy, deploying a "decoy" strategy, said MarcR. Schneebaum, the company's chief financial officer. GTI'sscientists will try to insert a gene into lymphocytes or bonemarrow cells to act as a decoy to beat invading HIV to aprotein the virus needs to replicate.

The product of the multiple-target vector may be used to"immunize" cells in vaccine development, and therapeuticallyto treat viral infections. "Unlike other similar vectors," readsthe announcement, "this invention is not limited by retroviralmutations or by variations between different HIV isolates."

If no substantive objections are submitted to OTT within 60days of the Federal Register announcement, the licenses willbe granted.

-- David N. Leff

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