Genetic Therapy Inc. (GTI) announced Tuesday that it receivedapproval to conduct the first human gene therapy trial to treatlung cancer from the Recombinant DNA Advisory Committee(RAC) of the National Institutes of Health (NIH).

The FDA still must approve the trial.

To be held at M.D. Anderson Cancer Center in Houston, the trialwill involve the direct in vivo administration into patients ofgenetically altered vectors to treat lung cancer.

The initial trial will involve a small number of patients withsmall-cell lung cancer, a fatal form of cancer that affectsmore than 100,000 people in the U.S. The study will evaluatetechnology, efficacy and safety issues, according to MarcSchneebaum, vice president and chief financial officer of theGaithersburg, Md., company.

In the study, a group of patients expressing the cancer-causinggene known as K-ras will receive vectors produced by GTIcontaining an antisense gene that may slow the rate of tumorcell growth.

As a mirror image of K-ras, this antisense gene, whenfunctioning in the rapidly dividing tumor cells, is expected tobind to and suppress the activity of K-ras molecules.

A second patient population, expressing an abnormal version ofthe p53 tumor suppresser gene, will receive vectors containingthe normal p53 gene.

In both approaches, non-cancerous, slowly dividing lung cells,which would not receive the inserted genes, should remainunaffected.

"These trials will apply an in vivo approach, which does notrequire the removal of patient cells and subsequentreintroduction of these cells," said M. James Barrett, GTI'spresident and chief executive officer.

GTI also received RAC approval of four gene transfer trials,including a human ex vivo gene therapy trial using interleukin-4 (IL-4) and an immune cell growth factor to treat cancer,which will involve a dose escalation to improve the body'snatural immune response to tumor cells by transferring the IL-4 gene into patient's cells.

Once in the body, these cells are expected to produce IL-4,which can potentially stimulate an enhanced immune responsewhile allowing for continuous in vivo production of the growthfactor.

The other studies include one by the NIH to assess lymphocytetherapy in HIV-infected patients, a study at St. Jude Children'sResearch Hospital in Memphis, Tenn., to assess the efficacy ofautologous bone marrow transplantation and bone marrowpurging in the treatment of neuroblastoma and studies at M.D.Anderson for the treatment of chronic lymphocytic leukemia.

These trials, using GTI-produced vectors, are expected to beginfollowing FDA approval.

GTI shares (NASDAQ:GTII) were up 38 cents a share on Tuesdayto $9.63.

Other companies using gene therapy for specific cancerapplications:

-- Vical Inc. of San Diego

In Phase I clinical trials with its HLA B7 antigen for cancerimmunotherapy by gene therapy in melanoma patients.

-- Somatix Therapy Corp. of Alameda, Calif.

Developing a gene therapy vaccine to stimulate patient'simmune system to selectively destroy cancer cells.

-- Cell-Pro Inc. of Seattle

In an NIH study, normal genes are inserted into Cell-Pro's stemcells to see if they will produce normal white cells for thetreatment of severe combined immunodeficiency syndrome;

an MD Anderson study is inserting a marker gene into Cell-Pro's stem cells in a step toward treating chronic myelogenousleukemia (CML).

--Targeted Genetics of Seattle

HyTK suicide vector for cancer treatment.

-- Michelle Slade Associate Editor

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