VIAGENE DIRECT GENE TRANSFER MELANOMA TRIALS EXPECTED TO BEGIN IN 1993

VIAGENE DIRECT GENE TRANSFER MELANOMA TRIALS EXPECTED TO BEGIN IN 1993, the company said Nov. 5. Viagene plans to submit a protocol for review by the National Institutes of Health's Recombinant DNA Advisory Committee during its March 1-2 meeting. If approved by RAC and cleared by FDA, Viagene said it believes the trial would be initiated in the first half of 1993. Viagene received RAC and FDA approval for its first gene transfer trial, involving an HIV treatment, this summer ("The Pink Sheet" June 22, p. 8). Under the planned protocol, 10 melanoma patients would be treated with a retroviral vector derived from the Moloney murine leukemia virus and containing the human gammainterferon gene. Viagene researcher Jack Barber, PhD, discussed the company's animal research to support the trial at the International Conference on Gene Therapy of Cancer Nov. 5 in San Diego. "The company believes that this is the first time that significant cell-mediated immune protection against cancer has been reported using direct gene transfer," Viagene said. National Heart, Lung and Blood Institute Hematology Branch Chief Arthur Nienhuis, MD, discussed a gene therapy technique to render the bone marrow of breast cancer patients resistant to toxicities associated with chemotherapy at the conference on Nov. 7. A proposed trial using vectors supplied by Genetic Therapy, Inc. will be reviewed by RAC at its Dec. 3-4 meeting ("The Pink Sheet" Nov. 9, T&G-17). The Nienhuis protocol, based on studies involving the insertion of a multidrug-resistance (MDR) gene in mice, will enroll 12 patients in the advanced stages of breast cancer. Nienhuis is proposing to isolate patients' stem cells, infect them with the Moloney retrovirus containing the MDR1 gene, and reinfuse the cells into the patients' bone marrow. Under the protocol, bone marrow cells infected with MDR1 are expected to enjoy a selective advantage over untreated marrow when exposed to anti-cancer drugs. After ablation of the normal cells, drug resistant cells will grow and replace the old marrow cell population. Resistance of the new cell population may then allow for dose escalation. Results from one of the first gene transfer trials were presented at the San Diego conference on Nov. 5. Malcolm Brenner, MD, St. Jude's Children's Research Hospital, presented data from an ongoing gene marking study of autologous bone marrow transplantation in childhood leukemia patients. "We can say definitively that marrow harvested in remission and reinfused into the patient can contribute to disease relapse," Brenner said. The experiment, also employing GTI vectors, was initiated in September 1991 ("The Pink Sheet" Feb. 3, p. 9). Brenner said the next step is to "extend this approach to almost any disease for which autologous bone marrow transplantation is used, and for which bone marrow contamination may be a problem." He cited multiple trials that are "open or about to open" in the U.S. and Europe designed to evaluate the procedure in other disease populations.