CELL GENESYS MODIFIED T-CELL CLINICAL TRIALS FOR HIV

CELL GENESYS MODIFIED T-CELL CLINICAL TRIALS FOR HIV could begin in 1993, according to a March 17 prospectus for an initial public offering. Cell Genesys is collaborating with researchers at Harvard Medical School and at the Medical Biology Institute of San Diego on the project, the prospectus says. The company and its collaborators also have received a $1.9 mil. three-year grant from the National Institute of Allergy and Infectious Disease. In addition, Cell Genesys has a separate agreement with NIAID "to facilitate initial clinical trials" of the genetically-modified T- lymphocytes, the prospectus says. Cell Genesys will use its gene targeting technology to modify a natural cell line of T lymphocytes so they will "have the ability to function effectively in patients with a specific disease, independent of the different immunologic fingerprints of those patients," the prospectus says. "An anti-HIV T-lymphocyte cell transplant product may help treat the disease by targeting cells actively infected with the virus and potentially eliminating reservoirs of infection." The company and NIAID are also collaborating on anti-cytomegalovirus T-cell implants. While Cell Genesys will rely on the immunocompromised status of AIDS patients to prevent rejection of its initial T-cell transplants, the company plans to develop "universal" cell transplants by modifying cells so that they are not recognized as foreign by the immune system. Initial targets include: retinal epithelial cell transplants to treat age-related macular degeneration, supported by a grant from the National Eye Institute; keratinocyte cells for skin transplants in burn or wound victims; and myoblast cell transplants for muscular dystrophy. Cell Genesys' gene targeting technology uses a targeting vector to insert a DNA segment into a specific site on a chromosome during homologous recombination. The company is applying this technology to two other research areas: therapeutic proteins and monoclonal antibodies. By using its gene targeting technology, Cell Genesys hopes "to produce human therapeutic proteins through a process of gene activation" rather than by cloning an entire gene, the prospectus says. The company said it uses "certain genetic regulatory elements capable of activating genes" which it inserts "in close proximity to the human gene to be activated." In this way, Cell Genesys has "successfully used gene targeting to produce gene activated Factor IX," the prospectus says. "Cell Genesys currently plans to identify corporate partners, including established pharmaceutical firms, to assist the company in the development, manufacturing and marketing of gene activated human therapeutic proteins." The firm's monoclonal antibody research, which involves the genetic alteration of mice to produce human monoclonals, is being conducted in collaboration with JT Immunotech, a subsidiary of Japan Tobacco. The two companies formed a joint venture, Xenotech, in June ("The Pink Sheet" June 17, 1991, T&G-4). Cell Genesys received $4.7 mil. from JT Immunotech in 1991 and expects to receive the same this year, the prospectus says. As part of the June agreement, JT America purchased a 14.4% stake (833,334 shares, or 9.5% post offering) in Cell Genesys for $5 mil. The regulatory and patent situation surrounding Cell Genesys' products is not entirely clear, the prospectus notes. "The company anticipates its products will be regulated as biologics by the FDA," the prospectus says. The regulation of cellular implants is an area where the agency is seeking to clarify its policy ("The Pink Sheet" Jan. 20, p. 11). Cell Genesys has filed for "several" patents, the prospectus says, but has not yet been issued any, the prospectus adds. Foster City, Calif.-based Cell Genesys is seeking $33 mil. from the offering of 3 mil. shares, 20% of which will go to fund the Xenotech joint venture. The firm estimates that the remainder will fund operations "through at least the end of 1993." Robertson Stephens and Oppenheimer & Co. are underwriters. Cell Genesys was formed in April 1988 by a University of Illinois researcher, Raju Kucherlapati, PhD, and Mayfield Medical Fund General Partner and former Genentech Project Leader Mark Levin, both of whom now serve as directors of the company. The management team is led by two other former Genentech employees: President and CEO Stephen Sherwin, MD, was Genentech's VP-clinical research and VP-Research Daniel Capon, PhD, was a Genentech staff scientist. Former Genetics Institute Corporate Development Director Scott Greer serves as Cell Genesys' chief financial officer. The company had 43 employees at the end of 1991.