By Frances Bishopp
Chiron Corp. said it is partnering with Baxter Healthcare Corp. on the development and commercialization of an ex vivo cell therapy product for the treatment of leukemia, and that major management changes are in the works for the 16-year old company.
The new partnership, for which financial details have not been disclosed, is based on the use of Chiron's proprietary gene therapy delivery technology and Baxter's blood cell processing technology. Under the agreement, Chiron, of Emeryville, Calif., will develop a kit containing its TK Retroviral Vector, which will be used with Baxter's cell processing technology to produce donor lymphocyte cells containing the thymidine kinase (HSV-tk) gene.
Chiron will be responsible for the manufacture of the TK Retroviral Vector, (gene therapy construct using the herpes simplex virus gene coding for thymidine kinase) and the clinical development of the kit. Baxter will be responsible for manufacturing the other kit components and will have exclusive worldwide distribution rights for the kit.
The two companies will work together to market the product with Baxter focusing on hospitals, clinics and cell processing centers and Chiron focusing on oncologists and primary care physicians.
Larry Kurtz, vice president of corporate communications at Chiron, told BioWorld Today that funds received from a $60 million windfall for Chiron when the FTC cleared the Ciba-Geigy Ltd., Sandoz Ltd. merger in December 1996 to form Novartis AG (see BioWorld Today, Dec. 12, 1996, p. 1) are being used to fund more expansive gene therapy programs, one of which is the Baxter agreement.
"The Baxter agreement is interesting in that when you are pursuing gene therapy, it is largely a research and clinical activity. One of the questions has always been how to deliver the products," Kurtz said.
"In this particular case, because Baxter is already present in the hospitals with its cell separation capabilities, we have delivery to the patient already established," he said.
"We hope to move to clinical trials as soon as possible, maybe this year," Kurtz said.
Baxter, of Deerfield, Ill., developed the technology, Isolex 300, or Magnetic Cell Separator, which uses magnetic beads coded with antibodies specific to the cell type to be selected. Cells are collected from the donor, and incubated with the beads that are specific for the target-cell type. The bead-cell mixture is then put in a magnetic field where the immunal magnetic beads, which are attached to the target cells, are then pulled to the magnet and the non-target cells are drained from the container.
Margaret Stanford, director of strategy development and public relations for Baxter's Biotech Group, explained that the HSV-tk gene will be introduced into target cells using the TK Retroviral Vector. Cells which include the gene are destroyed when exposed to the antiviral agent ganciclovir, she said.
"The Retroviral Vector is a delivery system to get a gene into a cell," Stanford said. "By getting the HSV-tk gene into the cell, it makes it susceptible to ganciclovir, which in turn kills the cell."
"By doing this, we can use the donor's immune system to fight the cancer. These patients," she added, "have gone through intensive chemotherapy and a bone marrow transplant."
"We will take cells from the bone marrow donor and those cells will add an immune response to the cancer, but if the immune response goes too far, then it becomes detrimental for the patient and it will be called graft vs. host disease," Stanford explained. "To do this on a clinical scale will require putting the gene in billions of cells that will be given to the patient."
Penhoet Moves To New Position
In other news, Chiron said it will seek a new CEO as its current president and CEO, Edward Penhoet, becomes vice chairman of the Chiron board of directors. His responsibilities, along with certain operating responsibilities of Chiron's chairman, William Rutter, will be assumed by the new CEO.
Rutter will continue as chairman with a focus on strategic planning and implementation and will have executive responsibility for Chiron Technologies and other research operations.
The men, both of whom helped to found the company, will continue with their current responsibilities until the new CEO joins Chiron sometime later this year.
"The company has expanded substantially and we are enlarging the management team and bringing in capabilities that neither Ed nor Bill have in commercial operating management," Kurtz said. "The size of this job is more than two people can handle, so it is a good idea to bring in a third person."
Kurtz explained that Rutter, who is responsible for the strategic direction of the company, also heads up the diagnostics and vaccines businesses at Chiron. Penhoet runs the therapeutics and vision businesses, and various operating aspects of the company.
Under the reorganization, Kurtz said, the diagnostic and vaccines businesses as well as most of Penhoet's operating responsibilities will go the new CEO. Penhoet will assume strategic and research responsibilities and take on the issues of relationships with the other companies and government agencies on a larger scale.
Chiron's stock ended the day (NASDAQ:CHIR) at $18.625, down $0.375. *