Cell Genesys Reports Positive Preclinical Studies of Oncolytic Virus Therapy For Bladder Cancer
FOSTER CITY, Calif., April 10 /PRNewswire-FirstCall/ -- Cell Genesys, Inc. (Nasdaq: CEGE - news) today reported encouraging data from preclinical studies evaluating CG8840, a proprietary oncolytic virus therapy for bladder cancer. Significant antitumor activity was demonstrated evaluating CG8840 alone and in combination with taxotere (docetaxel) in mouse models for bladder cancer. Moreover, the oncolytic virus therapy, which is highly selective for replication in cancer cells, demonstrated selective killing of up to 10,000 cancer cells for every normal cell, a far more favorable ratio than typically seen with cancer chemotherapies. These data were presented today by D.C. Yu, Ph.D., and colleagues at Cell Genesys at the American Association for Cancer Research (AACR) Annual Meeting in San Francisco, CA.
The preclinical study evaluated four groups in an experimental mice model of bladder cancer -- a group receiving CG8840 alone, a group receiving taxotere chemotherapy alone, a group receiving CG8840 in combination with taxotere and a group receiving no treatment. Seven weeks after single administrations of the respective therapies, animals receiving CG8840 alone demonstrated significant regression of tumor size compared to the no treatment control (p<0.01), and CG8840 plus taxotere resulted in complete elimination of experimental bladder cancers. Treatment with taxotere alone did not provide significant benefit, and untreated animals' tumors dramatically progressed.
``We are highly encouraged by the results of this preclinical study. Based on the strength of these preclinical data, CG8840 is now considered to be the most promising of our oncolytic viral therapies in preclinical development,'' stated Joseph J. Vallner, Ph.D., president and chief operating officer of Cell Genesys. ``Together with the positive data recently presented from our other clinical and preclinical programs, CG8840 demonstrates the depth of our product pipeline, which now includes multiple product candidates from three product platforms -- GVAX® cancer vaccines, oncolytic virus therapies and gene therapies.''
Cell Genesys' CG8840 is a genetically modified adenovirus (common cold virus) designed to replicate preferentially in bladder cancer cells, particularly those expressing a bladder-associated protein, uroplakin II. The virus replicates in bladder cancer cells expressing uroplakin II until the cells are destroyed, and then the newly created viruses spread throughout the tumor, repeating the replication cycle in other cancer cells. The CG8840 study reported at the AACR meeting evaluated both intravenous and intratumoral delivery and achieved similar results with each method of delivery.
Bladder cancer is the fifth most common cancer in the United States today. Approximately 621,000 people were living with bladder cancer in the United States in 2001, and 56,500 cases are expected to be diagnosed in 2002 -- a number which has increased substantially from fewer than 40,000 cases in 1980. While surgical resection of the cancerous lesion is the current primary therapy, up to 70 percent of patients relapse within one to two years. Upon relapse, patients may receive a variety of therapies including the installation into the bladder of BCG (Bacillus Calmette Guerin), a weakened form of the tuberculosis bacterium. Such treatments are often associated with significant treatment related side effects and 30 percent or more of these patients may relapse. Under these circumstances, a radical cystectomy (removal of the entire bladder) is often performed, although approximately 50 percent of such patients will ultimately succumb to their cancer. New therapies for bladder cancer are urgently needed.
In related news, separate preclinical studies relating to oncolytic viruses for colon cancer and melanoma were also presented at the AACR meeting. A preclinical animal study of CG7980 for colon cancer demonstrated significant antitumor activity in a mouse model including more than 80 percent tumor regression in the treated animals compared with untreated animals whose disease progressed. A preclinical in vitro study of CG9040, an oncolytic virus therapy for melanoma, demonstrated that the genetically modified virus was highly selective for replication in melanoma cells as compared with non-melanoma cells.
Cell Genesys currently has five oncolytic virus therapies in its product pipeline, two of which are clinical stage products. CG7060, a clinical stage intratumoral product being evaluated in patients with early stage prostate cancer, has demonstrated encouraging data in a Phase II trial including significant reductions in PSA (prostate-specific antigen) levels. A Phase I/II trial evaluating CG7060 in combination with external beam radiation therapy is expected to be initiated later this year which will set the stage for future Phase III trials. CG7870, an intravenously delivered oncolytic virus therapy, has been evaluated in a Phase I/II trial in hormone-refractory prostate cancer and is expected to be tested in combination with taxotere chemotherapy. In addition to the clinical stage oncolytic virus therapies, other product candidates utilizing this technology are CG8840, CG8900 and CG7980, preclinical product candidates for bladder cancer, liver cancer and colon cancer, respectively.
Cell Genesys is focused on the development and commercialization of innovative therapeutic products for cancer based on gene therapy technologies. The company is pursuing three cancer product platforms -- GVAX® cancer vaccines, oncolytic virus therapies and in vivo cancer gene therapies. Clinical trials of GVAX® vaccines are under way in lung cancer, prostate cancer, pancreatic cancer, leukemia and myeloma. Clinical trials of oncolytic virus therapies include CG7060 and CG7870 in prostate cancer. Preclinical stage programs include oncolytic virus therapies and gene therapies for multiple types of cancer. Cell Genesys' majority-owned subsidiary, Ceregene, is focused on gene therapies for neurologic disorders. Cell Genesys also continues to hold approximately nine million shares of common stock in its former subsidiary, Abgenix, an antibody products company. Cell Genesys is headquartered in Foster City, CA and has manufacturing operations in San Diego, CA, Hayward, CA and Memphis, TN. For additional information, please visit the company's website at www.cellgenesys.com.
Statements made herein about Cell Genesys and its subsidiaries, other than statements of historical fact, including statements about the progress, reports and timelines of clinical trials and preclinical studies, including those relating to the company's oncolytic virus therapies, success of potential products, nature of product pipelines, licenses and intellectual property are forward-looking statements and are subject to a number of uncertainties that could cause actual results to differ materially from the statements made, including risks associated with the success of research and development programs, the ability to manufacture products for clinical trials, the success and results of clinical trials and preclinical studies, the regulatory approval process, competitive technologies and products, patents and additional financings. For information about these and other risks which may affect Cell Genesys, please see the company's Annual Report on Form 10-K dated April 1, 2002 as well as Cell Genesys' reports on Form 10-Q and 8-K and other reports filed from time to time with the Securities and Exchange Commission.
CONTACT: Jennifer Cook Williams, Associate Director, Corporate Communications of Cell Genesys, Inc., +1-650-425-4542.
SOURCE: Cell Genesys, Inc. |
