• E-mail
• Print
• Comment
• Font Size
• Digg
• del.icio.us
• Discuss article

Cell Genesys Reports Additional Positive Data From Phase 2 Trial of GVAX(R) Vaccine for Leukemia

Posted on: Monday, 16 May 2005, 15:01 CDT

ORLANDO, Fla., May 16 /PRNewswire-FirstCall/ -- Cell Genesys, Inc. today reported follow up clinical data from an ongoing Phase 2 trial of GVAX(R) vaccine for acute myelogenous leukemia (AML). Patients with newly diagnosed leukemia were treated with chemotherapy, and if responsive, subsequently received autologous bone marrow stem cell transplantation and GVAX(R) vaccine for leukemia. The ongoing findings of this trial indicate that vaccine therapy is generally well tolerated and may reduce residual leukemic cells that persist after chemotherapy, as indicated by decreased levels of WT-1, a leukemia-associated genetic marker, which is detectable in over 95 percent of patients with active AML. In addition, there was an observed correlation between relapse-free survival, decreased WT-1 and the vaccine-associated immune response. These follow-up trial results were reported at the American Society of Clinical Oncology (ASCO) Annual Meeting in Orlando, FL, by Dr. Ivan Borrello from Johns Hopkins University, Baltimore, MD (ASCO Abstract #6539).

The Phase 2 trial was conducted at four leukemia bone marrow transplant centers in the United States and enrolled 54 patients. To date, 28 patients have initiated GVAX(R) vaccination after achieving a complete response to chemotherapy and thus far 21 of these patients have completed the stem cell transplantation and initiated a series of post-transplant vaccinations. The majority of patients had detectable WT-1 levels in their blood following chemotherapy, indicating persistent leukemic cells. There were post- vaccination declines in WT-1 in 11 of 16 patients (69%) in the blood and in 12 of 20 (60%) in the bone marrow after just a single pre-transplant vaccination. In addition, two-year relapse-free survival was greater in the 11 patients who showed a decrease in WT-1 in the blood following the single pre-transplant vaccination compared to those who did not (73% vs. 0%, log-rank p=0.03) and was also greater in the 19 patients who achieved an undetectable level of WT-1 in the blood following stem cell transplantation and further vaccination compared to the six patients who did not (89% vs. 17%, log-rank p=0.002). Finally, all six patients who mounted a vaccine-associated immune response, as measured by induction of a delayed-type hypersensitivity reaction to their own leukemic cells, have remained in complete remission from 16 to 29 months post transplant and all six of these patients have had a vaccine-associated WT-1 decline or undetectable levels at the time of vaccination. To date, there have been no serious side effects considered related to the vaccine therapy.

"We are encouraged by the results of our ongoing Phase 2 study of GVAX(R) vaccine in acute leukemia, particularly the observed correlation between vaccine-associated immune response, WT-1 response and relapse-free survival," stated Joseph J. Vallner, Ph.D., president and chief operating officer of Cell Genesys. "We believe that GVAX(R) vaccine for leukemia represents a potential new treatment option for acute leukemia that may be particularly important to consider for elderly patients and patients for whom bone marrow transplantation is not readily available or indicated."

The form of GVAX(R) vaccine used in this leukemia clinical trial is a non patient-specific GVAX(R) product manufactured at Cell Genesys that is mixed at the treatment center with the patient's irradiated tumor cells that were collected prior to chemotherapy. Cell Genesys believes that this product could potentially be developed as an off-the-shelf pharmaceutical for use in multiple types of hematologic malignancies. Future manufacturing of the product would be expected to occur at the company's plant in Hayward, California, which has Phase 3 and potential market launch production capabilities.

Clinical trials of GVAX(R) cancer vaccines are under way for multiple types of cancer including prostate cancer, lung cancer, pancreatic cancer, leukemia and myeloma. Cell Genesys' GVAX(R) cancer vaccines are whole-cell vaccines which are designed to stimulate an immune response against the patient's tumor. The vaccines are comprised of tumor cells that have been irradiated and genetically modified to secrete GM-CSF (granulocyte-macrophage colony stimulating factor), an immune stimulatory hormone that plays a key role in stimulating the body's immune response to vaccines.

Cell Genesys is focused on the development and commercialization of novel biological therapies for patients with cancer. The company is pursuing two clinical-stage cancer product platforms -- GVAX(R) cancer vaccines and oncolytic virus therapies. Clinical trials of GVAX(R) cancer vaccines include an ongoing Phase 3 trial of GVAX(R) vaccine for prostate cancer as well as trials of GVAX(R) vaccines for lung cancer, pancreatic cancer, leukemia and myeloma. Clinical programs of oncolytic virus therapies include CG7870 for prostate cancer and CG0070 for bladder cancer. Cell Genesys continues to hold equity interests in its two former subsidiaries -- Abgenix, Inc., an antibody products company and Ceregene, Inc., which is developing gene therapies for neurodegenerative disorders. Cell Genesys is headquartered in South San Francisco, CA and has manufacturing operations in San Diego, CA, Hayward, CA and Memphis, TN. For additional information, please visit the company's website at http://www.cellgenesys.com/.

Statements made herein about the company and its subsidiaries, other than statements of historical fact, including statements about the company's progress, results and timing of clinical trials and preclinical programs and the nature of product pipelines 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 clinical trials and research and development programs, the regulatory approval process for clinical trials, competitive technologies and products, patents, continuation of corporate partnerships and the need for 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 for the year ended December 31, 2004 dated March 14, 2005 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. The company assumes no obligation to update the forward-looking information in this press release.

Contact: Ina Cu

Investor Relations

Cell Genesys, Inc.

650-266-3200

Cell Genesys, Inc.

CONTACT: Ina Cu, Investor Relations of Cell Genesys, Inc.,+1-650-266-3200

Web site: http://www.cellgenesys.com/

Source: PRNewswire-FirstCall

More News in this Category