Mr. Market seems unimpressed by these results. Both are interim; not sure what was expected. Wondering where CEGE is with GVAX in lung cancer . . .
>>SOUTH SAN FRANCISCO, Calif., June 2 /PRNewswire-FirstCall/ -- Cell Genesys, Inc. (Nasdaq: CEGE - News) today reported initial clinical data from a Phase 1/2 trial of GVAX® cancer vaccine for multiple myeloma, a type of bone marrow cancer. Patients with advanced myeloma were treated with chemotherapy, and if responsive, subsequently received autologous bone marrow stem cell transplantation and GVAX® vaccination. The trial enrolled 20 patients, and 14 patients received at least one GVAX® vaccination. Combination therapy with transplantation and GVAX® vaccine resulted in two complete responses, six partial responses, two patients with stable disease and one patient with progression, and the three remaining patients are not yet evaluable. Two of the responders progressed after transplantation and then demonstrated antitumor activity following vaccination as measured by reductions in the myeloma-associated circulating protein (M-spike) of 25 percent and 70 percent, respectively. Treatment with GVAX® myeloma vaccine to date has been safe and well tolerated. The trial is being conducted by Ivan Borrello, M.D., Hyam I. Levitsky, M.D. and colleagues at the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins and was reported today at the American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, IL, by Dr. Borrello (ASCO Abstract #669).
"We are encouraged by the initial clinical activity observed in this Phase 1/2 trial of GVAX® myeloma vaccine and believe that these data support the evaluation of GVAX® vaccines in other hematologic malignancies such as acute leukemia," stated Joseph J. Vallner, Ph.D., president and chief operating officer of Cell Genesys. "Multiple myeloma represents the sixth type of cancer in which GVAX® vaccines have been evaluated to date. Importantly, antitumor activity has been observed in each type of cancer and the vaccines have had a favorable safety profile in over 500 patients."
The form of GVAX® vaccine used in this myeloma clinical trial is a non patient-specific GVAX® 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 (sometimes referred to as "bystander GVAX®") could potentially be developed as an off-the-shelf pharmaceutical for use in multiple types of hematologic malignancies. In addition to myeloma, the company is currently evaluating the product in a multicenter Phase 2 trial in acute myelogenous leukemia.
Preclinical studies supporting the Phase 1/2 trial were published in a May 2000 issue of the journal, Blood, the official journal of the American Society of Hematology. The goal of GVAX® vaccine therapy in hematologic malignancies is to stimulate an immune response directed against the patient's tumor cells and enhance the response induced by standard chemotherapy and transplantation. Dr. Levitsky, Dr. Borrello and colleagues at Johns Hopkins University reported that in animal studies of acute leukemia, GVAX® cancer vaccine, administered following bone marrow transplantation, significantly prevented tumor relapse and increased the therapeutic benefit of transplantation. Tumor-free survival rates were approximately 80 percent in animals receiving the combination of GVAX® vaccine and transplantation, 40 percent in animals receiving vaccination alone and zero percent in animals receiving neither treatment. Additionally, GVAX® vaccination resulted in the sustained production of an expanded population of tumor-specific immune cells, thereby redirecting the immune system to recognize and destroy tumor cells.
Multiple myeloma is the second most prevalent hematologic malignancy in the United States after non-Hodgkins lymphoma. Approximately 50,000 Americans currently have multiple myeloma, and approximately 11,000 die of the disease each year.
Clinical trials of GVAX® cancer vaccines are under way for multiple types of cancer including prostate cancer, lung cancer, pancreatic cancer, myeloma and leukemia, and Phase 3 trials of GVAX® prostate cancer vaccine and GVAX® lung cancer vaccine are expected to begin during the next year. Cell Genesys' GVAX® 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 which plays a key role in stimulating the body's immune response to vaccines.<<
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>>SOUTH SAN FRANCISCO, Calif., June 2 /PRNewswire-FirstCall/ -- Cell Genesys, Inc. (Nasdaq: CEGE - News) today reported positive interim results from a multicenter Phase 2 trial of GVAX® prostate cancer vaccine that provide further support for the advancement of this product into Phase 3 development. The study, which was designed to evaluate potential treatment regimens for Phase 3, recently completed enrollment and included 80 patients with advanced hormone-refractory prostate cancer with evidence of metastasis (spread) to the bone. Patients were sequentially assigned to one of five treatment groups and received GVAX® prostate cancer vaccine at doses ranging from 100 million to 300 million cells per injection every two to four weeks without concomitant chemotherapy. Full results are not yet available for patients in the highest dose group who received an initial dose of 500 million cells followed by every-two-week injections of 300 million cells, and therefore the final confirmation of the Phase 3 treatment regimen is pending. The interim data, which demonstrate the safety and clinical activity of the vaccine, were presented today at the American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, IL, by Jonathan Simons, M.D., director, Winship Cancer Institute at Emory University School of Medicine (ASCO Abstract #667).
Patients enrolled on the Phase 2 trial were monitored for safety and for evidence of vaccine activity with serial measurements of PSA (prostate-specific antigen) a marker for prostate cancer; ICTP (carboxy-terminal telopeptide of type I collagen), an independent biochemical marker of the bone destruction that occurs when prostate cancer spreads into the bone; and prostate cancer-associated antibodies induced by the vaccine. The preliminary findings demonstrate the safety and clinical activity of the vaccine in the four treatment groups analyzed to date. For purposes of interim analysis, the data for measurements of ICTP, PSA and prostate cancer-associated antibodies were pooled across the treatment groups. There was an improvement or stabilization in bone metastatic activity as measured by ICTP levels in 59 percent of patients (16 of 27 patients tested to date). Among 61 patients followed for a median of four months, there was one patient with a greater than 50 percent reduction in PSA levels and 10 patients with lesser reductions or stabilization, including four whose PSA levels decreased after initial progression, which is a pattern suggesting the onset of antitumor immunity following repeat vaccination. Prostate cancer-associated antibodies were detected post-vaccination in 83 percent of patients (15 of 18 tested to date) with titers of 1:30,000 to 1:100,000, levels that are significantly higher than those previously published for other cell-based cancer vaccines. Median survival -- an endpoint reported in an earlier Phase 2 trial that compared favorably with the published results for chemotherapy -- has not yet been reached for any treatment group.
"We are encouraged by the interim results from this new Phase 2 trial of GVAX® prostate cancer vaccine particularly with respect to the independent confirmation of vaccine activity provided by ICTP measurements and are continuing our efforts to advance this product into Phase 3 development," stated Joseph J. Vallner, Ph.D., president and chief operating officer of Cell Genesys. "GVAX® prostate cancer vaccine has the potential to provide a less toxic treatment alternative for late-stage prostate cancer patients, whose only current treatment option is chemotherapy."
The ongoing multicenter Phase 2 trial reported today is evaluating a higher potency version of GVAX® prostate cancer vaccine than the version previously tested. This higher potency version of the vaccine product contains higher levels of the immune stimulatory hormone (GM-CSF) which serves as the vaccine adjuvant and is the form of the vaccine that the company expects to advance into Phase 3 trials. In September 2002, the company updated long-term survival data from a Phase 2 trial of a lower potency version of GVAX® prostate cancer vaccine involving 34 patients with hormone-refractory prostate cancer metastatic to the bone. The overall median survival of the 34 patients was 24.1 months, which is longer than that previously reported for any chemotherapy, which is the current standard of care for hormone-refractory prostate cancer patients with bone metastases.
Cell Genesys recently announced that Phase 3 development of GVAX® prostate cancer vaccine is targeted to begin within the next six months. Discussions relating to a proposed Phase 3 development program have been initiated with the U.S. Food and Drug Administration (FDA). While the final design of the Phase 3 trial will be subject to further discussions with FDA, the company plans to evaluate GVAX® prostate cancer vaccine in hormone-refractory prostate cancer patients with bone metastases and compare the survival benefit to standard chemotherapy treatment. Product for this Phase 3 trial, as well as potential product launch, will be manufactured in Cell Genesys' GMP (good manufacturing practices) manufacturing facility located in Hayward, California. This 41,000 square-foot state-of-the-art bioreactor facility is currently producing GVAX® prostate cancer vaccine and, as recently announced, the company has had successful manufacturing runs from fermenter to vialed product.<<
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Cheers, Tuck |
