Initial clinical data reported from phase I/II trial of GVAX vaccine.

2003 JUL 2 - (NewsRx.com & NewsRx.net) -- Cell Genesys, Inc., (CEGE) reported initial clinical data from a phase I/II trial of GVAX cancer vaccine for multiple myeloma, a type of bone marrow cancer, as well as positive interim results on a prostate cancer vaccine.

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 1 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% and 70%, respectively. Treatment with GVAX myeloma vaccine to date has been safe and well tolerated.

The trial is being conducted by Ivan Borrello, MD, Hyam I. Levitsky, MD, and colleagues at the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins and was reported at the American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, Illinois.

"We are encouraged by the initial clinical activity observed in this phase I/II 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, PhD, 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 II trial in acute myelogenous leukemia.

Preclinical studies supporting the phase I/II 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.