Researchers from the Dana Farber Cancer Center have reported that GVAX, a cancer vaccine composed of autologous leukemia cells genetically modified to secrete granulocyte macrophage-colony stimulating factor (GM-CSF), may have anti-leukemic effects when administered after a reduced-intensity allogeneic stem cell transplant in patients with advanced myeloid malignancies. The details of this study were presented at the 2008 meeting of the American Society of Hematology on December 9, 2008, in San Francisco.[1]

GVAX is an investigative vaccine that utilizes a technology platform in which non patient-specific whole tumor cells are lethally irradiated and genetically modified to secrete GM-CSF. GVAX is administered intradermally on an outpatient basis and is intended to be marketed for “off-the-shelf” pharmaceutical use. GVAX is currently in ongoing clinical trials evaluating its efficacy in various types of cancers including prostate cancer and chronic myeloid leukemia.

In the current study, patient-specific leukemia cells were used to make the vaccine. The vaccine was successfully made in 24 patients in this study. Sixteen patients had AML, six had MDS, and one had CML in blast crisis. Fifteen of these patients underwent reduced-intensity allogeneic stem cell transplantation, and 10 completed all six vaccinations. Relapse-free and overall survival for these 15 patients was 45% and 56%, respectively, at two years. Matched control patients without vaccination with GVAX had a two-year relapse-free survival of 12% and an overall survival of 16%. Nine of the 10 patients who received all six post-transplant vaccinations remain alive and in remission with a median follow-up of 23 months. These authors suggested that GVAX had significant anti-leukemic effects.

Comments: These are very interesting data that strongly suggest activity for GVAX as post-transplant immunotherapy in patients with myeloid malignancies.

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