Clin Cancer Res
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Randomized Controlled Trial Clinical Trial
The influence of granulocyte macrophage colony-stimulating factor and prior chemotherapy on the immunological response to a vaccine (ALVAC-CEA B7.1) in patients with metastatic carcinoma.
Granulocyte macrophage colony-stimulating factor (GM-CSF) has been shown to be an effective vaccine adjuvant because it enhances antigen processing and presentation by dendritic cells. ALVAC-CEA B7.1 is a canarypox virus encoding the gene for the tumor-associated antigen carcinoembryonic antigen (CEA) and for a T-cell costimulatory molecule, B7.1. After an initial dose escalation phase, this study evaluated vaccination with 4.5 x 10(8) plaque-forming units ALVAC-CEA B7.1 alone (n = 30) or with GM-CSF (n = 30) in patients with advanced CEA-expressing tumors to determine whether the addition of the adjuvant GM-CSF enhances induction of CEA-specific T-cells. ⋯ However, the GM-CSF plus vaccine cohort of HLA-A2 positive did not demonstrate a statistically significant increase in their CEA-specific T-cell precursor frequencies compared with baseline results. The number of prior chemotherapy regimens was negatively correlated with the generation of a T-cell response, whereas there was a positive correlation between the number of months from the last chemotherapy regimen and the T-cell response. ALVAC-CEA B7.1 is safe in patients with advanced, recurrent adenocarcinomas that express CEA, is associated with the induction of a CEA-specific T-cell response in patients treated with vaccine alone but not with vaccine and GM-CSF, and can lead to disease stabilization for up to 13 months.