Irradiated AML cellular vaccines are ineffective against AML challenge if initiated after challenge with a lethal dose of AML cells.
Cohorts of naive B6 mice (n = 10 per group) received either 2 doses of irradiated AML cells (107 per mouse) administered subcutaneously 1 week apart beginning at time periods ranging from day −21 to day +14 relative to C1498 challenge (105 cells per mouse) on day 0. In each group, 10 mice were analyzed. A Kaplan-Meier survival plot shows days post–lethal C1498 challenge (day 0) on thex-axis and the proportion of mice surviving on they-axis. The actuarial survival rate of AML-vaccinated recipients that had AML vaccines initiated at time periods ranging from days −21 to +0 was significantly higher (P ≤ .0025) than the control animals or animals receiving AML vaccines initiated after this time. There was no survival advantage to mice that were given C1498 vaccines initiated on days +7 or +14 relative to C1498 challenge (P ≥ .27).
