Discussion
AML
REMISSION, AML
This study revealed that 1) there was no prognostic difference between the OCV-501 and placebo groups even on long-term follow-up, 2) Although the first finding is disappointing, the modest suppression of peripheral The third finding regarding IgG reactivity is a characteristic observed with this helper peptide. The most likely reason why OCV-501 did not contribute to improved prognosis overall despite IgG reactivity being correlated with prognosis is that vaccine responsiveness reflects general immune functions in AML patients, and that those who retain the functions may have a better prognosis irrespective the vaccine effect.Recently, there have been reports that there is a difference in immune functions in the bone marrow between a group of patients showing long-term remission with chemotherapy alone and a group of patients showing relapse [Regarding the fourth finding, the IFNγ-response was observed not only in the OCV-501 group but also in a small number of the placebo group, and both the IFNγ-response subgroups showed a trend towards a better prognosis than the IFNγ-nonresponse subgroup (data not shown). Cell-mediated immunity may have been enhanced by the adjuvants, which might be associated with that 5-year DFS rates exceeded 30% in both groups. WT1-specific cytotoxic T-cells were reportedly detected in AML patients with longer survival [This study shows that responsiveness to the WT1 vaccine in AML patients in CR is variable. For immune-response groups, it will be necessary to improve vaccines to induce earlier responses. For immunocompromised groups, passive immunotherapy, targeting immune suppression or a new kind of WT1 vaccine should be developed [