Immunoreactivity to WT1 peptide vaccine is associated with prognosis in elderly patients with acute myeloid leukemia: follow-up study of randomized phase II trial of OCV-501, an HLA class II-binding WT1 polypeptide

Cancer Immunol Immunother. 2023 Aug;72(8):2865-2871. doi: 10.1007/s00262-023-03432-4. Epub 2023 Apr 24.

Abstract

We previously conducted a randomized phase II trial of OCV-501, a WT1 peptide presented by helper T cells, in elderly AML (acute myeloid leukemia) patients in first remission, indicating no difference in 2-year disease-free survival (DSF) between the OCV-501 and placebo groups. Here, we analyzed 5-year outcome and biomarkers. Five-year DFS was 36.0% in the OCV-501 group (N = 52) and 33.7% in the placebo group (N = 53), with no significant difference (p = 0.74). The peripheral WT1 mRNA levels were marginally suppressed in the OCV-501 group compared with the placebo group. Enhanced anti-OCV-501 IgG response by the 25th week was an independent favorable prognostic factor. Anti-OCV-501 IFNγ responses were less frequent than the IgG reactions. These findings suggest that host immunoreactivity has a significant impact on the prognosis of AML and that further improvement of the WT1 peptide vaccine is needed.

Keywords: Acute myeloid leukemia (AML); Biomarker; Immunotherapy; Peptide vaccine; WT1.

Publication types

  • Randomized Controlled Trial
  • Clinical Trial, Phase II

MeSH terms

  • Aged
  • Follow-Up Studies
  • Humans
  • Immunoglobulin G
  • Leukemia, Myeloid, Acute* / genetics
  • Prognosis
  • Vaccines, Subunit / therapeutic use
  • WT1 Proteins*

Substances

  • WT1 Proteins
  • Vaccines, Subunit
  • Immunoglobulin G
  • WT1 protein, human