Phase I/IIa clinical trial of a novel hTERT peptide vaccine in men with metastatic hormone-naive prostate cancer

Cancer Immunol Immunother. 2017 Jul;66(7):891-901. doi: 10.1007/s00262-017-1994-y. Epub 2017 Apr 8.

Abstract

In newly diagnosed metastatic hormone-naive prostate cancer (mPC), telomerase-based immunotherapy with the novel hTERT peptide vaccine UV1 can induce immune responses with potential clinical benefit. This phase I dose escalation study of UV1 evaluated safety, immune response, effects on prostate-specific antigen (PSA) levels, and preliminary clinical outcome. Twenty-two patients with newly diagnosed metastatic hormone-naïve PC (mPC) were enrolled; all had started androgen deprivation therapy and had no visceral metastases. Bone metastases were present in 17 (77%) patients and 16 (73%) patients had affected lymph nodes. Three dose levels of UV1 were given as intradermal injections combined with GM-CSF (Leukine®). Twenty-one patients in the intention-to-treat population (95%) received conformal radiotherapy. Adverse events reported were predominantly grade 1, most frequently injection site pruritus (86.4%). Serious adverse events considered possibly related to UV1 and/or GM-CSF included anaphylactic reaction in two patients and thrombocytopenia in one patient. Immune responses against UV1 peptides were confirmed in 18/21 evaluable patients (85.7%), PSA declined to <0.5 ng/mL in 14 (64%) patients and in ten patients (45%) no evidence of persisting tumour was seen on MRI in the prostatic gland. At the end of the nine-month reporting period for the study, 17 patients had clinically stable disease. Treatment with UV1 and GM-CSF gave few adverse events and induced specific immune responses in a large proportion of patients unselected for HLA type. The intermediate dose of 0.3 mg UV1 resulted in the highest proportion of, and most rapid UV1-specific immune responses with an acceptable safety profile. These results warrant further clinical studies in mPC.

Keywords: Cancer vaccine; Immune response; Prostate cancer; hTERT.

Publication types

  • Clinical Trial, Phase I
  • Clinical Trial, Phase II

MeSH terms

  • Adenocarcinoma / blood
  • Adenocarcinoma / immunology
  • Adenocarcinoma / secondary
  • Adenocarcinoma / therapy*
  • Aged
  • Bone Neoplasms / secondary
  • Cancer Vaccines / adverse effects
  • Cancer Vaccines / immunology
  • Cancer Vaccines / therapeutic use*
  • Cohort Studies
  • Granulocyte-Macrophage Colony-Stimulating Factor / administration & dosage
  • Granulocyte-Macrophage Colony-Stimulating Factor / therapeutic use
  • Humans
  • Immunity, Active / immunology
  • Immunotherapy / methods*
  • Lymphatic Metastasis
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Peptide Fragments / adverse effects
  • Peptide Fragments / immunology
  • Peptide Fragments / therapeutic use*
  • Prostate-Specific Antigen / blood*
  • Prostate-Specific Antigen / immunology
  • Prostatic Neoplasms / blood
  • Prostatic Neoplasms / immunology
  • Prostatic Neoplasms / pathology
  • Prostatic Neoplasms / therapy*
  • Recombinant Proteins / administration & dosage
  • Recombinant Proteins / therapeutic use
  • Telomerase / adverse effects
  • Telomerase / immunology
  • Telomerase / therapeutic use*
  • Vaccines, Subunit / adverse effects
  • Vaccines, Subunit / immunology
  • Vaccines, Subunit / therapeutic use

Substances

  • Cancer Vaccines
  • Peptide Fragments
  • Recombinant Proteins
  • UV1 vaccine
  • Vaccines, Subunit
  • sargramostim
  • Granulocyte-Macrophage Colony-Stimulating Factor
  • Telomerase
  • Prostate-Specific Antigen