Novel multi-peptide vaccination in Hla-A2+ hormone sensitive patients with biochemical relapse of prostate cancer.
BACKGROUND
A phase I/II trial was conducted to assess feasibility and tolerability of tumor associated antigen peptide vaccination in hormone sensitive prostate carcinoma (PC) patients with biochemical recurrence after primary surgical treatment.


METHODS
Nineteen HLA-A2 positive patients with rising PSA without detectable metastatic disease or local recurrence received 11 HLA-A*0201-restricted and two HLA class II synthetic peptides derived from PC tumor antigens subcutaneously for 18 months or until PSA progression. The vaccine was emulgated in montanide ISA51 and combined with imiquimod, GM-CSF, mucin-1-mRNA/protamine complex, local hyperthermia or no adjuvant. PSA was assessed, geometric mean doubling times (DT) calculated and clinical performance monitored.


RESULTS
PSA DT of 4 out of 19 patients (21%) increased from 4.9 to 25.8 months during vaccination. Out of these, two patients (11%) exhibited PSA stability for 28 and 31 months which were still continuing at data cut-off. One patient showed no change of PSA DT during vaccination but decline after the therapy. Three patients had an interim PSA decline or DT increase followed by DT decrease compared to baseline PSA DT. Three of the responding patients received imiquimod and one the mucin-1-mRNA/protamine complex as adjuvant; both are Toll-like receptor-7 agonists. Eleven (58%) patients had progressive PSA values. The vaccine was well tolerated, and no grade III or IV toxicity occurred.


CONCLUSIONS
Multi-peptide vaccination stabilized or slowed down PSA progress in four of 19 cases. The vaccination approach is promising with moderate adverse events. Long-term stability delayed androgen deprivation up to 31 months. TLR-7 co-activation seems to be beneficial.
Feyerabend
Susan
S
Department of Urology, University of Tübingen, Germany. susan.feyerabend@med.uni-tuebingen.de
Stevanovic
Stefan
S
Gouttefangeas
Cécile
C
Wernet
Dorothee
D
Hennenlotter
Jörg
J
Bedke
Jens
J
Dietz
Klaus
K
Pascolo
Steve
S
Kuczyk
Markus
M
Rammensee
Hans-Georg
HG
Stenzl
Arnulf
A
D000368:Aged; D000634:Aminoquinolines / Q000008:administration & dosage; D000951:Antigens, Neoplasm / Q000008:administration & dosage / Q000009:adverse effects; D000970:Antineoplastic Agents / Q000008:administration & dosage; D019496:Cancer Vaccines / Q000008:administration & dosage* / Q000009:adverse effects; D003131:Combined Modality Therapy; D019008:Drug Resistance, Neoplasm; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000008:administration & dosage; D015789:HLA-A2 Antigen / Q000008:administration & dosage* / Q000009:adverse effects; D006728:Hormones; D006801:Humans; D006979:Hyperthermia, Induced; D000077271:Imiquimod; D008279:Magnetic Resonance Imaging; D008297:Male; D008353:Mannitol / Q000008:administration & dosage / Q000031:analogs & derivatives; D008875:Middle Aged; D018396:Mucin-1 / Q000235:genetics; D009829:Oleic Acids / Q000008:administration & dosage; D010446:Peptide Fragments / Q000008:administration & dosage* / Q000009:adverse effects; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000276:immunology* / Q000473:pathology; D011479:Protamines / Q000008:administration & dosage; D012333:RNA, Messenger / Q000008:administration & dosage; D055502:Secondary Prevention; D014057:Tomography, X-Ray Computed
D000634:Aminoquinolines; D000951:Antigens, Neoplasm; D000970:Antineoplastic Agents; D019496:Cancer Vaccines; D015789:HLA-A2 Antigen; D006728:Hormones; D018396:Mucin-1; D009829:Oleic Acids; D010446:Peptide Fragments; D011479:Protamines; D012333:RNA, Messenger; C477385:montanide ISA 51; D008353:Mannitol; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D017430:Prostate-Specific Antigen; D000077271:Imiquimod