Anti-CTLA-4 therapy results in higher CD4+ICOShi T cell frequency and IFN-gamma levels in both nonmalignant and malignant prostate tissues.
Cytotoxic lymphocyte antigen-4 (CTLA-4) blockade is an active immunotherapeutic strategy that is currently in clinical trials in cancer. There are several ongoing trials of anti-CTLA-4 in the metastatic setting of prostate cancer patients with reported clinical responses consisting of decreases in the prostate specific antigen (PSA) tumor marker for some patients. Immunologic markers that correlate with these clinical responses are necessary to guide further development of anti-CTLA-4 therapy in the treatment of cancer patients. We recently reported that CD4(+) inducible co-stimulator (ICOS)(hi) T cells that produce interferon-gamma (IFN-gamma) are increased in the peripheral blood and tumor tissues of bladder cancer patients treated with anti-CTLA-4 antibody. Here we present data from the same clinical trial in bladder cancer patients demonstrating a higher frequency of CD4(+)ICOS(hi) T cells and IFN-gamma mRNA levels in nonmalignant prostate tissues and incidental prostate tumor tissues removed at the time of radical cystoprostatectomy. Our data suggest immunologic markers that can be used to monitor prostate cancer patients who receive anti-CTLA-4 therapy and indicate that the immunologic impact of anti-CTLA-4 antibody can occur in both tumor and nonmalignant tissues. These data should be taken into consideration for evaluation of efficacy as well as immune-related adverse events associated with anti-CTLA-4 therapy.
Chen
Hong
H
Department of Genitourinary Medical Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA.
Liakou
Chrysoula I
CI
Kamat
Ashish
A
Pettaway
Curtis
C
Ward
John F
JF
Tang
Derek Ng
DN
Sun
Jingjing
J
Jungbluth
Achim A
AA
Troncoso
Patricia
P
Logothetis
Christopher
C
Sharma
Padmanee
P
D000906:Antibodies / Q000627:therapeutic use*; D015703:Antigens, CD / Q000187:drug effects*; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism*; D060908:CTLA-4 Antigen; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics / Q000378:metabolism*; D016246:Lymphocytes, Tumor-Infiltrating / Q000166:cytology*; D008297:Male; D011467:Prostate / Q000378:metabolism*; D011471:Prostatic Neoplasms / Q000378:metabolism / Q000628:therapy*; D012333:RNA, Messenger / Q000235:genetics
D000906:Antibodies; D015703:Antigens, CD; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D012333:RNA, Messenger; D007371:Interferon-gamma