Safety Study of Autologous Dendritic Cells Injected Into the Prostate After Cryoablation for Advanced Prostate Cancer (CRITICAL)
The purpose of this study is to determine if the intra-tumoral injection of a subject's own dendritic cells after cryotherapy of the prostate is a safe and effective treatment for advanced prostate cancer.
In theory, the injected dendritic cells will internalize antigens from the tumor cells which have been damaged by cryotherapy and activate the subject's immune system against that specific tumor.
Subjects will also receive a low dose chemotherapy designed to lower the number of T-regulatory cells which have been shown to lower or stop some immune system responses.
Hypothesis 1: Dendritic cell injection into cryotreated prostate cancer is non-toxic;
Hypothesis 2: Dendritic cell injection into cryotreated prostate cancer is medically beneficial to the subject.
|Study Design:||Endpoint Classification: Safety/Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||A Phase I/IIa Trial of Combined Cryotherapy and Intra-tumoral Immunotherapy With Autologous Immature Dendritic Cells (VDC2008) in Chemo-naïve Men With Prostatic Adenocarcinoma and Limited Metastases to Lymph Nodes and/or Bone|
- Maximum Tolerated Dose (MTD) [ Time Frame: Up to 1 year ] [ Designated as safety issue: Yes ]
PROTOCOL EXCERPT: The primary objective of the Phase I Portion of this study is the determination of the maximum tolerated dose (MTD) of intratumorally injected study agent VDC2008 administered following cryoablation of the prostate, and pre- and post-treatment with a low-dose cyclophosphamide therapy, as determined by toxicity and adverse event monitoring following treatment of metastatic androgen-independent prostate cancer.
ADDITIONAL INFORMATION: MTD was not reached by any study participant prior to end of the study. Additional participants would have been necessary to determine MTD.
|Study Start Date:||August 2009|
|Study Completion Date:||December 2011|
|Primary Completion Date:||May 2011 (Final data collection date for primary outcome measure)|
Cryoablation of prostate followed by dendritic cell injection (dose of 2.5 x 10^7, 7.5 x 10^7, or 1.0 x 10^8 cells depending on assigned cohort) into prostate and low dose cyclophosphamide therapy (dose: 25 mg, p.o., b.i.d. for 7 days on and 7 days off; a total of 6 cycles [1 cycle = 4 weeks] starting Week 2 after cryoablation and going to Week 26)
Intratumoral injection of VDC2008 post-cryotherapy.
Dosage will depend on cohort: 2.5 x 10^7, 7.5 x 10^7 or 1.0 x 10^8 cells
Other Name: Autologous dendritic cellsDrug: Cyclophosphamide
Cyclophosphamide i.v. given at day -3 (dose: 300mg/m2); Low-dose Cyclophosphamide pill given twice daily (dose: 25 mg, p.o., b.i.d. for 7 days on and 7 days off; a total of 6 cycles [1 cycle = 4 weeks] starting Week 2 after cryoablation and going to Week 26)
The study treatment dendritic cells (VDC2008) will be injected into the prostate following prostatic cryoablation. It is speculated that antigen from the cryoablated cancer will be available in the vicinity of the cryoablation field immediately following the procedure. Autologous, immature dendritic cells are capable of internalizing antigen, migrating to the lymphatic system, and presenting antigenic epitopes to T lymphocytes. In this way, dendritic cells are capable of initiating a cell-mediated systemic immune response.
In concept, the cancer itself should provide a specific and potentially broad spectrum of cancer-related antigens. Regulatory T lymphocytes, which have been implicated in dampening or halting cell-mediated, antigen-specific immune responses, will be selectively depleted using a regimen of low-dose cyclophosphamide. Low-dose cyclophosphamide has been empirically shown to selectively deplete the number of circulating regulatory T cells.
Using this combination of therapies, it is thought that a clinically significant anti-cancer immune response might be elicited.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00753220
|United States, California|
|Community Memorial Hospital|
|Ventura, California, United States, 93003|
|Principal Investigator:||Duke K Bahn, M.D.||Prostate Institue of America|