The use of a designed viral vector that can destroy cancer cells while leaving normal cells largely unharmed. The virus also stimulates an immunological response by producing a special factor (GM-CSF) to attract and promote the development of dendritic and T effector cells. It forms the hypothesis that this regimen may be used for people who have failed current forms of treatment and are recommended for cystectomy. It is with hope that this novel therapy will be able to delay or potentially avoid cystectomy for this patient population. Bladder instillation of this agent causes little long lasting side effects and may drastically improve the stimulation of the immune system for local cancer cell death as well as destroying those tumor cells that may have travelled to regional lymph nodes or distant organs.
After the phase I/II CG0070 trial review, it became apparent that the use of CG0070 oncolytic vaccine as an intravesical agent for oncolytic lysis of tumor cells, together with the transcription of GM-CSF on site, may have distinct advantages. This first study showed excellent tumor response rates of 48-77% depending on the dose schedule administered. All of these patients had residual non-muscle invasive bladder cancer who have previously failed BCG therapy at the time of treatment. With the addition of a transduction agent such as DDM, the intravesical instillation of CG0070 enabled uniform distribution of viral particles and exposure to the tumor during those 30-60 minutes instillations as contrast to the intra-tumor injection, intra-arterial or intravenous injection of viral particles in other oncolytic viral trials. Some or most of these delivering methodologies have obvious intrinsic imperfections and potential toxicity. This unique opportunity of an relatively easy intravesical tumor exposure is difficult to duplicate in other solid tumor models. The replication of CG0070 in the majority of patients during the first phase I/II trial indicated tumor lysis with release of tumor specific or tumor associated antigens that have been stably expressed, in abundant quantities during tumor cell death. Release of tumor antigens have been the key elements, together with sufficient on-site GM-CSF, in stimulating strong cross-presentation and confirmation signals to the antigen presenting cells such as dendritic cells interacting with CD4+ and CD8+ T cells. This concept of a "real time" vaccine like regimen is expected to compare favorably with other forms of cancer immunotherapy treatment such as BCG in this patient population. It is with this thought that CG0070 may find a success in this setting because of a reasonably and proven complete response rate in residual and failed BCG bladder cancer patients in the first phase I/II study (some cases with only one instillation). Of importance as well, is the demonstration in the study data of a strong GM-CSF expression during its replication phase. Those patients with carcinoma in situ disease and those with RB pathway dysfunction were particularly responsive. It is therefore, desirable to formulate a protocol to encompass the specialty of this oncolytic vaccine and the unique intravesical delivery to prove the efficacy by a randomized controlled study. This opportunity allows a study on the CG0070's beneficial effects, if any, on the standard of care for carcinoma in situ non muscle invasive bladder cancer patients after they failed BCG therapy. The prognosis of this group presently depends mainly on early radical cystectomy, which carries a high morbidity and decrease of quality of life generally viewed as unacceptable for this group of older patients.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
22
CG0070 adenoviral vector with GM-CSF expression given intravesically 1x10e12 viral particles for each instillations, weekly times six
Quadruple Choice Treatment Options: (same as listed above)
BCG Oncology
Phoenix, Arizona, United States
University of California, San Diego- Moores Cancer Center
La Jolla, California, United States
UCLA Institute of Urological Oncology
Los Angeles, California, United States
University of California, Davis- Cancer Center
Sacramento, California, United States
University of Chicago, Department of Surgery, Section of Urology
Chicago, Illinois, United States
Wake Forest University Health Sciences
Winston-Salem, North Carolina, United States
Vanderbilt University Medical Center Department of Urologic Surgery
Nashville, Tennessee, United States
Complete Response Proportion (CR)
'CR' Proportion is confirmed by negative biopsy, cystoscopy, cytology weekly times 2 with the first assessment three months after first intravesical treatment and then assessed again at 9 month. Two consecutive positive urine cytologies to confirm a persistent or recurrent disease if visual and biopsy is negative. Random biopsy mandatory at the first assessment in the trigone, bladder dome, right, left , anterior and posterior of the bladder wall.
Time frame: 9 months (Phase II)
Durable Complete Response Proportion (DCR)
DCR proportion of DCR lasting 12 months or longer will be conducted after a follow up period of 15 months for each patient. The first complete response assessment will be at 3 month.
Time frame: 15 months (Phase III)
Progression rate to muscle invasive disease
The Progression rate to muscle invasive disease rate is based on analysis from comparing disease status at the time of enrollment versus disease status (for those patients with muscle invasion) at the time of cystectomy or TURBT
Time frame: Throughout the study with expected average of 12 months
Complete Response Survival
The Complete Response Survival time to events of patients who have achieved a complete response at the 3 month assessment will be compared with a log rank test.
Time frame: 15 months
Safety Events
The number and percentage of patients experiencing one or more adverse events will be summarized by relationship to study drug, and severity.
Time frame: Expected average of two years throughout the study
Cystectomy Free Survival
The Cystectomy Free Survival time to events of patients will be compared with a log rank test.
Time frame: 15 month
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