Cell Genesys, Inc. announced that enrolment has been opened for an expanded multi-centre phase1 clinical trial of CG0070, to evaluate escalating multiple-dose regimens of CG0070 in patients, with recurrent bladder cancer.
The expanded trial was prompted by encouraging interim safety and efficacy data, recently reported for single-dose administration of CG0070 and will include up to 45 additional patients who have failed previous therapy, with Bacillus Calmette-Guerin (BCG), the current standard therapy for recurrent bladder cancer.
CG0070, an oncolytic virus therapy that is being developed through a global alliance with Novartis AG has been shown to destroy cancer cells of multiple types in numerous preclinical studies. CG0070 is the first "armed" oncolytic adenovirus therapy to enter clinical development, so-named because it has been engineered to include the therapeutic gene for GM-CSF, an immune- stimulating hormone which is also a key component in Cell Genesys' lead product platform, Gvax cancer immunotherapy's
As a result, CG0070 can potentially destroy cancer cells by two different mechanisms: direct cell killing by the virus and immune-mediated cell killing stimulated by GM-CSF.
"We are pleased to advance CG0070 into, a multiple-dose phase 1 trial, based on the initial clinical results for this oncolytic virus therapy product," stated Joseph J. Vallner, PhD., president and chief operating officer of Cell Genesys. "We are optimistic that the dual mechanism of action of CG0070 might result in enhanced local anti-tumour activity as well as potential systemic anti-tumour immunity following local administration."
The open-label, dose-escalation trial is evaluating intravesical (into the bladder) administration of CG0070 in patients with superficial bladder cancer who have failed previous therapy with BCG. The trial was designed to first evaluate escalating single-dose levels of CG0070 and now, expanded to evaluate escalating multiple-dose regimens.
The primary endpoints of the study are safety and the determination of a maximum tolerated dose. Other endpoints include clinical response based on follow-up cystoscopy and recurrence-free survival. The expansion of the trial from single-dose to multiple-dose regimens was prompted by data reported in May 2006 at the annual meeting of the American Urological Association including anti-tumour activity, documented by a complete response at follow-up cystoscopy, at approximately three months in three of the nine patients, evaluable to date. The duration of the complete responses after just a single administration of CG0070 were 6, 9, and 3+ months respectively. Treatment was generally tolerable and the majority of treatment-related side effects were local bladder toxicities.
Oncolytic (cancer cell-killing) virus therapies represent a new approach in the treatment of patients with cancer. Cell Genesys' oncolytic viruses are comprised of adenoviruses, a cause of the common cold, that are engineered to selectively replicate in and destroy cancer cells through the use of tumour- or tissue-specific promoters.
Cell Genesys is developing certain of its oncolytic virus therapy products through a global alliance with Novartis AG, which may provide funding for the further development and commercialization of these products.
The American Cancer Society estimates, that approximately 61,500 new cases of bladder cancer will be diagnosed in 2006, and that the majority of these will be superficial bladder cancer. Superficial bladder cancer has traditionally been treated by transurethral resection (TUR) upon initial diagnosis, but recurs in the majority of patients. The current standard therapy after TUR is intravesical BCG.