Viventia Biotech Initiates Patient Treatment For Vicinium Phase II Bladder Cancer Trial

Armen Hareyan's picture

Viventia Biotech Inc., a privately held biopharmaceutical company advancing a portfolio of novel antibody products focused on cancer, announced today that it has initiated patient treatment in its open-label Phase II clinical trial for Vicinium, administered using intravesical instillation for the treatment of locally persistent non-invasive bladder cancer.

The trial, which will initially enroll patients in Canada before expanding into the U.S., is expected to be fully enrolled by Q4 2007. Viventia's lead product, Proxinium, is being developed to treat late stage, locally advanced head and neck cancer and is currently enrolling patients in its TARGET trial, a pivotal Phase III global clinical trial that is also expected to complete accrual by the end of 2007. Vicinium and Proxinium are Armed Antibodies that target the cancer antigen EpCAM.

"The form of cancer we are treating, Tis bladder cancer, is frequently unresponsive following initial treatment and these patients usually require either partial or complete removal of the bladder to avoid metastasis to other organs," said Dr. Nick Glover, President and CEO of Viventia Biotech. "The goal of Vicinium treatment is to substantially reduce or eliminate the need for surgical resection or removal of the bladder. The potential of Vicinium was demonstrated in our previous trial, where an overall 95% response rate was observed."

The open-label Phase II clinical trial will enroll approximately 30 patients with locally persistent non-invasive Tis bladder cancer. Tis, or carcinoma in-situ of the urothelium, is a high-grade form of bladder cancer that behaves more aggressively than other forms of the disease. Patients with Tis bladder cancer frequently fail to respond to standard non-surgical interventions, such as intravesical BCG or local chemotherapy, often leaving persistent, untreatable tumors throughout the bladder. Surgical removal of the bladder remains the current standard treatment for this unresponsive form of bladder cancer. Vicinium is being tested in this challenging patient population to establish its effectiveness in eradicating persistent Tis, and thus potentially offering an alternative therapeutic option for patients with this tenacious form of disease. Initially, patients will be administered Vicinium weekly using intravesical instillation over a period of six weeks.

After this six week induction treatment phase, patients responsive to therapy may receive up to three additional maintenance cycles of Vicinium scheduled over a total treatment period of 51 weeks.

The primary clinical endpoint will be overall response rate assessed using histology of biopsy samples and urinary cytology.


Vicinium has completed a dose escalation Phase I/II clinical trial in 64 patients with high risk, non-invasive bladder cancer. Dosed on a weekly basis for 6 weeks, Vicinium was very well tolerated at all dose levels, demonstrating a safety profile far more favorable than those of established therapies. Moreover, significant tumor responses were also observed in this study: 42% of patients achieved a complete response, 13% had a partial response, and 40% had stable disease, for an overall response rate of 95%. The early clinical benefit observed with Vicinium strongly supported further clinical development as a therapy for superficial transitional cell carcinoma of the bladder.

Viventia Biotech retains full global product rights to Proxinium and Vicinium. The Company is seeking partners for Proxinium and Vicinium capable of complementing Viventia's development expertise with their global sales, marketing and commercial capabilities.

Bladder cancer is the 5th most common cancer in North America. Approximately 60,000 new cases are diagnosed each year, with an estimated 15,000 deaths attributed to the disease annually. The incidence rate of bladder cancer has risen by more than 35% in the past decade and its prevalence in the U.S. population is at least 400,000 cases. Tis is a particularly aggressive form of the disease.

In Tis, involvement of the urothelium ranges from a small focus to extensive disease throughout the bladder. The risk of progression to muscle invasive disease and subsequent metastases ranges from 40 to 80% with Tis, depending on the extent of disease. Standard treatment is cystectomy. Tis does not respond reliably to the most common forms of local therapy, BCG or chemotherapy. For many patients, Tis bladder cancer persists following initial treatment and they ultimately may require complete or partial removal of the bladder. There are currently limited therapeutic options for patients failing first line therapy for persistent disease.

Viventia Biotech Armed Antibodies are a new class of therapeutic anti-cancer products designed to be safer and more beneficial for cancer patients, based on an approach that leverages the principles of Power and Precision. The Power of these anti-cancer product candidates is derived from the potency of certain extremely active naturally occurring proteins, which are among the most lethal cancer killing agents known. This power is harnessed by engineering the natural proteins so that they retain all of their intrinsic potency, but in a form that is only activated when inside a cancer cell, yielding an exceptionally potent drug that is also far safer than typical chemotherapies.

The Precision of Viventia's product candidates comes from the cancer-targeting properties of monoclonal antibodies, carefully selected for their ability to specifically and preferentially bind to cancer cells. Viventia employs only the component of its engineered human or humanized monoclonal antibodies that is required to recognize and bind to its target on a cancer cell.

Viventia Biotech Inc. is a biopharmaceutical company developing Armed Antibodies, powerful and precise anti-cancer drugs that combine cytotoxic protein payloads with the highly precise tumor-targeting characteristics of monoclonal antibodies to overcome various forms of cancer. Viventia's lead product, Proxinium, is undergoing a global Phase III clinical trial - TARGET - for the treatment of head and neck cancer. Viventia is also developing Vicinium, which is in a Phase II clinical study for the treatment of bladder cancer, and VB6-845, beginning a Phase I/II clinical trial for the treatment of solid tumors. The Company has created a portfolio of follow-on antibody-based drug candidates and has a discovery engine to provide a rich and sustainable long-term pipeline.