Chemophase, our lead oncology product candidate, is an investigative chemoadjuvant designed to enhance the transport of chemotherapeutic agents to tumor tissue, increasing diffusion in tissues without affecting vascular permeability. Many solid tumor types (e.g., colon, breast, prostate) accumulate hyaluronic acid, creating a barrier to the effective penetration of current or future chemotherapeutics. Previous clinical trials of bovine PH20 in patients showed some promise in enhancing chemotherapy regimens using adjunctive systemic hyaluronidase in previously chemo-refractory patients.
Furthermore, we have observed significant reduction of tumor interstitial fluid pressure following the administration of rHuPH20 in solid tumors grown in mice. Tumor interstitial pressure is widely believed to be an important factor limiting the access of cytostatic regimens to solid tumors. By digesting the hyaluronic acid gel, rHuPH20 may reduce interstitial pressure in the tumor and promote more effective delivery of chemotherapy throughout the tumor, as it does under the skin in the case of Hylenex. This could potentially lead to increased patient survival and extended product lifecycles of many commonly used chemotherapeutic agents.
As we continue development of an intravenous formulation of rHuPH20, we hope to realize time and cost savings by leveraging our current manufacturing process and toxicology package to support a clinical program for a local oncology application. As such, during June 2005 we submitted an investigational new drug application (“IND”) in order to begin clinical testing of our Chemophase product candidate in combination with Mitomycin in superficial bladder cancer. We received authorization to initiate clinical testing of Chemophase in August 2005, and we commenced patient enrollment in our initial clinical protocol under this IND in October 2005. In March 2006, we completed enrollment in our Chemophase Phase I clinical trial. In April 2006, we commenced patient enrollment in our Chemophase Phase I/IIa clinical trial. In September 2007, we completed enrollment in our Phase I/IIa clinical trial.
Each year there are approximately 63,000 new cases of urinary bladder cancer in the United States (Source: American Cancer Society, 2005). Approximately 70% of these new cases are “superficial” bladder cancer (Source: AUA Bladder Cancer Guidelines Panel, 1999). There are approximately 500,000 prevalent cases of urinary bladder cancer (Source: NCI SEER Cancer Statistics Review, 2002) in the United States. Approximately 30% of treated patients have a recurrence within 12 months (Source: Southwest Oncology Group Study, 1995).
