Helix BioPharma awarded U.S. patent for adjunct chemotherapy applications

Helix BioPharma Corp. has announced the issuance of its second DOS47 patent (U.S. Patent # 7,264,800) from the United States Patent & Trademark Office, describing a method and composition for combining targeted DOS47 therapeutics with weakly basic chemotherapeutic drugs in adjunct treatment applications.

"This patent offers a significant extension to Helix's DOS47 intellectual property position, opening up the possibility for expanded commercial opportunities," said Dr. Donald H. Segal, President and CEO of Helix. "We believe there is significant market potential to combine DOS47-based therapeutics with certain chemotherapeutic drugs in so-called adjunct regimens because DOS47 therapy is designed to counteract tumor acidity. Tumor acidity is a property that otherwise makes it difficult for weakly basic chemotherapeutics to penetrate cancer cells and function effectively."

With the granting of this second DOS47 patent, Helix now has patent protection covering the use of targeted DOS47-based therapeutics alone and in certain combined chemotherapy applications. Moving forward, the Company intends to pursue the development of DOS47 therapies for both applications, with a view to maximizing its DOS47 commercialization potential.

At present, Helix is focused on the development of its first DOS47-based cancer therapeutic ("L-DOS47") which specifically targets lung adenocarcinoma. Helix has previously presented scientific findings which demonstrated the ability of L-DOS47 to destroy lung cancer cells alone and synergistically with selected chemotherapeutic compounds. Helix continues to advance its manufacturing and preclinical development programs with a view to phase I human clinical testing. With this newly issued patent, the Company is well-positioned to potentially broaden its late stage clinical development program to include both monotherapy and combined chemotherapy applications for L-DOS47.

L-DOS47 combines Helix's proprietary DOS47 new drug candidate with a highly specific single domain antibody, to form a potential new targeted drug product for the treatment of adenocarcinoma of the lung, the most common form of cancer in the world today. L-DOS47 is thought to function by leveraging a natural process in the body called the urea cycle, to produce an anti-cancer effect. It is based upon a naturally occurring enzyme called urease that essentially reverses the urea cycle by breaking down urea into metabolites that include ammonia and hydroxyl ions. By doing so at the site of cancerous tissues in the body, L-DOS47 is believed to modify the microenvironmental conditions of lung cancer cells in a manner that leads to their death. Among these theorized effects, L-DOS47 is believed to stimulate an increase in the pH of the microenvironment surrounding the cancerous cells, effectively reversing the acidic extra-cellular conditions that are known to be necessary for cancer cell survival. As well, the local production of ammonia at the site of cancerous tissues is thought to readily diffuse into the cancer cells to exert a potent cytotoxic effect by interfering with their critical metabolic functions. By inducing an alkalizing effect locally at the tumor site, L-DOS47 and other targeted DOS47-based cancer therapeutics may also promote enhanced cancer cell uptake of weakly basic chemotherapeutic compounds for more efficient and effective chemotherapeutic action.