A “Trojan Horse” for Cancer

News that a malignant tumor has spread to other parts of the body seems like a death knell to the ears of many cancer patients. But Endocyte Inc. and Purdue University researchers are developing treatment methods that ultimately may cure some cancers, even those that have reached an advanced stage. This potentially momentous development was given early support by Indiana’s 21st Century Research and Development Fund, support that enabled the fledgling company to attract further venture capital backing.

In fact, the Endocyte story encapsulates several important elements of economic development that the 21st Century Fund seeks to encourage throughout Indiana: transfer of a promising new technology from the academic laboratory to a start-up company; ongoing collaboration between university and industry; successful leveraging of the 21st Century Fund grant; and strong potential for commercial success.

Dr. Philip Low, Purdue’s Joseph F. Foster Distinguished Professor of Chemistry and Endocyte’s chief science officer, led the research team that discovered the company’s diagnostic and treatment method. This method uses folate—a form of water-soluble B vitamin—as a “Trojan horse” to target and deliver anticancer agents. Many types of cancer cells have a great affinity for folate because they need the nutrient in order to grow and divide. In fact, cancer cells have evolved a mechanism to capture folate more effectively than normal cells. Making use of this selectivity, researchers developed a way to trick cancer cells into attracting and even ingesting anticancer agents that are attached to folate molecules. As a result, these chemotherapeutic agents can be delivered specifically to cancer cells, leaving the surrounding normal tissue unharmed.

This approach has been applied in various ways by Endocyte researchers, both to diagnose and treat cancer. One treatment method involves forcing the body’s immune system to fight the disease. As Dr. Christopher Leamon, Endocyte’s vice president of research, points out: “There’s no better drug than your own immune system, but, unfortunately, many cancers develop ways to evade immune surveillance. We’ve found a way to redirect a patient’s immune system to kill those resistant cancer cells by using our folate-targeted approach.”

This method was recently used by a joint Purdue-Endocyte research team to successfully treat more than 200 mice with late-stage metastatic cancer. The mice, which would normally have been dead within 21 days, lived well beyond 120 days, a point at which they were considered to be cured. This innovative treatment will soon be tested in Phase I Food and Drug Administration-regulated human clinical trials. If human trials prove successful, the first to benefit will be the many thousands of cancer patients who may be given hope where there is none now. Other benefits from the commercialization of Endocyte’s folate-targeted approach would be creation of high-tech jobs, a boost to the Indiana economy and further strengthening of the state’s university-industry partnership.