Burgeoning science of cancer vaccine reaches University

By Janine Kranz

Scientists at the University Hosptials are currently researching a new form of cancer treatment that boosts a patient’s immune system. combating the deadly disease with relatively little damage to the recipient.

Although there is currently no easy cure for most types of cancers, doctors and researchers at the University of Chicago’s Department of Pathology and Medicine, Section of Hematology/Oncology, are experimenting in the developing field of cancer vaccines with encouraging rates of success.

Unlike most vaccines, which a patient receives as a precautionary measure before becoming ill, these new vaccines are designed to cure people already at advanced stages of the disease.

A person develops cancer when the T-cells in their immune system fail to destroy tumor cells. This can happen for three reasons: the T-cell is unable to penetrate the tumor, the T-cell penetrates the tumor and is killed, or the T-cell fails to respond to the tumor.

Cancer vaccines are designed to help patients’ immune systems create T-cells that can recognize specific antigens in the tumor cells. In turn, these antigens destroy the cancerous cells.

Professor Thomas Gajewski, program leader of the immunology and cancer program at the University’s Cancer Research Center, said that their research examines both the immune system and the tumors themselves, a twofold strategy aimed at discovering the reason that some T-cells are ineffective against tumors and find new ways to make them more effective.

Vaccine research has been an emerging field for the past several years, but the area has recently received popular attention from a promising drug that has had high success treating breast cancer patients. Studies from this and other cancer treatments were presented recently at an American College of Surgeons meeting in Chicago, according to CNN.com.

Besides surgery, the most common treatment of cancer is chemotherapy and radiation therapy—a process in which chemicals or radiation, respectively, are used to kill the cancer cells.  However, these treatments also kill healthy cells and induce painful physical side effects.

The new vaccines, if successful, would use the patient’s own immune system to build T-cells, killing only the cancerous cells. Unlike chemotherapy, there would be almost no physical side effects.

Past studies involving vaccines required much more time, as the T-cells had to first be produced in the lab and were then returned to the patient.

Although several studies have been completed, one of the most recent ones involves a vaccine for melanoma, a form of skin cancer skin cancer. The study focused on twenty patients that all had advanced metastatic melanoma, meaning that the cancer had spread from its original site.

The patients had an average life expectancy of six to nine months.  Each was given vaccine injections once every three weeks for three cycles.  Of the twenty patients, two had their tumors completely disappear, five others had some of their tumors decrease in size, and the other thirteen patients’ cancer continued to develop.

The median survival period of the patients in this study was 12.25 months.

Gajewski said that even though many studies have already been completed, his team still has much more work to do before they create a drug that would be available on the open market.

“Everything we’ve done is in the experimental stage,” he said. “There is a lot of research that needs to be completed.”

This study focused on melanoma because researchers know more about the immune system’s response to melanoma than its response to other cancers.  The University is also currently performing studies of vaccines for prostate cancer, leukemia, and colon cancer, while additional trials for kidney cancer and pancreatic cancer will begin in the coming months.

While the University performed this study independently, it has also participated in collaborative studies in the past.

Last year, the University participated in a nationwide, multi-center clinical trial to test vaccines on patients with lymphoma. The University is also starting a national clinical study of vaccines for colon cancer.

In addition to vaccines, the University is exploring other treatments, such as monoclonal antibodies and stem cell transplantation.

“There are many projects right now,” Gajewski said. “People need to know that academic research is being done in oncology and immunology to find new ways to fight cancer.”