Jefferson Medical College researchers are getting some positive results in early testing of an ovarian cancer vaccine made from a patient's own cancer cells.
In early results of a Phase I-II trial of patients with advanced ovarian cancer, eight of 10 patients have had some immunological response to the vaccine. One patient has had a clear anti-tumor response, meaning her tumor actually disappeared. In addition, an important blood serum tumor marker, CA125, became normal, an indication that the disease was lessening. Three other patients have had decreased CA125 levels, but doctors have been unable as yet to confirm their tumors are actually shrinking.
"We're getting some immunological results, and now it looks like we're starting to have some clinical results," says David Berd, M.D., professor of medicine at Jefferson Medical College of Thomas Jefferson University in Philadelphia and a member of Jefferson's Kimmel Cancer Center, who along with Charles J. Dunton, M.D., associate professor of obstetrics and gynecology at Jefferson Medical College, leads the project.
Dr. Berd reports his team's results May 21 at the American Society of Clinical Oncology meeting in New Orleans.
The patients Dr. Berd has studied to date have had cancer that didn't respond to chemotherapy, making them among the sickest with the disease. Each patient's ovarian cancer was not helped by treatment with standard chemotherapy drugs, platinum and taxol, and at least one second-line treatment.
The vaccine was given in six weekly injections. Despite their advanced disease and poor response to chemotherapy, eight of 10 patients developed delayed-type hypersensitivity, indicating the vaccine has at least caught the immune system's attention.
According to Dr. Berd, AVAX Technologies, Inc., of Kansas City, MO, AVAX Technologies, Inc., of Kansas City, MO - which has exclusive rights to the Jefferson-based vaccine - is planning to sponsor another Phase II trial and possibly two Phase III randomized studies at several sites.
"The idea is to target various stages of ovarian cancer from patients who just get their chemotherapy to people who have relapsed disease to people with advanced disease in a systematic way with a large number of patients," he explains. Dr. Berd plans to expand the current study to 20 patients. "I think we will see some more therapeutic results," he says. "The trials we've done are on extremely sick patients. These new trials will be on those who are less sick, so we think results will be better. The question is, how much of a result do we need to tell if we have something important?"
He and his co-workers plan to measure how much the patient's tumor shrinks after receiving the vaccine, and among other things, levels of CA125 in patients with no evidence of measurable tumor but whose CA125 had risen, which portends recurrence.
Nearly 80 percent of ovarian cancer patients have advanced disease, which is extremely difficult to treat. The standard treatment is surgery and chemotherapy; 75 percent of patients will get a complete remission for six months to a year and a half, but only about 15 to 20 percent are cured. The National Cancer Institute estimates approximately 27,000 women in the country will be diagnosed with ovarian cancer this year; some 14,000 will die of it. Dr. Berd created the vaccine technology. The current vaccine is custom made, prepared from a patient's own cancer cells. Before injecting the cells into patients, the cells are inactivated and modified with a chemical, dinitrophenyl. The modified cells apparently appear foreign to the body's immune system, causing a reaction against them.
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Editors: This information is embargoed for release May 21 at 8 a.m. EST at the American Society of Clinical Oncology meeting in New Orleans