Experimental Ovarian Cancer Vaccine Shows Promise
Researchers say one patient in long-term remission after novel treatment
By Randy Dotinga
SATURDAY, April 6 (HealthDay News) -- A novel but preliminary new treatment for ovarian cancer has apparently produced complete remission for one patient with an advanced form of the disease, researchers are reporting.
The promising results of a phase 1 clinical trial for the immunotherapy approach also showed that seven other women had no measurable disease at the end of the trial, the researchers added.
Their results are scheduled to be presented Saturday at the American Association for Cancer Research's annual meeting in Washington, D.C.
Ovarian cancer is fairly rare -- an estimated 1.38 percent of females born today will be diagnosed with the condition -- but it's an especially deadly form of cancer because it is usually diagnosed in an advanced stage.
The new treatment uses a personalized vaccine to try to teach the body's immune system how to fight off tumors.
Researchers took bits of tumor and blood from women with stage 3 or 4 ovarian cancer and created individualized vaccines, said study lead author Lana Kandalaft, director of clinical development and operations at the Ovarian Cancer Research Center in the University of Pennsylvania's Perelman School of Medicine.
"Each patient's tumor is unique like a fingerprint," she added. "We're trying to rewire the immune system to target the tumor."
Once the immune system has learned how to more effectively fight the cancer, the researchers isolate immune cells called dendritic cells, coax them to multiply, then put them back into the body to strengthen it.
The research is only in the first of three stages that are required before drugs can be sold in the United States. The first-phase studies aren't designed to determine if the drugs actually work, but are instead supposed to analyze whether they're safe.
This study, funded in part by the U.S. National Institutes of Health, found signs of improvement in 19 out of 31 patients. All 19 developed an anti-tumor immune response. Of those, eight had no measurable disease and are on maintenance vaccine therapy. And one of the eight, whose cancer recurred several times, has been in remission for 45 months, the study authors said.
The researchers added a further step for 11 patients who responded to the vaccine treatment but still had residual disease. They removed immune cells called T cells from patients' blood, stimulated and expanded the cells in the laboratory, and then reinjected them into the patients. Of the 11 patients, seven had stable disease and one had a complete response, the investigators found.
Both treatments were given in conjunction with bevacizumab, a drug that controls blood vessel growth.
Side effects were mild, Kandalaft said. As for cost, she believes that it will be cheaper than some existing cancer drugs that cost $75,000 to $100,000 for a regimen.