Emens is also trying different drugs a week after the vaccine is given to see what effects they might have on immune system response. The women in Emens' first trial received a chemotherapy drug called doxorubicin. The women in Emens' second trial - which has enrolled 14 and is looking for six more patients with HER-2 positive breast cancer, a particularly aggressive type - receive a drug called Herceptin, which Emens calls one of the great recent advances in treating breast cancer.
The timing of when the various drugs are given during the trials came out of mouse models. When mice got the same treatment as the women in the first trial, about 30 percent were cured of their tumors.
When they got what Emens is giving the patients in the second trial, between 55 percent and 60 percent of the mice were cured. Finding the right combination of medications to give to improve the efficacy of the vaccine could be a key to its success.
"Folks have a tendency to add a vaccine to standard treatments without really considering how they might interact," Emens said.
Whether the vaccine is working can be measured in a variety of ways. Emens looks in the blood for antibodies and T-cells. She also looks at scratch tests done with a protein in the vaccine that would show a systemic response. If the area around the test gets red and swollen, there has been an immune reaction. The doctor
Dr. Leisha Emens, 46, an oncologist and researcher at Johns Hopkins University, where she has worked for nearly a decade. She is the principal investigator on two small clinical trials of an experimental breast cancer vaccine she developed.
The patients
Annie Siple, 43, near Orlando, Fla. Entered Emens' second trial after her breast cancer spread to her liver and received her first shots in February. She lives with her husband and younger son and works as a waitress at a Disney World restaurant. The vaccine, to her, is as close to alternative medicine as she could find. She chose it to avoid what she considers the "poison" of chemotherapy.
Peggy Murphy, 57, near Lancaster, Pa. Entered Emens' first trial in October 2007. She complained of pain in her hip for years before doctors finally diagnosed it as a recurrence of the breast cancer she thought she had kicked. Her disease appears to be spreading. She lives with her daughter and grandchildren.
