Treating Lymphoma: Will a Customized Vaccine Work?
Posted Aug 24 2008 1:49pm
ANNOUNCER: Non-Hodgkin's Lymphoma is the sixth most common cause of death from cancer. It's a disease where certain cells in the immune system grow uncontrolled.
JOHN LEONARD, MD: The cells of the immune system typically have a job to do to fight infections. And in lymphoma the switches that regulate the cell's growth are broken, and the cells accumulate. They may make a lump or they may involve or infiltrate one of the organs and cause a problem that leads to the diagnosis of lymphoma.
RONALD LEVY, MD: Among the different kinds of non-Hodgkin's lymphoma we have two major kinds, which is what we call low-grade lymphoma and high-grade lymphoma. And the low-grade lymphoma major type is follicular lymphoma.
ANNOUNCER: The low-grade or indolent NHL is a slower form of the disease. IRONALDically it's the one that can create the most difficult challenge.
RONALD LEVY, MD: The traditional treatments for follicular, low-grade lymphomas are mostly chemotherapy treatments. Many of the treatments that we have slow it down even further and keep it under control, but none of them at the moment seem to cure the condition - make it go away forever and never come back - Whereas high-grade lymphomas many of the patients actually do get cured - permanently cured - with the treatments we currently have.
For all people diagnosed with follicular lymphoma, on the average, their survival is ten to twelve years from the time that they're diagnosed
ANNOUNCER: But the outlook for follicular NHL could be changing. A new therapy being developed uses the patient's own cancer cells to create a vaccine which instructs the patient's own immune system to fight the cancer. The very nature of NHL, a b-cell lymphoma, makes this idea work
JOHN LEONARD, MD: B cell lymphomas, as they develop put on the surface of the cell something called the idiotype, and the idiotype is a molecule that is on the tumor cells. Each B-cell as it develops, wears a hat in its surface. In lymphoma, all of the B-cells come from one parent B-cell, and they all have the same hat. So it's along the lines of, all of the bad B-cells have a black hat, whereas the normal B-cells have all different-colored hats. So essentially what we're doing is to try to train the immune system to fight the black hat wherever it is. The only cells that have the black hat are the bad cells, the bad guys. So the concept is basically that we're vaccinating the patient with the black hat.
RONALD LEVY, MD: Up until now, the immunotherapy that we've been using is based on antibodies. So we can make these antibodies in the test tube and then give the antibodies to the person. And these antibodies then find the target and bind to it and eliminate it. So this is what we call "passive" immunotherapy. It's made somewhere else, it goes into the person, it works, and then it goes away.
And that's to be contrasted with active immunotherapy, where we teach the person's own immune system to make their own antibodies.
ANNOUNCER: In active immunotherapy, a vaccine is created specifically for that patients from their own tumors.
JOHN LEONARD, MD: We're trying to take a portion of the tumor and to train the patient's immune system to fight that portion of the tumor so that basically we're teaching the patient's immune system to fight the tumor on its own.
ANNOUNCER: To create the vaccine, a simple biopsy is taken.
JOHN LEONARD, MD: The biopsy has to be taken in order to make the idiotype or the black hat. That usually involves a small surgical procedure. The cells are taken and they are sent to a laboratory that basically allows for the preparation of the vaccine.
ANNOUNCER: Each idiotype vaccine is "personalized", custom made for one, and only one, patient.
JOHN LEONARD: This vaccine is something that is special and unique for each patient. Basically each patient's lymphoma is unique and different from every other patient. So it's not like a flu shot, that the same vaccine is used for everybody.
ANNOUNCER: Currently the vaccine is being used in partnership with standard chemotherapy.
JOHN LEONARD: The situation has generally been that patients have received a treatment, usually chemotherapy, to get their disease into remission. Then they have a rest period to allow the immune system to recover, and then they start the vaccines. So the goal of the vaccine is usually to try to keep the disease in remission longer.
ANNOUNCER: These vaccines are given through injection every four weeks for either five or seven injections. Side effects from the vaccine are minimal.
JOHN LEONARD: This approach is something that is relatively less toxic than, say, chemotherapy. Patients don't lose their hair. They don't get nausea.
RONALD LEVY, MD: People get a little soreness at the place that they get the injection under the skin, and that's about it.
ANNOUNCER: Another big plus for this vaccine will be that its' power could conceivably keep working forever.
RONALD LEVY, MD: The immune system has memory. It remembers what happened in the past. So when you get a polio shot, your immune system remembers that, and if you ever get infected by polio, the immune system remembers that vaccine and makes a quick immune response against it.
So that's what we hope is going to happen with the vaccine against cancer. That the immune system will keep remembering that it was taught to fight the cancer and it will keep fighting it forever.
ANNOUNCER: At present, several late-stage, pre-approval Phase III patient trials are underway. Two large trials are looking at idiotype vaccine in combination with chemotherapy. Earlier stage Phase II trials will combine passive and active immunotherapy.
While the jury is still out, hopes are high.
JOHN LEONARD: So far, the studies that have been performed have suggested that patients treated in this fashion tend to do better than patients who have received similar chemotherapy without the vaccination afterwards.
ANNOUNCER: Experts are quietly optimistic that, with more research, some day, NHL might be just one of the cancers that can be fought with a simple shot.
RONALD LEVY, MD: If we learn how to make a vaccine from an idiotype for a lymphoma, the way of delivering it-- these ways will be usable for other kinds of vaccines for other kinds of cancer.
ANNOUNCER: For more information on the Clinical Trials of Idiotype Vaccine in Non-Hodgkin's Lymphoma, visit the Lymphoma Research Foundation website at www.lymphoma.org.