Personalized Cancer Vaccine Improves Disease Free Survival
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The search for effective anti-cancer therapies increasingly leads medical scientists to immune-based agents like anti-vaccines, or a “personalized” approach based on a patient’s unique disease status. A new study reported by Tampa-based Accentia Biopharmaceuticals, achieves promising treatment objectives by exploiting both therapeutic approaches simultaneously.
Results from an ongoing clinical trial suggest that patients with non-Hodgkins lymphoma (NHL), a cancer of the lymphatic system, can benefit from treatment with a novel anti-cancer vaccine based on the patient’s specific tumor. The study results, published September 20 in the prestigious Journal of the National Cancer Institute, demonstrated that administration of the BiovaxID™ anti-cancer vaccine formulation resulted in long-lasting remission in NHL patients.
The BiovaxID vaccine is under investigation at Accentia’s subsidiary, Biovest International, Inc., (based in Worchester, MA). This independent study was lead by Dr. Susana Inoges and her colleagues at the University of Navarra. located in Pamplona, Spain.
Among its functions, the lymphatic system holds disease-fighting white blood cells. In lymphoma, specialized white blood cells known as lymphocytes, begin to grow out of control. Eventually, they spread to the lymph nodes and other parts of the body, forming solid tumors. Approximately 57,000 Americans will be diagnosed with NHL in 2006, with about 25,000 deaths. Like many cancers, NHL is usually not diagnosed before it has spread, at which point a cure is unlikely.
Traditionally, treatment for NHL involves standard anti-cancer chemotherapy drugs, combination therapies, and lately newer agents such as Biogen Idec’s Rituxan™. Patients undergoing these therapies often go into remission, meaning their tumors shrink or disappear and the patient can resume a more or less normal life. Tumors grow back again in most cases, usually more virulent than ever, necessitating additional rounds of chemotherapy. In most cases the remissions become shorter with every round of treatment, until the therapy stops working.
In the study, patients whose NHL had relapsed after conventional chemotherapy with or without Rituxan study received the BiovaxID™ cancer vaccine after another round of chemotherapy. In her paper, Dr. Inoges reported that the remission period induced by BiovaxID treatment was significantly longer than the remission following initial treatment.
BiovaxID induced a cancer-fighting immune response in 80% of patients treated. Among these, the median time for tumor remission has not yet been reached, 33 months after the treatment. The initial remissions averaged about 17 months in duration. In an accompanying editorial, Dr. Dan Longo of the National Institutes of Health, characterized the results as “remarkable,” suggesting that this work could lead to a cure for NHL, which is generally considered incurable.
Patients who mounted the immune response, known as “immunologic responders,” fared much better than those who did not respond. All five of the non-responding patients enjoyed remissions, but these were shorter than their first chemotherapy-induced remission, and at this time all have relapsed. In his opinion piece Dr. Longo noted that long second remissions are quite uncommon among NHL patients, “even after high-dose therapy and autologous hematopoietic stem cell transplant.”
Most people are familiar with vaccines that prevent disease by inducing an immune response against infectious diseases, for example influenza and hepatitis. Cancer vaccines work differently because they generally are used to treat cancer, not prevent it. The BiovaxID vaccine is a special type of anti- cancer vaccine, known as an “anti-idiotype” vaccine, meaning that the vaccine components responsible for generating the immune response are derived from the patient’s own tumor. These components, called antigens, closely resemble chemical structures that appear on the outside of the patient’s cancer cells. If the body’s immune system primes itself to recognize and attack the vaccine antigens, it will likely also act against the cancer cells. This was the observation made in the Navarra University study. Researchers believe that once an immune response is achieved, their vaccine might be even more effective if delivered through an initial dose plus a series of “booster” injections.
Antigens used to make the Biovaxid anti-cancer vaccine are produced for each patient by growing the structures within specialized cells outside the body, in culture. Because their manufacture is derived from patient-specific tissues, idiotype vaccines cannot be mass-produced. Fortunately, parent firm Biovest has developed an automated cell culture system, the AutovaxID™, which promises to greatly facilitates and speeds up production of individualized cancer vaccines and other cell-based materials and therapeutics by automating the process.
AutovaxID produces therapeutically relevant quantities of antigens, vaccines, proteins, and other bioproducts by “growing” the products inside production-worthy cells. Compared with older methods that involve manipulation of many cell culture vessels spread out across a laboratory, the AutovaxID method is self-contained and thereby eliminates the potential for cross-contamination among products for different patients.
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