A lymphoma vaccine uniquely made for each patient extended time in remission during a Phase III clinical trial, scientists reported today at the 2009 annual meeting of the American Society of Clinical Oncology in
"This is the first vaccine in lymphoma that's shown a positive result, improving time to relapse," said Sattva Neelapu, M.D., assistant professor in M. D. Anderson's Department of Lymphoma and Myeloma.He is also principal investigator for M. D. Anderson's portion of the multicenter clinical trial. The vaccine, derived from a patient's cancer cells, sparks an immune system response against the disease.
A likely key to success, Neelapu noted, is that only patients in complete remission or with minimal residual disease after chemotherapy were vaccinated. Two other recent Phase III vaccine trials that vaccinated patients who were in partial remission or with stable disease were negative.
"With lymphoma, you can get patients to a minimal disease state with chemotherapy and then bring in the vaccine to mop up remaining cancer cells. That's the strategy, and it should work for other cancers," said Larry Kwak, M.D., Ph.D., who invented the vaccine while at the National Cancer Institute and now chairs M. D. Anderson's Department of Lymphoma and Myeloma.
The 234 patients enrolled in the trial were first treated with a chemotherapy combination known as PACE. The 117 patients who were in complete remission or had a complete response (unconfirmed) for at least six months then received either the vaccine or a placebo. Median time to relapse for the 76 vaccinated patients was 44.2 months, compared with 30.6 months for the 41 who received placebo. Follicular lymphoma is a slow-growing type of non-Hodgkin lymphoma.
"Immunology shows us that there's a weak immune response at the onset of cancer but it's somehow shut down very early," Kwak said. "The next generation of vaccines probably will be combined with therapy that interferes with mechanisms that shut off immune response."
The crucial component of Kwak's vaccine is a receptor protein extracted from the patient's malignant B cell lymphocytes and purified in large amounts. The protein is combined with a delivery agent and an adjuvant growth factor and the whole cocktail is injected back into the patient. "It's the ultimate in personalized therapy," Kwak said. "Even if two patients have the same type of lymphoma, their tumors will still have different proteins."
The NCI advanced the vaccine by sponsoring its first randomized phase III clinical trial, Kwak said, with the intention of handing the trial off to a corporate partner. BioVest International subsequently prevailed in a competitive process to collaborate with the NCI and took over the trial as planned in 2004. BioVest is developing the vaccine under the brand name BioVaxID™.