Unfortunately, these results are rarely lasting. Most patients treated with the vaccine eventually die as their disease resumes its progress.
Since blocking CTLA-4 could bolster the immune response spurred by the vaccine, researchers studied whether combining GVAX vaccines with monoclonal antibody therapy could lengthen remissions and quell the inflammatory problems associated with antibody therapy alone.
"Using a vaccine to provoke a stronger immune response to cancer may enable us to use lower levels of CTLA-4 blockers, which could reduce the severity of their side effects," Hodi explained.
The new study tested the combination on 11 melanoma patients. They were infused with a CTLA-4-blocking antibody one to four months after receiving GVAX, and every two to three months thereafter, as needed.
In contrast to previous, more intensive antibody doses, none of the patients had severe side effects, although they all developed mild, low-level inflammatory conditions (usually a rash that went away in a few days). Moreover, in eight participants, tumors throughout the body either receded or became stable. The three other patients experienced less dramatic improvements that became apparent after several months of therapy.
Similarly encouraging results were obtained in nine patients with advanced ovarian cancer, although two of them did develop severe inflammatory problems. Although large die-offs of tumor tissue were less common than in the melanoma group, some of the ovarian cancer patients did experience such results.
More information
The National Cancer Institute has more about cancer vaccines.
