Researchers have announced that in initial tests, a multiple myeloma vaccine protected some mice from developing cancer and helped those with established tumors to enter remission.

In the current study, researchers constructed an anti-myeloma vaccine by isolating proteins from myeloma tumor cells. After inoculation, the vaccine prompts antibodies to develop against myeloma proteins, which in turn causes the immune system to view myeloma cells as “foreign” and destroy them. This form of cancer treatment, known as “immunotherapy,” provides an alternative or additional option to chemotherapy.

The study authors first vaccinated healthy mice with varying strains of myeloma proteins, and two weeks later, they injected the mice with a specific strain of myeloma tumor cell. While all of the mice who received the placebo vaccination developed full-blown myeloma, only 10 percent of those vaccinated against this particular myeloma strain developed cancer. Mice vaccinated against other myeloma strains exhibited some cross-protection.

The vaccinated mice also demonstrated long-lasting protection, as they failed to develop myeloma when the study authors re-injected them with tumor cells weeks later. These results suggest that the immune system remains primed to attack tumor cells long after the point of vaccination, thereby possibly protecting against myeloma recurrence.

Likewise, in mice with established multiple myeloma, vaccination helped to reduce tumor burden, though it showed better results in the mice that were vaccinated while still healthy. When researchers vaccinated mice with myeloma, half of the mice entered remission. If the researchers added an immune boosting molecule to the vaccination, though, the myeloma disappeared in all of the mice.

However, in mice with large tumor burdens, which most closely approximate humans with multiple myeloma, vaccination was less successful. Myeloma directly interferes with and suppresses immune system function, and vaccination requires a robust immune response in order to provide protection. Researchers hypothesize that treating patients with established myeloma via vaccination will require the identification of compounds capable of improving immune system function, particularly at the tumor sites.

The current vaccine study is a significant milestone in the fight against myeloma, but it also holds important implications for overall cancer vaccine research. Significantly, researchers derived the current vaccine from general myeloma cell lines, rather than individually tailoring the vaccine to each mouse. Previously, most immunotherapy attempts required developing a personal vaccine by isolating and culturing an individual patient’s tumor cells.

By enabling creation of a universal myeloma vaccine, this novel method could help overcome many of the financial and pragmatic hurdles that are currently hindering large-scale cancer vaccine trials in humans. Developing tailored vaccines is not only exceedingly expensive, but it is also a lengthy and exacting process that is not always successful. A general vaccine could make it financially and practically feasible to undertake larger studies, and evidence suggests that these vaccines provide better broad-spectrum protection against recurrences and development of other cancers.

“[O]ur study suggests that pooled [protein] from established tumor cell lines can be used as universal tumor vaccines for immunotherapy of patients with the same type of cancers,” the study authors explained. “As established tumor cell lines are available to many if not most human cancers…this novel approach is feasible and applicable to human cancer treatments.”

For more information, please see the article (abstract) in the journal Blood ^[1].