Most cancer vaccines are intended to rally a patient’s immune system to fight cancers that have already progressed. But the startup company OncoPep, based in North Andover, Massachusetts, is developing a vaccine designed to prevent one kind of cancer—multiple myeloma—by treating patients who have only a precursor of the disease.
Multiple myeloma is a cancer of blood plasma cells. It develops when abnormal plasma cells in bone marrow multiply and accumulate, eventually damaging bones and other tissues in the body, and finally overwhelming the immune system. Currently, treatments can extend the lives of patients with the cancer but not cure it.
The company’s approach grew out of research by Kenneth Anderson, Nikhil Munshi, and Jooen Bae at the Dana-Farber Cancer Institute in Boston. The researchers deployed a combination of peptides—small pieces of protein—that are known to be specific to multiple myeloma cells and are important for their survival. The goal is to train the immune system to recognize and attack cancer cells bearing these peptides; the vaccine would also contain substances designed to boost immune response.
Plans call for the vaccine to be administered to people diagnosed with smoldering multiple myeloma, a condition in which plasma cells are unusually abundant and produce abnormal proteins but cause no symptoms of disease. Currently, patients with SMM are not treated. Although a majority of them go on to develop symptomatic cancer, it may take many years. Anderson hopes that the ability to detect the cancer in this early phase will make possible early, effective intervention. “The idea would be to prevent the development of an active cancer,” he says. Administering the vaccine to patients before they have received other, possibly debilitating cancer treatments, and while their immune systems are healthy, may give it a better chance of working.
Doris Peterkin, CEO of OncoPep, says that like several other experimental cancer vaccines in development, this one will be matched to people with a particular immune-system type: HLA type A2, the most common type in the U.S. Peterkin says the vaccine is most likely to be effective in these patients because the peptides are have a better chance of triggering an immune response in them.
Ronald Levy, an oncologist and cancer researcher at Stanford University, says that despite the advantages of vaccinating early, targeting this early stage of the disease may pose practical problems in testing the vaccine. Although nearly 80 percent of patients with SMM go on to develop multiple myeloma, they do so at a rate of only about 10 percent per year—so it may take a while to collect enough patients to test the vaccine. And limiting the vaccine to people with a particular HLA type will narrow the already small field. Levy says that the ultimate test of the vaccine’s success will be how well its chosen peptides provoke a specific immune response against the cancer, which has been the challenge for all peptide-based cancer vaccines.