“This is the beginning of a long but exciting process,?says Angela Dispenzieri, M.D., hematologist and lead researcher on the multiple myeloma clinical trial in the measles virus investigation. “We are very hopeful that this will be a step toward helping our patients.?
Mayo Clinic Cancer Center is the only institution in the world currently pursuing using engineered measles viruses for cancer treatment. It has shepherded the research from basic laboratory science to therapies being tested today in several tumor types, including glioblastoma multiforme (a brain tumor), recurrent ovarian cancer and now multiple myeloma.
The measles viruses being used for these studies were constructed by inserting additional genes into the measles vaccine strain.
Many cancers, including multiple myeloma, overexpress a protein, CD46, which allows them to evade destruction by the immune system. Laboratory strains of measles virus seek out this protein and use it as a receptor by which to enter the cancer cells. Upon entry, the virus spreads, infecting nearby tumor cells and fusing them together, increasing cancer cell death.
This study differs from the other two open clinical trials because researchers are administering the measles virus strain intravenously, rather than directly to the tumor site. For multiple myeloma, the researchers are using a strain of measles virus which was engineered to carry an additional gene that codes for the sodium iodide symporter (NIS) protein.
NIS is produced by the thyroid where it attracts and concentrates iodine. This characteristic of the NIS protein can be exploited as a target in cancer the