Researchers from the University of Texas MD Anderson Cancer Center, the Houston Methodist Cancer Center and the University of Alabama at Birmingham have demonstrated a new type of immunotherapy that may provide more effective late-stage treatments for lethal cancers such as the ones affecting the ovaries and pancreas.
The researchers developed a monoclonal antibody 130A to block the action of a protein secreted by the cells surrounding and supporting tumours in ovarian and pancreatic cancers, called MFAP5. This protein is found at high levels in patients with both these cancers and associated with decreased survival rates.
“We found that blocking MFAP5 enhances the effectiveness of chemotherapy treatments and suppresses tumour growth in ovarian and pancreatic cancers, as well as inhibits progression of these two cancers in mice,” says co-author Stephen T.C. Wong, Professor of bioengineering in oncology at the Houston Methodist Research Institute.
“This new immunotherapy drug targets supporting cells surrounding a tumour rather than just the tumour cells alone. This tumour microenvironment contains newly developed blood vessels and fibrous connective tissue—created through the processes of angiogenesis and fibrosis—that feed and support the tumour.”he said
The MFAP5 protein has been shown to trigger the formation of these surrounding elements that supply and stimulate the tumour, influencing how it grows and spreads. Blocking it prevents new blood vessels and excess tissue from forming within the microenvironment, thereby cutting off the tumour’s blood supply and support.
“MFAP5 promotes fibrosis in ovarian and pancreatic cancers, and fibrosis promotes progression, chemoresistance, and reduces survival of people with these cancers. By blocking this secretory protein with an antibody, we can treat the tumour by targeting multiple cellular types—fibroblasts and blood vessels—in the tumour microenvironment,.”explains Samuel C. Mok, Professor of Gynaecologic Oncology and Reproductive Medicine at MD Anderson.
The study was published online on July 22 in the journal Clinical Cancer Research.