Newswise — CLEVELAND, Ohio — Many solid tumors, including many cancers of the pancreas, breast, colon and lung, protect themselves with a dense wall of scar-like tissue. That wall keeps the immune system’s cancer killing T cells out. It is a major reason why immunotherapy drugs, which have transformed treatment for some patients, help only a minority of people with solid tumors.

A study published today in Cancer Cell describes an experimental drug that breaks down this barrier from inside the tumor and lets T cells in to attack. In mice, the drug cleared aggressive pancreatic tumors, stopped breast cancer from spreading, and left the animals with long-lasting immune memory. That memory protected against new tumors, including some different types of cancer.

The international study was led by Dr. Seong-Jin Kim and his team of scientists at MedPacto, Inc., in Seoul, Korea. Co-author John J. Letterio, MD, PhD, is Director of the Angie Fowler Adolescent and Young Adult Cancer Institute at University Hospitals Rainbow Babies & Children’s Hospital and Director of the Developmental Therapeutics Program at Case Comprehensive Cancer Center, Case Western Reserve University.