Current testing of immunotherapy approaches against cancer involves patients in whom standard therapies have failed. “That really puts us at a great disadvantage because a lot of the standard therapies are immunosuppressive, as is the tumor itself as it grows,” Olivera Finn, PhD, said at a press conference on immunotherapy at the American Association for Cancer Research Annual Meeting. “But many of us have run clinical trials of immunotherapy in advanced-stage cancer, and everything that we know about the immunosuppressive tumor microenvironment has been derived from those trials.”
Cellular and molecular analyses to find out why patients don’t respond have revealed information about T-regulatory and T-suppressor cells. “We can now give you a perfect picture of the tumor microenvironment because we discovered it by looking at the failures of our late-stage disease immunotherapy trials,” Dr. Finn stated.
At least some of the immunosuppressive factors that compromise success in treating advanced disease may not exist in early-stage disease. “We are working on this,” Dr. Finn said, and if this work can be integrated with work of other scientists looking for biomarkers of disease and indicators of risk for recurrence, then vaccines or other immunotherapy approaches could be applied earlier or used to prevent disease. “We think the successes are going to be much greater,” Dr. Finn said. ■
Immunotherapeutic approaches, including vaccines, a monoclonal antibody, and a combination of low-dose interleukin (IL)-2 (Proleukin) and retinoic acid, are showing some success in clinical trials investigating the prevention of breast cancer recurrence in women at high risk, the treatment of...