The term “immunotherapy” covers a wide variety of treatments that use the natural defensive abilities of the human immune system to fight diseases. Cancer is capable of hiding from the immune system and even using it to support tumor growth. The goal of immunotherapy is to wake up the immune system so that it recognizes cancer and attacks the disease—just as it does with most bacteria or viruses.
Many of the key elements of immunotherapy have been around for decades. Interferon was discovered in the 1950s; the mechanisms of monoclonal antibodies have been understood since the 1970s. Both have been in use therapeutically since the 1980s.
However, the last decade has seen an explosion in the number, type, and effectiveness of immunotherapies. This spectacular growth results from critical advances in understanding of how genetic signals operate along molecular pathways to regulate the immune system and other basic functions.
Below, we identify five types of immunotherapy that are currently in use at Seattle Cancer Care Alliance (SCCA). In many cases, these therapies are used in combination to attack cancer on multiple fronts.
Bone marrow transplants represent the first big treatment breakthrough in immunotherapy. One of Fred Hutchinson Cancer Research Center’s founders, Nobel laureate E. Donnall Thomas, MD, pioneered the technique through intensive experimentation in the 1960s and 70s. Since then, the transplant survival rate for patients with some blood cancers has gone from nearly zero to upwards of 85 percent.
As with antibodies, T-cell-based immunotherapy has to address the “needle-in-the-haystack” challenge of getting the right kind of T-cell, with the right receptor, to the tumor. Most approaches fall under the umbrella of adoptive cell therapy (ACT)—a technique pioneered by Philip Greenberg, MD, and a team at the Hutchinson Center in the early 1990s.
Antibodies selectively target a particular molecule, either on the tumor itself or another strategic location.
The prostate cancer vaccine sipuleucel-T (Provenge) is the first T-cell-driven immunotherapy that has received FDA approval. As the leader of the clinical trials for Provenge at Seattle Cancer Care Alliance (SCCA) over a span of more than 15 years, Celestia S. Higano, MD, played a key role in the development of the vaccine.
Oncologists often describe cytokines, such as the various interferon and interleukin molecules, as growth factors for the immune system.