Researchers at the Moores Cancer Center at the University of California, San Diego (UCSD) are conducting clinical trials of a novel therapy aimed at revving up the immune system to combat a particularly difficult-to-treat form of leukemia.
The experimental therapy is being offered to patients with chronic lymphocytic leukemia (CLL) whose cancer did not respond or was resistant to initial treatment or harbors a particular chromosomal abnormality called a 17p deletion. In most of these cases, the cancer has failed to respond to further conventional therapy.
In this clinical trial, patients will receive a vaccine of an immune-boosting molecule, ISF35 (Immune Stimulatory Factor 35) followed by three courses of rituximab, a monoclonal antibody, and the chemotherapy drugs fludarabine and cyclophosphamide (FCR). The trial is termed Phase I, meaning that it is aimed at testing the safety of the combination of repeat infusions of ISF35 and FCR, the latter being considered the standard and best possible CLL treatment.
“This approach – activating immune cells followed by chemotherapy – may lead to new strategies that could be applied to other cancers,” said Januario E. Castro, M.D., assistant clinical professor of medicine at the UC San Diego School of Medicine and the Moores UCSD Cancer Center, who leads the work. The vaccine therapy approach makes it possible to target the cancer cells and activate the immune system by making the cancerous leukemia B cells more visible. The activated immune system can then find and eliminate the cancer cells.