Novel anti-cancer treatment exposes tumors to immune responses
Peregrine Pharmaceuticals plans to present data from three Phase II clinical trials involving its unique phosphatidylserine (PS)-targeting antibody bavituximab for the treatment of solid tumors. PS-targeting antibodies use a novel immunomodulatory mechanism that allows a patient's own immune system to attach and destroy a tumor.
The findings of past studies have revealed that in combination with chemotherapy in patients with advanced breast and lung cancers, bavituximab has achieved objective tumor response rates that compare favorably with chemotherapy alone.
“PS is a highly immunosuppressive molecule that inactivates the immune system and allows tumors to evade detection,” explained Philip Thorpe, MD, professor of pharmacology at the University of Texas Southwestern Medical Center, scientific advisor to Peregrine, and a pioneer in the development of PS-targeting therapies. “Supported by a growing body of research, PS-targeting antibodies appear to play a critical role in blocking this immunosuppressive molecule and reactivating the immune system's ability to mount a robust anti-tumor response. Since chemotherapy increases the exposure of PS on tumor blood vessels, bavituximab has even more of this immunosuppressive molecule to target, potentially offering a new synergistic approach for the treatment of cancer.”
The authors explained that Peregrine's PS-targeting antibodies such as bavituximab target and block this immunosuppressive PS target, enabling the immune system to recognize the cancer cells as foreign and to reactive the immune system to attack the tumor and inhibit its growth.
According to the press release announcing the data, Peregrine plans to initiate a new randomized, placebo-controlled, double-blind Phase II trial of bavituximab in combination with chemotherapy in patients with refractory non-small cell lung cancer.