Combination therapy promising for shrinking prostate tumors

The monoclonal antibody bavituximab significantly shrank resistant human prostate tumors in mice when added to a standard regimen of androgen deprivation and docetaxel (Taxotere), according to researchers at the University of Texas Southwestern Medical Center in Dallas.

“These exciting results mimic the real-life situation facing many prostate cancer patients whose disease is failing to respond to the standard combination of androgen deprivation and chemotherapy drugs such as docetaxel,” said senior author Philip Thorpe, PhD. “In this study of human prostate tumors in mice, we have shown that administering a bavituximab equivalent significantly enhances the tumors’ response to androgen deprivation and docetaxel, with the result that these large, resistant tumors shrank by an average of more than 50% over the 13-week study.

“These findings further strengthen the rationale for use of bavituximab as part of combination therapy regimens for the treatment of prostate cancer.”

In a phase Ib trial in advanced cancer patients to assess its safety in combination with common chemotherapy agents, bavituximab plus chemotherapy appeared to have a safety profile consistent with chemotherapy alone and showed positive signs of clinical activity, achieving objective response or disease stabilization in 50% of the evaluable patients, according to researchers.

The study findings were presented at the inaugural Innovative Minds in Prostate Cancer Today Conference in Atlanta by Yi Yin, MD, PhD, of UT Southwestern.