Mayo Clinic Reports Data On Prostate Cancer Study With Ipilimumab

The Mayo Clinic has reported data on a prostate cancer study with ipilimumab, a fully human antibody that binds to CTLA-4 (cytotoxic T lymphocyte-associated antigen 4), a molecule on T-cells that plays a critical role in regulating natural immune responses.

Two patients, whose prostate cancer had been considered inoperable, have no evidence of disease, in part, to an experimental drug therapy used in combination with standardized hormone treatment and radiation therapy.

In both the cases, the aggressive tumors had grown well beyond the prostate into the abdominal areas.

The patients first received a type of hormone therapy called androgen ablation, which removes testosterone and usually causes some initial reduction in tumor size. Researchers then launched a single dose of ipilimumab, an antibody, which builds on the anti-tumor action of the hormone and causes a much larger immune response, resulting in massive death of the tumor cells.

Both the men experienced consistent drops in their prostate specific antigen (PSA). During surgery, extensive tumor shrinkage was observed. One patient underwent radiation therapy after surgery but both resumed their regular lives, the researcher reported.

Medarex provided the study drug free of charge and supported safety monitoring during the protocol.