Corcept Therapeutics Incorporated, a pharmaceutical company engaged in the discovery, development and commercialization of drugs that treat severe metabolic, oncologic and psychiatric disorders by modulating the effects of cortisol, today announced results of a multi-center Phase 1/2 dose-escalation study of mifepristone and chemotherapy drug eribulin (Halaven®)
Mifepristone (or RU-486)
that show it is well tolerated and clinically active in patients with triple-negative breast cancer. These results were published in the 2015 American Society of Clinical Oncology (ASCO) Annual Meeting Program (abstract e12070), which was released today.
“Triple-negative breast cancers are among the most aggressive and difficult to treat of all the breast cancer types. We are encouraged by the results we have seen using mifepristone to enhance the efficacy of chemotherapy in this patient population,” said Rita Nanda, MD, principal investigator and Associate Director, Breast Medical Oncology, University of Chicago Medicine. “Cancer patients abundantly produce the stress hormone cortisol, which can help tumor cells escape chemotherapy effectiveness when cortisol binds to the cells’ glucocorticoid receptors (GR). Because mifepristone also binds with tumor GR, we are postulating that mifepristone will lessen the cortisol activity in tumor cells and make chemotherapy more effective. Patients with triple-negative breast cancer need better treatments and we are hopeful that mifepristone when combined with chemotherapy, will benefit them.”
Researchers enrolled 13 metastatic breast cancer patients for the first phase of the study to determine the maximum tolerated dose of the mifepristone-eribulin combination. The results showed that the combination regimen was well-tolerated with evidence of clinical activity for patients with triple-negative breast cancer (TNBC). The recommended Phase 1/2 dose of 300 mg of mifepristone daily with 1.1./mg/m2 of eribulin showed no evidence of a drug-drug interaction and will be used in the next phase of the study. An additional 20 patients with GR-positive metastatic TNBC will be enrolled into the study’s efficacy phase.