The Phase 1 portion of the seviteronel study has completed and a once-daily dose was selected for advancement into Phase 2 development.
William Moore, Ph.D., Innocrin’s Chief Executive Officer stated, "The importance of the androgen receptor (AR) to the development of ER+ and TN BCa disease progression has become better recognized by the medical community.
"Seviteronel both reduces androgens and estrogens through its inhibition of CYP17 lyase and directly antagonizes the AR, so it has the potential to provide benefit for women with cancers that have not responded to traditional anti-estrogen therapies. We look forward to presenting the results from our Phase 1 study at the upcoming ASCO Annual Meeting."
Innocrin also announced that once-daily seviteronel has advanced to Stage 2 in two separate Phase 2 CRPC studies. One is an open-label Phase 2 study funded by the National Cancer Institute (NCI), evaluating the efficacy and safety of seviteronel in men who have previously been treated with enzalutamide (NCT02130700).
The second is an Innocrin-sponsored Phase 2 study of seviteronel in men who have been previously treated with both enzalutamide and abiraterone (NCT02012920). Phase 2 oncology studies typically employ early ‘stopping rules’ that prevent large numbers of patients from being exposed to inactive drugs. Seviteronel has advanced to Stage 2 in both studies based upon early signs of therapeutic activity in each population.
Dr. Moore further commented, "It is gratifying that seviteronel has demonstrated early signs of therapeutic benefit in both of these very important clinical studies. Novel therapies for men whose CRPC has progressed despite treatment with enzalutamide or with abiraterone represent a growing unmet medical need.
"Positive results from these studies will enable us to advance seviteronel as a therapeutic alternative to systemic radio- or chemo-therapy for these men. Correlative results from these studies, which include AR-v7 analyses, will help us identify the populations that will most benefit from seviteronel."
Innocrin anticipates presenting final results from these Phase 2 BCa and CRPC clinical trials at future medical conferences.
About Seviteronel (VT-464)
Seviteronel is a once-daily oral therapeutic given without prednisone. Seviteronel selectively inhibits CYP17 lyase, a target of abiraterone, and also directly blocks the AR, the target of enzalutamide.
A growing body of preclinical and clinical evidence shows that seviteronel is active in prostate cancers that have become resistant to abiraterone or enzalutamide. CRPC disease progression following treatment with abiraterone, enzalutamide or both represents a major unmet medical need due to the widespread and growing use of both agents, and to the high cross-resistance between these agents (e.g., cancers that are resistant to either abiraterone or enzalutamide typically are also resistant to the other).
Seviteronel may also have significant potential for the treatment of breast cancer due to its ability to down-regulate both AR and ER signaling through its selective inhibition of CYP17 lyase, which results in the depletion of both androgens and estrogens, and to its direct AR antagonist activity.
It is thought that the AR may stimulate disease progression in tumors that are triple-negative or are ER+ and are resistant to ER-directed therapies such as aromatase inhibitors or tamoxifen. Recent preclinical study results, presented at the 2015 San Antonio Breast Cancer Symposium, confirmed that seviteronel blocks the growth of resistant ER+ and AR+ breast cancer cells more potently than enzalutamide.