- Observed Dose-Response Trends Suggest Improved Efficacy with Higher Doses
- Dose Escalation Ongoing -
SAN FRANCISCO and CHICAGO, June 2 /PRNewswire-FirstCall/ -- Medivation, Inc. (Nasdaq: MDVN) today announced that data from an ongoing Phase 1-2 clinical trial of the Company's novel androgen receptor antagonist, MDV3100, showed encouraging anti-tumor activity as measured by declining serum levels of prostate specific antigen (PSA) and circulating tumor cells (CTC), as well as radiographic disease stabilization, after three months of treatment. An increased number of androgen receptors present on prostate cancer cells is believed to play a major role in the growth of castration-resistant prostate cancer, also known as hormone-refractory prostate cancer. The observed clinical effects of MDV3100 on PSA levels, CTC counts and radiographic disease are consistent with blockade of androgen receptor signaling and inhibition of tumor growth. To date, 90 patients have been enrolled in the trial with enrollment completed at doses up to 240 mg/day. MDV3100 has been well tolerated and dose escalation at 360 mg/day is in progress.
The data were presented at the American Society of Clinical Oncology 2008 Annual Meeting in Chicago in an oral presentation entitled "Phase 1-2 study of MDV3100 in patients (pts) with progressive Castration-Resistant Prostate Cancer (CRPC)" by principal investigator, Howard Scher, M.D., chief of the Genitourinary Oncology Service and the D. Wayne Calloway Chair in Urologic Oncology at Memorial Sloan-Kettering Cancer Center in New York.
The ongoing Phase 1-2 trial is an open-label U.S. dose-escalation study enrolling prostate cancer patients who have failed standard hormonal therapies. The dose-expansion study has enrolled 84 patients in three cohorts (60, 150, 240 mg/day) to date. Dr. Scher's presentation covered PSA data from all patients who have been followed for at least 12 weeks, the standard minimum duration of observation used to assess the treatment effects of prostate cancer drugs. Of the 42 chemo-naive and 31 post-chemotherapy evaluable patients across the three dose levels, 23 patients (55 percent) and 13 patients (42 percent) showed PSA declines greater than 50 percent at week 12 compared to baseline, respectively. Of the 28 evaluable patients from the 240 mg/day dose group of the trial, eight patients (29 percent) experienced a decline in PSA levels of greater than 90 percent compared to 9 percent and 13 percent in the 60 mg/day and 150 mg/day dose groups, respectively.
The number of CTC in a blood sample from a prostate cancer patient can indicate prognosis; patients with higher CTC counts (greater than or equal to five) are thought to have less favorable prognoses. MDV3100 treatment preserved favorable prognosis CTC counts below five in 92 percent of patients in the 60 and 150 mg/day dose groups and converted CTC counts from unfavorable to favorable prognoses in 33 percent of patients in the 60 mg/day dose group and in 56 percent of patients in the 150 mg/day dose group, respectively.
Importantly, radiographic data from both the 60 mg/day and 150 mg/day dosing cohorts showed stabilization of disease through 12 weeks of treatment. Of the 15 evaluable patients with soft tissue disease, 12 patients (80 percent) had stabilization of disease. Prior to enrollment in this study, all these patients had progressive disease despite standard-of-care hormonal therapies, and in roughly half the patients, also chemotherapy. As opposed to most previous studies in CRPC that have used the RECIST criteria to define evaluable patients and assess radiographic changes, the MDV3100 data were analyzed using the more recent and rigorous Prostate Cancer Clinical Trials Working Group (PCWG2) consensus guidelines.
"Castration-resistant prostate cancer is a devastating disease with high mortality rates and limited treatment options," said Dr. Scher. "MDV3100 has been well tolerated and early results suggest encouraging anti-tumor activity. Additional data currently being generated will clarify its role as a potential therapy for patients with castration-resistant prostate cancer."
"We continue to be very encouraged by the results with MDV3100 obtained to date," said David Hung, M.D., president and chief executive officer of Medivation. "Analysis of the data showed a dose-dependent effect of MDV3100 on PSA levels, CTC counts and clinical outcomes. We continue to gather longer-term data on these patients and are also exploring higher doses."
Medivation expects to complete the study, and report final top-line results, in 2008. If these results are positive, Medivation expects to seek U.S. Food and Drug Administration agreement to enter a pivotal Phase 3 registration study in castration-resistant prostate cancer.
About Prostate Cancer
Prostate cancer is the most common non-skin cancer in the United States and the third most common cancer worldwide. More than 1 million men in the United States have prostate cancer. An estimated 186,320 new cases are expected to be diagnosed in 2008, and approximately 28,660 men are expected to die this year from the disease. Patients with castration-resistant (also known as hormone-refractory) prostate cancer have few treatment options and a poor prognosis.
Medivation, Inc. is a biopharmaceutical company focused on the rapid development of novel small molecule drugs to treat serious diseases of the central nervous system and cancers for which there are limited treatment options. Medivation aims to revolutionize the treatment of these diseases and offer hope to critically ill patients and their caregivers. The Company's current clinical development program includes a pivotal and confirmatory Phase 3 trial of Dimebon(TM) in Alzheimer's disease, a Phase 2 clinical trial of Dimebon in patients with Huntington's disease, and a Phase 1-2 clinical trial of MDV3100 in patients with castration-resistant (also known as hormone-refractory) prostate cancer. For more information, please visit us at http://www.medivation.com.
This press release contains forward-looking statements, including statements regarding anticipated clinical and regulatory milestones, which are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Forward-looking statements involve risks and uncertainties that could cause actual results to differ significantly from those projected. You are cautioned not to place undue reliance on the forward- looking statements, which speak only as of the date of this release. None of the Company's product candidates has been approved for sale, significant additional animal and human testing is required in order to seek marketing approval for any of its product candidates, and Medivation cannot assure you that marketing approval can be obtained for any of its product candidates. Furthermore, as is typically the case at this stage of the regulatory review process, the FDA has not yet performed an in-depth review of Medivation's preclinical and clinical data, so its views remain subject to change. Medivation's filings with the Securities and Exchange Commission, including its Annual Report on Form 10-KSB for the year ended December 31, 2007 and its Quarterly Report on Form 10-Q for the quarter ended March 31, 2008, include information about additional factors that could affect the Company's financial and operating results.
|SOURCE Medivation, Inc.|
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