Arno Therapeutics Enrolls First Patient in a Phase I/II Trial Evaluating Onapristone in Men with Advanced Castration-Resistant Prostate Cancer

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FLEMINGTON, N.J., April 7, 2014 (GLOBE NEWSWIRE) -- Arno Therapeutics, Inc. (OTCQB:ARNI), a clinical stage biopharmaceutical company focused on the development of oncology therapeutics, today announced that it has enrolled the first patient in a Phase I/II trial (NCT02049190) evaluating its lead compound onapristone in men with advanced castration-resistant prostate cancer (CRPC) after failure of abiraterone or enzalutamide. Patient enrollment of this study follows approval of an Investigational Medicinal Product Dossier from the United Kingdom (UK) Health Authority, Medicines and Healthcare products Regulatory Agency, ethics committee authorization and subsequent site authorization.

Glenn Mattes, President and Chief Executive Officer of Arno Therapeutics, remarked, "Globally, prostate cancer is the second most common cancer in men, and the fifth leading cause of death from cancer in men, with an estimated 1.1 million new cases diagnosed and 307,000 deaths during 2012 alone, according to the International Agency for Research on Cancer. These numbers are staggering, and our ultimate goal is to evaluate onapristone in the subset of advanced CRPC patients who are more likely to respond to this personalized treatment, for which there is an immense unmet medical need. The trial marks Arno's second Phase I study actively enrolling this year and we are excited by the momentum generated thus far."

Onapristone is an oral, anti-progestin hormone blocker that has been shown in previous Phase II clinical trials to exhibit anti-tumor activity in patients with breast cancer. In pre-clinical testing, onapristone has been shown to block the activation of the progesterone receptor (PR), which is believed to be a mechanism that inhibits the growth of APR-driven breast, endometrial and other tumors. Tests for the activated form of the progesterone receptor (APR) have the potential to function as a biomarker of anti-progestin activity, as detected by a companion diagnostic under development.

The randomized, open-label trial is currently enrolling patients and is designed to evaluate the safety and anti-cancer activity of onapristone in the select patient population. This single-site trial is taking place at The Institute of Cancer Research, London, and The Royal Marsden NHS Foundation Trust in the UK and additional UK sites are planned. The study is expected to enroll a total of 60 patients. Arno has engaged Biotrial, a drug evaluation and pharmacology research company, as its contract research organization for this trial.

Professor Johann de Bono, MD, PhD, MSc, FRCP, Professor of Experimental Cancer Medicine at The Institute of Cancer Research (ICR) and Honorary Consultant in Medical Oncology at The Royal Marsden, and an investigator for the trial, said, "Advanced prostate cancer remains a difficult disease to treat due to the development of various resistance mechanisms. We are very interested in developing new personalized therapies to improve treatment outcomes for these patients. Through Arno Therapeutics' early trial in advanced castration-resistant prostate cancer, we hope to gain a deeper understanding of the safety profile and potential anti-cancer activity of onapristone with the goal of accelerating the development of the APR biomarker and this targeted anti-progestin."

Onapristone is also being developed for other indications including breast and endometrial cancers. The potential treatment is concurrently being evaluated in a Phase I clinical trial in France in women who have progesterone receptor expressing tumors. This targeted therapy has the potential to be the first approved anti-progestin for oncology indications and provide chemotherapy-sparing treatment to cancer patients who express a specific biomarker.

The Phase I/II study will evaluate onapristone in extended-release tablet formulations in up to five dose levels (10-50 mg BID) in patients with advanced CRPC in which PR may be contributing to tumor progression. Study subjects will be evaluated for whether their tumors express APR, which may help identify patients who are more likely to respond to onapristone. A second cohort of patients will be included at the recommended Phase II dose to gain additional understanding of the onapristone safety profile and potential anti-cancer activity.

Alex Zukiwski, MD, Chief Medical Officer of Arno Therapeutics, commented, "Tolerance to chemotherapy and various targeted therapies is known to be different in males undergoing androgen deprivation treatment. While the percentage of castration-resistant prostate cancer that is APR positive remains to be determined, the initial series of preclinical tumor specimens we examined has demonstrated evidence of APR, and we are looking forward to evaluating the safety and anti-cancer activity of onapristone in this patient population."

About Prostate Cancer

In the United States, prostate cancer is the most frequently diagnosed cancer in men aside from skin cancer. An estimated 233,000 new cases of prostate cancer will be diagnosed during 2014 in the U.S. alone. With an estimated 29,500 deaths expected to occur in 2014, prostate cancer is the second-leading cause of cancer death in men.i

On the global scale, prostate cancer is the fourth most common cancer in both sexes combined and the second most common cancer in men.ii Worldwide in 2012, an estimated 1.1 million men were diagnosed – accounting for 15 percent of the cancers diagnosed in men – and there were an estimated 307,000 deaths, making prostate cancer the fifth leading cause of death from cancer in men (6.6% of the total men deaths). ii

About Arno Therapeutics

Arno Therapeutics is a clinical stage biopharmaceutical company developing innovative products for the treatment of cancer. Arno has exclusive worldwide rights to develop and market three innovative anti-cancer product candidates. These compounds are in clinical or preclinical development as product candidates to treat hematologic malignancies and solid tumors. For more information about the company, please visit

Forward-Looking Statements

This press release contains forward-looking statements that involve substantial risks and uncertainties. These statements are often, but not always, made through the use of words or phrases such as "anticipates," "expects," "plans," "believes," "intends," and similar words or phrases. These forward-looking statements include, without limitation, statements regarding the timing, progress and anticipated results of the clinical development of onapristone, statements regarding the potential of onapristone as a treatment for prostate and other cancers, statements regarding Arno's use and development of a diagnostic test to identify patients with APR tumors, as well as Arno's strategy, future operations, outlook, milestones, future financial position, future financial results, plans and objectives. We may not actually achieve these plans, intentions or expectations and Arno cautions investors not to place undue reliance on our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements we make. Various important factors could cause actual results or events to differ materially from the forward-looking statements that we make. Such factors include, among others, risks that the results of clinical trials will not support our claims or beliefs concerning the effectiveness of onapristone or any of our other product candidates, our ability to successfully develop a diagnostic to identify APR tumors, our ability to finance the development of our product candidates, regulatory risks, and our reliance on third party researchers and other collaborators. Additional risks are described in the company's Annual Report on Form 10-K for the year ended December 31, 2013. Arno is providing this information as of the date of this press release and does not undertake any obligation to update any forward-looking statements as a result of new information, future events or otherwise.

i American Cancer Society. Cancer Facts & Figures 2014. Available at:
Last accessed: February 5, 2014.

ii International Agency for Research on Cancer. GLOBOCAN 2012: Estimated Cancer Incidence, Mortality and Prevalence Worldwide in 2012. Available at:
Last accessed. February 6, 2014.

CONTACT: The Ruth Group Lee Roth (investors) (646) 536-7012 Kirsten Thomas (media) (646) 536-7014 Arno Therapeutics Glenn Mattes (862) 703-7176

Source:Arno Therapeutics Inc.