Arno Therapeutics to Focus Clinical Developmental Activities on Advanced Prostate Cancer in First-of-its-Kind Phase II Study of Onapristone in Combination with ZYTIGA®

FLEMINGTON, N.J., April 19, 2016 (GLOBE NEWSWIRE) -- Arno Therapeutics, Inc. (OTCQB:ARNI), a clinical stage biopharmaceutical company dedicated to the development of therapeutics for cancer and other life threatening diseases, today announced that it has determined to focus its onapristone development program on metastatic castration-resistant prostate cancer (CRPC) that has become resistant to ZYTIGA® (abiraterone acetate) therapy.  To support this milestone decision, Arno Therapeutics is pleased to announce the formation of a special Prostate Cancer Advisory Board.

The ongoing onapristone prostate cancer Phase II study is supported by the increasing scientific evidence for the role of the progesterone receptor (PR) pathway as a negative prognostic factor in men with advanced prostate cancer.  Published studies report a significant increase in progesterone blood levels and higher expression of PR by cancer cells in patients with CRPC who progress while being treated with ZYTIGA.  The ongoing Phase II study in CRPC is evaluating onapristone in combination with ZYTIGA in men who fail ZYTIGA alone. This multi-site trial, which is expected to enroll approximately 75 patients, is taking place in Europe, led by investigators from the Institute of Cancer Research, Royal Marsden Hospital in the UK with expansion to include sites in the United States.  

The newly-formed Prostate Cancer Advisory Board at ARNO will be chaired by Stuart Holden, MD, a Clinical Professor of Urology, Spielberg Family Chair in Urologic Oncology Associate Director, and Institute of Urologic Oncology at the UCLA David Geffen School of Medicine. The additional members of the Advisory Board include:

  • Gerhardt Attard MD, PhD, Cancer Research UK Clinician Scientist and Honorary Consultant, The Institute of Cancer Research and the Royal Marsden, Sutton, Surrey
  • Suzanne D. Conzen, MD, Professor of Medicine, The University of Chicago Medicine, Chicago, IL
  • Christopher J. Logothetis, MD, Professor, Department of Genitourinary Medical Oncology, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX
  • Peter S. Nelson, MD, Professor School of Medicine University of Washington, Fred Hutchinson Cancer Research Center, Seattle, Washington
  • Kenneth J. Pienta, MD, Donald S. Coffey Professor and Director of Research, Brady Urological Institute, Johns Hopkins School of Medicine, Baltimore, Maryland

Stuart Holden, MD remarked, “I am very pleased to be named the Chair of the Onapristone Prostate Cancer Advisory Board. We have an excellent, experienced group of advisors. The evolving science has created substantial interest in the role of the progesterone receptor in castration-resistant prostate cancer. This opens a potentially new treatment for men with prostate cancer and a significant opportunity for Arno Therapeutics.”

Arie Belldegrun, MD, Arno's Executive Chairman, "The science supporting the potential of onapristone in the treatment of prostate cancer continues to increase at a rapid pace and enables us to advance onapristone's clinical development, which presents an exciting opportunity to treat potentially thousands of patients with CRPC.  I want to thank Dr. Holden for putting together an advisory board of eminent thought leaders whose insights will be invaluable to the Arno development team and our clinical investigators."

With the recently-announced enrollment of the first patient in the Phase II prostate cancer study (March 21, 2016 press release) and the supporting body of scientific and clinical rationale, Arno Therapeutics has made the strategic decision to focus its resources on its prostate cancer program and will be closing the onapristone Phase II study of patients with recurrent or metastatic endometrioid cancer. This decision was not based on any safety or lack of efficacy signal and the Company will continue to provide onapristone to all patients currently enrolled in this trial on a compassionate use basis. 

Alex Zukiwski, MD, Chief Executive Officer of Arno Therapeutics, remarked, “The prostate cancer study is progressing and we look forward to quickly bringing U.S. sites on board. The strategic decision to focus on the prostate cancer indication will allow us to concentrate our attention and resources on this promising development program.”

Onapristone is an oral, anti-progestin hormone blocker that has been shown in previous Phase II clinical trials (not sponsored by Arno) to exhibit anti-tumor activity in patients with breast cancer. In pre-clinical testing, onapristone has been shown to block the activation of the PR, which is believed to be a mechanism that inhibits the growth of activated progesterone receptor (APR) driven castration-resistant prostate cancer tumors.

About Prostate Cancer

In the United States, prostate cancer is the most frequently diagnosed cancer in men aside from skin cancer. Approximately 180,890 new cases of prostate cancer are estimated to be diagnosed in 2016 in the U.S. alone. With an estimated 26,120 deaths expected to occur in 2016, prostate cancer is the second-leading cause of cancer death in men.

On the global scale, prostate cancer is the fourth most common cancer in both sexes combined and the second most common cancer in men. 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). ZYTIGA is a CYP17 inhibitor indicated in combination with prednisone for the treatment of patients with metastatic castration-resistant prostate cancer and had word wide sale of US $2.231 billion in 2015.

About Arno Therapeutics

Arno Therapeutics is a clinical stage biopharmaceutical company developing innovative products for the treatment of cancer and other life threatening diseases.  Arno has exclusive worldwide rights to develop and market three innovative 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, as well as Arno's strategy, future operations, outlook, milestones, future financial position, future financial results, plans and objectives. Arno 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 made here. Various important factors could cause actual results or events to differ materially from these forward-looking statements. Such factors include, among others, risks that the results of clinical trials will not support claims or beliefs concerning the safety or effectiveness of onapristone or any other product candidates, the ability to finance the development of Arno’s product candidates, regulatory risks, and 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, 2015. 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.

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