Arno Therapeutics Enrolls First Patient in a Phase I Trial to Evaluate Lead Compound Onapristone in Progesterone Receptor Positive Solid Tumors

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FLEMINGTON, N.J., Jan. 21, 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 dose escalation study evaluating onapristone in post-menopausal women with progesterone receptor (PR) positive tumors, including breast, endometrial and other solid tumors. The Phase I trial is designed to identify the recommended Phase II dose and determine the overall safety profile of onapristone.

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

The Phase I study will evaluate onapristone in sustained release and immediate release formulations in up to six dose levels (10-50 mg BID and 100 mg QD) to identify the recommended Phase II dose. In addition, the study will gather data showing antitumor activity. This multi-site trial is taking place in France and expected to enroll a total of 60 patients. The first patient has been enrolled by investigator Andrea Varga, MD at Gustave Roussy Institute of Oncology, Villejuif, France.

Arno has engaged Biotrial, a drug evaluation and pharmacology research company that conducted the pharmacokinetic (PK) study, as its contract research organization for the Phase I trial.

Glenn Mattes, President and Chief Executive Officer of Arno Therapeutics, remarked, "The enrollment of the first patient in this Phase I trial is a tremendous milestone for Arno and is testament to the considerable strides we have made in the past year. We are focused on driving forward the development of onapristone in the most efficient and cost-effective manner and believe it could fill a unique position in the market as there is significant potential for it be the first approved anti-progestin in oncology. We are at the forefront of establishing a genuine appreciation for the role of the progesterone receptor in cancer and the activated form as a biomarker, and we look forward to successfully developing our program."

Alex Zukiwski, MD, Chief Medical Officer of Arno Therapeutics, said, "Through a clearly defined development pathway, our initial strategy is to target the activated form of progesterone receptor positive cancers in two indications with high unmet medical need – endometrioid cancer and castration-resistant prostate cancer. Through preclinical work, we've established that a significant percentage of endometrioid cancer tumor specimens are APR positive. The goal of the Phase I study underway is to determine the recommended dose for onapristone that we can utilize for a Phase II trial of patients with recurrent or metastatic endometrioid cancer."

About Endometrial Cancer

In the United States, about 49,500 cases of cancer of the uterine corpus (endometrium) - the body of the uterus - were expected to be diagnosed in 2013 and typically occur in the endometrium (lining of the uterus). About 8,200 deaths were expected in 2013.i

About Breast Cancer

In the United States, over 232,300 new cases of invasive breast cancer are expected to be diagnosed in women and over 2,200 new cases were expected in men during 2013. After cancers of the skin, breast cancer is the most frequently diagnosed cancer in women. More than 40,000 breast cancer deaths were expected in 2013, with the majority in women. Breast cancer ranks second as a cause of cancer death in women, following lung cancer.i

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 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, 2012. 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 2013. Available at:

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.