Arno Therapeutics Doses First Patient in Expansion Stage of Modified Phase I/II Trial Evaluating Onapristone in Progesterone Receptor Positive Tumors

FLEMINGTON, N.J., Dec. 10, 2014 (GLOBE NEWSWIRE) -- Arno Therapeutics, Inc. (OTCQB:ARNI), a clinical stage biopharmaceutical company primarily focused on the development of oncology therapeutics, today announced that it has dosed the first patient in the Phase II component of a modified Phase I/II clinical study evaluating its lead compound onapristone in women with progesterone receptor expressing tumors. The Phase II study will include up to 29 patients with recurrent or metastatic endometrioid tumors that have been shown to express the activated progesterone receptor (APR), and who have received no more than one prior chemotherapy and no prior hormone therapy.

Alex Zukiwski, MD, Chief Executive Officer of Arno Therapeutics, remarked, "We are pleased that we were able to quickly implement the Phase II study in patients with APR positive endometrioid tumors, which is the same patient population of our planned registration program. The current study has been ongoing in France and we intend to open additional investigative sites both in France and the United States early next year."

All patients in the Phase II component of the study will receive 50mg of extended release onapristone twice daily. The study protocol provides that if at least two of the first 10 patients have a confirmed response by RECIST 1.1 criteria, an additional 19 patients will be enrolled, for a total of 29 patients. The study also incorporates a diagnostic test targeting women with tumors expressing the APR, which is intended to select those patients most likely to respond to onapristone treatment.

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 progesterone receptor (PR), which is believed to be a mechanism that inhibits the growth of APR driven breast, endometrial and other, primarily gynecological tumors. APR has the potential to function as a biomarker of anti-progestin activity, as detected by a companion diagnostic currently under development with Arno's partner, Leica Biosystems.

The ongoing, open-label Phase I/II study is currently enrolling patients and is designed to evaluate the safety of onapristone in the selected patient population, determine the recommended Phase II dose, and assess any antitumor activity. This multi-site trial is currently enrolling patients in France and is expected to begin enrolling patients in the United States in early 2015. Arno is working with Biotrial S.A.S., a drug evaluation and pharmacology research company, as its contract research organization for this trial.

Arno Therapeutics has improved the manufacturing process for onapristone and developed a proprietary, sustained release formulation to avoid the high peak concentrations associated with previously investigated immediate release type formulations and to enable the continuous suppression of the APR.

About Endometrial Cancer

In the United States, about 52,630 cases of cancer of the uterine corpus (body of the uterus) are expected to be diagnosed in 2014. These usually occur in the endometrium (lining of the uterus). About 8,590 deaths are expected in 2014.

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 number and tumor type of patients to be enrolled in the Phase II expansion stage, statements regarding the timing, progress and anticipated results of the clinical development of onapristone, statements regarding the potential of onapristone as a treatment for gynecological and other cancers, statements regarding Arno's use and development of a diagnostic test to identify patients with APR tumors, statements regarding the potential of APR to function as a biomarker for anti-progestin activity, as well as Arno's strategy, including its strategy to target endometrioid cancer in a proposed registration trial, 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 and its Quarterly Report for the quarter ended September 30, 2014. 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.

CONTACT: The Ruth Group Lee Roth (investors) (646) 536-7012 Kirsten Thomas (media) (646) 536-7014 Arno Therapeutics Lawrence Kenyon (862) 703-7171

Source:Arno Therapeutics Inc.