Arno Therapeutics to Present Data Validating Target Biomarker at European Cancer Congress 2013

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Poster Session: Diagnostics/Biomarkers, Hall 4
Abstract #1001; Poster #258
Abstract #1002; Poster #274

- Underscores role of anti-progestins -
- Supports further evaluation of onapristone and development of companion diagnostic -
- Expands on findings presented at ASCO 2013 -

FLEMINGTON, N.J., Sept. 28, 2013 (GLOBE NEWSWIRE) -- Arno Therapeutics, Inc. (OTCQB:ARNI), a clinical stage biopharmaceutical company focused on the development of oncology therapeutics, today announced data from two preclinical studies supporting its lead compound onapristone to be presented at poster sessions at the European Cancer Congress (ECC) 2013 Annual Meeting, being held September 27-October 1, 2013 in Amsterdam, Netherlands. ECC incorporates three conferences – ECCO, ESMO and ESTRO.

The findings, which are summarized below, will be presented during the Diagnostics/Biomarkers poster session on Saturday, September 28 from 8:00 – 10:30 a.m. EDT (14:00 - 16:30 CEST) in Hall 4 of the Amsterdam RAI Exhibition and Convention Centre. The two separate preclinical studies further support the development of a diagnostic test to identify patients with activated progesterone receptor (APR) in tumor specimens as a potential biomarker of anti-progestin activity.

Onapristone is an oral, anti-progestin hormone blocker that has been shown to have considerable anti-tumor activity in breast cancer. Onapristone appears to have a unique ability to block the activated progesterone receptor (APR), which is believed to be a mechanism that may inhibit the growth of breast, endometrial and other tumors. The APR has the potential to function as a biomarker of anti-progestin activity.

"These findings are an expansion of the data set presented at the American Society of Clinical Oncology (ASCO) meeting earlier this year and further support the activated form of progesterone receptor as a target for treatment with an anti-progestin," said Alex Zukiwski, Chief Medical Officer of Arno Therapeutics and one of the authors for study abstract #1001. "With the development of a commercially-viable diagnostic test to recognize APR positive tumors, we will be able to identify the patients most likely to respond to treatment with onapristone, which is moving toward a Phase I trial."

  • Clinical and pathological correlation of the activated form of the progesterone receptor (PR) in breast cancer (BC)
    Abstract #1001; Poster #273
    The study evaluated 397 archived breast cancer samples to correlate the APR status (PR nuclear morphology) using immunohistochemistry (IHC) in BC biopsies to any clinical and/or pathological relationships. APR positive was defined as any tumor with more than 5 percent APR cells. The study found two distinct PR nuclear distribution patterns, an aggregated pattern (A) indicative of activated PR and a diffused, or finely granular pattern, (D) reflecting inactive PR.

The study concluded that although there was an association with higher tumor grade, the APR status was not clearly linked or associated with other prognostic variables such as clinical characteristics, markers for proliferation, estrogen receptor (ER), PR positivity or disease stage. This indicated that APR cannot be predicted by routine clinical data or pathological testing. Overall, the study established that further work on the APR is warranted, as the biomarker has the potential to determine which patients could benefit from anti-progestin treatment. Arno is currently developing a companion diagnostic to identify APR in solid tumors.

  • Clinical and pathological correlation of the activated form of the progesterone receptor (APR) in endometrial cancer (EC)
    Abstract #1002; Poster #274
    The study evaluated 76 archived endometrial cancer samples using a standard IHC technique to determine the APR status in EC and to describe any clinical or pathological relationships with the ultimate goal of developing a companion diagnostic predicting the efficacy of anti-progestins in patients with EC.

The study suggests PR is constitutively active in a subset of endometrial tumors, but not in normal tissue. In such cases, investigation of anti-progestin treatment is warranted as it could inhibit tumor PR activity to disrupt any PR-driven proliferation. The study also concluded that detection of APR can be potentially performed in a routine clinical diagnostic setting, and that APR detection in endometrioid cancer is potentially valuable to identify patients who may benefit from anti-progestin treatment.

These findings support further evaluation of APR as a target for treatment with an anti-progestin, such as onapristone.

"This data underscores the role of anti-progestins and supports using APR as a biomarker in solid tumors. We are moving forward in parallel the development of the diagnostic test and the clinical development of onapristone," remarked Glenn Mattes, President and Chief Executive Officer of Arno Therapeutics.

Recently, Arno Therapeutics initiated a pharmacokinetic study in healthy volunteers and is moving toward its first Phase I trial with the submission of an Investigational Medicinal Product Dossier (IMPD) to the French Health Authority, L'Agence Nationale de Sécurité du Médicament et des Produits de Santé (ANSM), to request the clinical trial authorization of a Phase I dose escalation study evaluating onapristone.

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 are 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 are 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 Endometrial Cancer

In the United States, about 49,500 cases of cancer of the uterine corpus (endometrium) - the body of the uterus - are expected to be diagnosed in 2013 and typically occur in the endometrium (lining of the uterus). About 8,200 deaths are expected in 2013.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: Last accessed: September 25, 2013.

CONTACT: The Ruth Group Stephanie Carrington (investors) (646) 536-7017 Kirsten Thomas (media) (646) 536-7014 (508) 280-6592 (mobile) Arno Therapeutics Glenn Mattes (862) 703-7176

Source:Arno Therapeutics Inc.