Arno Therapeutics, Inc. (OTCBB: ARNI) announced today that it has signed an exclusive, worldwide licensing agreement with privately held Invivis Pharmaceuticals to develop the investigational drug, onapristone, an anti-progestin hormone blocker that has been shown to have considerable anti-tumor activity in breast cancer. “Almost half of all breast cancers are associated with a bio-marker which may predict for the activity of onapristone regardless of menopausal status,” said Glenn Mattes, president and chief executive officer of Arno Therapeutics. “Onapristone appears to have a unique ability to block the activated bio-marker and tumor growth, which makes it a promising potential treatment for breast, endometrial and other cancers. We have prepared a detailed development program for this compound and look forward to evaluating it in future clinical trials.” Arno also plans to develop a companion diagnostic to identify patients who are positive for the bio-marker and may benefit from treatment with onapristone. Dr. Erard M. Gilles, founder and chief executive officer of Invivis, stated: “Invivis and Arno share a deep commitment to oncology drug development and are enthusiastic about the therapeutic potential of onapristone. Together, we have the expertise and resources to advance this promising therapy.” Pursuant to the terms of the license agreement, Arno will pay Invivis certain research, clinical and regulatory milestone payments as well as royalties on net sales of licensed products. In addition to the license agreement, Arno will receive certain clinical development support services from Invivis pursuant to a separate agreement. 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 clinical-stage anti-cancer product candidates with unique mechanisms of action. These compounds are in clinical testing as potential best- or first-in-class products to treat hematologic malignancies and solid tumors. For more information about the company, please visit www.arnothera.com. 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 potential for onapristone to treat cancer and other diseases, the timing, progress and anticipated results of the clinical development of onapristone, Arno’s ability to fund the development of onapristone to completion, 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 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, 2010. 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.