Biotrial to Serve as Contract Research Organization for Paris-Based Trial

FLEMINGTON, NJ, USA I August 21, 2013 I Arno Therapeutics, Inc. (ARNI), a clinical stage biopharmaceutical company focused on the development of oncology therapeutics, today announced it has initiated a pharmacokinetic (PK) study of onapristone. The initiation follows the submission and approval of an Investigational Medicinal Product Dossier (IMPD) by the French Health Authority, L’Agence Nationale de Securite du Medicament et des Produits de Sante (ANSM).

Onapristone is an 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 (PR), which is believed to be the mechanism that may inhibit the growth of breast, endometrial and other tumors.

Mr. Glenn Mattes, Chief Executive Officer and President of Arno Therapeutics, stated, “This significant milestone marks the advancement of our clinical program for our lead candidate onapristone. We initiated the PK study less than two weeks after receiving IMPD approval in late July and are on track to commence the Phase 1 trial in patients with PR positive tumors later this year.”

The PK study is designed to recruit twelve healthy volunteers. It will investigate the pharmacokinetic parameters and examine the effect of food on the absorption of onapristone. All volunteers will receive 10 mg of onapristone, receiving the drug after fasting or with food.

The Company has selected Biotrial, a drug evaluation and pharmacology research company, as its contract research organization (CRO) for this trial. The PK study will be conducted by Biotrial’s clinical unit in Paris, France.

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 www.arnothera.com.

SOURCE: Arno Therapeutics