Arno Therapeutics, Inc., a clinical-stage biopharmaceutical company focused on oncology therapeutics, today announced the presentation of a poster at the annual American Society of Hematology (ASH) meeting that describes the preclinical activity of Arno's drug candidate AR-42 against leukemia stem cells (LSCs). AR-42 is a broad spectrum inhibitor of both histone and non-histone deacetylation proteins that demonstrated potent activity against Acute Myeloid Leukemia (AML) stem cells. The poster, entitled "Identification of the Histone Deacetylase Inhibitor (HDACi), AR-42, as a Novel Anti-Leukemia Stem Cell Agent in Acute Myeloid Leukemia (AML)" was presented at the 51st ASH Annual Meeting and Exposition held December 5-8, 2009 in New Orleans, LA.

LSCs are believed to be able to initiate and perpetuate AML while displaying resistance to standard chemotherapies. The ability to target these cells with therapeutic compounds may help improve patient outcomes. The poster's findings show that AR-42 preferentially targets LSCs compared to normal healthy cells. The research also suggests that AR-42 is active through a mechanism that differentiates it from other compounds with preclinical anti-LSC activity.

"The ability to target cancer stem cells presents an opportunity to change the way that we treat patients, particularly those stricken with diseases that are currently difficult to cure," stated Monica Guzman, Ph.D., a co-author of the poster with AR-42 at Weill Cornell Medical College. "Patients with AML are prone to recurrent disease, even if therapies are initially effective. Current evidence suggests that the survival of LSCs after treatment may ultimately contribute to the persistence of this disease and its poor clinical prognosis. Inhibiting LSCs may help treat and prevent recurrence of AML in patients."

"We identified AR-42 by screening a large number of gene expression profiles from the National Center for Biotechnology Information (NCBI) Gene Expression Omnibus (GEO) for potential anti-LSC agents. We were very excited to see our hypothesis confirmed both in vivo and in vitro, and we look forward to discovering if the same promising activity will be seen in the clinical setting," said co-author Duane Hassane, Ph.D. of Weill Cornell Medical College.

"Arno is very excited about the results from these recent studies and feels that this data helps to support our belief that AR-42 has the potential to emerge as a meaningful addition to the landscape of cancer therapies," stated David Tanen, President of Arno.

About AR-42

AR-42 (formerly known as "HDAC-42") is an orally available, broad spectrum inhibitor of both histone and non-histone deacetylation proteins ("pan-DAC"), which may both be important in cancer progression. Histone deacetylase ("HDAC") inhibitors are a growing class of compounds that target histone deactylase, a molecule involved in determining which genes are expressed in a particular cell. In preclinical studies, AR-42 has shown activity against a broad spectrum of deacetylation targets and increased potency compared to vorinostat ("SAHA," or Zolinza®), the first HDAC inhibitor to obtain FDA approval. Arno currently plans to commence an investigator-initiated Phase I/IIa study with AR-42 in collaboration with an academic institution in the first half of 2010.

Source
Arno Therapeutics