NEW YORK, December 4, 2009/PRNewswire/ -- Stemline Therapeutics, Inc. today announced that data from pre-clinical studies of its IL-3R targeting agents, SL-401 and SL-501, in both in vitro and animal models of human chronic myeloid leukemia (CML) have been selected for poster presentation at the upcoming 51st Annual Meeting of the American Society of Hematology (ASH), to be held in New Orleans from December 5-8, 2009. The poster will be presented by Stemline’s collaborators at The University of Texas M.D. Anderson Cancer Center.

The data demonstrate in vitro and in vivo activity of both SL-401 and SL-501 against CML and CML cancer stem cells as single agents, and in combination with tyrosine kinase inhibitors (TKIs). Results also include activity of these IL-3R targeting agents against CML cells with mutations that render them resistant to TKIs.

Details on the abstract selected for presentation are as follows:

Abstract #: 2172

Title: Targeting IL-3 Receptor in Chronic Myeloid Leukemia

Lead Author: Olga Frolova, MD, PhD

Session Name: Chronic Myeloid Leukemia - Biology and Pathophysiology excluding Therapy Poster I

Date: Sunday, December 6, 2009

Presentation Time: 6:00PM – 8:00PM

Location: Hall E (Ernest N. Morial Convention Center)

Poster Board no.: II-149

A copy of the above referenced abstract can be viewed online through the ASH website (www.hematology.org).

About Stemline Therapeutics, Inc. Stemline Therapeutics, Inc. is a clinical stage biotechnology company developing novel oncology compounds directed to cancer stem cell targets. Stemline’s lead compound, SL-401, targets the interleukin-3 receptor which is expressed on multiple hematological cancers including leukemia blasts and leukemia cancer stem cells. SL-401 has demonstrated single agent anti-tumor activity at tolerable doses in a multi-center Phase I/II clinical trial. Stemline is also developing a proprietary portfolio of biological and small molecule compounds directed at high value cancer stem cell targets of a variety of hematological and solid cancers. Stemline has built a robust discovery platform called StemScreen® which the Company has utilized to identify candidate compounds that target cancer stem cells. For more information, please visit the Company’s website at www.stemline.com.

Stemline Contact: Tom Cirrito, PhD Director of Operations Stemline Therapeutics, Inc. Tel: 212-531-5976 Email: tcirrito@stemline.com