Stemline Therapeutics, Inc. Announces Presentations of SL-401 Clinical and Pre-Clinical Efficacy at the 52nd Annual Meeting of the American Society of Hematology

NEW YORK, Dec. 1, 2010 /PRNewswire/ -- Stemline Therapeutics, Inc. today announced that two abstracts featuring SL-401 clinical efficacy in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), and pre-clinical activity in chronic myeloid leukemia (CML) have been selected for presentation at the upcoming 52nd Annual Meeting of the American Society of Hematology (ASH) to be held in Orlando, FL from December 4-7, 2010. The posters will be presented by Stemline’s collaborators at MD Anderson Cancer Center.

The clinical results with SL-401 demonstrate efficacy, including two durable complete remissions (CRs), multiple blast reductions and disease stabilizations in relapsed/refractory AML, poor risk elderly AML, and high risk MDS. Importantly, an overall survival benefit was also seen in heavily pre-treated AML patients, a very difficult to treat population and an unmet medical need. Results also include preliminary signals of a clinical anti-CSC effect that further supports the importance of targeting CSCs in patients. SL-401 was safe, well-tolerated, and uniquely bone marrow-sparing. In addition, the pre-clinical studies demonstrate SL-401 activity against CML blasts and CSCs from patients who are resistant to tyrosine kinase inhibitors (TKIs).

SL-401 is a novel CSC-directed compound that targets the interleukin-3 receptor (IL-3R). IL-3R is over-expressed on AML CSCs relative to normal hematopoietic stem cells. IL-3R is also over-expressed on AML blasts as well as on multiple other hematological malignancies including MDS, CML, Hodgkin’s disease, and certain non-Hodgkin’s lymphomas. SL-401 is currently in ongoing Phase I/II trials of patients with poor risk elderly AML, high risk MDS, and CML who are not candidates for TKI therapy. In addition, given the promising clinical results in relapsed/refractory AML, SL-401 is also now poised for later stage Phase II/III trials in this indication. Details on the abstracts selected for presentation are as follows:

A copy of the above referenced abstracts can be viewed online through the ASH website at www.hematology.org.

About Stemline Therapeutics, Inc.

Stemline Therapeutics, Inc. is a clinical stage biopharmaceutical company developing novel oncology compounds that target cancer stem cells (CSCs). Stemline is currently developing two clinically active compounds, both of which have demonstrated durable complete responses (CR) and an overall survival (OS) benefit in Phase I/II studies. SL-401, the Company’s lead compound, has completed a multicenter Phase I/II trial in advanced stage AML where it has demonstrated single agent activity including two durable CRs and an OS benefit, and is now poised for later stage studies. SL-401 is also currently being tested in additional indications including AML (de novo/elderly), MDS (high risk), and CML (not candidate for TKI therapy).In addition to advancing its clinical programs, Stemline is also developing a broad portfolio of pre-clinical small molecules and antibodies for a variety of solid and hematological cancer types. Many of these compounds have derived from StemScreen®, the Company’s proprietary discovery platform. Stemline also possesses a landmark portfolio of intellectual property that includes the earliest filings in the CSC field covering CSC-directed therapeutics, diagnostics, and drug discovery. For more information, please visit the Company’s website at www.stemline.com.

This announcement contains forward-looking statements relating to Stemline’s business, which are based on the Company’s current expectations concerning future developments. These statements are subject to risks, uncertainties and other factors that may cause Stemline’s actual performance to differ materially from the statements in this announcement. There can be no assurance that future developments affecting Stemline will be those the Company has anticipated.

SOURCE Stemline Therapeutics, Inc.