Stemline Therapeutics, Inc. Announces Two Poster Presentations of SL-401 Efficacy Data Against Lymphoid Cancers at the 53rd Annual Meeting of the American Society of Hematology (ASH)

NEW YORK, Dec. 8, 2011 /PRNewswire/ -- Stemline Therapeutics, Inc. today announced that two studies of SL-401, a clinical stage therapeutic being developed in patients with myeloid malignancies, have also demonstrated preclinical activity against a variety of lymphoid malignancies and have been selected for presentation at the upcoming 53rd Annual Meeting of the American Society of Hematology (ASH) to be held in San Diego, CA from December 10-13, 2011.

One study demonstrates that SL-401 potently inhibits the growth of several Hodgkin's lymphoma (HL) cell lines, and has activity against mantle cell lymphoma (MCL), a non-Hodgkin's lymphoma, as well as T-cell acute lymphoblastic leukemia (T-ALL) cell lines. The other study shows that SL-401 is cytotoxic against primary tumor cells obtained from patients with blastic plasmacytoid dendritic cell neoplasm (BPDCN), a rare lymphoma with limited treatment options. These results indicate that further evaluation of SL-401 against lymphoid cancers is warranted.

Stemline and its collaborators from NYU Langone Medical Center, Scott and White Memorial Hospital, and the Institut National de la Sante et de la Recherche Medicale will present the posters.

Owen O'Connor, MD, PhD, of NYU Langone Medical Center and a collaborator on these studies, noted: "Patients with recurrent lymphoid malignancies, in particular, Hodgkin's disease, have few viable treatment options. The initial efficacy data with SL-401 are exciting and we look forward to working with Stemline to further explore this agent in animal studies and beyond."

Ivan Bergstein, MD, CEO of Stemline, commented: "SL-401 is currently being developed in patients with myeloid malignancies. These new data provide an additional potential path forward in lymphoid cancers. We look forward to continuing our collaboration with Dr. O'Connor's group as we continue to pursue this opportunity."

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 SL-401

SL-401 is a novel clinically active oncology compound that targets the interleukin-3 receptor (IL-3R). IL-3R is overexpressed on cancer stem cells (CSCs) and tumor bulk of multiple hematologic cancers. In a Phase I/II trial of patients with advanced acute myeloid leukemia (AML), SL-401 demonstrated single agent efficacy, including complete responses (CRs) and an overall survival benefit, in heavily pretreated patients. In addition, SL-401 was well-tolerated and was not toxic to the bone marrow. Given these promising results, SL-401 is being advanced into later stage trials in this indication. SL-401 is also being clinically tested in Phase I/II studies of patients with high risk myelodysplastic syndrome (MDS) and advanced chronic myeloid leukemia (CML). SL-401 was granted Orphan Drug Designation by the FDA for the treatment of AML.

About Stemline Therapeutics, Inc.

Stemline Therapeutics, Inc. is a clinical stage biopharmaceutical company developing novel oncology compounds that target cancer stem cells (CSCs) and tumor bulk. Stemline is currently developing two clinically active compounds, both of which have demonstrated durable complete responses (CRs) and an overall survival (OS) benefit in Phase I/II studies. SL-401 has completed a multicenter Phase I/II trial in patients with advanced acute myeloid leukemia (AML) where it has demonstrated single agent activity, including two durable CRs and an OS benefit, in heavily pretreated patients. In addition, SL-401 was well-tolerated and was not toxic to the bone marrow. SL-401 is being advanced into later stage trials in advanced AML. SL-401 is also currently being tested in additional indications including chronic myeloid leukemia (CML) and myelodysplastic syndrome (MDS). The Company's second clinical program, SL-701, has demonstrated single agent activity including durable tumor responses, which includes CRs, multiple partial responses (PRs) and an OS benefit, in Phase I/II trials of adult patients with refractory or recurrent high grade glioma and pediatric patients with malignant glioma. SL-701 is now poised for later stage trials in pediatric and adult patients with advanced brain cancer. Stemline is also developing a broad portfolio of preclinical small molecules and antibodies for a variety of solid and hematological cancer types. Many of these compounds have derived from the Company's proprietary discovery platform, StemScreen®. For more information, please visit the Company's website at www.stemline.com.

Stemline Contact:
Mark Jacobson
Associate Director, Business Development
Stemline Therapeutics, Inc.
Tel: 212-584-5747
Email: mjacobson@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.