Stemline Therapeutics Licenses Phase I/II Brain Cancer Vaccine - Shows Promise in Clinical Trial Conducted at University of Pittsburgh

NEW YORK, Feb. 23, 2011 /PRNewswire/ -- Stemline Therapeutics, Inc., a clinical stage biopharmaceutical company developing novel oncology compounds that target cancer stem cells (CSCs), today announced that it holds the license, from the University of Pittsburgh ("Pitt"), for the exclusive worldwide rights to a clinically active oncology vaccine directed to multiple defined targets on tumor bulk and CSCs. Developed by Dr. Hideho Okada, Associate Professor of Neurological Surgery and his colleagues at Pitt, the vaccine demonstrated safety, tolerability, and anti-tumor activity as a single agent in a Phase I, National Institutes of Health-funded study conducted at Pitt in 22 participants with recurrent high-grade glioma.

According to Dr. Okada's research findings, published recently in the Journal of Clinical Oncology, the most common grade 1-2 adverse events (AEs) were injection site reactions and fatigue. There were no grade 3 or 4 AEs. The vaccine elicited immune responses in 81% of evaluable patients. A high rate of overall response and disease stabilization was observed in this heavily pre-treated population, including 46% (6/13) in glioblastoma (GBM), and 67% (6/9) in anaplastic glioma (AG). Notably, there was one durable complete response (CR) of greater than 12 months in a 1st salvage GBM patient, and one partial response (PR) of 7 months duration in a 2nd salvage GBM patient. In both cases, the vaccine induced tumor shrinkage as determined by MRI according to standard RECIST criteria. A survival improvement over historical data was also observed in both the recurrent GBM and AG populations. The vaccine and its derivatives are being developed by Stemline under the name SL-701 as both an "off-the-shelf" peptide vaccine and a dendritic cell (DC) vaccine.

Tom Cirrito, PhD, Director of Operations at Stemline noted, "We became interested in Pitt's vaccine because of its dual targeting of both tumor bulk and cancer stem cells. In addition, by virtue of its targeting of multiple defined epitopes, we are able to determine the specificity and magnitude of the immune response in patients. Importantly, we have also observed reductions in tumor size as well as improvements in survival, consistent with the drug's mechanism of action."

Stemline's CEO, Ivan Bergstein, MD, commented on the in-licensing, "We are excited to add another clinical stage therapeutic to our pipeline. With this acquisition, we now have two clinical programs that have demonstrated complete responses and a survival benefit in heavily pre-treated populations. We are committed to a development strategy that rapidly advances these programs through the regulatory process toward commercialization."

About Stemline Therapeutics, Inc.

Stemline Therapeutics, Inc. is a clinical stage biopharmaceutical company developing novel oncology compounds that target cancer stem cells (CSCs). SL-401, the Company's lead program, has completed a multicenter Phase I/II trial in advanced stage acute myeloid leukemia where it has demonstrated single agent activity including two durable complete responses (CR) and an overall survival (OS) benefit, and is now poised for Phase III studies. SL-401 is also currently being tested in additional indications including myelodysplastic syndrome (high risk) and chronic myeloid leukemia (not candidate for TKI therapy). The vaccine that is the basis of the Company's second clinical program has completed a Phase I/II trial at Pitt in adult patients with recurrent malignant glioma (brain cancer) where it has demonstrated single agent activity including a durable CR and an OS benefit. This cancer vaccine, now being further developed by Stemline as SL-701, is poised for Phase II/III trials in patients with recurrent malignant glioma. 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. 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.