Stemline Therapeutics Initiates SL-401 Clinical Trial in Four Rare Myeloproliferative Neoplasms

NEW YORK, Dec. 16, 2014 (GLOBE NEWSWIRE) -- Stemline Therapeutics, Inc. (Nasdaq:STML) announced today the initiation of a clinical trial with SL-401 in four rare myeloproliferative neoplasms (MPN). SL-401 is a targeted therapy directed to the interleukin-3 receptor (IL-3R) present on cancer stem cells (CSCs) and tumor bulk of a wide range of hematologic cancers. This represents the third clinical trial with SL-401, across seven oncologic indications, that Stemline has opened in the second half of 2014.

This latest SL-401 trial to open will enroll patients with four types of advanced high-risk MPNs, including systemic mastocytosis, advanced symptomatic hypereosinophilic disorder, myelofibrosis, and chronic myelomonocytic leukemia, which represent indications that overexpress IL-3R and appear to derive from a common IL-3R+ progenitor cell. The study consists of a brief lead-in stage that will transition into a larger expansion stage in which the antitumor activity of SL-401 will be evaluated in each of the four aforementioned types of advanced high-risk MPNs. Participating clinical sites currently include the Mayo Clinic (Rochester, MN) and the MD Anderson Cancer Center (Houston, TX). This trial follows the recent opening of trials with SL-401 in patients with blastic plasmacytoid dendritic cell neoplasm (BPDCN) and relapsed/refractory acute myeloid leukemia (AML) and in patients with AML in first complete response (CR) with minimal residual disease (MRD).

Eric K. Rowinsky, M.D., Stemline's Chief Medical Officer and Head of Research and Development commented, "The impetus for this trial is based on the robust tumor responses observed in patients with hematologic malignancies that overexpress SL-401's target, the IL-3R, particularly BPDCN and AML." He continued, "In addition to the scientific rationale for evaluating the antitumor activity of SL-401 in these IL-3R-expressing cancers, there are no impactful agents available to effectively treat these rare MPNs when in advanced stages, and therefore each of these four malignancies represents an unmet medical need. We have designed an efficient trial that is, in essence, four Phase 2 studies in one, with any one or more of its arms providing a foundation for registration."

About Stemline Therapeutics

Stemline Therapeutics, Inc. is a clinical stage biopharmaceutical company developing novel therapeutics that target both cancer stem cells (CSCs) and tumor bulk. Stemline is currently developing two clinical stage product candidates, SL-401 and SL-701. SL-401 is a targeted therapy directed to the interleukin-3 receptor (IL-3R). A multicenter clinical trial with SL-401 is currently open and accruing patients with blastic plasmacytoid dendritic cell neoplasm (BPDCN) and advanced acute myeloid leukemia (AML). Additional clinical trials with SL-401 are currently open in patients with AML who are in first complete remission (CR) with minimal residual disease (MRD), which is associated with a high relapse rate, and several uncommon, stem cell-derived myeloproliferative disorders. Previously, SL-401 demonstrated single-agent activity, including multiple durable CRs, in a Phase 1/2 trial in several indications including BPDCN and relapsed/refractory AML. SL-701 is an enhanced immunotherapy designed to activate the immune system to attack tumors. A multicenter clinical trial with SL-701 is currently open and accruing adult patients with glioblastoma multiforme (GBM) in first recurrence. Previously, an earlier version of the therapy demonstrated clinical activity, including durable CRs and partial responses (PRs), in Phase 1/2 trials in adults and children with advanced brain cancers. For more information about Stemline Therapeutics, visit

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Source:Stemline Therapeutics, Inc.