Stemline Therapeutics, Inc., a clinical-stage biopharmaceutical company, focuses on the discovering, acquiring, developing, and commercialization of proprietary oncology therapeutics in the United States. The company develops SL-401, a targeted therapy directed to the interleukin-3 receptor (IL-3R), which is in Phase II clinical trial for patients with blastic plasmacytoid dendritic cell neoplasm, myeloproliferative neoplasms, and acute myeloid leukemia; and in Phase I clinical trial in combination with other agents for patients with relapsed/refractory multiple myeloma. It also develops SL-801, a novel oral small molecule reversible inhibitor of a tumor-promoting nuclear transport protein, which is in Phase I clinical trial for the treatment of solid and hematologic cancers; and SL-701, an immunotherapy that is in Phase II clinical trial to attack brain cancer. In addition, it develops SL-501, a next generation IL-3R-targeted therapy that is in preclinical development. Stemline Therapeutics, Inc. was founded in 2003 and is based in New York, New York.