Stemline Therapeutics, Inc. announced that SL-401, the company’s lead compound, has received Orphan Drug designation from the US Food and Drug Administration (FDA) for the treatment of acute myeloid leukaemia (AML).
 
SL-401 has completed a multi-centre phase I/II clinical trial in AML where it has demonstrated single agent efficacy, including two durable complete responses (CRs), multiple blast reductions and disease stabilizations, and an overall survival (OS) benefit in heavily pre-treated patients. SL-401 was well-tolerated and bone marrow-sparing. The trial results were presented at the 52nd Annual Meeting of the American Society of Haematology (ASH) in December 2010. SL-401 is now poised for phase III clinical trials in patients with advanced AML.
 
Stemline’s CEO, Ivan Bergstein, MD, noted, “Receipt of Orphan Drug designation represents another key milestone in the advancement of SL-401 through the regulatory process. We are also very encouraged by the potential of SL-401 to benefit patients with advanced stage AML, an unmet medical need, as well as additional haematologic malignancies including MDS, CML and potentially certain lymphomas.”
 
Orphan Drug designation granted by the FDA provides companies with incentives to support the development of novel therapies that treat rare diseases or conditions affecting fewer than 200,000 people in the U.S. Those incentives include seven years of marketing exclusivity in the designated indication, tax credits and grants for clinical development, and a waiver of Prescription Drug User Fee Act (PDUFA) filing fees.

AML is a haematologic cancer characterized by dysregulated maturation of myeloid cells and failure of the bone marrow as a whole to properly function. It has become increasingly established that leukaemia stem cells, which comprise a subpopulation of the cells within AML, are the cells that give rise to and sustain AML and are resistant to standard therapies. According to the American Cancer Society, AML is one of the most common types of leukaemia, with approximately 12,000 new cases in 2010. Most patients treated for AML will unfortunately relapse and the majority of relapsing patients will ultimately die from their disease, often within one year of relapse. With high relapse rates and a poor survival outlook, there is an urgent need to develop novel therapies for this devastating disease.
 
Stemline Therapeutics, Inc. is a clinical stage biopharmaceutical company developing novel oncology compounds that target cancer stem cells (CSCs) and tumour bulk. SL-401, the company’s lead programme, has completed a multicenter phase I/II trial in advanced stage acute myeloid leukaemia (AML) 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.