Stemline Therapeutics Inc. plans to sell 6,600,000 common shares through an underwritten public offering.

The New York-based cancer drug developer expects to grant underwriters a 30-day option to buy up to 990,000 additional common shares.

Net proceeds will be used on commercial activities for Elzonris, Stemline Therapeutics' treatment for blastic plasmacytoid dendritic cell neoplasm, a rare blood disease. Funds will also go toward clinical trials, including those for additional indications of Elzonris, research and development activities, potential acquisitions and in-licensing, as well as other general corporate purposes.

J.P. Morgan Securities LLC is acting as book-running manager for the offering.