X0306 4 2016-01-19 0 0001264587 STEMLINE THERAPEUTICS INC STML 0001456864 Gionco David C/O STEMLINE THERAPEUTICS, INC. 750 LEXINGTON AVENUE, ELEVENTH FLOOR NEW YORK NY 10022 0 1 0 0 Chief Accounting Officer Common Stock 2016-01-19 4 S 0 3171 4.82 D 35290 D Common Stock 2016-01-20 4 S 0 46 4.69 D 35244 D In connection with the vesting of 7,500 shares on January 16, 2016, a total of 3,217 of such shares were sold by the Company in order to satisfy the reporting person's tax withholding obligations. The reporting person had no discretion with respect to such sale, which was conducted automatically in accordance with the issuer's corporate policies. Reflects the weighted average sale price. The range of prices for such transaction is $4.80 to $4.85. The reporting person effected multiple same-way open market sale transactions on the same day at different prices through a trade order executed by a broker-dealer. The reporting person reported on a single line all such transactions that occurred within a one dollar price range. The reporting person hereby undertakes to provide upon request by the Securities Exchange Commission staff, the issuer, or a shareholder of the issuer, full information regarding the number of shares sold at each separate price. Of the 35,290 shares, 26,569 shares are restricted stock. Reflects the weighted average sale price. The range of prices for such transaction is $4.67 to $4.69. The reporting person effected multiple same-way open market sale transactions on the same day at different prices through a trade order executed by a broker-dealer. The reporting person reported on a single line all such transactions that occurred within a one dollar price range. The reporting person hereby undertakes to provide upon request by the Securities Exchange Commission staff, the issuer, or a shareholder of the issuer, full information regarding the number of shares sold at each separate price. Of the 35,244 shares, 26,569 shares are restricted stock. /s/ David Gionco 2016-01-21