X0306 4 2015-04-06 0 0001157601 SYNTA PHARMACEUTICALS CORP SNTA 0001325713 Kovner Bruce C/O CAXTON CORPORATION 731 ALEXANDER ROAD, BLDG 2 PRINCETON NJ 08540 1 0 1 0 Common Stock 3060860 D Common Stock 2015-04-06 4 P 0 6857143 1.75 A 15278610 I By KFO Holdings LLC Common Stock 5460000 I By OB Select Opportunities, LLC Common Stock 3100000 I By Kovner 2012 Family Trust B Common Stock 250000 I By Kovner 2011 Family Trust Common Stock 125000 I By Kovner 2011-C Investment Trust Common Stock 125000 I By Kovner 2011-D Investment Trust Common Stock 475000 I By Kovner 2012 Family Trust A Common Stock 475000 I By Kovner 2012-B Synta Investment Trust Common Stock 475000 I By Kovner 2012-C Synta Investment Trust Common Stock 475000 I By Kovner 2012-D Synta Investment Trust Common Stock 7761716 I By CxSynta LLC These shares are owned directly by KFO Holdings LLC ("KFO") and indirectly by the Reporting Person as chairman and sole shareholder of Caxton Corporation, the manager of KFO. The Reporting Person disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of all of the reported shares for purposes of Section 16 or for any other purpose. These shares are owned directly by OB Select Opportunities, LLC and indirectly by the Reporting Person as chairman and sole shareholder of Caxton Corporation, the manager of OB Select Opportunities, LLC. The Reporting Person disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of all of the reported shares for purposes of Section 16 or for any other purpose. Reflects the transfer of 125,000 shares from Kovner 2011-B Investment Trust to Kovner 2011 Family Trust since the last filing by the Reporting Person. Reflects the transfer of 475,000 shares from Kovner 2012-A Synta Investment Trust to Kovner 2012 Family Trust A since the last filing by the Reporting Person. These shares are owned directly by CxSynta LLC and indirectly by the Reporting Person as chairman and sole shareholder of Caxton Corporation, the managing member of CxSynta LLC. The Reporting Person disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein, and the inclusion of these shares in this report shall not be deemed an admission of the beneficial ownership of all of the reported shares for purposes of Section 16 or for any other purpose. /s/ Heath Weisberg, Attorney-in-Fact 2015-04-08