Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
Common Stock, $0.0001 par value^F2	Aug 24, 2015	P	25,485	$19.6547	A	355,020	I	See Footnote
Common Stock, $0.0001 par value^F1	holding	—	—		—	4,087,900	I	See Footnote

Table II — derivative securities

No Table II lines on this filing.

Explanation of responses

F1Shares are owned directly by Foresite Capital Fund II, L.P. ("FCF II"). Foresite Capital Management II, LLC ("FCM II"), the general partner of FCF II, may be deemed to have the sole voting and dispositive power over these shares. James Tananbaum (" Mr. Tananbaum"), in his capacity as managing member of FCM II, may be deemed to have the sole voting and dispositive power over these shares. Each Reporting Person disclaims the existence of a "group." Each of FCM II and its members and Mr. Tananbaum disclaims beneficial ownership of any of these shares except to the extent of any pecuniary interest therein, and the filing of this report is not an admission that FCM II and its members or Mr. Tananbaum is the beneficial owner of these shares for purposes of Section 16 or any other purpose.
F2Shares are owned directly by Foresite Capital Fund III, L.P. ("FCF III"). Foresite Capital Management III, LLC ("FCM III"), the general partner of FCF III, may be deemed to have the sole voting and dispositive power over these shares. James Tananbaum (" Mr. Tananbaum"), in his capacity as managing member of FCM III, may be deemed to have the sole voting and dispositive power over these shares. Each Reporting Person disclaims the existence of a "group." Each of FCM III and its members and Mr. Tananbaum disclaims beneficial ownership of any of these shares except to the extent of any pecuniary interest therein, and the filing of this report is not an admission that FCM III and its members or Mr. Tananbaum is the beneficial owner of these shares for purposes of Section 16 or any other purpose.