Related Party Transactions	3 Months Ended
Mar. 31, 2018
Related Party Transactions
Related Party Transactions	Note 11. Related Party Transactions Overview of Related Parties Youssef El Zein, a member of the Company’s Board until his resignation in October 2017, is a director and controlling stockholder of Pillar Invest Corporation (“Pillar Invest”), which is the general partner of Pillar Pharmaceuticals I, L.P. (“Pillar I”), Pillar Pharmaceuticals II, L.P. (“Pillar II”), Pillar Pharmaceuticals III, L.P. (“Pillar III”), Pillar Pharmaceuticals IV, L.P. (“Pillar IV”) and Pillar Pharmaceuticals V, L.P. (“Pillar V”) and limited partner of Pillar I, Pillar II, Pillar III, Pillar IV and Pillar V. Entities affiliated with Pillar Invest and Participations Besancon (“Besancon”), an investment fund advised by Pillar Invest having no affiliation with Mr. El Zein, Pillar I, Pillar II, Pillar III, Pillar IV, Pillar V or Pillar Invest (collectively, the “Pillar Investment Entities”), owned approximately 12% of the Company's common stock as of March 31, 2018. Julian C. Baker, a member of the Company’s Board, is a principal of Baker Bros. Advisors, LP. Baker Bros. Advisors, LP and certain of its affiliated funds (collectively, “Baker Brothers”) owned approximately 18% of the Company's common stock as of March 31, 2018. Additionally, one of the Company’s directors, Kelvin M. Neu, is an employee of Baker Bros. Advisors, LP as of March 31, 2018. Pillar Investment Entities As of March 31, 2018, Besancon held warrants to purchase up to 1,200,000 shares of the Company’s common stock at an exercise price of $0.47 per share. In April 2018, Besancon exercised these warrants for a total exercise price of approximately $0.6 million. Baker Brothers During the three months ended March 31, 2018, Baker Brothers exercised warrants to purchase 20,316,327 shares of the Company’s common stock at an exercise price of $0.47 per share for a total exercise price of approximately $9.5 million. As of March 31, 2018, Baker Brothers held pre-funded warrants to purchase up to 22,151,052 shares of the Company’s common stock at an exercise price of $0.01 per share. Note 11. Related Party Transactions (Continued) Board Fees Paid in Stock Pursuant to the Company’s director compensation program, in lieu of director board and committee fees incurred of less than $0.1 million during both the three months ended March 31, 2018 and 2017, the Company issued 13,349 and 12,917 shares of common stock, respectively, to certain of its directors. Director board and committee fees are paid in arrears (including fees paid in stock) and the number of shares issued was calculated based on the market closing price of the Company’s common stock on the issuance date.

Note 11. Related Party Transactions

Overview of Related Parties

Youssef El Zein, a member of the Company’s Board until his resignation in October 2017, is a director and controlling stockholder of Pillar Invest Corporation (“Pillar Invest”), which is the general partner of Pillar Pharmaceuticals I, L.P. (“Pillar I”), Pillar Pharmaceuticals II, L.P. (“Pillar II”), Pillar Pharmaceuticals III, L.P. (“Pillar III”), Pillar Pharmaceuticals IV, L.P. (“Pillar IV”) and Pillar Pharmaceuticals V, L.P. (“Pillar V”) and limited partner of Pillar I, Pillar II, Pillar III, Pillar IV and Pillar V. Entities affiliated with Pillar Invest and Participations Besancon (“Besancon”), an investment fund advised by Pillar Invest having no affiliation with Mr. El Zein, Pillar I, Pillar II, Pillar III, Pillar IV, Pillar V or Pillar Invest (collectively, the “Pillar Investment Entities”), owned approximately 12% of the Company's common stock as of March 31, 2018.

Julian C. Baker, a member of the Company’s Board, is a principal of Baker Bros. Advisors, LP. Baker Bros. Advisors, LP and certain of its affiliated funds (collectively, “Baker Brothers”) owned approximately 18% of the Company's common stock as of March 31, 2018. Additionally, one of the Company’s directors, Kelvin M. Neu, is an employee of Baker Bros. Advisors, LP as of March 31, 2018.

Pillar Investment Entities

As of March 31, 2018, Besancon held warrants to purchase up to 1,200,000 shares of the Company’s common stock at an exercise price of $0.47 per share. In April 2018, Besancon exercised these warrants for a total exercise price of approximately $0.6 million.

Baker Brothers

During the three months ended March 31, 2018, Baker Brothers exercised warrants to purchase 20,316,327 shares of the Company’s common stock at an exercise price of $0.47 per share for a total exercise price of approximately $9.5 million.

As of March 31, 2018, Baker Brothers held pre-funded warrants to purchase up to 22,151,052 shares of the Company’s common stock at an exercise price of $0.01 per share.

Note 11. Related Party Transactions (Continued)

Board Fees Paid in Stock

Pursuant to the Company’s director compensation program, in lieu of director board and committee fees incurred of less than $0.1 million during both the three months ended March 31, 2018 and 2017, the Company issued 13,349 and 12,917 shares of common stock, respectively, to certain of its directors. Director board and committee fees are paid in arrears (including fees paid in stock) and the number of shares issued was calculated based on the market closing price of the Company’s common stock on the issuance date.