Related Party Transactions	12 Months Ended
Dec. 31, 2019
Related Party Transactions
Related Party Transactions	Note 16. Related Party Transactions Baker Brothers Julian C. Baker, a member of the Company’s Board until his resignation in September 2018, is a principal of Baker Bros. Advisors, LP. Additionally, Kelvin M. Neu, a member of Company’s Board until his resignation in June 2019, is an employee of Baker Bros. Advisors, LP. As of December 31, 2019, Baker Bros. Advisors, LP and certain of its affiliated funds (collectively, “Baker Brothers”) held sole voting power with respect to an aggregate of 4,608,786 shares of the Company’s common stock, representing approximately 16% of the Company's outstanding common stock. During 2019, Baker Brothers purchased shares of the Company’s Series B1 Preferred Stock and accompanying warrants to purchase common stock in connection with the 2019 Private Placement, as more fully described in Note 7. Concurrent with the 2019 Private Placement, the Company amended the warrants initially issued to Baker Brothers and other holders on May 7, 2013, September 30, 2013 and February 10, 2014 to remove expiration date. Following the amendment, these warrants will not expire. During 2018, Baker Brothers exercised warrants to purchase 2,700,791 shares of the Company’s common stock at an exercise price of $3.76 per share for a total exercise price of approximately $9.5 million. During 2017, Baker Brothers purchased shares of the Company’s common stock in connection with underwritten public offerings of shares of the Company’s common stock as more fully described in Note 8. As of December 31, 2019, Baker Brothers held warrants to purchase up to 2,708,812 shares of the Company’s common stock at an exercise price of $0.08 per share, warrants to purchase up to 2,368,400 shares of the Company’s common stock (or, if Baker Brothers elects to exercise the warrants for shares of Series B1 Preferred Stock, 23,684 shares of Series B1 Preferred Stock), at an exercise price of $1.52 per share (or, if Baker Brothers elects to exercise the warrants for shares of Series B1 Preferred Stock, $152 per Series B1 Preferred Warrant Share. Pillar Investment Entities Youssef El Zein, a member of the Company’s board of directors 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 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”), Pillar Pharmaceuticals 6 L.P. and Pillar Partners Foundation L.P. (collectively, the “Pillar Investment Entities”). As of December 31, 2019, the Pillar Investment Entities own approximately 11% of the Company's common stock. During 2018, Participations Besancon, an investment fund advised by Pillar Invest having no affiliation with Mr. El Zein, exercised warrants to purchase 150,000 shares of the Company’s common stock at an exercise price of $3.76 per share for a total exercise price of approximately $0.6 million. During 2017, Pillar II exercised 629,257 warrants to purchase shares of the Company’s common stock at a total exercise price of approximately $3.5 million and Besancon exercised 364,752 warrants to purchase shares of the Company’s common stock at a total exercise price of approximately $1.9 million. The warrant exercise prices had been established at the time that the warrants were purchased. Board Fees Paid in Stock Pursuant to the Company’s director compensation program, in lieu of director board and committee fees of approximately $0.1 million incurred during each of the years ended December 31, 2019, 2018 and 2017, respectively, the Company issued 53,985, 13,654, and 7,867 shares of common stock, respectively, to certain of its directors. Director board and committee fees are paid in arrears 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 16. Related Party Transactions

Baker Brothers

Julian C. Baker, a member of the Company’s Board until his resignation in September 2018, is a principal of Baker Bros. Advisors, LP. Additionally, Kelvin M. Neu, a member of Company’s Board until his resignation in June 2019, is an employee of Baker Bros. Advisors, LP. As of December 31, 2019, Baker Bros. Advisors, LP and certain of its affiliated funds (collectively, “Baker Brothers”) held sole voting power with respect to an aggregate of 4,608,786 shares of the Company’s common stock, representing approximately 16% of the Company's outstanding common stock.

During 2019, Baker Brothers purchased shares of the Company’s Series B1 Preferred Stock and accompanying warrants to purchase common stock in connection with the 2019 Private Placement, as more fully described in Note 7. Concurrent with the 2019 Private Placement, the Company amended the warrants initially issued to Baker Brothers and other holders on May 7, 2013, September 30, 2013 and February 10, 2014 to remove expiration date. Following the amendment, these warrants will not expire.

During 2018, Baker Brothers exercised warrants to purchase 2,700,791 shares of the Company’s common stock at an exercise price of $3.76 per share for a total exercise price of approximately $9.5 million.

During 2017, Baker Brothers purchased shares of the Company’s common stock in connection with underwritten public offerings of shares of the Company’s common stock as more fully described in Note 8.

As of December 31, 2019, Baker Brothers held warrants to purchase up to 2,708,812 shares of the Company’s common stock at an exercise price of $0.08 per share, warrants to purchase up to 2,368,400 shares of the Company’s common stock (or, if Baker Brothers elects to exercise the warrants for shares of Series B1 Preferred Stock, 23,684 shares of Series B1 Preferred Stock), at an exercise price of $1.52 per share (or, if Baker Brothers elects to exercise the warrants for shares of Series B1 Preferred Stock, $152 per Series B1 Preferred Warrant Share.

Pillar Investment Entities

Youssef El Zein, a member of the Company’s board of directors 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 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”), Pillar Pharmaceuticals 6 L.P. and Pillar Partners Foundation L.P. (collectively, the “Pillar Investment Entities”). As of December 31, 2019, the Pillar Investment Entities own approximately 11% of the Company's common stock.

During 2018, Participations Besancon, an investment fund advised by Pillar Invest having no affiliation with Mr. El Zein, exercised warrants to purchase 150,000 shares of the Company’s common stock at an exercise price of $3.76 per share for a total exercise price of approximately $0.6 million.

During 2017, Pillar II exercised 629,257 warrants to purchase shares of the Company’s common stock at a total exercise price of approximately $3.5 million and Besancon exercised 364,752 warrants to purchase shares of the Company’s common stock at a total exercise price of approximately $1.9 million. The warrant exercise prices had been established at the time that the warrants were purchased.

Board Fees Paid in Stock

Pursuant to the Company’s director compensation program, in lieu of director board and committee fees of approximately $0.1 million incurred during each of the years ended December 31, 2019, 2018 and 2017, respectively, the Company issued 53,985, 13,654, and 7,867 shares of common stock, respectively, to certain of its directors. Director board and committee fees are paid in arrears and the number of shares issued was calculated based on the market closing price of the Company’s common stock on the issuance date.