Quarterly report pursuant to Section 13 or 15(d)

Senior Convertible Notes

Senior Convertible Notes
6 Months Ended
Jun. 30, 2016
Debt Disclosure [Abstract]  
Senior Convertible Notes

6. Senior Convertible Notes

The Company issued approximately $15.0 million in aggregate principal amount of its 8.00% Convertible Notes due May 31, 2015 (the “Convertible Notes”) from June 2013 through June 2014. On August 1, 2014, in conjunction with the closing of the Company’s initial public offering, the principal amount of the Convertible Notes, and all accrued and unpaid interest thereon, automatically converted into 5,109,988 shares of common stock. Upon the closing of the offering, the Company accelerated the amortization of the remaining debt discount balance to interest expense.

Each purchaser of the Convertible Notes received a warrant (the “Note Warrants”). Upon the closing of the initial public offering and based on the terms of the Note Warrants, the Company determined the total number of shares of the Company’s common stock underlying the Note Warrants to be 3,321,416 at an exercise price of $3.00 per share. There were 3,315,878 shares of common stock underlying the outstanding Note Warrants as of June 30, 2016 and December 31, 2015. The Note Warrants expire five years from the date of issuance.