Stockholders' Equity Note Disclosure [Text Block] | 7. Common Stock Warrants for Common Stock As of March 31, 2016, outstanding warrants to purchase an aggregate of 401,446 shares of common stock were as follows: Number of Shares Outstanding Exercisable Expiration Exercise Under Issuance Date for Date Price Warrants September 2014 Common Shares September 23, 2019 $ 4.24 110,550 September 2014 Common Shares September 30, 2024 $ 4.24 58,962 October 2014 Common Shares October 13, 2019 $ 4.24 29,000 October 2014 Common Shares October 31, 2019 $ 4.24 469 November 2014 Common Shares November 12, 2019 $ 4.24 12,500 February 2015 Common Shares February 17, 2025 $ 4.00 75,697 March 2015 Common Shares March 26, 2025 $ 2.72 1,454 May 2015 Common Shares May 12, 2025 $ 4.24 36,229 May 2015 Common Shares May 14, 2025 $ 2.96 3,125 May 2015 Common Shares May 17, 2020 $ 4.24 21,585 December 2015 Common Shares December 16, 2025 $ 5.60 26,875 March 2016 Common Shares March 31, 2026 $ 6.08 25,000 401,446 In connection with a private offering that closed on September 30, 2014, the Company issued warrants to purchase a total of 117,535 shares of common stock at an exercise price of $4.24 per share. The warrants have a contractual life of five years and are exercisable immediately in whole or in part, on or before five years from the issuance date. A total of 735 and 6,250 shares issuable pursuant to these warrants were exercised in 2015 and March 2016, respectively. In connection with the Loan Agreement entered into on September 30, 2014, the Company issued a warrant to purchase a total of 58,962 shares of common stock at an exercise price of $4.24 per share. The warrant has a contractual life of ten years and is exercisable immediately in whole or in part, on or before ten years from the issuance date. The fair value of the warrant was recorded as debt issuance costs, presented in the condensed consolidated balance sheets as a deduction from the carrying amount of the note payable, and will be amortized to interest expense over the loan term. During the three months ended March 31, 2016 and 2015, the Company recorded $45,000 and $48,000, respectively, of interest expense relating to the debt issuance costs. As of March 31, 2016, the remaining unamortized debt issuance costs were $342,000 and the warrant remained outstanding. In connection with the first loan amendment in February 2015, the Company also amended the terms of the warrant issued to the lender to provide for an automatic increase of the number of shares the lender may acquire in the event the Company fails to meet certain covenants to achieve certain OUS Clinical Trial milestones or capital raising requirements as set forth in the Loan Agreement, as amended, by a number equal to the quotient derived by dividing (i) 1% of the principal balance outstanding under the Loan Agreement by (ii) the exercise price of $4.24 per share. In October and November of 2014, the Company issued common stock warrants to various vendors and nonemployee contractors to purchase a total of 47,751 shares of common stock at an exercise price of $4.24 per share. The warrants have a contractual life of five years and are exercisable in whole or in part, either immediately upon grant or in some cases upon achieving certain milestones or vesting terms. The fair values of the warrants were recorded as professional consulting fees or clinical costs, which are included in selling, general and administrative and research and development expenses in the consolidated statements of operations for the year ended December 31, 2014, depending on the nature of the services provided. Stock-based compensation expense related to these warrants is recognized as the warrants are earned and was zero and $15,000 for the three months ended March 31, 2016 and 2015, respectively. A total of 5,157 and 625 shares issuable pursuant to warrants issued to two vendors in October 2014 were cancelled in 2015 and March 2016, respectively, as the milestones related to these shares were not achieved. In February 2015, the Company issued to employees for performance bonuses common stock warrants to purchase a total of 75,697 shares of common stock at an exercise price of $4.00 per share. The warrants have a contractual life of ten years and are exercisable immediately in whole or in part, on or before ten years from the issuance date. The fair values of the warrants were recorded in selling, general and administrative and research and development expenses in the condensed consolidated statements of operations for the three months ended March 31, 2015, depending on the department classification of the employee. The Company recorded zero and $244,000 of stock-based compensation expense related to these warrants in the three months ended March 31, 2016 and 2015, respectively. In March 2015, the Company issued a common stock warrant to a nonemployee contractor to purchase a total of 1,454 shares of common stock at an exercise price of $2.72 per share. The warrant has a contractual life of ten years and is exercisable immediately in whole or in part, on or before ten years from the issuance date. The fair value of the warrant was recorded as professional consulting fees, which are included in selling, general and administrative expenses in the condensed consolidated statements of operations for the three months ended March 31, 2015. The Company recorded zero and $3,000 of stock-based compensation expense related to these warrants in the three months ended March 31, 2016 and 2015, respectively. In May 2015, the Company issued common stock warrants to nonemployee contractors to purchase a total of 36,229 shares of common stock at an exercise price of $4.24 per share. The warrants have a contractual life of ten years and are exercisable immediately in whole or in part, on or before ten years from the issuance date. The fair values of the warrants were recorded as professional consulting fees, which are included in selling, general and administrative expenses in the condensed consolidated statements of operations for the three months ended June 30, 2015. Stock-based compensation expense related to these warrants was zero for both the three months ended March 31, 2016 and 2015. In conjunction with the second loan amendment in May 2015, the Company issued a warrant to the lender to purchase a total of 3,125 shares of common stock at an exercise price of $2.96 per share. The warrant has a contractual life of ten years and is exercisable immediately in whole or in part, on or before ten years from the issuance date. The fair value of the warrant was recorded as debt issuance costs, and was amortized to interest expense over the period from the date of issuance to the end of the extended period to draw down the additional funds in connection with the third tranche or July 15, 2015. During the three months ended March 31, 2016 and 2015, the Company recorded zero of interest expense relating to the debt issuance costs for this warrant. As of March 31, 2016, the remaining unamortized debt issuance costs were zero. In May 2015, the Company issued a common stock warrant to a nonemployee contractor to purchase a total of 21,585 shares of common stock at an exercise price of $4.24 per share. The warrant has a contractual life of five years and is exercisable immediately in whole or in part, on or before five years from the issuance date. The fair value of the warrant was recorded as professional consulting fees, which are included in selling, general and administrative expenses in the condensed consolidated statements of operations. Stock-based compensation expense related to these warrants was zero for both the three months ended March 31, 2016 and 2015. In December 2015, the Company issued common stock warrants to employees and nonemployee contractors for performance bonuses to purchase a total of 26,875 shares of common stock at an exercise price of $5.60 per share. The warrants have a contractual life of ten years and are exercisable immediately in whole or in part, on or before ten years from the issuance date. The fair values of the warrants were recorded in selling, general and administrative and research and development expenses in the consolidated statements of operations, depending on the department classification of the employee or nonemployee contractor. The stock-based compensation expense related to these warrants was zero for both the three months ended March 31, 2016 and 2015. In March 2016, the Company issued a common stock warrant to a distributor to purchase a total of 25,000 shares of common stock at an exercise price of $6.08 per share. The warrant has a contractual life of ten years and is exercisable immediately in whole or in part, on or before ten years from the issuance date. The Company determined the fair value of the warrant using the Black-Scholes option pricing model. Assumptions used were dividend yield of 0%, volatility of 72.1%, risk free interest rate of 1.78% and a contractual life of ten years. The Company recorded $142,000 of stock-based compensation expense related to these warrants in the three months ended March 31, 2016. |