Convertible Notes Payable	12 Months Ended
Dec. 31, 2014
Convertible Notes Payable
Convertible Notes Payable	2. Convertible Notes Payable In 2009, we issued $7.7 million of convertible promissory notes (the 2009 Notes) to existing preferred stockholders. Originally, the 2009 Notes had an interest rate of 10.0% per annum and original maturity date of September 30, 2009 which was subsequently extended to July 31, 2011. In June 2011, the 2009 Notes were amended to increase the interest rate on the Note from 10.0% to 12.5% and to extend the maturity date to December 31, 2012. In December 2010, we issued an additional $7.5 million of convertible promissory notes (the 2010 Notes) to existing preferred stockholders. The 2010 Notes bear similar terms as the 2009 notes and, originally had an interest rate of 10.0% per annum and an original maturity date of December 31, 2011. In December 2011, the 2010 Notes were amended to increase the interest rate from 10.0% to 12.5% and to extend the maturity date of the Notes to December 31, 2012. In December 2012 the maturity dates for the 2009 Notes and the 2010 Notes were extended to April 15, 2013 and in April 2013 the maturity dates were extended again to June 15, 2013, with each such extension considered to be a modification of debt under ASC 470‑50‑40. In June 2013, and prior to the maturity dates of the 2009 Notes and the 2010 Notes, our Board of Directors and the requisite stockholders and holders of the 2009 Notes and 2010 Notes agreed to exchange the outstanding principal into shares of our Series A‑1 convertible preferred stock in connection with a concurrent financing . The exchange of the 2009 Notes and 2010 Notes was not pursuant to the terms of the applicable notes so we accounted for the exchange as an extinguishment of the original debt instrument.

2. Convertible Notes Payable

In 2009, we issued $7.7 million of convertible promissory notes (the 2009 Notes) to existing preferred stockholders. Originally, the 2009 Notes had an interest rate of 10.0% per annum and original maturity date of September 30, 2009 which was subsequently extended to July 31, 2011. In June 2011, the 2009 Notes were amended to increase the interest rate on the Note from 10.0% to 12.5% and to extend the maturity date to December 31, 2012.

In December 2010, we issued an additional $7.5 million of convertible promissory notes (the 2010 Notes) to existing preferred stockholders. The 2010 Notes bear similar terms as the 2009 notes and, originally had an interest rate of 10.0% per annum and an original maturity date of December 31, 2011. In December 2011, the 2010 Notes were amended to increase the interest rate from 10.0% to 12.5% and to extend the maturity date of the Notes to December 31, 2012.

In December 2012 the maturity dates for the 2009 Notes and the 2010 Notes were extended to April 15, 2013 and in April 2013 the maturity dates were extended again to June 15, 2013, with each such extension considered to be a modification of debt under ASC 470‑50‑40.

In June 2013, and prior to the maturity dates of the 2009 Notes and the 2010 Notes, our Board of Directors and the requisite stockholders and holders of the 2009 Notes and 2010 Notes agreed to exchange the outstanding principal into shares of our Series A‑1 convertible preferred stock in connection with a concurrent financing . The exchange of the 2009 Notes and 2010 Notes was not pursuant to the terms of the applicable notes so we accounted for the exchange as an extinguishment of the original debt instrument.