April 2014 Credit Facility	9 Months Ended
Sep. 30, 2018
Debt Disclosure [Abstract]
April 2014 Credit Facility	6. April 2014 Credit Facility On April 30, 2014, the Company received net cash proceeds of approximately $4,898,000 pursuant to the execution of the April 2014 Credit Facility. Upon entering into the April 2014 Credit Facility, the Company was required to pay the lender a facility fee of $50,000 in conjunction with the funding of the term loan. The April 2014 Credit Facility was secured by substantially all of the Company’s personal property other than its intellectual property. The term loan under the April 2014 Credit Facility bore interest at an annual rate of 7.95%. The Company was required to make interest-only payments on the term loan through August 1, 2015. The outstanding term loan under the April 2014 Credit Facility began amortizing at the end of the applicable interest-only period, with monthly payments of principal and interest being made by the Company to the lender in consecutive monthly installments following such interest-only period. The term loan under the April 2014 Credit Facility matured on July 1, 2018. Under the original terms of the underlying agreement, the Company was also required to make a final payment to the lender equal to 5.5% of the original principal amount of the term loan funded. A warrant to purchase up to 588 shares of the Company’s common stock at an exercise price of $424.80 per share with a term of 10 years was issued to Oxford Finance LLC on April 30, 2014. Issuance costs of approximately $102,000 associated with the term loan under the April 2014 Credit Facility were recorded as a discount to outstanding debt as of the closing date, resulting in net proceeds of approximately $4,898,000. The estimated fair value of the warrant issued of approximately $233,000 was also recorded as a discount to outstanding debt as of the closing date. The discounts and other issuance costs were amortized to interest expense utilizing the effective interest method over the underlying term of the loan, with a total unamortized discount of approximately $33,000 at December 31, 2017. The effective annual interest rate associated with the April 2014 Credit Facility was 13.87% at both December 31, 2017 and June 30, 2018. A principal payment of approximately $175,000 remained outstanding at June 30, 2018 and was paid on July 1, 2018.

6. April 2014 Credit Facility

On April 30, 2014, the Company received net cash proceeds of approximately $4,898,000 pursuant to the execution of the April 2014 Credit Facility. Upon entering into the April 2014 Credit Facility, the Company was required to pay the lender a facility fee of $50,000 in conjunction with the funding of the term loan. The April 2014 Credit Facility was secured by substantially all of the Company’s personal property other than its intellectual property. The term loan under the April 2014 Credit Facility bore interest at an annual rate of 7.95%. The Company was required to make interest-only payments on the term loan through August 1, 2015. The outstanding term loan under the April 2014 Credit Facility began amortizing at the end of the applicable interest-only period, with monthly payments of principal and interest being made by the Company to the lender in consecutive monthly installments following such interest-only period. The term loan under the April 2014 Credit Facility matured on July 1, 2018. Under the original terms of the underlying agreement, the Company was also required to make a final payment to the lender equal to 5.5% of the original principal amount of the term loan funded.

A warrant to purchase up to 588 shares of the Company’s common stock at an exercise price of $424.80 per share with a term of 10 years was issued to Oxford Finance LLC on April 30, 2014. Issuance costs of approximately $102,000 associated with the term loan under the April 2014 Credit Facility were recorded as a discount to outstanding debt as of the closing date, resulting in net proceeds of approximately $4,898,000. The estimated fair value of the warrant issued of approximately $233,000 was also recorded as a discount to outstanding debt as of the closing date. The discounts and other issuance costs were amortized to interest expense utilizing the effective interest method over the underlying term of the loan, with a total unamortized discount of approximately $33,000 at December 31, 2017. The effective annual interest rate associated with the April 2014 Credit Facility was 13.87% at both December 31, 2017 and June 30, 2018. A principal payment of approximately $175,000 remained outstanding at June 30, 2018 and was paid on July 1, 2018.