Loan and Security Agreement	6 Months Ended
Jun. 30, 2019
Debt Disclosure [Abstract]
Loan and Security Agreement	6. Loan and Security Agreement In August 2017, the Company entered into a loan and security agreement with Oxford Finance LLC (“Oxford”) and Silicon Valley Bank (“SVB”) under which it borrowed $15.0 million (the “August 2017 Loan”). The loan is due in 30 monthly installments from March 2019 through its repayment in August 2021, with interest-only monthly payments until March 2019. The Company commenced repayment of the loan in March 2019. The August 2017 Loan is secured by all assets of the Company, excluding intellectual property and certain other assets. The August 2017 Loan contains customary affirmative and restrictive covenants, including with respect to fundamental transactions, the incurrence of additional indebtedness, grant liens, pay any dividend or make any distributions to the Company’s holders, make investments, merge or consolidate with any other person, or engage in transactions with its affiliates, but does not include any financial covenants. The loan agreement provides that an event of default will occur if, among other triggers, any circumstances occur that could reasonably be expected to result in a material adverse effect on the Company’s business, operations or condition, or on its ability to perform its obligations under the loan. The loan agreement also includes customary representations and warranties, other events of default and termination provisions. As of June 30, 2019, the Company has classified $5.8 million of the outstanding debt balance as current and $7.0 million as non-current, which reflects the scheduled repayment terms under the August 2017 Loan. The interest charges on the loan are based on a floating rate that equals the greater of 7.39% or the sum of the 30-day U.S. Dollar London Interbank Offered Rate (“LIBOR”) plus 6.40%. For the six months ended June 30, 2019, the average interest rate was 8.88%. In addition, the Company will make a final payment equal to 3.83% of the original principal amount of the loan, or $0.6 million, which is being accrued over the term of the loan using the effective-interest method. As of June 30, 2019, total interest expense accrued was $0.4 million. In connection with the August 2017 Loan, the Company issued to Oxford and SVB a warrant to purchase the Company’s Series D-2 redeemable convertible preferred stock (the “2017 Warrant”). The 2017 Warrants were later converted into warrants to purchase Series E redeemable convertible preferred stock in May and July 2018, and upon the Company’s IPO on October 1, 2018, all Series E redeemable convertible preferred stock warrants were converted to warrants to purchase 46,359 shares of common stock. The estimated fair value upon issuance of the 2017 Warrant of $0.3 million was recorded as a debt discount on the associated borrowings on the Company’s balance sheet. The debt discount is being amortized to interest expense over the repayment period of the loan using the effective-interest method. During the three months ended June 30, 2019 and 2018, the Company recorded interest expense related to this loan of $0.3 million and $0.3 million, respectively, and interest related to the accretion of debt discount of $85,000 and $86,000, respectively. During the six months ended June 30, 2019 and 2018, the Company recorded interest expense related to this loan of $0.6 million and $0.6 million, respectively, and interest related to the accretion of debt discount of $175,000 and $168,000, respectively.

Loan and Security Agreement

6 Months Ended

Jun. 30, 2019

6. Loan and Security Agreement

In August 2017, the Company entered into a loan and security agreement with Oxford Finance LLC (“Oxford”) and Silicon Valley Bank (“SVB”) under which it borrowed $15.0 million (the “August 2017 Loan”). The loan is due in 30 monthly installments from March 2019 through its repayment in August 2021, with interest-only monthly payments until March 2019. The Company commenced repayment of the loan in March 2019.

The August 2017 Loan is secured by all assets of the Company, excluding intellectual property and certain other assets. The August 2017 Loan contains customary affirmative and restrictive covenants, including with respect to fundamental transactions, the incurrence of additional indebtedness, grant liens, pay any dividend or make any distributions to the Company’s holders, make investments, merge or consolidate with any other person, or engage in transactions with its affiliates, but does not include any financial covenants. The loan agreement provides that an event of default will occur if, among other triggers, any circumstances occur that could reasonably be expected to result in a material adverse effect on the Company’s business, operations or condition, or on its ability to perform its obligations under the loan. The loan agreement also includes customary representations and warranties, other events of default and termination provisions.

As of June 30, 2019, the Company has classified $5.8 million of the outstanding debt balance as current and $7.0 million as non-current, which reflects the scheduled repayment terms under the August 2017 Loan.

The interest charges on the loan are based on a floating rate that equals the greater of 7.39% or the sum of the 30-day U.S. Dollar London Interbank Offered Rate (“LIBOR”) plus 6.40%. For the six months ended June 30, 2019, the average interest rate was 8.88%. In addition, the Company will make a final payment equal to 3.83% of the original principal amount of the loan, or $0.6 million, which is being accrued over the term of the loan using the effective-interest method. As of June 30, 2019, total interest expense accrued was $0.4 million.

In connection with the August 2017 Loan, the Company issued to Oxford and SVB a warrant to purchase the Company’s Series D-2 redeemable convertible preferred stock (the “2017 Warrant”). The 2017 Warrants were later converted into warrants to purchase Series E redeemable convertible preferred stock in May and July 2018, and upon the Company’s IPO on October 1, 2018, all Series E redeemable convertible preferred stock warrants were converted to warrants to purchase 46,359 shares of common stock. The estimated fair value upon issuance of the 2017 Warrant of $0.3 million was recorded as a debt discount on the associated borrowings on the Company’s balance sheet. The debt discount is being amortized to interest expense over the repayment period of the loan using the effective-interest method.

During the three months ended June 30, 2019 and 2018, the Company recorded interest expense related to this loan of $0.3 million and $0.3 million, respectively, and interest related to the accretion of debt discount of $85,000 and $86,000, respectively. During the six months ended June 30, 2019 and 2018, the Company recorded interest expense related to this loan of $0.6 million and $0.6 million, respectively, and interest related to the accretion of debt discount of $175,000 and $168,000, respectively.