On August 16, 2021, the Company entered into a Loan and Security Agreement (the “Loan Agreement”) with Hercules Capital, Inc. (“Hercules”), with respect to a venture debt facility. Under the Loan Agreement, Hercules provided the Company with access to a term loan with an aggregate principal amount of up to $30,000 (the “Term Loan Facility”), available in three tranches, subject to certain terms and conditions. The first tranche of $15,000 was advanced to the Company on the date the Loan Agreement was executed. Upon the occurrence of specified milestones and continuing through December 31, 2022, a loan in the aggregate principal amount of up to $10,000 (“the second tranche”), and upon the occurrence of specified milestones and continuing through September 30, 2023, a loan in the aggregate principal amount of up to $5,000 (“the third tranche”), may become available. The milestones for the remaining tranches have not yet been reached as of December 31, 2021. The Company is required to make interest only payments through March 1, 2023, or extended to September 1, 2023 upon satisfaction of certain milestones, and is required to then repay the principal balance and interest in equal monthly installments through September 1, 2025.

The Company may prepay advances under the Loan Agreement, in whole or in part, at any time subject to a prepayment charge equal to: (a) 3.0 % of amounts prepaid, if such prepayment occurs during the first 12 months following the closing date; (b) 2.0% after 12 months but prior to 24 months; (c) 1.0% after 24 months but prior to 36 months, and (d) no charge after 36 months. Upon prepayment or repayment of all or any of the term loans under the Term Loan Facility, the Company is required to pay an end of term charge (“End of Term Charge”) equal to 6.55% of the total aggregate amount of the term loans being prepaid or repaid.

Interest on the term loan accrues at a per annum rate equal to the greater of (i) the Prime Rate as reported in The Wall Street Journal plus 5.70% and (ii) 8.95%. On December 31, 2021, the Prime Rate was 3.25%. Interest expense is calculated using the effective interest method and is inclusive of non-cash amortization of capitalized loan issuance costs. Debt issuance costs are recorded on the consolidated balance sheet as a reduction of liabilities. Amounts allocated to the debt, net of issuance cost, are subsequently recognized at amortized cost using the effective interest method. On December 31, 2021, the effective interest rate was 13.73%.

As of December 31, 2021, the carrying value of the term loan consists of $15,000 principal outstanding less the debt discount and issuance costs of approximately $775. The End of Term Charge of $983 is recognized over the life of the term loan as interest expense using the effective interest method. The debt issuance costs have been recorded as a debt discount which are being accreted to interest expense through the maturity date of the term loan.

Interest expense relating to the term loan, which is included in interest expense in the consolidated statements of operations was $699 for the year ended December 31, 2021.

Under the terms of the Loan Agreement, the Company granted first priority liens and security interests in substantially all of the Company’s intellectual property as collateral for the obligations thereunder. The Company also granted Hercules the right, at their discretion, to participate in any closing of any single subsequent broadly marketed financing as defined up to a maximum aggregate amount of $2,000 under the terms as afforded to other investors in such financing. The Loan Agreement also contains representations and warranties by the Company and Hercules, indemnification provisions in favor of Hercules and customary affirmative and negative covenants, including a liquidity covenant beginning October 1, 2022, requiring the Company to maintain a minimum aggregate compensating cash balance of $5,000, and events of default, including a material adverse change in the Company’s business, payment defaults, breaches of covenants following any applicable cure period, and a material impairment in the perfection or priority of Hercules’ security interest in the collateral. In the event of default by the Company under the Loan Agreement, the Company may be required to repay all amounts then outstanding under the Loan Agreement.

Future principal payments for the long-term debt are as follows: