In 2017, the Company entered into two amendments (the “Amendments”) to its existing loan agreement (the “Loan Agreement”) with Western Alliance Bank and Solar Capital Ltd. (the “Lenders”) and Western Alliance, as Collateral Agent (the “Collateral Agent”). Under terms of the Amendments, the Company will be required to pay interest on the borrowings under the Loan Agreement at a per annum rate equal to 8.54% plus the then effective one-month U.S. LIBOR rate.

In addition to principal and interest, a final payment equal to $312,500 will be due upon maturity date of April 1, 2020 or such earlier date specified in the Loan Agreement and the Amendments, of which $321,000, including related interest, has been accrued and recorded in the other accrued liabilities line item in the accompanying condensed consolidated balance sheet as of March 31, 2019. If the Company repays all amounts owed under the Loan Agreement and the Amendments prior to the maturity date, the Company will pay a prepayment fee equal to 0.5% of the amount prepaid. The outstanding principal balance of this loan was $6,094,000 as of March 31, 2019.

In conjunction with the Loan Agreement, the Lenders were issued five-year warrants to purchase an aggregate of up to 208,002 shares of the Company’s common stock at a per share exercise price of $3.2454. The fair value of the warrants issued was estimated to be $0.5 million using a Black-Scholes valuation model. The fair value was recorded as a debt discount within notes payable and an increase to additional paid-in capital on the Company’s balance sheet. The debt discount is being amortized as interest expense over the term of the loan agreement, using the effective interest method.

Pursuant to the Loan Agreement and the Amendments, the Company is bound during the term of the Loan Agreement and the Amendments by a variety of affirmative covenants, including, without limitation, certain information delivery requirements and notice requirements, and negative covenants, including, without limitation, restrictions on incurring certain additional indebtedness, making certain asset dispositions, entering into certain mergers, acquisitions or other business combination transactions or incurring any non-permitted lien or other encumbrance on the Company’s assets. Upon the occurrence of an event of default under the Loan Agreement and the Amendments (subject to cure periods for certain events of default), all amounts owed by the Company thereunder would begin to bear interest at a rate that is 5.0% higher than the rate that would otherwise be applicable and may be declared immediately due and payable by the Collateral Agent. In the event of default by the Company, the Lenders would be entitled to exercise their remedies thereunder, including the right to accelerate the debt, upon which the Company may be required to repay all amounts then outstanding under the Loan Agreement and the Amendments, which could harm the Company's financial condition. The Company was in compliance with all applicable covenants set forth in the Loan Agreement and the Amendments as of March 31, 2019 and December 31, 2018. The principal payments due under the Loan Agreement and the Amendments have been classified as a current liability at December 31, 2018 due to the considerations discussed in Note 1 and the assessment that the material adverse change clause under the Loan Agreement and the Amendments is not within the Company's control. The Company has not been notified of an event of default by the Lenders as of the date of the filing of this Form 10-Q.

The Collateral Agent, for the benefit of the Lenders, has a perfected security interest in substantially all of the Company’s property, rights and assets, except for intellectual property, to secure the payment of all amounts owed to the Lenders under the Loan Agreement and the Amendments.

Aggregate future minimum payments due under the Loan Agreement and the Amendments as of March 31, 2019 were as follows (in thousands):

Through December 31,	Total
2019		4,568
2020		2,231
Total minimum payments		6,799
Less amount representing interest		(705	)
Total notes payable as of March 31, 2019		6,094
Less unamortized debt discount and issuance costs		(62	)
Less carrying amount of notes payable		(6,032	)
Non-current portion of notes payable	$	—

In April 2019, the Company entered into a term loan agreement with SVB (“SVB Loan Agreement”), pursuant to which the Company borrowed $5.5 million. The Company used the proceeds of the SVB Loan Agreement plus cash on hand to repay its remaining obligations in the amount of $5.9 million under the Loan Agreement and the Amendments (refer to Note 10 Subsequent Events for additional details).