7. Debt Facility

On April 28, 2017, the Company entered into a loan and security agreement with Silicon Valley Bank (the “Loan Agreement”). During the year ended December 31, 2017, upon satisfaction of the conditions of the Loan Agreement, the Company executed two tranches totaling $15.0 million, the maximum credit available pursuant to the debt facility. The capital was utilized for the repayment of $3.7 million of principal debt and fees of Mast assumed in the Merger. The residual capital is being utilized to fund ongoing development programs of the Company and for general corporate purposes.

The Loan Agreement contains customary affirmative and negative covenants, including among others, covenants limiting our ability and that of our subsidiaries to dispose of assets, permit a change in control, merge or consolidate, make acquisitions, incur indebtedness, grant liens, make investments, make certain restricted payments and enter into transactions with affiliates, in each case subject to certain exceptions.

The Loan Agreement bears interest at the prime rate reported in The Wall Street Journal, plus a spread of 4.25%. Interest only payments are due through September 2018 followed by monthly payments of principal plus interest over the following 30 months. Since the second tranche was fully extended, the interest only period was extended for an additional 6 months, through March 2019 followed by monthly payments of principal plus interest over the following 24 months through the maturity date of March 1, 2021 under the Loan Agreement provisions. We were obligated to pay customary closing fees and are obligated to pay a final payment of 6.0% of the aggregate principal amount of term loans advanced under the facility. The end of term charge of $0.9 million will be due on the scheduled maturity date and is being recognized as an increase to the principal with a corresponding charge to interest expense over the term of the facility using the effective interest method.

In connection with the Loan Agreement, we paid $0.1 million in legal costs directly attributable to issuing the debt instrument. Such charges were accounted for as debt issuance costs and are being amortized to interest expense using the effective interest method through the scheduled maturity date.

Upon funding the first tranche of the Loan Agreement, the Company was obligated to issue warrants to purchase shares of the Company’s common stock equal to 3.0% of the funded amount divided by the exercise price to be set based on the average price per share over the preceding 10 trading days prior to funding or the price per share prior to the day of funding. The number of shares callable under the warrant agreement for the first tranche and exercise price were 24,725 shares of the Company’s common stock at an exercise price of $9.10 per share, with a ten year life, expiring April 28, 2027 (“April 2017 Warrants”).

Upon funding the second tranche of the Loan Agreement, the Company was obligated to issue warrants to purchase shares of the Company’s common stock equal to 3.0% of the funded amount divided by an exercise price to be set based on the average price per share over the preceding 10 trading days prior to funding or the price per share prior to the day of funding. As such, the Company issued additional warrants for 41,736 shares at an exercise price of $5.39 with a ten year life, expiring June 15, 2027 (“June 2017 Warrants”).

The April 2017 Warrants and June 2017 Warrants were valued using the Black-Scholes option pricing model with the following assumptions: volatility of 71.42% and 71.57%, respectively, expected term of ten years, risk-free interest rate of 2.33% and 2.16%, respectively, and a zero dividend yield. The collective warrant fair value of $0.4 million has been recorded as a debt discount and is being amortized through interest expense using the effective interest method through the scheduled maturity date.

Summary of Carrying Value

The following table summarizes the components of the debt facility carrying value, which approximates the fair value (in thousands):

	As of September 30, 2018
	Short-term		Long-term
Principal payments to lender and end of term charge	$	3,750	$	11,601
Debt Issuance costs		—		(54	)
Debt discount related to warrants		—		(190	)
Carrying Value	$	3,750	$	11,357