BORROWINGS

12 Months Ended

Dec. 31, 2019

Term Loan

On February 28, 2018, the Company entered into the Term Loan with Hercules. The Term Loan provided for a loan in an aggregate principal amount of up to $100.0 million to be funded in five tranches subject to certain performance-based milestones. The first tranche, in the amount of $25.0 million, was funded on the closing date of the Term Loan.

On October 15, 2018, the Company and Hercules entered into the second amendment to the Term Loan, which amended certain terms of the Term Loan. After giving effect to the second amendment, the Term Loan continued to provide for a loan in an aggregate principal amount of up to $100.0 million to be funded in five tranches subject to certain performance-based milestones. The second tranche was reduced from $25.0 million to $15.0 million and was funded on December 28, 2018. The Company accounted for the second amendment as a modification to the existing Term Loan.

On March 27, 2019, the Company modified the Term Loan with Hercules by entering into the third amendment to the Term Loan. After giving effect to the third amendment, the amount available under the Term Loan is increased from up to $100.0 million to up to $200.00 million to be funded in tranches, subject to certain performance-based milestones, and the maturity of the Term Loan is extended. Under the terms of the Term Loan, as amended by the third amendment, the $40.0 million principal outstanding under the Term Loan at the date of the modification remains outstanding, and additional tranches of $20.0 million and $15.0 million will be available for draw down prior to December 15, 2019 and December 15, 2020, respectively. An additional tranche of $75.0 million will be available for draw down between January 1, 2020 and December 15, 2020, on the condition that the Company obtains final approval from the U.S. Food and Drug Administration, or FDA, for the New Drug Application, or NDA, for veverimer. A final tranche of $50.0 million will be available for draw down on or prior to December 15, 2021, upon request by the Company and the approval of Hercules' investment committee. The Company accounted for the third amendment as a modification to the existing Term Loan. On December 13, 2019, the third tranche of the Term Loan was funded in the amount of $20.0 million.

The Term Loan bears interest at a floating per annum interest rate equal to the greater of either (i) 8.35% or (ii) the lesser of (x) 8.35% plus the prime rate as reported in The Wall Street Journal minus 6.00% and (y) 9.85%. The maturity date is extended to April 1, 2023 and may be extended to April 1, 2024 if the tranche of $75.0 million described above is drawn. The Company will initially be making interest-only payments until April 1, 2021. If the Company achieves certain performance milestones and financial covenants, the interest-only period could be extended for up to an additional 24 months. Upon expiration of the interest-only period, the Company will repay the Term Loan in equal monthly installments comprised of principal and interest, based on a 30-month amortization schedule, through maturity. The Company will pay an additional amount of (a) $2.6 million due on March 1, 2022 and (b) the product of 7.55% and the aggregate loans funded under the Term Loan due at maturity or on any earlier date on which the loans become due. If the Company prepays the Term Loan, the Company will be required to pay a prepayment charge equal to (i) 2.00% of the amount being prepaid at any time during the first 12 months following the effective date of the third amendment (ii) 1.50% of the amount being prepaid after 12 months but prior to 24 months following the effective date of the third amendment (iii) 1.00% of the amount being prepaid after 24 months but prior to 36 months following the effective date of the third amendment and (iv) zero if prepaid any time after 36 months following the effective date of the third amendment but prior to the maturity.

The Term Loan is secured by substantially all of the Company's assets, except its intellectual property, which is the subject of a negative pledge; however, the collateral does consist of rights to payments and proceeds from the sale, licensing or disposition of all or any part of, or rights in, its intellectual property. Under the Term Loan, the Company is subject to certain covenants, including but not limited to requirements to deliver financial reports at designated times of the year and maintain a minimum level of cash. These covenants also limit or restrict the Company's ability to incur additional indebtedness or liens, acquire, own or make any investments, pay cash dividends, repurchase stock or enter into certain corporate transactions, including mergers and changes of control.

Warrants

In conjunction with the Term Loan entered into on February 28, 2018, the Company issued a warrant to Hercules to purchase 53,458 shares of its common stock with an exercise price of $9.35 per share. The estimated fair value of the warrant at the date of issuance was approximately $0.2 million. The fair value of the common stock warrant liability was determined using the probability-weighted expected return method. It was recorded at its fair

value at inception and was remeasured at each financial reporting period with any changes in fair value being recognized as a component of other income (expense), net in the accompanying statements of operations and comprehensive loss.

On April 10, 2018, the Company entered into amendments with Hercules that resulted in the reclassification of the warrant liability to stockholders' equity (deficit) as the amended terms of the warrants qualified for them to be accounted for as equity instruments and as such were no longer subject to remeasurement. The fair value of the common stock warrants of approximately $0.2 million was reclassified to stockholders' equity (deficit) upon execution of the amendment.

In connection with the funding of the second tranche on December 28, 2018, the Company issued to Hercules a warrant to purchase 53,458 shares of its common stock at an exercise price of $9.35 per share. The common stock warrant was recorded in stockholders' equity (deficit) at its fair value of approximately $0.9 million on December 28, 2018.

In conjunction with the third amendment, the Company issued warrants to Hercules to purchase 16,721 shares of its common stock with an exercise price of $23.92 per share. The common stock warrants were recorded in stockholders' equity (deficit) at their fair value of approximately $0.3 million on March 27, 2019. The fair value of the common stock warrants were determined using an option-pricing model with the following assumptions: time to liquidity of 7.0 years, volatility of 75.0%, risk-free rate of 2.3% and stock price based on the March 27, 2019 closing price of the Company's common stock reported by The Nasdaq Global Select Market.

In connection with the funding of the third tranche on December 13, 2019, or the issuance date, the Company issued to Hercules a warrant to purchase 8,361 shares of its common stock at an exercise price of $23.92 per share. The common stock warrant was recorded in stockholders' equity (deficit) at its fair value of approximately $0.3 million on the issuance date. The fair value of the common stock warrants was determined using an option-pricing model with the following assumptions: time to liquidity of 7.0 years, volatility of 72.7%, risk-free rate of 1.8% and stock price based on the December 13, 2019 closing price of the Company's common stock reported by The Nasdaq Global Select Market.

In connection with each subsequent draw down under the tranches described above, the Company is obligated to issue additional warrants to purchase a number of shares of the Company's common stock determined by dividing (x) an amount equal to 1.0% of the principal amount of the applicable tranche by (y) $23.92 subject to adjustments following certain corporate events.

Embedded Derivatives and Other Debt Issuance Costs

The Company determined that certain loan features were embedded derivatives requiring bifurcation and separate accounting. Those embedded derivatives were bundled together as a single, compound embedded derivative and then bifurcated and accounted for separately from the host contract. The Company initially recorded a compound derivative liability of $0.7 million, which is required to be marked to market in future periods.

As of December 31, 2019, the Company calculated the fair values of the compound derivative using the “with and without” method under the income approach by computing the difference between the fair value of the Term Loan with the compound derivative and the fair value of the Term Loan without the compound derivative. The Company calculated the fair values using a probability-weighted discounted cash flow analysis. The key valuation assumptions used consist of the discount rate of 10.7% and the probability of the occurrence of certain events of 20%. The compound derivative liability is being remeasured at each financial reporting period with any changes in fair value being recognized as a component of other income (expense), net in the statements of operations and comprehensive loss. The fair value of the compound derivative liability was approximately $1.0 million and was classified as other long-term liabilities on the balance sheet.

The facility fee, fair value of warrants at issuance, fair value of embedded derivatives which were bifurcated, and other debt issuance costs have been treated as debt discounts on the Company’s balance sheet and together with the additional payment are being amortized to interest expense throughout the life of the Term Loan using the effective interest rate method.

As of December 31, 2019 and 2018, there were unamortized issuance costs and debt discounts of $3.6 million and $2.7 million, respectively, which were recorded as a direct deduction from the Term Loan on the balance sheets.

The following table presents future payments of principal and interest on the Term Loan as of December 31, 2019.


(in thousands)	December 31, 2019
2020	$	5,038
2021	21,259
2022	26,675
2023	19,893
	72,865
Less: amount representing interest	(12,865)
Present value of Term Loan	60,000
Less: current portion	—
Long-term portion of Term Loan	$	60,000