Long-Term Debt

Western Alliance LSA

On March 8, 2016, the Company entered into a new term Loan and Security Agreement with Western Alliance Bank (the “Western Alliance LSA”) for $7.0 million. The loan proceeds were used to repay the outstanding $5.0 million loan with Square 1Bank, as required by the twelfth amendment to that certain Loan and Security Agreement with Square 1Bank.

Additionally, in conjunction with the entry into Western Alliance LSA, the Company issued to Western Alliance Bank warrants to purchase 802,084 shares of Series D and D-1 convertible preferred stock at an exercise price of $0.48 per share. The Company valued the warrants using the Black-Scholes-Merton model, and the initial fair value of the warrants of $99,684 was recorded as a debt discount and was being amortized to interest expense over the term of the loan. Upon the closing of the IPO in August 2018, these warrants were adjusted to warrants exercisable for 18,739 shares of common stock for $20.56 per share. The warrants expire in 2026.

In February 2018, the Western Alliance LSA was amended requiring the Company to secure $21.0 million in funding prior to June 30, 2018. As part of the amendment, Western Alliance Bank agreed to forbear from exercising any of its default remedies set forth in the Western Alliance LSA as a result of the Company’s previous loan default as of December 31, 2017.

On June 13, 2018, the Western Alliance LSA was amended, replacing previously amended funding requirements and requiring the Company to secure $5.0 million in funding prior to August 3, 2018. Additionally, the amendment restricted the Company's use of all cash collected from customers, received on and after amendment date, until the Company collected a total of $2.5 million. As part of this amendment, Western Alliance Bank waived the existing default.

On June 29, 2018, the Company repaid the Western Alliance LSA in connection with the MidCap Financial CSA (as defined below).

MidCap Financial CSA

On June 29, 2018, the Company entered into a Credit and Security Agreement with MidCap Financial Trust (the "MidCap Financial CSA") which provided a $15.0 million term loan facility available in a first tranche of $10 million (“Tranche 1”), a second tranche of $2.5 million and a third tranche of $2.5 million. The Company borrowed $10.0 million from Tranche 1 immediately upon execution of the MidCap Financial CSA. Proceeds from the loan were used to repay the outstanding $7.0 million due to Western Alliance LSA.

On March 14, 2019, the Company repaid the MidCap Financial CSA in connection with the Innovatus LSA (as defined below).

The MidCap Financial CSA bore interest at an annual rate of one month LIBOR plus 7.5%, subject to a LIBOR floor of 1.5%. The loan had a 60-month term, with interest only for the first 18 months and straight-line amortization of principal and interest for the remaining 42 months. The MidCap Financial CSA was secured by substantially all of the assets of the Company and was scheduled to mature on July 1, 2023.

The Company paid issuance fees of approximately $0.3 million at the inception of the loan, which was recorded as a debt discount and was recognized as additional interest expense over the term of the loan. Subject to certain limited exceptions, amounts prepaid in relation to the MidCap Financial CSA are subject to a prepayment fee determined by multiplying the amount being prepaid by 4% in the first year of the term, 3% in year two, and 2% thereafter. When the Company paid-off the MidCap Financial CSA, it incurred a prepayment fee of $0.4 million. The prepayment fee is recognized as loss on debt extinguishment during the three months ended March 31, 2019. In addition, upon repayment of the total amounts borrowed, the Company was required to pay an end of term charge equal to 4% of the total amount borrowed. Accordingly, an end of term charge of $0.4 million was included in other long-term liabilities on the balance sheet as of December 31, 2018. The end of term charge was being recognized as additional interest expense over the term of the loan. The unamortized portion of the end of term charge was written-off as loss on debt extinguishment during the three months ended March 31, 2019 in conjunction with the Company's repayment of the MidCap Financial CSA.

In conjunction with entering into the MidCap Financial CSA, the Company issued to MidCap a warrant to purchase 625,000 shares of Series D-1 convertible preferred stock at an exercise price of $0.48 per share that was immediately exercisable. The Company valued the warrant to purchase Series D convertible preferred stock using the Black-Scholes-Merton model, and the initial fair value of the warrant to purchase Series D-1 convertible preferred stock of $0.2 million was recorded as a debt discount and is being amortized to interest expense over the term of the loan. The assumptions used in the model were: the fair value of the Series D-1 convertible preferred stock, which was determined using an OPM analysis, an expected life of 10 years, a risk-free interest rate of 2.83% and an expected volatility of 59%. Upon the closing of the IPO in August 2018, the warrants exercisable for shares of Series D convertible preferred stock were adjusted to warrants exercisable for 14,602 shares of common stock for $20.56. The warrants expire on June 29, 2028.

In addition, MidCap invested $1.0 million in the convertible note offering at terms identical to other investors described in the Convertible Notes section below.

Innovatus LSA

On March 14, 2019, the Company entered into a Loan and Security Agreement (the “Innovatus LSA”) by and among Innovatus Life Sciences Lending Fund I, LP, a Delaware limited partnership (“Innovatus”), as collateral agent and the lenders listed on Schedule 1.1 thereto, including East West Bank (the "Bank", and together with the Lenders, the "Lenders") . Under the Innovatus LSA, Innovatus agreed, among other things, to make a first term loan of $17.5 million to the Company (the “Term A-1 Loan”), a second term loan of $2.5 million to the Company (the “Term A-2 Loan”) and a third term loan of $5.0 million to the Company (the "Term B Loan"), each upon satisfaction of certain funding conditions. In addition, the Bank has agreed to make available to the Company a revolving line of credit in an amount not to exceed $5.0 million.

Under the Innovatus LSA, interest is payable, at the Company’s option (i) in cash at a rate of 10.25% per annum or (ii) at a discounted rate of 7.25% in cash, with 3.0% of the 10.25% per annum rate (the “PIK Loan”) added to the principal of the loan and subject to accruing interest through the end of the interest only payment period. Interest only payments are due on the first of each month through March 1, 2022. Thereafter, in addition to interest accrued during such period, the monthly payments will include an amount equal to the outstanding principal at March 1, 2022 divided by 24 months. At maturity (or earlier prepayment), the Company is also required to make a final payment equal to 3.75% of the original principal amount borrowed. At inception the Company elected to pay interest in cash at a rate of 7.25% per annum and have 3.0% per annum of the interest added back to the outstanding principal.

The Innovatus LSA provides for prepayment fees of 3.0% of the outstanding balance of the loan if the loan is repaid on or prior to March 14, 2020, 2.0% of the amount prepaid if the prepayment occurs after March 14, 2020 but prior to March 14, 2021, 1.0% of the amount prepaid after March 14, 2021 but prior to March 14, 2022 and 0% of the amount prepaid if the prepayment occurs thereafter. In addition, upon repayment of the total amounts borrowed, the Company is required to pay an end of term charge of $0.8 million. This end of term charge is being recognized as additional interest expense over the term of the Innovatus LSA.

The Innovatus LSA is collateralized by all of the Company’s assets. The Innovatus LSA also imposes various affirmative and negative covenants on the Company. At March 31, 2019, the Company was in compliance with all of the covenants in the Innovatus LSA.

Additionally, in connection with the Innovatus LSA, on March 14, 2019, the Company entered into a Common Stock Purchase Agreement (the “Innovatus Purchase Agreement”) with certain entities affiliated with Innovatus (the “Innovatus Investors”), pursuant to which the Company agreed to issue and sell 406,504 shares of common stock at $3.69 per share for proceeds of $1.5 million. Upon execution of the Innovatus Purchase Agreement, the Company sold all of such shares to the Innovatus Investors. Because the shares were issued at a discount to the fair market value of the Company’s common stock on the issuance date, the Company recorded the difference of $0.2 million between the issuance price and fair value which was allocated to the debt on a relative fair value basis.

On March 22, 2019, in connection with the receipt of $20.0 million of in funding with respect to the Term A-1 Loan and Term A-2 Loan, the Company issued to Innovatus a warrant to purchase up to 161,987 shares of common stock at an exercise price of $4.63 per share, which has a term of 10 years. The Company applied the Black-Scholes option pricing model to estimate fair value of the warrants, with the following assumptions: a) risk-free rate of 2.43%; b) expected volatility of 66.93%; c) no dividend would be payable; and d) expected life of 10 years. Based on this model, the aggregate relative fair value of the warrants was determined to be $0.6 million. Upon future issuance of the Term B Loan, the Lender will be entitled to a warrant to purchase an additional 40,496 shares of the Company’s common stock.

The Company paid issuance fees of approximately $0.8 million which was recorded as part of the debt discount. The issuance fee will be amortized as additional interest expense over the life of the debt using the effective interest method. The Company recognized the fair value of the warrants and the discount of the common stock as a debt discount and along with the issuance costs will amortize these amounts using the effective interest rate method over the life of the applicable term loan. The effective interest rate at March 31, 2019 was 13.4%.

At March 31, 2019, the Company had $20.0 million in term loans borrowed under the Innovatus LSA.

Convertible Notes

On February 9, 2018, the Company entered into a Note Purchase Agreement (the “Note Purchase Agreement”) with various investors, which included related parties (the “Investors”), pursuant to which the Company agreed to sell to the Investors convertible promissory notes (the “Convertible Notes”) in the original principal amount of up to $16.0 million. On April 2, 2018, the Company amended the Note Purchase Agreement to, among other things, increase the principal amount available for issuance under the Note Purchase Agreement to $18.4 million. The Convertible Notes had a maturity date of September 30, 2018 and were convertible either into the Company’s common stock or convertible preferred stock, dependent on the conversion events.

On June 29, 2018, the Note Purchase Agreement was amended to increase the principal amount available for issuance from $18.4 million to $19.4 million.

In August 2018, the outstanding convertible promissory notes of $14.9 million of principal and interest were converted into 3,239,294 shares of common stock upon completion of the IPO. As of March 31, 2019, there are no convertible notes outstanding.

Summary

Debt and unamortized discount balances relating to the MidCap Financial CSA are as follows:



	December 31, 2018
Term loan face value	$	10,000,000
Fair value of warrant	(176,813		)
End of term charge	(400,000		)
Capitalized debt issuance costs	(499,354		)
Accretion of debt issuance costs and end of term charge	87,859
Accretion of warrant fair value	17,682
Balance	9,029,374
Less current portion	—
Long-term debt	$	9,029,374

Non-cash interest expense related to debt discount amortization and accretion of end of term fees was $49,130 and $21,330, for the three months ended March 31, 2019 and 2018, respectfully.

Debt and unamortized discount balances relating to the Innovatus LSA are as follows:



	March 31, 2019
Term loan face value	$	20,000,000
Warrants issued	(629,830		)
Stock discount issued	(201,789		)
Capitalized debt issuance costs	(792,597		)
Balance	18,375,784
Less current portion	—
Long-term debt	$	18,375,784

Future minimum payments including interest under the Innovatus LSA are as follows as of March 31, 2019:




2019	$	1,018,392
2020	1,505,249
2021	1,964,030
2022	9,875,878
2023-2024	14,941,449
Total minimum loan payments	$	29,304,998
Unamortized interest	(8,554,998		)
End of term charge	(750,000		)
Warrants issued	(629,830		)
Stock discount issued	(201,789		)
Capitalized debt issuance costs and end of term charge	(792,597		)
Term loan	18,375,784
Less current portion	—
Long-term debt	$	18,375,784