7. Long-term Debt

Convertible Senior Notes

On September 16, 2019, the Company completed a private offering of convertible notes the 2019 Convertible Notes with an aggregate principal amount of $220.0 million issued pursuant to an indenture (the “Indenture”) with U.S. Bank National Association, as trustee.

The net proceeds from the sale of the 2019 Convertible Notes were approximately $212.9 million after deducting the initial purchasers’ discounts and commissions of $6.6 million and offering expenses of $0.5 million paid by the Company. The Company

used $28.4 million of the net proceeds from the sale of the 2019 Convertible Notes to pay the cost of the capped call transactions in September 2019, described below.

On May 12, 2020, the Company issued convertible notes (the “2020 Convertible Notes”) with an aggregate principal amount of $300.0 million. The net proceeds from the sale of the 2020 Convertible Notes were approximately $322.9 million after deducting the purchasers’ discounts and commission of $5.7 million and offering expenses of $0.3 million. The Company used $43.1 million of the net proceeds from the sale of the 2020 Convertible Notes to pay the cost of the additional capped call transactions in May 2020, described below.

The 2019 Convertible Notes and the 2020 Convertible Notes are referred to together as the “Convertible Notes”. The Convertible Notes are senior unsecured obligations of the Company and bear interest at a rate of 3.5% per year, payable semi-annually in arrears on March 15 and September 15 of each year, beginning on March 15, 2020. The Convertible Notes will mature on September 15, 2026, unless converted earlier, redeemed or repurchased in accordance with their terms.

The Convertible Notes are convertible into shares of the Company’s common stock at an initial conversion rate of 25.3405 shares per $1,000 principal amount of Convertible Notes (equivalent to an initial conversion price of approximately $39.4625 per share of common stock). The conversion rate is subject to customary anti-dilution adjustments. In addition, following certain events that occur prior to the maturity date or if the Company deliver a notice of redemption, the Company will increase the conversion rate for a holder who elects to convert its Convertible Notes in connection with such corporate event or a notice of redemption, as the case may be, in certain circumstances as provided in the Indenture.

Prior to March 15, 2026, the Convertible Notes are convertible only under the following circumstances:

 

during any calendar quarter, if the last reported sale price of the Company’s common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day;
during the five-business day period after any five consecutive trading day period in which the trading price per $1,000 principal amount of the Convertible Notes for each such trading day was less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate on each such trading day;
if the Company calls any or all of the Convertible Notes for redemption, at any time prior to the close of business on the second scheduled trading day immediately preceding the redemption date; or
upon the occurrence of corporate events specified in the Indenture.

On or after March 15, 2026 until the close of business on the second scheduled trading day immediately preceding the maturity date of the Convertible Notes, holders may convert the Convertible Notes at any time. Upon conversion of the Convertible Notes, the Company will pay or deliver, as the case may be, cash, shares of the Company’s common stock or a combination of cash and shares of common stock, at the Company’s election.

During 2021 and 2022, holders of the 2019 Convertible Notes and the 2020 Convertible Notes converted approximately $425.4 million in aggregate principal amount into a total of 12,926,104 shares of the Company’s common stock. The Company accounted for these exchanges as induced conversions, resulting in the expensing of the fair value of shares issued in excess of the original terms of the Convertible Notes.

None of the circumstances outlined above were achieved during the years ended December 31, 2025 and 2024, and as such, the conditional conversion feature of the Convertible Notes was not triggered as of December 31, 2025 and 2024.

After September 20, 2023, the Company may redeem for cash all or a portion of the Convertible Notes, at its option, if the last
reported sale price of the Company’s common stock has been at least
130% of the conversion price then in effect for at least 20
trading days (whether or not consecutive), including the trading day immediately preceding the date on which the Company provides a
notice of redemption, durin
g any 30 consecutive trading day period ending on, and including, the trading day immediately preceding
the date on which the Company provides notice of redemption. The redemption price will be equal to
100% of the principal amount of
the Convertible Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. If the Company calls
any Convertible Notes for redemption, it will constitute a “make-whole fundamental change” with respect to such Convertible Notes,
in which case the conversion rate applicable to the conversion of such Notes, if converted in connection with the redemption, will be
The Company has not called for redemption or redeemed any of the Convertible Notes as of
December 31, 2025.

If the Company undergoes a “fundamental change,” as defined in the Indenture, prior to maturity, subject to certain conditions,
holders may require the Company to repurchase for cash all or any portion of their Convertible Notes at a fundamental change
 

repurchase price equal to 100% of the principal amount of the notes to be repurchased, plus any accrued and unpaid interest to, but
excluding, the fundamental change repurchase date.

 

As of December 31, 2025 and 2024, the Company held in treasury Convertible Notes in principal amount of $425.4 million which have not been cancelled.

As the Convertible Notes mature on September 15, 2026, the Company classified the Convertible Note as current liabilities as of December 31, 2025 and non-current liabilities as of December 31, 2024 on the Company’s consolidated balance sheets.

The outstanding balance of the Convertible Notes as of December 31, 2025 and 2024 consisted of the following (in thousands):

 

 

December 31,

 

 

 

2025

 

 

2024

 

Principal

 

$

93,897

 

 

$

93,897

 

Less: debt discount and issuance costs, net

 

 

(235

)

 

 

(556

)

Net carrying amount

 

$

93,662

 

 

$

93,341

 

The following table sets forth total interest expense recognized related to the Convertible Notes during the years ended December 31, 2025, 2024 and 2023 (in thousands):

 

 

 

Year Ended December 31,

 

 

 

2025

 

 

2024

 

 

2023

 

Amortization of debt issuance costs

 

$

321

 

 

$

309

 

 

$

297

 

Contractual interest expense

 

 

3,286

 

 

 

3,286

 

 

 

3,286

 

  Total interest expense

 

$

3,607

 

 

$

3,595

 

 

$

3,583

 

Capped Call Transactions

On September 11, 2019 and May 6, 2020, concurrently with the pricings of the Convertible Notes, the Company entered into capped call transactions with two counterparties. The capped call transactions are expected generally to reduce the potential dilution to the Company’s common stock upon any conversion of Convertible Notes and/or offset any cash payments the Company is required to make in excess of the principal amount of converted Convertible Notes, as the case may be, in the event that the market price per share of the Company’s common stock, as measured under the terms of the capped call transactions, is greater than the strike price of the capped call transactions, which is initially $39.4625 (the conversion price of the Convertible Notes) and is subject to anti-dilution adjustments substantially similar to those applicable to the conversion rate of such Convertible Notes. If, however, the market price per share of the Company’s common stock, as measured under the terms of the capped call transactions, exceeds the cap price of the capped call transactions, which is initially $63.14 per share, there would nevertheless be dilution and/or there would not be an offset of such potential cash payments, in each case, to the extent that such market price exceeds the cap price of the capped call transactions.

On February 27, 2024, the Company unwound a portion of the capped call transactions with the capped call counterparties, which resulted in cash proceeds to the Company of $98.8 million. The unwind transactions were settled at a volume-weighted average price per share of $64.11 on March 8, 2024.

As of December 31, 2025, the Company holds remaining capped call transactions in a notional amount corresponding to $93.9 million principal amount of Convertible Notes.

Financing Agreement and Credit Facility

On May 13, 2024, the Company and certain of its subsidiaries entered into a financing agreement (the “Sixth Street Financing Agreement”) with the lenders party thereto (the “Lenders”), and Sixth Street Lending Partners (“Sixth Street”), as the administrative agent and collateral agent for the Lenders.

The Sixth Street Financing Agreement provides for a senior secured term loan facility of up to $475.0 million (the “Credit Facility”), consisting of an initial draw of $375.0 million at closing and a potential additional $100.0 million draw at the Company’s option upon satisfaction of a $50.0 million minimum cash requirement and a requirement that the Company’s trailing three-month sales of SYFOVRE is at least $180.0 million prior to the $100.0 million draw by September 30, 2025. The Company did not draw down the additional $100.0 million and the option expired September 30, 2025.

The Credit Facility matures on May 13, 2030 (the “Maturity Date”) and bears interest at (i) in the case of SOFR Loans, an annual rate equal to 3-month Term SOFR (subject to 1.00% floor), plus (ii) 5.75%. Certain additional commitment and undrawn amount fees are also payable in connection with the Credit Facility.

The net proceeds from the initial draw of the Credit Facility were approximately $358.2 million, net of $16.8 million of issuance costs. The Company used $326.5 million of the proceeds from the initial draw of the Credit Facility to buy out its remaining obligations to SFJ Pharmaceuticals Group.

The Credit Facility does not provide for scheduled amortization payments during the term. All principal will be due on the Maturity Date. The Company will have the right to prepay loans under the Credit Facility at any time. The Company is required to repay loans under the Credit Facility with proceeds from certain asset sales, condemnation events and extraordinary receipts, subject, in some cases, to reinvestment rights. Repayments are subject to a prepayment premium. Repayments may be made after the first year of the loan and are subject to a prepayment premium up to 3%, depending on timing.

On July 1, 2025, the Lenders and Sixth Street consented to the Royalty Agreement as further described in Note 10 (the “Six Street Consent”). In connection with the Sixth Street Consent, the Company agreed to extend by one year from the effective date of the Consent the periods in which certain prepayment premiums would be owed under the Sixth Street Financing Agreement. This effectively extended the period the prepayment premium would be owed from one year after the date of the initial draw, or May 13, 2024, to one year after the effective date of the Sixth Street Consent, or July 1, 2025.

All obligations under the Sixth Street Financing Agreement are secured on a first-priority basis, subject to certain exceptions, by security interests in substantially all assets of the Company and certain subsidiaries of the Company, including its intellectual property, and are guaranteed by certain subsidiaries of the Company, including foreign subsidiaries, subject to certain exceptions.

The Sixth Street Financing Agreement contains customary covenants, including, without limitation, a financial covenant to maintain liquidity of at least $50.0 million if the Company’s market capitalization is below $3.0 billion, and negative covenants that, subject to certain exceptions, restrict indebtedness, liens, investments (including acquisitions), fundamental changes, asset sales and licensing transactions, dividends, modifications to material agreements, payment of subordinated indebtedness, and other matters customarily restricted in such agreements. Among other permissions, the Company is permitted, on terms and conditions set forth on the Sixth Street Financing Agreement, to enter into a separate asset-based financing arrangement with a third-party in an amount of up to $100.0 million, which amount is increased to $200.0 million upon certain sales or market capitalization thresholds, and to have outstanding convertible unsecured notes in an amount equal to the greater of $400.0 million and 10% of the Company’s market capitalization, but not to exceed $600.0 million. The Company is subject to restrictions on sales and licensing transactions with respect to its core intellectual property, defined to include SYFOVRE, EMPAVELI, and other pegcetacoplan product assets, subject to certain exceptions, including certain transactions related to areas outside the United States and Europe.

The outstanding balance of the Credit Facility as of December 31, 2025 and 2024 consisted of the following (in thousands):

 

 

 

December 31,

 

 

December 31,

 

 

 

2025

 

 

2024

 

Principal

 

$

375,000

 

 

$

375,000

 

Less: debt discount and issuance costs

 

 

(13,336

)

 

 

(15,511

)

Net carrying amount

 

$

361,664

 

 

$

359,489

 

The following table sets forth total interest expense recognized related to the Credit Facility as of December 31, 2025 and 2024 (in thousands):

 

 

 

December 31,

 

 

 

2025

 

 

2024

 

Amortization of debt issuance costs

 

$

2,175

 

 

$

1,250

 

Contractual interest expense

 

 

37,947

 

 

 

26,082

 

   Total interest expense

 

$

40,122

 

 

$

27,332

 

No interest expense incurred for the year ended December 31, 2023 as the Credit Facility commenced in 2024.

Historical Timeline

Fiscal YearFiled
2025Feb 24, 2026Showing above
2024Feb 28, 2025
2023Feb 27, 2024
2022Feb 21, 2023
2021Feb 28, 2022
2020Feb 25, 2021
2019Feb 27, 2020
2018Feb 26, 2019
2017Mar 19, 2018

About Debt Disclosures

Debt disclosures detail a company's borrowing structure — the types of instruments, interest rates, maturity schedule, and covenant restrictions that define its financial obligations and flexibility. This section is essential for assessing refinancing risk, interest rate exposure, and the margin of safety against financial distress.

Key signals: the maturity schedule reveals concentration risk — large maturities within 1-2 years during tight credit markets can force dilutive refinancing or asset sales. Compare the fair value of debt against carrying amount to gauge whether the market views the company's credit risk differently than the balance sheet suggests. Watch covenant compliance disclosures for tightening cushions, especially leverage and interest coverage ratios. Variable-rate debt exposure quantifies sensitivity to interest rate changes. Secured versus unsecured mix affects recovery rates and future borrowing capacity. Compare net debt-to-EBITDA against industry peers and covenant limits to assess financial health.