CYTOKINETICS INC

NOTES TO UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

Note 1 — Organization and Significant Accounting Policies

Cytokinetics, Incorporated was incorporated under the laws of the state of Delaware on August 5, 1997. The Company is a late-stage biopharmaceutical company focused on the discovery and development of novel small molecule therapeutics that modulate muscle function for the potential treatment of serious diseases and medical conditions.

Our financial statements contemplate the conduct of our operations in the normal course of business. We have incurred an accumulated deficit of approximately$2.2 billion since inception and there can be no assurance that we will attain profitability. We had a net loss of$135.6 million and net cash used in operations of$129.5 million for the three months ended March 31, 2024. Cash, cash equivalents, and investments decreased to$634.3 million as of March 31, 2024 from$655.4 million as of December 31, 2023. We anticipate that we will have operating losses and net cash outflows in future periods.

We are subject to risks common to late-stage biopharmaceutical companies including, but not limited to, development of new drug candidates, dependence on key personnel, and the ability to obtain additional capital as needed to fund our future plans. Our liquidity will be impaired if sufficient additional capital is not available on terms acceptable to us. To date, we have funded operations primarily through sales of our common stock, contract payments under our collaboration agreements, sales of future revenues and royalties, debt financing arrangements and interest income. Until we achieve profitable operations, we intend to continue to fund operations through payments from strategic collaborations, additional sales of equity securities, grants and debt financings. We have never generated revenues from commercial sales of our drugs and may not have drugs to market for at least several years, if ever. Our success is dependent on our ability to enter into new strategic collaborations and/or raise additional capital and to successfully develop and market one or more of our drug candidates. We cannot be certain that sufficient funds will be available from such a financing or through a collaborator when required or on satisfactory terms. Additionally, there can be no assurance that our drug candidates will be accepted in the marketplace or that any future products can be developed or manufactured at an acceptable cost. These factors could have a material adverse effect on our future financial results, financial position and cash flows.

Based on the current status of our research and development activities, we believe that our existing cash, cash equivalents and investments will be sufficient to fund cash requirements for at least the next 12 months after the issuance of this Quarterly Report on Form 10-Q. If, at any time, our prospects for financing our research and development programs decline, we may decide to reduce research and development expenses by delaying, discontinuing or reducing our funding of one or more of our research or development programs. Alternatively, we might raise funds through strategic collaborations, public or private financings or other arrangements. Such funding, if needed, may not be available on favorable terms, or at all. The financial statements do not include any adjustments that might result from the outcome of this uncertainty.

Basis of Presentation

Our condensed consolidated financial statements include the accounts of Cytokinetics and our wholly-owned subsidiaries. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with GAAP for interim financial information and the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. The financial statements include all adjustments (consisting only of normal recurring adjustments) that management believes are necessary for the fair statement of our financial information. These interim results are not necessarily indicative of results to be expected for the full fiscal year or any future interim period. The balance sheet as of December 31, 2023 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by GAAP for complete financial statements. The financial statements and related disclosures have been prepared with the presumption that users of the interim financial statements have read or have access to the audited financial statements for the preceding fiscal year. Accordingly, these financial statements should be read in conjunction with the audited financial statements and notes thereto contained in the Company’s Form 10-K for the year ended December 31, 2023, as filed with the Securities and Exchange Commission.

Use of Estimates

The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. We evaluate our estimates on an ongoing basis. We base our estimates on our historical experience and also on assumptions that we believe are reasonable; however, actual results could significantly differ from those estimates.

Recently Issued Accounting Pronouncements

In November 2023, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. This standard requires disclosure of significant segment expenses and other segment items by reportable segment. The ASU becomes effective for annual periods beginning in 2024 and interim periods in 2025.

In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. This standard enhances disclosures related to income taxes, including the rate reconciliation and information on income taxes paid. The ASU becomes effective January 1, 2025.

Note 2 — Net Loss Per Share

The following instruments were excluded from the computation of diluted net loss per share for the periods presented because their effect would have been antidilutive (in thousands):

Note 3 — Research and Development Arrangements

Ji Xing Omecamtiv Mecarbil License and Collaboration Agreement

On December 20, 2021, we entered into the Ji Xing OM License Agreement, pursuant to which we granted to Ji Xing an exclusive license to develop and commercialize omecamtiv mecarbil in China and Taiwan. Under the terms of the Ji Xing OM License Agreement, we received a $50.0 million nonrefundable payment from Ji Xing comprised of a $40.0 million payment as consideration for the rights granted by us to Ji Xing and $10.0 million attributable to our having submitted to FDA an NDA for omecamtiv mecarbil. We may be eligible to receive from Ji Xing additional payments totaling up to $330.0 million for the achievement of certain commercial milestone events in China and Taiwan in connection to omecamtiv mecarbil. In addition, Ji Xing will pay us tiered royalties in the mid-teens to the low twenties range on the net sales of pharmaceutical products containing omecamtiv mecarbil in China and Taiwan, subject to certain reductions for generic competition, patent expiration and payments for licenses to third party patents. The Ji Xing OM License Agreement, unless terminated earlier, will continue on a market-by-market basis until expiration of the relevant royalty term.

In addition to the Ji Xing OM License Agreement, we entered into common stock purchase agreements with each of the RTW Investors, pursuant to which we sold and issued an aggregate of 0.5 million shares of our common stock at a price per share of $39.125 and an aggregate purchase price of $20.0 million. The closing of the transaction occurred on December 31, 2021.

Ji Xing Aficamten License and Collaboration Agreement

On July 14, 2020, we entered into the Ji Xing Aficamten License Agreement, pursuant to which we granted to Ji Xing an exclusive license to develop and commercialize aficamten in China and Taiwan. Under the terms of the Ji Xing Aficamten License Agreement, we received from Ji Xing a nonrefundable upfront payment of $25.0 million. Under the terms of the Ji Xing Aficamten License Agreement, we may be eligible to receive from Ji Xing milestone payments totaling up to $200.0 million for the achievement of certain development and commercial milestone events in connection to aficamten in the field of oHCM, and/or nHCM and other indications. In addition, Ji Xing will pay us tiered royalties in the low-to-high teens range on the net sales of pharmaceutical products containing aficamten in China and Taiwan, subject to certain reductions for generic competition, patent expiration and payments for licenses to third party patents. The Ji Xing Aficamten License Agreement, unless terminated earlier, will continue on a market-by-market basis until expiration of the relevant royalty term.

Accounting for the Ji Xing License and Collaboration Agreements

We assessed the arrangements of the Ji Xing OM License Agreement and the Ji Xing Aficamten License Agreement in accordance with ASC 606 and concluded that there is one performance obligation relating to the license of functional intellectual property for each agreement. The performance obligation was satisfied, and we recognized the residual allocation of arrangement consideration as revenue of $54.9 million in 2021 for the Ji Xing OM License Agreement and $36.5 million in 2020 for the Ji Xing Aficamten License Agreement. Due to the nature of development, including the inherent risk of development and approval by regulatory authorities, we are unable to estimate if and when the development milestone payments could be achieved or become due and, accordingly, we consider the milestone payments to be fully constrained and exclude the milestone payments from the initial transaction price.

The consideration related to sales-based milestone payments, including royalties, will be recognized when the related sales occur under the sales and usage-based royalty exception of ASC 606 as these amounts have been determined to relate predominantly to the license.

We re-evaluate the probability of achievement of development milestones and any related constraints each reporting period. We will include consideration, without constraint, in the transaction price to the extent it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur.

We recognized a $2.5 million milestone from Ji Xing in 2023 for the initiation of a phase 3 clinical trial for aficamten in nHCM which was collected in the fourth quarter of 2023.

Research and development revenue from Ji Xing for the three months ended March 31, 2024 and 2023 was$0.8 million and$0.3 million, respectively, related to certain development cost reimbursements.

We had accounts receivable from Ji Xing of$0.8 million as of March 31, 2024 and$0.3 million as of December 31, 2023.

Astellas

The Company and Astellas entered into the Astellas FSRA Agreement on April 23, 2020. As a result of the Astellas FSRA Agreement, the Company will now have exclusive control and responsibility for the Company's future development and commercialization of reldesemtiv, CK-601 and other FSRA compounds and products, and accordingly, Astellas has agreed to terminate its license to all FSRA compounds and related products.

Under the Astellas FSRA Agreement, Astellas agreed to pay one-third of the out-of-pocket clinical development costs which may be incurred in connection with the Company’s Phase 3 clinical trial of reldesemtiv in ALS, up to a maximum contribution by Astellas of $12 million. Astellas also agreed to non-cash contributions to the Company, which included the transfer of its existing inventories of active pharmaceutical ingredient of reldesemtiv and CK-601. As of December 31, 2023, we have billed and collected from Astellas up to the maximum contribution of $12.0 million. On March 31, 2023, we announced that we will discontinue COURAGE-ALS, our Phase 3 clinical trial of reldesemtiv in patients with ALS, and COURAGE-ALS OLE.

We hadno research and development revenue from Astellas for thethree months ended March 31, 2024. Research and development revenue from Astellas was$1.8 million for the three months ended March 31, 2023.

Note 4 — Fair Value Measurements

We value our financial assets and liabilities at fair value, defined as the price that would be received for assets when sold or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). We utilize market data or assumptions that we believe market participants would use in pricing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs can be readily observable, market corroborated or generally unobservable.

We primarily apply the market approach for recurring fair value measurements and endeavor to utilize the best information reasonably available. Accordingly, we use valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible and consider the security issuers’ and the third-party issuers’ credit risk in our assessment of fair value.

We classify fair value based on the observability of those inputs using a hierarchy that prioritizes the inputs used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurement) and the lowest priority to unobservable inputs (Level 3 measurement):

Level 1 — Observable inputs, such as quoted prices in active markets for identical assets or liabilities;

Level 2 — Inputs, other than the quoted prices in active markets, that are observable either directly or through corroboration with observable market data; and

Level 3 — Unobservable inputs, for which there is little or no market data for the assets or liabilities, such as internally-developed valuation models.

Fair Value of Financial Assets:

The follow tables set forth the fair value of our financial assets, which consists of cash equivalents and investments classified as available-for-sale securities, that were measured on a recurring basis (in thousands):

No credit losses on debt securities were recognized during thethree months ended March 31, 2024 or 2023. In its evaluation to determine expected credit losses, management considered all available historical and current information, expectations of future economic conditions, the type of security, the credit rating of the security, and the size of the loss position, as well as other relevant information. The Company does not intend to sell, and is unlikely to be required to sell, any of these available-for-sale investments before their effective maturity or market price recovery.

Note 5 — Balance Sheet Components

A reconciliation of cash, cash equivalents, and restricted cash reported in the accompanying condensed consolidated balance sheets to the amount reported within the accompanying condensed consolidated statements of cash flows was as follows (in thousands):

As of March 31, 2024, our restricted cash balance of$0.4 million is used to collateralize letters of credit.

Accrued liabilities were as follows (in thousands):

Note 6 — Agreements with Royalty Pharma

On January 7, 2022, we announced that we had entered into the 2022 RPI Transactions with affiliates of Royalty Pharma International plc.

The RP Loan Agreement and the RP Aficamten RPA described below, are determined to be debt instruments subsequently measured at amortized cost and were entered into with parties that were at the time of our entry into the 2022 RPI Transactions affiliated and in contemplation of one another. We used the relative fair value method and made separate estimates of the fair value of each freestanding financial instrument and then allocated the proceeds in proportion to those fair value amounts. Arrangement consideration for the RP Loan Agreement and the RP Aficamten RPA totaled $150 million, consisting of the two $50 million upfront payments for the signing of the RP Loan Agreement and the RP Aficamten RPA and milestone of $50 million for initiation of the first pivotal trial in oHCM for aficamten that was deemed probable at the signing of the agreements.

The initial consideration was allocated as follows (in thousands):

2022 RP Loan Agreement

Under the RP Loan Agreement, we were initially entitled to receive up to $300.0 million in term loans, $50.0 million of which was disbursed to us on closing and the remaining $250.0 million scheduled to have been available to us upon our satisfaction of customary disbursement conditions and certain development conditions by specific deadlines, as follows:

•

$50.0 million of tranche 2 term loans during the one year period following the receipt on or prior to March 31, 2023 of marketing approval from FDA of omecamtiv mecarbil;

•

$25.0 million of tranche 3 term loans during the one year period following the commercial availability of a diagnostic test measuring levels of omecamtiv mecarbil to support the final FDA label language applicable to such drug, subject to such commercial availability and the conditions to the tranche 2 term loans having occurred on or prior to March 31, 2023;

•

$75.0 million of tranche 4 term loans during the one year period following the receipt on or prior to September 30, 2024 of positive results from SEQUOIA-HCM, the Phase 3 trial for aficamten; and

•

$100.0 million of tranche 5 term loans during the one year period following the acceptance by the FDA on or prior to March 31, 2025 of an NDA for aficamten, subject to the conditions to the tranche 4 term loans having occurred on or prior to September 30, 2024.

As a result of our receipt of a CRL on February 28, 2023, in connection to our NDA for omecamtiv mecarbil, we have not satisfied the conditions to the availability of the tranche 2 and tranche 3 loans under the RP Loan Agreement.

In December 2023, we announced positive topline results from SEQUOIA-HCM, the Phase 3 trial for aficamten. This entitled us to receive $75.0 million under tranche 4 during the one year period following the receipt of the positive results and requires us to complete a minimum mandatory draw of at least $50.0 million of the $75.0 million available.

The remaining $100.0 million under tranche 5 remains available for disbursement to us, subject to satisfaction of the conditions described above.

Each term loan under the RP Loan Agreement matures on the 10 year anniversary of the funding date for such term loan and is repayable in quarterly installments of principal, interest and fees commencing on the last business day of the seventh full calendar quarter following the calendar quarter of the applicable funding date for such term loan, with the aggregate amount payable in respect of each term loan (including interest and other applicable fees) equal to 190% of the principal amount of the term loan for the tranche 1, tranche 4 and tranche 5 term loans and 200% of the principal amount of the term loan for tranche 2 and tranche 3 term loans (such amount with respect to each term loan, “Final Payment Amount”). We accounted for amounts initially drawn under the RP Loan Agreement using the effective interest method which resulted in an effective interest rate of 7.65% over theten-year term. As of the date of the prepayment or maturity of the term loan (or the date such prepayment or repayment is required to be paid), we will be required to pay an additional amount equal to $34.6 million accreted over the term of the loan. We have made our first payment in the fourth quarter of 2023.

We may prepay the term loans in full (but not in part) at any time at our option by paying an amount equal to the unpaid portion of Final Payment Amount for the outstanding term loans under the RP Loan Agreement; provided that if the conditions for either the tranche 4 term loans or the tranche 5 term loans have been met, we must have borrowed at least $50 million principal amount of the tranche 4 or 5 term loans. In addition, the term loans under the RP Loan Agreement are repayable in full at the option of either us or the lender in an amount equal to the unpaid portion of Final Payment Amount for the outstanding term loans upon a change of control of Cytokinetics.

Future minimum payments under the existing borrowing under RP Loan Agreement are (in thousands):

As of March 31, 2024, the estimated fair value of our RP Loan Agreement was$51.9 million. The fair value was estimated based on Level 3 inputs.

2022 RP Aficamten Royalty Purchase Agreement

In addition, on January 7, 2022, we entered into the RP Aficamten RPA with RPI ICAV, pursuant to which RPI ICAV purchased rights to certain revenue streams from net sales of pharmaceutical products containing aficamten by us, our affiliates and our licensees in exchange for up to $150.0 million in consideration, $50.0 million of which was paid on the closing date, $50.0 million of which was paid to us in March 2022 following the initiation of the first pivotal trial in oHCM for aficamten, and $50.0 million of which was paid to us in September 2023 following the initiation of the first pivotal clinical trial in nHCM for aficamten. The RP Aficamten RPA also provides that the parties will negotiate terms for additional funding if we achieve proof of concept results in certain other indications for aficamten, with a reduction in the applicable royalty if we and RPI ICAV fail to agree on such terms in certain circumstances.

Pursuant to the RP Aficamten RPA, RPI ICAV purchased the right to receive a percentage of net sales equal to 4.5% for annual worldwide net sales of pharmaceutical products containing aficamten up to $1 billion and 3.5% for annual worldwide net sales of pharmaceutical products containing aficamten in excess of $1 billion, subject to reduction in certain circumstances. Our liability to RPI ICAV is referred to as the “RP Aficamten Liability”.

We account for the RP Aficamten Liability as a liability primarily because we have significant continuing involvement in generating the related revenue stream from which the liability will be repaid. If and when aficamten is commercialized and royalties become due, we will recognize the portion of royalties paid to RPI ICAV as a decrease to the RP Aficamten Liability and a corresponding reduction in cash.

The carrying amount of the RP Aficamten Liability is based on our estimate of the future royalties to be paid to RPI ICAV over the life of the arrangement as discounted using an imputed rate of interest. The imputed rate of interest on the carrying value of the RP Aficamten Liability was approximately 24.8% and 22.4% as of March 31, 2024 and 2023, respectively.

2017 RP Omecamtiv Mecarbil Royalty Purchase Agreement

In February 2017, we entered into the RP OM RPA pursuant to which we sold a portion of our right to receive royalties from Amgen on future net sales of omecamtiv mecarbil to RPFT for a one-time payment of $90 million, which is non-refundable even if omecamtiv mecarbil is never commercialized. Concurrently, we entered into a common stock purchase agreement with RPFT through which RPFT purchased 875,656 shares of the Company’s common stock for $10.0 million. We allocated the consideration and issuance costs on a relative fair value basis to our liability to RPFT related to sale of future royalties under the RP OM RPA (the “RP OM Liability”) and the common stock sold to RPFT, which resulted in the RP OM Liability being initially recognized at $92.3 million. The RP OM RPA provides for the sale of a royalty to RPFT of 4.5% on worldwide net sales of omecamtiv mecarbil, subject to a potential increase of up to an additional 1% under certain circumstances. As a result of our receipt of a CRL on February 28, 2023 in connection to our NDA for omecamtiv mecarbil, pursuant to the terms of the RP OM RPA, the applicable royalty rate will increase to a maximum of 5.5% if omecamtiv approval obtains FDA approval at any time after June 30, 2023.

As a result of the termination of the Amgen Agreement and pursuant to our obligations under the RP OM RPA, we and RPFT amended the RP OM RPA on January 7, 2022 to preserve RPFT’s rights under the RP OM RPA by providing for direct payments by us to RPFT of up to 5.5% of our and our affiliates and licensees worldwide net sales of omecamtiv mecarbil. The RP OM RPA, as amended, had no impact on the original accounting for the $92.3 million associated with the RP OM Liability established in February 2017.

We account for the RP OM Liability as a liability primarily because we have significant continuing involvement in generating the related revenue stream from which the liability will be repaid. If and when omecamtiv mecarbil is commercialized and royalties become due, we will recognize the portion of royalties paid to RPFT as a decrease to the RP OM Liability and a corresponding reduction in cash.

The carrying amount of the RP OM Liability is based on our estimate of the future royalties to be paid to RPFT over the life of the arrangement as discounted using an imputed rate of interest. The excess of future estimated royalty payments over the $92.3 million of allocated proceeds, less issuance costs, is recognized as non-cash interest expense using the effective interest method. The imputed rate of interest on the carrying value of the RP OM Liability was approximately 0.1% and 1.9% as of March 31, 2024 and 2023, respectively.

Accounting for the Royalty Pharma Royalty Purchase Agreements

We periodically assess the amount and timing of expected royalty payments using a combination of internal projections and forecasts from external sources. To the extent such payments are greater or less than our initial estimates or the timing of such payments is materially different than its original estimates, we will prospectively adjust the amortization of the RP OM Liability and the RP Aficamten Liability and the effective interest rate.

There are a number of factors that could materially affect the amount and timing of royalty payments, a number of which are not within our control. The RP OM Liability and the RP Aficamten Liability are recognized using significant unobservable inputs. The estimates of future royalties requires the use of several assumptions such as: the probability of clinical success, the probability of regulatory approval, the estimated date of a product launch, estimates of eligible patient populations, estimates of prescribing behavior and patient compliance behavior, estimates of pricing, payor reimbursement and coverage, and sales ramp. A significant change in unobservable inputs could result in a material increase or decrease to the effective interest rate of the RP OM Liability and the RP Aficamten Liability.

We recorded $50.0 million of additional consideration associated with the 2022 RP Aficamten Royalty Purchase Agreement upon receipt of the cash in the third quarter of 2023.

We review our assumptions on a regular basis and our estimates may change in the future as we refine and reassess our assumptions.

Changes to the RP Aficamten Liability and the RP OM Liability are as follows (in thousands):

Note 7 — Debt

Convertible Notes

On November 13, 2019, we issued $138.0 million aggregate principal amount of 2026 Notes. On July 6, 2022, we issued $540.0 million aggregate principal amount of 2027 Notes and used approximately $140.3 million of the net proceeds from the offering of 2027 Notes and issued 8,071,343 shares of common stock to repurchase approximately $116.9 million aggregate principal amount of the 2026 Notes pursuant to privately negotiated exchange agreements entered into with certain holders of the 2026 Notes concurrently with the pricing of the offering of the 2027 Notes. As of March 31, 2024, there remains $21.1 million aggregate principal amount of 2026 Notes outstanding and $540.0 million of aggregate principal amount of 2027 Notes outstanding.

The 2026 Notes are unsecured obligations and bear interest at an annual rate of 4.0% per year, payable semi-annually on May 15 and December 15 of each year, beginning May 15, 2020. The 2026 Notes will mature on November 15, 2026, unless earlier repurchased or redeemed by us or converted at the option of the holders. We may redeem the 2026 Notes prior to the maturity date but we are not required to andno sinking fund is provided for the 2026 Notes. The 2026 Notes may be converted, under certain circumstances, based on an initial conversion rate of 94.7811 shares ofcommon stock per $1,000 principal amount (which represents an initial conversion price of $10.55 per share).

The 2027 Notes are our senior unsecured obligations and shares equal in right of payment with our other indebtedness, including the 2026 Notes. The 2027 Notes bear interest at a rate of 3.5% per year, payable semiannually in arrears on January 1 and July 1 of each year, beginning on January 1, 2023. The 2027 Notes will mature on July 1, 2027, unless earlier converted, redeemed or repurchased. The 2027 Notes are convertible into cash, shares of our common stock or a combination of cash and shares of our common stock, at our election, based on the applicable conversion rate(s). The initial conversion rate for the 2027 Notes is 19.5783 shares of ourcommon stock per $1,000 principal amount of such Notes, which is equivalent to an initial conversion price of approximately $51.08 per share.

The conversion rate for the 2026 Notes and 2027 Notes will be subject to adjustment upon the occurrence of certain specified events as described above. In addition, upon the occurrence of a make-whole fundamental change (as defined in the indenture), we will, in certain circumstances, increase the conversion rate by a number of additional shares for a holder that elects to convert its notes in connection with such make-whole fundamental change.

The 2026 Notes are redeemable, in whole or in part, at our option at any time, and from time to time, and, in the case of any partial redemption, on or before the 60th scheduled trading day before the maturity date, at a cash redemption price equal to the principal amount of the 2026 Notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date but only if the last reported sale price per share of our common stock exceeds 130% of the conversion price on (i) each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date we may send the related redemption notice; and (ii) the trading day immediately before the date we may send such notice.

Holders of the 2027 Notes have the option to convert their convertible notes only in the following circumstances: (i) if the last reported sale price per share of our common stock exceeds 130% of the conversion price for at least 20 trading days within a 30-day period starting from the last trading day of the preceding quarter after September 30, 2022; (ii) within 5 consecutive business days following any 10 consecutive trading day period if the trading price per $1,000 principal amount of 2027 Notes during such period falls below 98% of the product of the last reported sale price per share of our common stock and the conversion rate; (iii) upon certain corporate events or distributions on our common stock outlined in the 2027 Indenture; (iv) upon our call for redemption of the 2027 Notes; and (v) from March 1, 2027, until the scheduled trading day immediately preceding the maturity date. Circumstance (i) defined above was triggered upon the calculation completed for April 1, 2024. Consequently the 2027 Notes are redeemable at the option of the holders for the second quarter of 2024. This calculation will continue to be re-evaluated on a quarterly basis.

We may not redeem the 2027 Notes at our option at any time before July 7, 2025. The 2027 Notes will be redeemable, in whole or in part (subject to the “Partial Redemption Limitation” (as defined in the 2027 Indenture)), at our option at any time, and from time to time, on or after July 7, 2025

The following table presents the total amount of interest cost recognized relating to the 2026 Notes (in thousands):

The effective interest rate of the 2026 Notes was 4.6% for the three months ended March 31, 2024 and 2023. As of March 31, 2024, the unamortized debt issuance cost for the 2026 Notes was$0.3 million and will be amortized over approximately 2.7 years. The 2026 Notes are convertible at March 31, 2024 at the option of the holder.

The following table presents the total amount of interest cost recognized relating to the 2027 Notes (in thousands):

The effective interest rate of the 2027 Notes was 4.2% as of March 31, 2024 and 2023. As of March 31, 2024, the unamortized debt issuance cost for the 2027 Notes was$11.0 million and will be amortized over approximately 3.3 years. During the three months ended March 31, 2024, the conditions allowing holders of the 2027 Notes to convert were not met. As a result, the 2027 Notes are not convertible during the three months ended March 31, 2024.

Future minimum payments under the 2027 Notes and 2026 Notes are (in thousands):

As of March 31, 2024, the estimated fair value of the 2027 Notes and 2026 Notes was$866.6 million and$141.7 million, respectively, and was based upon observable, Level 2 inputs, including pricing information from recent trades of the convertible notes.

Note 8 — Stockholders’ Equity

Equity Incentive Plan

Our 2004 Plan provides for us to grant incentive stock options, non-statutory stock options, restricted stock, stock appreciation rights, restricted stock units, performance shares and performance units to employees, directors, and consultants. We may grant options for terms of up toten years at prices not lower than 100% of the fair market value of our common stock on the date of grant. Options granted to new employees generally vest 25% afterone year and monthly thereafter over a period offour years. Options granted to existing employees generally vest monthly over a period offour years.

Our annual grant of stock-based compensation takes place during the first quarter of each year. Our stock options and restricted stock units granted for the first quarter of 2024 was as follows:

As of March 31, 2024, the total authorized shares under the 2004 Plan available for grant was 5.6 million.

Stock-based compensation expense was$21.6 million and$15.2 million for the three months ended March 31, 2024 and 2023, respectively.

Warrants

As of December 31, 2023, we had the following warrants outstanding to purchase shares of our common stock which were exercised in January 2024:

Controlled Equity Offering Sales Agreement with Cantor Fitzgerald & Co.

On March 1, 2023, we entered into the Amended ATM Facility, with Cantor, under which we may offer and sell, from time to time at our sole discretion, shares of the Common Stock having an aggregate offering price of up to$300.0 million through Cantor, as sales agent. The Amended ATM Facility amends, restates and supersedes the Controlled Equity Offering Sales Agreement dated as of March 6, 2019 between the Company and Cantor.

Cantor may sell the Common Stock by any method that is deemed to be an “at the market offering” as defined in Rule 415 of the Securities Act of 1933, as amended, including sales made directly on the Nasdaq Global Select Market or any other trading market for our common stock. Cantor will use commercially reasonable efforts to sell the Common Stock from time to time, based upon instructions from us (including any price, time or size limits or other customary parameters or conditions we may impose). We will pay Cantor a commission of up to 3.0% of the aggregate gross sales proceeds of any common stock sold through Cantor under the Amended ATM Facility, and also have provided Cantor with customary indemnification rights.

In 2023, we issued 5,016,170 shares of our common stock for net proceeds of$164.2 million under the Amended ATM Facility. During the three months ended March 31, 2024, we issued 1,237,460 shares of our common stock for net proceeds of$93.6 million under the Amended ATM Facility.

Performance Stock Units

In March 2024, the Compensation Committee granted a total of 359,992 performance stock units ("PSUs") to certain employees with a grant date fair value of $63.75 per unit. The fair value of the PSUs was determined on the grant date based on the fair value of the Company’s common stock at such time. The PSU awards are subject totwo performance goals and will be earned as to up to 50% of the number of shares subject to the PSU award upon the certification by the Compensation and Talent Committee of the Company’s Board of Directors (the “Compensation Committee”) that the Company has achieved the first performance goal and as to up to 50% of the number of shares subject to the PSU award upon the certification by the Compensation Committee that the Company has achieved the second performance goal, in each case vesting as to 50% of the earned shares on applicable Compensation Committee certification date and as to 50% of the earned shares following the one-year anniversary of the applicable Compensation Committee certification date.

During the three months ended March 31, 2024, the Company recognized expense of$0.4 million for the PSUs. As of March 31, 2024, there was$11.1 million of unamortized stock-based compensation related to the PSUs. The Company will assess the probability of achieving the performance conditions quarterly and the expense recognized will be adjusted accordingly.

Note 9 — Commitments and Contingencies

Operating Leases

In July 2019, we entered into the Oyster Point Lease of office and laboratory space at a facility located in South San Francisco, California, and we entered into amendments to the Oyster Point Lease in 2020, 2021, 2022, and 2023. The Oyster Point Lease commenced on March 31, 2021 and has an expiration date of October 31, 2033.