GERON CORP

1. ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Organization

The terms “Geron”, the “Company”, “we” and “us” as used in this report refer to Geron Corporation, which was incorporated in the State of Delaware on November 28, 1990, and its wholly-owned subsidiaries, Geron UK Limited, or Geron UK, a United Kingdom company, and Geron Netherlands B.V., or Geron Netherlands, a Netherlands company. Geron UK was incorporated in September 2021, and its operations commenced in January 2022. Geron Netherlands was incorporated in February 2023, and its operations commenced in June 2023. We are a late-stage clinical biopharmaceutical company that is focused on the development and potential commercialization of imetelstat, an innovative therapeutic for hematologic malignancies. We have global rights to imetelstat, an investigational first-in-class telomerase inhibitor, which was discovered and developed at Geron. Principal activities to date have included obtaining financing, securing operating facilities and conducting research and development.

Principles of Consolidation

The consolidated financial statements include the accounts Geron Corporation and its wholly-owned subsidiaries, Geron UK and Geron Netherlands. We have eliminated intercompany accounts and transactions. We prepare the financial statements of Geron UK and Geron Netherlands using the local currency as the functional currency. We translate the assets and liabilities of Geron UK and Geron Netherlands at rates of exchange at the balance sheet date and translate income and expense items at average monthly rates of exchange. The resultant translation adjustments are included in accumulated other comprehensive income (loss), a separate component of stockholders’ equity, on our consolidated balance sheets.

Net Loss Per Share

Basic net income (loss) per share is calculated by dividing net income (loss) by the weighted-average number of shares of common stock outstanding for the periods presented without consideration of potential common shares. In April 2022, we entered into an underwriting agreement in connection with a public offering of our common stock, pursuant to which we issued a pre-funded warrant to purchase 18,095,238 shares of our common stock, also known as the 2022 pre-funded warrant, together with accompanying warrants to purchase shares of our common stock. In May 2020, we entered into an underwriting agreement in connection with a public offering of our common stock, pursuant to which we issued a pre-funded warrant to purchase 8,335,239 shares of our common stock, or the 2020 pre-funded warrant, together with accompanying warrants to purchase shares of our common stock. The 2022 pre-funded warrant and 2020 pre-funded warrant each are exercisable immediately at an exercise price of $0.001 per share. In January 2023, we completed an underwritten public offering of 68,007,741 shares of our common stock and a pre-funded warrant to purchase 25,000,000 shares of our common stock, or the 2023 pre-funded warrant. We included the 2023 pre-funded warrant, the 2022 pre-funded warrant and the 2020 pre-funded warrant in the computation of basic net loss per share, as applicable, since their exercise price is negligible, and they may be exercised at any time. See Note 9 on Stockholders' Equity for further discussion of our public offerings.

Diluted net income per share would be calculated by adjusting the weighted-average number of shares of common stock outstanding for the dilutive effect of additional shares of common stock that would have been outstanding if potentially dilutive securities had been issued, as determined using the treasury-stock method. Potential dilutive securities consist of outstanding stock options and warrants to purchase our common stock. Diluted net loss per share excludes potential dilutive securities for all periods presented as their effect would be anti-dilutive. Accordingly, basic and diluted net loss per share is the same for all periods presented in the accompanying consolidated statements of operations. Since we incurred a net loss for 2023, 2022, and 2021, the diluted net loss per share calculation excludes potential dilutive securities of 75,458,854,145,726,765 and 105,725,875 shares, respectively, related to outstanding stock options and warrants, as their effect would have been anti-dilutive.

Use of Estimates

The accompanying consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States, or U.S. GAAP. The preparation of financial statements in conformity with U.S. GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, we evaluate our estimates, including those related to accrued liabilities, revenue recognition, fair value of marketable securities and equity investments, operating leases, right-of-use assets, lease liabilities, income taxes, and stock-based compensation. We base our estimates on historical experience and on various other market specific and relevant assumptions that we believe to be reasonable under the circumstances. Actual results could differ from those estimates.

Fair Value of Financial Instruments

Cash Equivalents and Marketable Securities

We consider all highly liquid investments with an original maturity of three months or less to be cash equivalents. We are subject to credit risk related to our cash equivalents and marketable securities. Our marketable debt securities include U.S. Treasury securities, municipal securities, government-sponsored enterprise securities, commercial paper and corporate notes.

We classify our marketable debt securities as available for sale. We record available for sale debt securities at fair value with unrealized gains and losses reported in accumulated other comprehensive income (loss) in stockholders’ equity. Realized gains and losses are included in interest income and are derived using the specific identification method for determining the cost of securities sold and have been insignificant to date. Dividend and interest income are recognized when earned and included in interest income on our consolidated statements of operations. We recognize a charge when the declines in the fair values below the amortized cost bases of our available for sale securities are judged to be other than temporary. We consider various factors in determining whether to recognize an other than temporary charge, including whether we intend to sell the security or whether it is more likely than not that we would be required to sell the security before recovery of the amortized cost basis. Declines in market value judged as other than temporary result in a charge to interest income. We have not recorded any other‑than‑temporary impairment charges on our available‑for‑sale securities for the years ended December 31, 2023, 2022 and 2021. See Note 2 on Fair Value Measurements.

Equity Investments

We measure our investment in equity securities at fair value at each reporting date. Changes in fair value resulting from observable price changes are included in change in fair value of equity investment and changes in fair value resulting from foreign currency translation are included in other expense on our consolidated statements of operations.

Leases

At the inception of an arrangement, we determine whether the arrangement is or contains a lease based on the unique facts and circumstances present. Operating leases are included in operating leases, right-of-use assets and lease liabilities on our consolidated balance sheets. Right-of-use assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. Operating lease liabilities and their corresponding right-of-use assets are recorded based on the present value of remaining lease payments over the expected lease term. The present value of remaining lease payments within the 12 months following the balance sheet date are classified as current lease liabilities. The present value of lease payments not within the 12 months following the balance sheet date are classified as noncurrent lease liabilities. The interest rate implicit in lease contracts is typically not readily determinable. As such, to calculate the net present value of lease payments, we apply our incremental borrowing rate, which is the estimated rate to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment as of the lease commencement date. We may adjust the right-of-use assets for certain adjustments, such as initial direct costs paid or incentives received. In addition, we include any options to extend or terminate the lease in the expected lease term when it is reasonably certain that we will exercise any such option. Lease expense is recognized on a straight-line basis over the expected lease term.

For lease agreements entered into after January 1, 2019 that include lease and non-lease components, such components are generally accounted for separately. We have also elected not to recognize on our consolidated balance sheets leases with terms of one year or less.

Debt Issuance Costs and Debt Discounts

Debt issuance costs include legal fees, accounting fees, and other direct costs incurred in connection with the execution of our debt financing. Debt discounts represent costs paid to the lenders. Debt issuance costs and debt discounts are deducted from the carrying amount of the debt liability and are amortized to interest expense over the term of the related debt using the effective interest method.

Revenue Recognition

We recognize revenue in accordance with the provisions of Accounting Standards Codification Topic 606, Revenue from Contracts with Customers, or Topic 606. In determining the appropriate amount and timing of revenue to be recognized under this guidance, we perform the following five steps: (i) identify the contract(s) with our customer; (ii) identify the promised goods or services in the agreement and determine whether they are performance obligations, including whether they are distinct in the context of the agreement; (iii) measure the transaction price, including the constraint on variable consideration; (iv) allocate the transaction price to the performance obligations based on stand-alone selling prices; and (v) recognize revenue when (or as) we satisfy each performance obligation.

A performance obligation is a promise in an agreement to transfer a distinct good or service to the customer and is the unit of account in Topic 606. Significant management judgment is required to determine the level of effort required and the period over which completion of the performance obligations is expected under an agreement. If reasonable estimates regarding when performance obligations are either complete or substantially complete cannot be made, then revenue recognition is deferred until a reasonable estimate can be made. Revenue is then recognized over the remaining estimated period of performance using the cumulative catch-up method.

We allocate the total transaction price to each performance obligation based on the estimated relative stand-alone selling prices of the promised goods or services underlying each performance obligation. Estimated selling prices for license rights are calculated using an income approach model and include the following key assumptions, judgments and estimates: the development timeline, revenue forecast, commercialization expenses, discount rate and probabilities of technical and regulatory success.

Following is a description of the principal activities from which we generate revenue. License fees and royalty revenue primarily represent amounts earned under agreements that out-license our technology to various companies.

License Agreements

We previously entered into several license agreements with various oncology, diagnostics, research tools and biologics production companies, whereby we granted certain rights to our non-imetelstat related technologies. Under these agreements, non-refundable upfront fees and annual license maintenance fees were considered fixed consideration, while milestone payments and royalties were identified as variable consideration. Since June 30, 2021, no active license agreements remain. The license related to our specialized oligonucleotide backbone chemistry, as well as patent rights covering the synthesis of monomers, the building blocks of oligonucleotides, terminated effective April 2021.

In connection with the divestiture of our human embryonic stem cell assets, including intellectual property and proprietary technology, to Lineage Cell Therapeutics, Inc. (formerly BioTime, Inc. which acquired Asterias Biotherapeutics, Inc.) in 2013, we are entitled to receive royalties on sales of certain research or commercial products utilizing our divested intellectual property.

Licenses of Intellectual Property. If we determine the license to intellectual property is distinct from the other performance obligations identified in the agreement and the licensee can use and benefit from the license, we recognize revenue from non-refundable upfront fees allocated to the license upon the completion of the transfer of the license to the licensee. For such licenses, we recognize revenue from annual license maintenance fees upon the start of the new license period. For licenses that are bundled with other performance obligations, we assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable upfront fees or annual license maintenance fees. At each reporting date, we reassess the progress and, if necessary, adjust the measure of performance and related revenue recognition.

Milestone Payments. At the inception of each agreement that includes milestone payments, we evaluate whether the milestones are considered probable of being achieved and estimate the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the value of the associated milestone is included in the transaction price. For milestones that we do not deem to be probable of being achieved, the associated milestone payments are fully constrained and the value of the milestone is excluded from the transaction price with no revenue being recognized. For example, milestone payments that are not within our control, such as regulatory-related accomplishments, are not considered probable of being achieved until those accomplishments have been communicated by the relevant regulatory authority. Once the assessment of probability of achievement becomes probable, we recognize revenue for the milestone payment. At each reporting date, we assess the probability of achievement of each milestone under any current agreements.

Royalties. For agreements with sales-based royalties, including milestone payments based on the level of sales, where the license is deemed to be the predominant item to which the royalties relate, we recognize revenue at the later of (a) when the related sales occur, or (b) when the performance obligation, to which some or all of the royalty has been allocated, has been satisfied (or partially satisfied). At each reporting date, we estimate the sales incurred by each licensee during the reporting period based on historical experience and accrue the associated royalty amount.

Restricted Cash

Restricted cash consists of funds maintained in separate money market or certificate of deposit accounts for credit card purchases.

Research and Development Expenses

Research and development expenses currently consist of expenses incurred in developing and testing imetelstat and research related to potential next generation telomerase inhibitors. These expenses include, but are not limited to, payroll and personnel expense, lab supplies, non-clinical studies, clinical trials, including support for investigator-led clinical trials, raw materials to manufacture clinical trial drugs, manufacturing costs for research and clinical trial materials, sponsored research at other labs, consulting, costs to maintain technology licenses and research-related overhead.

Our current imetelstat clinical trials are being supported by contract research organizations, or CROs, and other vendors. We accrue expenses for clinical trial activities performed and managed by CROs based upon the amount of work completed on each trial. Expenses are recorded based on contracted amounts agreed to with our CROs and through monthly reporting provided by CROs. We monitor activities conducted and managed by the CROs to the extent possible through internal reviews, review of contractual terms and correspondence with CROs. We record expense on the best information available at the time. However, additional information may become available to us which may require us to record adjustments to research and development expenses in future periods.

Depreciation and Amortization

We record property and equipment at cost and calculate depreciation using the straight‑line method over the estimated useful lives of the assets, generally four years. Leasehold improvements are amortized over the shorter of the estimated useful life or remaining term of the lease.

Stock‑Based Compensation

We maintain various stock incentive plans under which stock options and restricted stock awards can be granted to employees, non-employee directors and consultants. We also have an employee stock purchase plan for all eligible employees. We recognize stock-based compensation expense based on grant-date fair values of service-based stock options on a straight-line basis over the requisite service period, which is generally the vesting period. For performance-based stock options with vesting based on the achievement of certain strategic milestones, stock-based compensation expense is recognized over the period from the date the performance condition is determined to be probable of occurring through the date the applicable condition is expected to be met and is reduced for estimated forfeitures, as applicable. If the performance condition is not considered probable of being achieved, no stock-based compensation expense is recognized until such time as the performance condition is considered probable of being met, if at all. If the assessment of probability of the performance condition changes, the impact of the change in estimate would be recognized in the period of the change. The determination of grant-date fair values for our service-based and performance-based stock options and employee stock purchases using the Black-Scholes option pricing model is affected by our stock price as well as assumptions regarding a number of complex and subjective variables. The grant-date fair value for service-based restricted stock awards is determined using the fair value of our common stock on the date of grant. We evaluate whether an adjustment to the assumptions of fair value of our common stock and historical volatility are required if observed prices of our common stock materially differ from historical information.

We measure share-based payments to non-employees based on the grant-date fair value of the equity awards to be issued. We recognize stock-based compensation expense for the fair value of the vested portion of non-employee stock-based awards on our consolidated statements of operations. For additional information, see Note 9 on Stockholders’ Equity.

Accumulated Other Comprehensive Gain (Loss)

Accumulated other comprehensive gain (loss) includes certain changes in stockholders’ equity which are excluded from net income (loss). Accumulated other comprehensive loss on our consolidated balance sheets as of December 31, 2023 and 2022, respectively, is comprised of net unrealized losses on marketable securities and cumulative translation adjustments.

Income Taxes

We maintain deferred tax assets and liabilities that reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes and are subject to tests of recoverability. Our deferred tax assets include net operating loss carryforwards, federal and state tax credits and capitalized research and development. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. Our net deferred tax asset has been fully offset by a valuation allowance because of our history of losses. Any potential accrued interest and penalties related to unrecognized tax benefits would be recorded as income tax expense.

Segment Information

Our executive management team represents our chief decision maker. We view our operations as a single segment, the development of therapeutic products for oncology. As a result, the financial information disclosed herein materially represents all of the financial information related to our principal operating segment.

Recent Accounting Pronouncements

New Accounting Pronouncements – Issued But Not Yet Adopted

In November 2023, the FASB issued ASU 2023-07, Segment Reporting (ASU 2023-07), which requires issuers to make additional disclosures with respect to segment expenses, including required disclosure on an annual and interim basis for significant segment expenses and other segment items. ASU 2023-07 also permits the disclosure of more than one measure of a segment’s profit or loss. ASU 2023-07 is effective for the Company as of January 1, 2024 for annual periods and as of January 1, 2025 for interim periods. We are evaluating the impact of this ASU on our consolidated financial statements.

In December 2023, the Financial Standards Accounting Board (FASB) issued Accounting Standards Update (ASU) 2023-09, Income Taxes (ASU 2023-09), which requires issuers to make additional discloses on an annual basis related to specific categories in the rate reconciliation and provide additional information for reconciling items that meet a quantitative threshold on an annual basis, disclose additional information about income taxes paid as well as other disaggregated disclosures. ASU 2023-09 is effective for the Company as of January 1, 2025 for annual periods. We are evaluating the impact of this ASU on our consolidated financial statements.

New Accounting Pronouncements – Issued and Adopted

In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments, or ASU 2016-13. The main objective of ASU 2016-13 is to provide financial statement users with more decision-useful information about an entity's expected credit losses on financial instruments and other commitments to extend credit at each reporting date. To achieve this objective, the amendments in this update replace the incurred loss impairment methodology currently used today with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to develop credit loss estimates. Subsequent to issuing ASU 2016-13, the FASB issued ASU 2018-19, Codification Improvements to Topic 326, Financial Instruments – Credit Losses, or ASU 2018-19, for the purpose of clarifying certain aspects of ASU 2016-13. In May 2019, the FASB issued ASU 2019-05, Financial Instruments – Credit Losses (Topic 326): Targeted Transition Relief, or ASU 2019-05, to provide entities with more flexibility in applying the fair value option on adoption of the credit impairment standard. In November 2019, the FASB issued ASU 2019-11, Codification Improvements to Topic 326, Financial Instruments – Credit Losses, which expands the scope of the practical expedient that allows entities to exclude the accrued interest component of amortized cost from various disclosure. Entities that elect to apply the practical expedient must disclose the total amount of accrued interest that they exclude from their disclosures of amortized cost. ASU 2018-19, ASU 2019-05 and ASU 2019-11 have the same effective date and transition requirements as ASU 2016-13. ASU 2016-13 became effective for fiscal years beginning after December 15, 2022, using a modified retrospective approach, for smaller reporting companies. Early adoption is permitted. We adopted ASU 2016-13 and related updates as of January 1, 2023. The adoption of this standard did not have a material impact on our financial statements.

Other recent accounting pronouncements issued by the FASB did not or are not believed by management to have a material impact on our financial statements.

2. FAIR VALUE MEASUREMENTS

Cash Equivalents and Marketable Securities

Cash equivalents, restricted cash and marketable securities by security type at December 31, 2023 were as follows:

Cash equivalents, restricted cash and marketable securities by security type at December 31, 2022 were as follows:

Cash equivalents and marketable securities with unrealized losses that have been in a continuous unrealized loss position for less than 12 months and 12 months or longer at December 31, 2023 and 2022 were as follows:

The gross unrealized losses related to U.S. Treasury securities, municipal securities, government-sponsored enterprise securities, commercial paper and corporate notes as of December 31, 2023 and 2022 were due to changes in interest rates and not credit risk. We determined that the gross unrealized losses on our cash equivalents and marketable securities as of December 31, 2023 and 2022 were temporary in nature. Our exposure to unrealized losses may increase in the future due to the economic pressures or uncertainties associated with local or global economic recessions as a result of ongoing geopolitical events, such as the current military conflict between Ukraine and Russia, as well as recent and potential future disruptions in access to bank deposits or lending commitments due to bank failure. We review our investments quarterly to identify and evaluate whether any investments have indications of possible other-than-temporary impairment. Factors considered in determining whether a loss is temporary include the length of time and extent to which the fair value has been less than the amortized cost basis and whether we intend to sell the security or whether it is more likely than not that we would be required to sell the security before recovery of the amortized cost basis. We currently do not intend to sell these securities before recovery of their amortized cost bases.

Fair Value on a Recurring Basis

We categorize financial instruments recorded at fair value on our consolidated balance sheets based upon the level of judgment associated with inputs used to measure their fair value. The categories are as follows:

A financial instrument’s categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Below is a description of the valuation methodologies used for financial instruments measured at fair value on our consolidated balance sheets, including the category for such financial instruments.

Money market funds and certificates of deposit are categorized as Level 1 within the fair value hierarchy as their fair values are based on quoted prices available in active markets. Commercial paper, U.S. Treasury securities, municipal securities, government-sponsored enterprise securities and corporate notes are categorized as Level 2 within the fair value hierarchy as their fair values are estimated by using pricing models, quoted prices of securities with similar characteristics or discounted cash flows.

The following table presents information about our financial instruments that are measured at fair value on a recurring basis as of December 31, 2023 and 2022 and indicates the fair value category assigned.

(1)

Included in cash and cash equivalents on our consolidated balance sheets.

(2)

Included in restricted cash on our consolidated balance sheets.

(3)

Included in current portion of marketable securities on our consolidated balance sheets.

(4)

Included in noncurrent portion of marketable securities on our consolidated balance sheets.

Equity Investment

In December 2007, we received 13,842,625 ordinary shares in Sienna Cancer Diagnostics Limited, or Sienna, in connection with a license we granted to them for our hTERT technology for use in human diagnostics. The shares, which represented less than 20% ownership, were recorded at azero cost basis under the cost method of accounting, upon receipt. Since the adoption of ASU 2016-01 on January 1, 2018, we reassessed the fair value of our equity investment in Sienna at each reporting date and any resulting change in fair value was recognized on our consolidated statements of operations. In April 2020, Sienna announced its merger with BARD1 Life Sciences Limited, or BARD1, subject to approval by Sienna’s shareholders. Effective August 3, 2020, the merger was complete, andwe received 13 BARD1 shares for every five shares of Sienna ordinary shares, resulting in our ownership of 35,990,825 shares of BARD1.

During the first quarter of 2021, we sold all of our holdings in BARD1 and recognized a net gain of approximately $1,233,000 from the sales, including gains from foreign currency translation adjustments, which has been included in other income and expense on our consolidated statements of operations. As of March 31, 2021, no value remained for our equity investment in BARD1.

Credit Risk

We currently place our cash, restricted cash, cash equivalents and marketable securities with multiple institutions in the United States. Generally, these deposits may be redeemed upon demand and therefore, bear minimal risk. Deposits with banks may exceed the amount of insurance provided on such deposits. Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash equivalents and marketable securities. Cash equivalents and marketable securities currently consist of money market funds, government-sponsored enterprise securities, U.S. Treasury securities, municipal securities, commercial paper and corporate notes. Our investment policy, approved by the audit committee of our board of directors, limits the amount we may invest in any one type of investment issuer, thereby reducing credit risk concentrations. However, we are exposed to credit risk in the event of default by the financial institutions holding our cash and cash equivalents to the extent recorded in our consolidated balance sheets. We have not experienced any losses in such accounts and we believe that we are not exposed to significant credit risk of our financial position at the depository institutions in which those deposits are held.

3. PROPERTY AND EQUIPMENT

Property and equipment, stated at cost, is comprised of the following:

4. LICENSE AGREEMENT

Janssen Pharmaceuticals, Inc. License Agreement

On September 15, 2016, we entered into the License Agreement with Janssen Pharmaceuticals whereby we granted to Janssen Pharmaceuticals an exclusive worldwide license, or the Exclusive License, under our proprietary patents for the research, development and commercialization of products based on specialized oligonucleotide backbone chemistry and novel amidates for ribonucleic acid interference. In addition to the Exclusive License, we granted to Janssen Pharmaceuticals a non‑exclusive worldwide license, or the Non‑Exclusive License, under our patents covering the synthesis of monomers. This agreement was terminated effective April 2021.

5. ACCRUED LIABILITIES

Accrued liabilities consisted of the following:

6. COMMITMENTS AND CONTINGENCIES

Purported Securities Lawsuits

In 2020, three securities class action lawsuits were filed against us and certain of our officers. One of the lawsuits was voluntarily dismissed. The other two lawsuits, filed in the U.S. District Court for the Northern District of California, were consolidated by the court. In September 2022, the parties agreed to a settlement and entered into a Stipulation and Agreement of Settlement, which was subject to court approval. The court granted final approval of the settlement on September 28, 2023 and final judgment was entered on October 3, 2023.

Under the terms of the Stipulation, in exchange for the release and dismissal with prejudice of all claims against the defendants in the consolidated class action complaint, we agreed to pay and/or to cause our insurance carriers to pay a total of $24,000,000, comprised of $17,000,000 in cash, which was paid into an escrow account under our available D&O insurance coverage and, $7,000,000 in cash which was paid after final approval of the settlement by the court. The settlement does not constitute an admission of fault or wrongdoing by Geron or any of our officers. As of December 31, 2022, our portion of the settlement amount of $7,000,000 had been included in accrued liabilities on our consolidated balance sheets and recognized as general and administrative expense on our consolidated statements of operations for the year ended December 31, 2022. Our portion of the settlement amount was paid in the fourth quarter of 2023. There is no liability outstanding as of December 31, 2023 as the matter was fully settled during the year ended December 31, 2023.

In 2020 and 2021, seven shareholder derivative actions were filed in a number of courts, naming as defendants certain of our then current officers and certain of our then current and former members of our board. On December 21, 2022, the parties to the shareholder derivative action filed in the Delaware Court of Chancery entered into a stipulation of settlement, or the Derivative Stipulation, and on May 17, 2023, the Delaware Court of Chancery approved the Derivative Stipulation, and the case was dismissed with prejudice. Subsequently, each of the remaining derivative cases were dismissed with prejudice.

Under the terms of the Derivative Stipulation, in exchange for the release and dismissal with prejudice of all claims against the defendants in the consolidated shareholder derivative actions filed in the Northern District, we agreed to pay and/or to cause our insurance carriers to pay a total of $1,350,000, comprised of $525,000 in cash, which was payable under our available D&O insurance coverage and $825,000 in cash payable by us. The settlement does not constitute an admission of fault or wrongdoing by any of our officers ormembers of our board. As of December 31, 2022, we had recorded the total settlement amount of $1,350,000 as accrued liabilities and $525,000 as interest and other receivables on our consolidated balance sheets. For the year ended December 31, 2022, we had recognized our portion of the settlement of $825,000 as general and administrative expense on our consolidated statements of operations. In the second quarter of 2023, our insurance carriers paid $525,000 incash, andwe paid $825,000 in cash, for an aggregate total payment of $1,350,000. Accordingly, there areno outstanding amount to settle against this as of December 31, 2023.

While we have settled these lawsuits, it is possible that additional lawsuits might be filed, or allegations might be received from stockholders, with respect to these same or other matters and also naming us and/or our officers and directors as defendants. Such lawsuits and any other related lawsuits are subject to inherent uncertainties, and the actual defense and disposition costs will depend upon many unknown factors. The outcome of such lawsuits is necessarily uncertain. We could be forced to expend significant resources in the defense of any additional lawsuits, and we may not prevail. In addition, we have and may continue to incur substantial legal fees and costs in connection with such lawsuits. Monitoring, initiating and defending against legal actions is time-consuming for our management, is likely to be expensive, and may detract from our ability to fully focus our internal resources on our business activities. We could be forced to expend significant resources in any potential future lawsuits, and we may not prevail in such lawsuits. Additionally, we may not be successful in having any such lawsuits dismissed or settled within the limits of our insurance coverage. Expenses associated with any potential future lawsuits could be material to our consolidated financial statements if we do not prevail in the defense of such lawsuits, or even if we do prevail. We have not established any reserve for any potential liability relating to any potential future lawsuits. It is possible that we could, in the future, incur judgments or enter into settlements of claims for monetary damages.

Indemnifications to Officers and Directors

Our corporate bylaws require that we indemnify our directors, as well as those who act as directors and officers of other entities at our request, against expenses, judgments, fines, settlements and other amounts actually and reasonably incurred in connection with any proceedings arising out of their services to Geron. In addition, we have entered into separate indemnification agreements with each of our directors and officers which provide for indemnification of these directors and officers under similar circumstances and under additional circumstances. The indemnification obligations are more fully described in our bylaws and the indemnification agreements. We purchase standard insurance to cover claims or a portion of the claims made against our directors and officers. Since a maximum obligation is not explicitly stated in our bylaws or in our indemnification agreements and will depend on the facts and circumstances that arise out of any future claims, the overall maximum amount of the obligations cannot be reasonably estimated.

Severance Plan

We have adoptedtwo severance plans that apply to all of our employees who are not subject to performance improvement plans, one plan covering employees above the Vice President level, i.e., executives, and all other employees hired before January 1, 2022, and the other plan covering all non-executive employees hired on or after January 1, 2022. The severance plans provide for, among other benefits: (i) a severance payment upon a Change of Control Triggering Event and Separation from Service and (ii) a severance payment for each non‑executive employee upon a Non‑Change of Control Triggering Event and Separation from Service. As defined in the severance plans, a Change of Control Triggering Event and Separation from Service requires a “double trigger” where: (i) an employee is terminated by us without cause in connection with a change of control or within 12 months following a change of control provided, however, that if an employee is terminated by us in connection with a change of control but immediately accepts employment with our successor or acquirer, the employee will not be eligible for the benefits outlined in the plans, (ii) an employee resigns because in connection with a change of control, the offered terms of employment (new or continuing) by us or our successor or acquirer within 30 days after the change of control results in a material change in the terms of employment, or (iii) after accepting (or continuing) employment with us after a change of control, an employee resigns within 12 months following a change of control due to a material change in the terms of employment. Under the severance plans, a Non‑Change of Control Triggering Event and Separation from Service is defined as an event where an employee is terminated by us without cause. Severance payments range from three to 18 months of base salary in connection with a Change of Control Triggering Event or fromsix weeks to 12 monthsof base salary in connection with a Non-Change of Control Triggering Event, as well as a pro-rata portion of the employee’s annual target bonus, depending on the employee’s position with us, payable in a lump sum payment, and monthly COBRA payments for the severance period. The severance plans also provide that they shall not supersede the provisions of any individual employment agreements entered into between us and our employees, and that the employees with such agreements will be entitled to whichever benefits are greater under the severance plan or their employment agreement. A copy of the severance plan covering our executive officers is filed as an exhibit to our annual report on Form 10-K. As of December 31,

2023, all our executive officers have employment agreements with severance provisions and will receive the greater severance benefits of their agreements or those in the severance plan applicable to them.

7. OPERATING LEASES

New Jersey Office Space Lease

In April 2019, we entered into an operating lease agreement for office space located at 3 Sylvan Way, Parsippany, New Jersey, or the New Jersey Lease. The initial term of the New Jersey Lease is 11 years with an option to extend for an additional five years and aone-time option to terminate the New Jersey Lease without cause as of the 103 rd month anniversary of the commencement date of the lease. The New Jersey Lease commenced on October 1, 2019, upon our control of the office space on that date. Based on the initial term of the New Jersey Lease of 11 years, the right-of-use asset and corresponding operating lease liability was approxima tely $2,356,000, which represented the present value of lease payments over the initial lease term, net of aseven-month rent abatement period, using an incremental borrowing rate of 8% based on information available as of October 1, 2019. Under the New Jersey Lease, we are also obligated to pay certain variable expenses separately from the base rent, including electricity and common area maintenance. Such costs are being expensed in the period they are incurred. As of December 31, 2023, the remaining lease term for the New Jersey Lease is 6.8 years.

Foster City Office Space Lease

In October 2019, we entered into an operating lease agreement for office space located at 919 East Hillsdale Boulevard, Foster City, California, or the Foster City Lease. The initial term of the Foster City Lease is 87 months with an option to extend for an additional five years.

The Foster City Lease commenced on March 10, 2020, upon the substantial completion of all tenant improvements. As of the lease commencement date, the right-of-use asset and corresponding operating lease liability was approximately $1,868,000, which represented the present value of remaining lease payments using an incremental borro wing rate of 7% over the initial lease term of 87 months, net of athree-month rent abatement period. Under the Foster City Lease, we are also obligated to pay certain variable expenses separately from the base rent, including taxes and common area maintenance. Such costs are considered non-lease components and have been excluded from the calculation of the right-of-use asset and corresponding operating lease liability and are being expensed in the period they are incurred. As of December 31, 2023, the remaining lease term for the Foster City Lease is 3.5 years.

The components of lease costs included in operating expenses on our consolidated statements of operations for the New Jersey Lease, the Foster City Lease and a lease from a former location in Menlo Park, California, were as follows:

(1)

Variable lease costs represent non-lease components, such as common area maintenance charges.

The undiscounted future non-cancellable lease payments under the New Jersey Lease and the Foster City Lease as of December 31, 2023 were as follows (in thousands):

8. DEBT

On September 30, 2020, or the Closing Date, we, Hercules Capital, Inc., or Hercules, and Silicon Valley Bank, or SVB, entered into a term loan facility, or the Term Loan, up to $75.0 million, which was amended in August 2021, or the Original Loan Agreement. On June 30, 2022, we entered into a second amendment to the Original Loan Agreement. Under the second amendment, the aggregate principal amount available to us increased from $75,000,000 to $125,000,000, with such principal being available in a series of tranches, subject to certain terms and conditions. On December 14, 2023, we entered into a third amendment to the Original Loan Agreement, or as amended, the Loan Agreement. As of December 31, 2023, a total of $80.0 million has been drawn under the Loan Agreement.

On the effective date of the second amendment, we paid $100,000 as a facility charge that we recognized as a debt discount and are amortizing such cost to interest expense over the life of the loan using the effective interest rate method. Additional facility charges applied to future draw downs will be treated similarly. We also incurred legal fees in connection with the second amendment, which we recognized as debt issuance costs and are amortizing such cost to interest expense over the life of the loan using the effective interest rate method.

Under the third amendment, the aggregate principal amount drawn down and remaining available to us under the Term Loan remains at $125.0 million, with such principal being available in a series of tranches, subject to certain terms and conditions. The third amendment also provides that (i) the fourth tranche of the Term Loan was increased from $10.0 million to $30.0 million, (ii) the commitment period for the fifth tranche of the Term Loan of $20.0 million, which is available subject to achievement of a regulatory milestone and satisfaction of certain capitalization requirements, was extended through December 15, 2024, (iii) the variable annual interest rate on the outstanding loans has been decreased to the greater of: (x)9.0%, or (y) the sum of (A) the Prime Rate (as reported in The Wall Street Journal) minus 4.5%, plus (B)9.0%; and (iv) the interest only period of the Term Loan has been extended through June 30, 2024, and is further extendable to December 31, 2024 upon achievement of a regulatory and financial milestone and satisfaction of certain capitalization requirements. In connection with the third amendment, on the third amendment effective date, we borrowed and received the entire fourth tranche of the Term Loan in the amount of $30.0 million. After giving effect to such borrowing, the outstanding principal amount under the Loan Agreement is $80.0 million. On the effective date of the third amendment, we paid $300,000 as a facility charge that we recognized as a debt discount and are amortizing such cost to interest expense over the life of the loan using the effective interest rate method. Additional facility charges applied to future draw downs will be treated similarly. We also incurred legal fees in connection with the third amendment, which we recognize as debt issuance costs and amortize such cost to interest expense over the life of the loan using the effective interest rate method. The third amendment of the Loan Agreement is not substantially different as compared to the Original Loan Agreement, and accordingly, we treated the amendment as a modification of the debt in accordance with ASC 470. On September 15, 2023, the third tranche of $20.0 million of the Term Loan expired and is no longer available for us, but was added to the fourth tranche as part of the third amendment to the Loan Agreement.

Under the Term Loan as amended, the Term Loan matures on April 1, 2025, or the Loan Maturity Date, and may be extended up to an additional six months upon the achievement of certain regulatory and financial milestones. The Term Loan bears interest at a floating rate per annum equal to the greater of either (i)9.0% or (ii) the sum of (A) the Prime Rate (as reported in The Wall Street Journal) minus 4.5%, plus (B)9.0% (8.5% as of December 31, 2023). The interest only period of the Term Loan is through June 30, 2024, and is further extendable to December 31, 2024 upon achievement of a regulatory and financial milestone and satisfaction of certain capitalization requirements. Following the expiration of the interest-only period, we are required to repay the Term Loan in equal monthly amortization payments of principal and interest until the Loan Maturity Date. Upon full repayment of the

Term Loan, we are also obligated to pay an end of term charge in an amount equal to 6.55% of the amount of the Term Loans actually borrowed. Such end of term charge is being accrued to interest expense over the term of the Term Loan using the effective interest rate method. At our option, upon at least five business days’ prior written notice to Hercules, we may prepay all or any portion greater than or equal to $5.0 million of the outstanding loan by paying the entire principal balance (or portion thereof) and all accrued and unpaid interest. There isno prepayment charge for prepayments of drawdowns under Tranche 1 or Tranche 2. Prepayments of drawdowns under Tranche 3, Tranche 4, Tranche 5 or Tranche 6 are subject to a prepayment charge of 1.5% of the prepayment amount, if the prepayment is made prior to June 30, 2025. Thereafter, any prepayment of Tranche 3, Tranche 4, Tranche 5 or Tranche 6 is not subject to a prepayment charge.

The Term Loan is secured by substantially all of Geron’s assets, except our intellectual property, which is the subject of a negative pledge. The Term Loan contains certain representations and warranties, affirmative covenants, negative covenants and conditions that are customarily required for similar financings. We are in compliance with the covenants under the Term Loan as of December 31, 2023.

In the event of default (subject, in certain instances, to specified grace periods), the principal, interest and any other monetary obligations on all then outstanding amounts under the Term Loan may become due and payable immediately. Upon the occurrence of an event of default, a default interest rate of an additional 5% may be applied to the outstanding principal balance, and Hercules, as the administrative agent, may declare all outstanding obligations immediately due and payable (subject, in certain instances, to specified grace periods) and take such other actions as set forth in the Term Loan. Upon the occurrence of certain bankruptcy and insolvency events, the obligations under the Term Loan would automatically become due and payable.

Embedded Derivatives and Debt Discounts

The conditional exercisable call option related to the event of default is considered to be an embedded derivative which is required to be bifurcated and accounted for as a separate financial instrument. In the periods presented, the value of the embedded derivative is not material and therefore, no amount has been recognized. If an event of default becomes more probable than is currently estimated, then the embedded derivative could become material in future periods and would be recognized as a separate financial instrument at that time.

As of December 31, 2023, the net carrying value of the Term Loan was$81.9 million, which includes the principal amount of $80.0 million less the net unamortized discounts and debt issuance costs of $605,000 plus an accrued end of term charge of $2,691,000. The carrying value of the debt approximates the fair value as of December 31, 2023. The debt discounts and debt issuance costs are being amortized to interest expense over the life of loan amounts under Term Loan using the effective interest rate method.

Future Minimum Payments

The following table presents future minimum payments, including interest and the end of term charge, under the Term Loan as of December 31, 2023 (in thousands):

9. STOCKHOLDERS’ EQUITY

Authorized Common Stock

In May 2023 our stockholders approved an amendment to our Restated Certificate of Incorporation to increase the total number of authorized shares of common stock from 675,000,000 to 1,350,000,000 shares.

Public Offering

On April 1, 2022, we completed an underwritten public offering of 53,333,334 shares of our common stock and a pre-funded warrant to purchase 18,095,238 shares of our common stock, or the 2022 pre-funded warrant, together with accompanying warrants to purchase 35,714,286 shares of our common stock, also known as the 2022 stock purchase warrants. The shares of common stock and the 2022 pre-funded warrant were immediately separable from the 2022 stock purchase warrants. All of the securities were issued separately. The combined public offering price of the common stock and accompanying 2022 stock purchase warrants was $1.05 per share. The 2022 stock purchase warrants have an exercise price of $1.45 per share and are exercisable immediately. The term of the 2022 stock purchase warrants expired in the third quarter of 2023, pursuant to the terms of the warrant agreement.. The combined public offering price of the 2022 pre-funded warrant and accompanying 2022 stock purchase warrant was $1.049 per share. The 2022 pre-funded warrant has an exercise price of $0.001 per share and may be exercised at any time until the 2022 pre-funded warrant is exercised in full. As of December 31, 2023, none of the 2022 pre-funded warrant and all of the 2022 stock purchase warrants have been exercised. The net cash proceeds from this offering were $69,916,000, after deducting the underwriting discount and other offering expenses paid by us, and exclude any future proceeds from the exercise of the 2022 pre-funded warrant and 2022 stock purchase warrants.

Upon the issuance of the 2022 pre-funded warrant and 2022 stock purchase warrants, we evaluated the terms of each warrant to determine the appropriate accounting and classification pursuant to FASB Accounting Standards Codification Topic 480, Distinguishing Liabilities from Equity, and FASB Accounting Standards Codification Topic 815, Derivatives and Hedging. Warrants are classified as liabilities when the warrant terms allow settlement of the warrant exercise in cash and classified as equity when the warrant terms only allow settlement in shares of common stock. The terms of the 2022 pre-funded warrant and the 2022 stock purchase warrants include certain provisions related to fundamental transactions and a cashless exercise provision in the event registered shares are not available, and do not include any mandatory redemption provisions. Based on our evaluation, we concluded the 2022 pre-funded warrant and the 2022 stock purchase warrants should be classified as equity with no subsequent remeasurement as long as such warrants continue to be classified as equity.

On January 10, 2023 we completed an underwritten public offering consisting of 68,007,741 shares of our common stock and the 2023 pre-funded warrant. All of the securities were issued separately. The public offering price of the common stock was $2.45 per share. The public offering price of the 2023 pre-funded warrant was $2.449 per share. The 2023 pre-funded warrant has an exercise price of $0.001 per share and may be exercised at any time until the 2023 pre-funded warrant is exercised in full. As of December 31, 2023, none of the 2023 pre-funded warrant has been exercised. The net cash proceeds from this offering were $213,337,000, after deducting the underwriting discount and other offering expenses paid by us, and exclude any future proceeds from the exercise of the 2023 pre-funded warrant.

Upon the issuance of the 2023 pre-funded warrant, we evaluated the warrant terms to determine the appropriate accounting and classification pursuant to FASB Accounting Standards Codification Topic 480, Distinguishing Liabilities from Equity, and FASB Accounting Standards Codification Topic 815, Derivatives and Hedging. Warrants are classified as liabilities when the warrant terms allow settlement of the warrant exercise in cash and classified as equity when the warrant terms only allow settlement in shares of common stock. The terms of the 2023 pre-funded warrant include certain provisions related to fundamental transactions and a cashless exercise provision in the event registered shares are not available, and do not include any mandatory redemption provisions. Based on our evaluation, we concluded the 2023 pre-funded warrant should be classified as equity with no subsequent remeasurement as long as such warrant continue to be classified as equity.

Warrant Exercises

For the year ended December 31, 2023, warrants to purchase 77,349,859 shares of our common stock were exercised for net cash proceeds of approximately $105,912,000. The warrants were issued in connection with underwritten public offerings of common stock and pre-funded warrants, together with accompanying stock purchase warrants in May 2020, April 2022, and January 2023. As of December 31, 2023, the following warrants remained outstanding:

•

pre-funded warrants with an exercise price of $0.001 per share to purchase 51,430,477 shares of our common stock, which have no expiration date; and

•

stock purchase warrants with an exercise price of $1.30 per share to purchase 2,474,503 shares of our common stock related to the public offering of our common stock in May 2020, which expire on December 31, 2025.

For the year ended December 31, 2022, warrants to purchase 11,663,387 shares of our common stock were exercised for net cash proceeds of approximately$15,163,000. The warrants were issued in connection with an underwritten public offering of common stock and a pre-funded warrant, together with accompanying stock purchase warrants in May 2020. As of December 31, 2022, the pre-funded warrant to purchase 8,335,239 shares of our common stock was outstanding and stock purchase warrants to purchase 44,110,079 shares of our common stock associated with the May 2020 public offering remained outstanding.

Sales Agreement

On September 4, 2020, we entered into an At Market Issuance Sales Agreement, or the 2020 Sales Agreement, with B. Riley Securities, Inc., or B. Riley, pursuant to which we were able to elect to issue and sell shares of our common stock having an aggregate offering price of up to $100 million in such quantities and on such minimum price terms as we set from time to time through B. Riley as our sales agent. We agreed to pay B. Riley an aggregate commission rate equal to up to 3.0% of the gross proceeds of the sales price per share for common stock sold through B. Riley under the 2020 Sales Agreement. In connection with the 2020 Sales Agreement, we terminated the 2018 Sales Agreement. The 2020 Sales Agreement expired on September 4, 2023.

On November 1, 2023, we entered into an At Market Issuance Sales Agreement, or the 2023 Sales Agreement with B. Riley, pursuant to which we may issue and sell shares of our common stock having an aggregate offering price of up to $100 million from time to time through B. Riley as the sales agent. We have agreed to pay B. Riley an aggregate commission rate equal to up to 3.0% of the gross proceeds of the sales price per share for common stock sold through B. Riley under the 2023 Sales Agreement. The 2023 Sales Agreement will automatically terminate upon the earlier of (i) the sale of all common stock subject to the 2023 Sales Agreement, or (ii) termination of the 2023 Sales Agreement in accordance with its terms.

For the year ended December 31, 2021, we sold an aggregate of 10,571,556 shares of our common stock pursuant to the 2020 Sales Agreement, resulting in net cash proceeds to us of approximately $20.4 million after deducting sales commissions and other offering expenses paid by us. No shares of our common stock were sold pursuant to the 2020 Sales Agreement or the 2023 Sales Agreement during the year ended December 31, 2023.

Equity Plans

2011 Incentive Award Plan

In May 2011, our stockholders approved the adoption of the 2011 Incentive Award Plan, or 2011 Plan. The 2011 Plan provided for grants of either incentive stock options or nonstatutory stock options and stock purchase rights to employees (including officers and employee directors) and consultants (including non‑employee directors). Upon the adoption of the 2018 Equity Incentive Plan in May 2018 (see below), no further grants of stock options or stock purchase rights were made under the 2011 Plan. Stock options granted under the 2011 Plan expire no later thanten years from the date of grant. Stock option exercise prices were equal to the fair market value of the underlying common stock on the date of grant.

Service‑based stock options under the 2011 Plan generally vested over a period offour years from the date of grant. Other stock awards (restricted stock awards and restricted stock units) had variable vesting schedules which were determined by our board of directors on the date of grant. All outstanding awards granted under the 2011 Plan remain subject to the terms of the 2011 Plan and the individual award agreements thereunder.

2018 Equity Incentive Plan

On May 15, 2018, our stockholders approved the adoption of the 2018 Equity Incentive Plan, or 2018 Plan, as the successor to the 2011 Plan. The 2018 Plan provides for the grant of incentive stock options, nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, other stock awards, and performance awards that may be settled in cash, stock, or other property. Eligible participants under the 2018 Plan include our employees, consultants and non-employee directors. The number of shares reserved for issuance under the 2018 Plan (subject to adjustment for certain changes in capitalization) is equal to the sum of (i) the unallocated shares of common stock remaining available for grant under the 2011 Plan as of May 15, 2018, (ii)10,000,000 newly reserved shares of common stock and (iii) the number of shares subject to awards granted under the 2002 Equity Incentive Plan, and the 2011 Plan as such shares become available from time to time, referred to as the Prior Plans’ Returning Shares. Such Prior Plans’ Returning Shares become available for issuance under the 2018 Plan if outstanding stock awards granted under the 2002 Equity Incentive Plan and the 2011 Plan, after May 15, 2018, expire or terminate for any reason prior to exercise or settlement or are forfeited, cancelled or otherwise returned to us because of the failure to meet a contingency or condition required for the vesting of such shares, or, subject to certain exceptions, are reacquired or withheld (or not issued) by us to satisfy a tax withholding obligation in connection with a stock award. In May 2023, May 2022 and May 2021, our stockholders approved amendments to our 2018 Equity Incentive Plan to increase the total number of shares issuable under such plan by 43,360,000,11,000,000, and 12,500,000 shares of our common stock, respectively.

Stock options granted under the 2018 Plan expire no later thanten years from the date of grant. Stock option exercise prices shall be equal to the fair market value of the underlying common stock on the date of grant. If, at the time we grant a stock option, the optionee directly or by attribution owns stock possessing more than 10% of the total combined voting power of all classes of our stock, the stock option exercise price shall be at least 110% of the fair market value of the underlying common stock and shall not be exercisable more than five years after the date of grant.

We grant service-based and performance-based stock options to employees under the 2018 Plan. Service-based stock options generally vest over a period offour years from the date of the stock option grant. Performance-based stock options vest upon the achievement of specified milestones. Other stock awards (restricted stock awards and restricted stock units) have variable vesting schedules as determined by our board of directors on the date of grant.

Under certain circumstances, stock options may be exercised prior to vesting, subject to our right to repurchase the shares underlying such stock option at the exercise price paid per share. Our repurchase rights would generally terminate on a vesting schedule identical to the vesting schedule of the exercised stock option. During 2023 and 2022, we did not repurchase any shares under the 2018 Plan. As of December 31, 2023, we have no shares outstanding subject to repurchase under the 2018 Plan.

As of December 31, 2023, our Non‑Employee Director Compensation Policy adopted by our board of directors in March 2014, as amended and restated in February and March 2022, provides for the automatic grant to non‑employee directors of the following types of equity awards under the 2018 Plan:

First Director Option. Each person who becomes a non‑employee director, whether by election by our stockholders or by appointment by our board of directors to fill a vacancy, will automatically be granted a stock option to purchase 200,000 shares of common stock, or First Director Option, on the date such person first becomes a non‑employee director. The First Director Option vests annually over three years upon each anniversary date of appointment to our board of directors.

Subsequent Director Option. Each non‑employee director (other than any director receiving a First Director Option on the date of the annual meeting) will automatically be granted a subsequent stock option to purchase 125,000 shares of common stock, a Subsequent Director Option, on the date of the annual meeting of stockholders in each year during such director’s service on our board of directors. The Subsequent Director Option vests in full on the earlier of: (i) the date of the next annual meeting of our stockholders or (ii) the first anniversary of the date of grant.

2006 Directors’ Stock Option Plan

The 2006 Directors’ Stock Option Plan, or 2006 Directors Plan, was terminated by our board of directors and replaced by the 2011 Plan in March 2014. No further grants of stock options were made from the 2006 Directors Plan upon the 2006 Directors Plan’s termination. All outstanding awards granted under the 2006 Directors Plan remain subject to the terms of the 2006 Directors Plan and the individual award agreements thereunder.

The stock options granted to non-employee directors under the 2006 Directors Plan were nonstatutory stock options, and they expire no later thanten years from the date of grant. The option exercise price was equal to the fair market value of the underlying common stock on the date of grant. The first director option granted to non-employee directors under the 2006 Directors Plan vested annually over three years upon each anniversary date of appointment to the board of directors. The subsequent director option granted to non-employee directors on the date of the annual meeting of stockholders in each year during such director’s service on our board of directors under the 2006 Directors Plan vestedone year from the date of grant.

2018 Inducement Award Plan

In December 2018, our board of directors approved the adoption of the 2018 Inducement Award Plan, or the Inducement Plan, pursuant to which we reserved 3,000,000 shares of our common stock to be used exclusively for grants of inducement awards to individuals who were not previously Geron employees or non-employee directors, other than following a bona fide period of non-employment. In May 2023, the compensation committee of our board of directors approved amendments to our 2018 Inducement Award Plan to increase the total number of shares issuable under such plan by 13,900,000, shares of our common stock. As of December 31, 2023, an aggregate total of 32,306,638 shares of common stock have been reserved under the Inducement Plan, with 11,616,841 available for grant.

The Inducement Plan provides for the grant of nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock units and other stock awards, and all awards under the Inducement Plan are intended to meet the standards under Rule 5635(c)(4) of the Nasdaq Listing Rules. The terms and conditions of the Inducement Plan and the inducement awards to be granted thereunder are substantially similar to our stockholder-approved 2018 Plan.

Directors’ Market Value Stock Purchase Plan

In October 2018, our board of directors adopted a Directors’ Market Value Stock Purchase Plan, or the Directors Market Plan. A total of 1,000,000 shares of our common stock have been reserved for the Directors Market Plan. Under the Directors Market Plan, non-employee directors may purchase shares of our common stock at the prevailing market price on the purchase date with cash compensation payable to them for their services as a board member. As stated in Geron’s Non-Employee Director Compensation Policy, each non-employee director receives annual cash compensation, payable quarterly in arrears, for their services on the board and various committees of the board. As provided in the Non-Employee Director Compensation Policy, a non-employee director may elect to receive fully vested shares of common stock in lieu of cash and such shares shall be issuable from the Directors Market Plan.

For the years ended December 31, 2023, 2022 and 2021, we issued 36,864,15,962 and 20,783 shares of common stock, respectively, under the Directors Market Plan. The weighted average grant date fair value of stock granted during the years ended December 31, 2023, 2022 and 2021 was$2.37, $1.92 and $1.38 per share, respectively. The total fair value of vested stock grants during 2023, 2022 and 2021 was$85,400, $29,000 and $29,000, respectively.

Aggregate stock option and award activity for the 2011 Plan, 2018 Plan, 2006 Directors Plan, Inducement Plan and Directors Market Plan is as follows:

(1)

Includes 7,936,030 perfo rmance-based stock options granted that have not achieved the specified performance milestones.

The aggregate intrinsic value in the preceding table represents the total intrinsic value, based on Geron’s closing stock price of $2.11 per share as of December 31, 2023, which would have been received by the option holders had all the option holders exercised their stock options as of that date.

We have not granted any stock options with an exercise price below or greater than the fair market value of our common stock on the date of grant in 2023, 2022, and 2021. As of December 31, 2023, 2022 and 2021, there were 39,995,642, 36,085,389 and 30,459,136 exercisable stock options outstanding at weighted average exercise prices per share of $2.16, $2.17 and $2.35, respectively.

The total pretax intrinsic value of stock options exercised during 2023, 2022, and 2021 was $11,986,000 $787,000 and $93,000, respectively. Cash received from the exercise of stock options in 2023, 2022, and 2021 totaled approximately $12,356,000, $1,799,000 and $556,000, respectively.

Employee Stock Purchase Plan

In March 2014, our board of directors adopted the 2014 Employee Stock Purchase Plan, or 2014 Purchase Plan. The 2014 Purchase Plan was approved by our stockholders in May 2014. The 2014 Purchase Plan replaced the 1996 Employee Stock Purchase Plan, or 1996 Purchase Plan, which was terminated effective as of the date the 2014 Purchase Plan was approved by our stockholders. In May 2022, our stockholders approved an amendment to our 2014 Purchase Plan to increase the total number of shares issuable under such plan by 1,000,000 shares of our common stock, for an aggregate total reserve of 2,000,000 shares. As of December 31, 2023, an aggregate of 1,254,162 shares of our common stock have been issued under the 2014 Purchase Plan since its adoption.

The 2014 Purchase Plan is comprised of a series of offering periods, each with a maximum duration (not to exceed 12 months) with new offering periods commencing on January 1st and July 1st of each year. The date an employee enters the offering period will be designated as the entry date for purposes of that offering period. An employee may participate only inone offering period at a time. Each offering period consists oftwo consecutive purchase periods ofsix months’ duration, with the last day of such period designated a purchase date.

Under the terms of the 2014 Purchase Plan, employees can choose to have up to 10% of their annual salary withheld to purchase our common stock, up to a limit of $25,000 per year. An employee may not make additional payments into such account or increase the withholding percentage during the offering period.

The purchase price per share at which common stock is purchased by the employee on each purchase date within the offering period is equal to 85%of the lower of (i) the fair market value per share of our common stock on the employee’s entry date into that offering period or (ii) the fair market value per share of our common stock on the purchase date. If the fair market value per share of our common stock on the purchase date is less than the fair market value at the beginning of the offering period, a new 12 month offering period will automatically begin on the first business day following the purchase date with a new fair market value.

Stock‑Based Compensation for Employees and Directors

We measure and recognize compensation expense for all share‑based payment awards made to employees and directors, including employee stock options, restricted stock awards and employee stock purchases, based on grant‑date fair values for these instruments. We use the Black-Scholes option‑pricing model to estimate the grant‑date fair value of our service-based and performance-based stock options and employee stock purchases. The fair value for service‑based restricted stock awards is determined using the fair value of our common stock on the date of grant.

As stock‑based compensation expense recognized on the consolidated statements of operations for the years ended December 31, 2023, 2022 and 2021 is based on awards ultimately expected to vest, it has been reduced for estimated forfeitures, but at a minimum, reflects the grant‑date fair value of those awards that actually vested in the period. Forfeitures have been estimated at the time of grant based on historical data and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates.

In 2023, 2022 and 2021, our board of directors awarded 832,790,2,741,750 and 550,000 perform ance-based stock options, respectively, to certain employees. These performance-based stock options are included in the outstanding stock options table above. Performance-based stock options vest only upon achievement of discrete milestones. Stock-based compensation expense for performance-based stock options is recognized over the period from the date the performance condition is determined to be probable of occurring through the date the applicable condition is expected to be met and is reduced for estimated forfeitures, as applicable. If the performance condition is not considered probable of being achieved, no stock-based compensation expense is recognized until such time as the performance condition is considered probable of being achieved, if ever.

We recognize stock‑based compensation expense for service-based stock options on a straight‑line basis over the requisite service period, which is generally the vesting period. We recognized $3,167,000 of stock-based compensation expense for performance-based stock options on our consolidated statements of operations for the year ended December 31, 2023. We did not recognize any stock-based compensation expense for performance-based stock options on our consolidated statements of operations for the years ended December 31, 2022 and 2021, as the achievement of the specified milestones was not considered probable during that time. The following table summarizes the stock‑based compensation expense related to service-based stock options and employee stock purchases for the years ended December 31, 2023, 2022 and 2021, which was allocated as follows:

The fair value of stock options granted in 2023, 2022, and 2021 has been estimated at the date of grant using the Black-Scholes option‑pricing model with the following assumptions:

The fair value of employee stock purchases in 2023, 2022, and 2021 has been estimated using the Black-Scholes option‑pricing model with the following assumptions:

Dividend yield is based on historical cash dividend payments and we have paid no cash dividends to date. The expected volatility range is based on historical volatilities of our stock, since traded options on our common stock do not correspond to option terms and the trading volume of options is limited. The risk‑free interest rate range is based on the U.S. Zero Coupon Treasury Strip Yields for the expected term in effect on the date of grant for an award. The expected term of stock options is derived from actual historical exercise and post‑vesting cancellation data and represents the period of time that stock options granted are expected to be outstanding. The expected term of employees’ purchase rights is equal to the purchase period.

Based on the Black-Scholes option‑pricing model, the weighted-average estimated fair value of stock options granted during the years ended December 31, 2023, 2022 and 2021 was $1.95, $0.92 and $1.17 pershare, respectively. The weighted average estimated fair value of employees’ purchase rights for the years ended December 31, 2023, 2022 and 2021 was $1.10, $0.48 and $0.56 per share, respectively. As of December 31, 2023, total compensation cost related to unvested share‑based payment awards not yet recognized, net of estimated forfeitures and assuming no probability of achievement for outstanding performance-based stock options, was $37,628,000, which is expected to be recognized over the next 26 months on a weighted‑average basis.

Stock‑Based Compensation to Service Providers

We grant stock options to consultants from time to time in exchange for services performed for us. In general, the stock options vest over the contractual period of the consulting arrangement. The fair value of stock options held by consultants is recorded as operating expenses over the vesting term of the respective equity awards. With the adoption of Accounting Standards Update 2018-07, Improvements to Nonemployee Share-Based Payment Accounting, or ASU 2018-07, in the first quarter of 2019, the measurement date of stock options granted to consultants was fixed at the grant date. We recorded stock‑based compensation expense of $742,000, $235,000 and $62,000 for the vested portion of the fair value of stock options held by consultants in 2023, 2022, and 2021, respectively.

Common Stock Reserved for Future Issuance

Common stock reserved for future issuance as of December 31, 2023 is as follows:

10. INCOME TAXES

The following table reconciles the federal statutory tax rate to the effective income tax rate from continuing operations:

Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of our deferred tax assets are as follows:

We record net deferred tax assets to the extent we believe these assets will more likely than not be realized. In making such determination, we consider all available positive and negative evidence, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax planning strategies and recent financial performance. Forming a conclusion that a valuation allowance is not required is difficult when there is negative evidence such as cumulative losses in recent years. Because of our history of losses, the net deferred tax assets have been fully offset by a valuation allowance. The valuation allowance increased by $45.6 million and $38.9 million for the years ended December 31, 2023 and 2022, respectively.

As of December 31, 2023, we had domestic federal net operating loss carryforwards of approximately $1.0 billion. Of this, $635.6 million will expire at various dates beginning in 2024 through 2037 and the remaining will carryforward indefinitely under the new tax laws, but is subject to an 80% taxable income limitation for tax years beginning after 2020. As of December 31, 2023, we had state net operating loss carryforwards of approximately $841.2 million expiring at various dates beginning in 2028 through 2043, if not utilized. We also had federal tax credit carryforwards of approximately $72.7 million expiring at various dates beginning in 2024 through 2043, if not utilized. Our state tax credit carryforwards of approximately $21.4 million carry forward indefinitely.

Utilization of net operating loss and tax credit carryforwards may be subject to an annual limitation due to ownership change limitations provided by the Internal Revenue Code and similar state provisions. Annual limitations may result in expiration of net operating loss and tax credit carryforwards before some or all of such amounts have been utilized. The impact of any limitations that may be imposed due to such ownership changes has not yet been determined. Due to the Company's stock issuance in January 2023, the utilization of the Company's net operating loss and tax credit carryforwards are subject to an annual limitation due to the ownership change limitations provided by the Internal Revenue Code and similar state provisions. The annual limitation may result in the expiration of the net operating loss and tax credit carryforwards before some or call of such amounts have been utilized. The final amount of the limitations imposed due to such ownership changes has not yet been determined.

In March and December 2020, in response to the COVID-19 pandemic, the Coronavirus Aid, Relief and Economic Security Act, or the CARES Act, and the Consolidated Appropriations Act, 2021 were passed into law and provide additional economic stimulus to address the impact of the COVID-19 pandemic, including among other items, several U.S. income tax provisions related to, among other things, net operating loss carrybacks, alternative minimum tax credits, modifications to interest expense limitations, and an option to defer payroll tax payments for a limited period. In 2021, we assessed our eligibility to claim a refund of employer taxes available under the Employee Retention Credit provisions of the CARES Act. For the years ended December 31, 2022 and 2021, we calculated eligible credits of approximately $483,000 and $1.1 million, respectively, provided by the CARES Act, which have been recognized as offsets to salaries costs in operating expenses in 2022 and 2021, respectively. As of December 31, 2022, the aggregate eligible credit amount has been accrued as a receivable on our consolidated balance sheets. We received the Employee Retention Credit from the IRS, and there areno outstanding receivables as of December 31, 2023.

We adopted the provision of the standard for accounting for uncertainties in income taxes on January 1, 2007. Upon adoption, we recognized no material adjustment in the liability for unrecognized tax benefits. At December 31, 2023, we had approximately $26.3 million of unrecognized tax benefits, none of which would currently affect our effective tax rate if recognized due to our net deferred tax assets being fully offset by a valuation allowance.

A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows (in thousands):

If applicable, we would classify interest and penalties related to uncertain tax positions in income tax expense. Through December 31, 2023, there has been no interest expense or penalties related to unrecognized tax benefits.

We do not currently expect any significant changes to unrecognized tax benefits during the fiscal year ended December 31, 2023. In certain cases, our uncertain tax positions are related to tax years that remain subject to examination by the relevant tax authorities. Tax years for which we have carryforward net operating loss and credit attributes remain subject to examination by federal and most state tax authorities.

11. CONSOLIDATED STATEMENTS OF CASH FLOWS DATA