MEDICINOVA INC

1. Organization and Summary of Significant Accounting Policies

Organization and Business

MediciNova, Inc. (the “Company” or “MediciNova”) was incorporated in the state of Delaware in September 2000 and is a public company. The Company’s common stock is listed in both the United States and Japan and trades on the Nasdaq Global Market and the Standard Market of the Tokyo Stock Exchange. The Company is a biopharmaceutical company focused on developing novel therapeutics for the treatment of serious diseases with unmet medical needs with a commercial focus on the United States market. The Company’s current strategy is to focus its development activities on MN-166 (ibudilast) for neurological and other disorders such as progressive multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), chemotherapy-induced peripheral neuropathy, degenerative cervical myelopathy, glioblastoma, substance dependence and addiction (e.g., methamphetamine dependence, opioid dependence, and alcohol dependence), prevention of acute respiratory distress syndrome (ARDS), and Long COVID, and MN-001 (tipelukast) for fibrotic and other diseases such as nonalcoholic fatty liver disease (NAFLD) and idiopathic pulmonary fibrosis (IPF). The Company’s pipeline also includes MN-221 (bedoradrine) for the treatment of acute exacerbation of asthma, and MN-029 (denibulin) for solid tumor cancers.

Principles of Consolidation

The consolidated financial statements include the accounts of MediciNova, Inc. and its wholly owned subsidiaries MediciNova Japan, Inc., MediciNova (Europe) Limited, MediciNova Europe GmbH and Avigen Inc. The financial statements of the Company’s foreign subsidiaries are measured using their local currency as the functional currency. The resulting translation adjustments are recorded as a component of other comprehensive income or loss. Intercompany transaction gains or losses at each period end are included as translation adjustments and recorded within other comprehensive income or loss. All intercompany transactions and balances are eliminated in consolidation.

Segment Reporting

Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. The Company operates in a single operating segment – the acquisition and development of small molecule therapeutics for the treatment of serious diseases with unmet medical needs.

Use of Estimates

The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Cash and Cash Equivalents

Cash and cash equivalents consist of cash and other highly liquid investments, including money market and mutual funds accounts, with original maturities of three months or less from the date of purchase.

Investments

Investments purchased with an original maturity of greater than three months are classified as investments. Investments are stated at fair value and are classified as current or non-current based on the nature of the securities as well as their stated maturities. There wereno investments held as of December 31, 2023. As of December 31, 2022, investments consisted of bank certificates of deposit with original purchased maturity dates between seven and 13 months.

Concentrations and Credit Risk

The Company maintains cash balances and has purchased certificates of deposit at various financial institutions and such balances and certificates of deposit commonly exceed the $250,000 amount insured by the Federal Deposit Insurance Corporation. The Company also maintains money market funds at various financial institutions which are not federally insured although are invested primarily in U.S. government securities. The Company has not experienced any losses in such accounts and management believes that the Company does not have significant credit risk with respect to such cash and cash equivalents.

Fair Value of Financial Instruments

Financial instruments, including cash equivalents and accounts payable, are carried at cost, which management believes approximates fair value because of the short-term nature of these instruments.

IPR&D, Long-Lived Assets and Goodwill

Amounts incurred related to in-process research and development (“IPR&D”) or asset purchases of IPR&D are expensed as incurred. Amounts allocated to IPR&D in connection with a business combination are recorded at fair value and are considered indefinite-lived intangible assets until completion or abandonment of the associated research and development efforts. If and when development is complete, which generally occurs when regulatory approval to market a product is obtained, the associated assets are deemed finite-lived and amortized over a period that best reflects the economic benefits provided by these assets. During the period the assets are considered indefinite-lived, they will not be amortized but will be tested annually for impairment or more frequently if indicators of impairment exist. The Company first assesses qualitative factors to determine whether it is more likely than not that the fair value of the IPR&D is less than its carrying amount as a basis for determining whether it is necessary to perform a quantitative assessment. If, after assessing qualitative factors, the Company determines it is not more likely than not that the fair value is less than its carrying amount, then a quantitative assessment is unnecessary. If the quantitative assessment is deemed necessary, the excess of the carrying value over fair value will be recorded as an impairment. The qualitative assessment focuses on the key inputs, assumptions and rationale utilized in the establishment of the carrying value and related changes since the last quantitative assessment. Based on the results of the Company’s annual qualitative assessment, the Company concluded that it is not more likely than not that IPR&D was impaired for any of the periods presented.

The Company’s long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying value of an asset (or asset group) may not be recoverable, and the Company will perform an impairment analysis. Long-lived assets are deemed to be impaired when the undiscounted cash flows expected to be generated by the asset (or asset group) are less than the asset’s carrying amount. Any required impairment loss would be measured as the amount by which the asset’s (or asset group’s) carrying value exceeds its fair value and would be recorded as a reduction in the carrying value of the related asset and a charge to operating expense. There were no events or changes in circumstances to indicate that the carrying value of an asset (or asset group) may not be recoverable for any of the periods presented.

Goodwill is reviewed for impairment annually (as of December 31st) or more frequently if indicators of impairment exist. As the Company operates in asingle operating segment and reporting unit, goodwill is assessed at a consolidated level. The Company first assesses qualitative factors to determine whether it is more likely than not that the fair value of the reporting unit is less than its carrying amount, including goodwill. If so, the Company will proceed with a quantitative assessment that compares the fair value of the reporting unit with its carrying amount. If the fair value exceeds the carrying value as a result of either the qualitative or quantitative test, goodwill is not considered impaired. The qualitative factors include economic environment, business climate, market capitalization, operating performance, competition, and other factors. The Company placed the highest weight in excess cushion of the market capitalization to the equity carrying value in the analysis. Based on the results of the Company’s annual qualitative assessment, the Company concluded that it is not more likely than not that goodwill was impaired for any of the periods presented.

Research, Development and Patents

Research and development costs are expensed in the period incurred. Research and development costs primarily consist of salaries and related expenses for personnel, facilities and depreciation, research and development supplies, licenses and outside services. Such research and development costs totaled $5.3 million and $8.7 million for the years ended December 31, 2023 and 2022, respectively.

Costs related to filing and pursuing patent applications are expensed as incurred, as recoverability of such expenditures is uncertain. The Company includes all external costs related to the filing of patents in Research, Development and Patents expenses. Such patent-related expenses totaled $0.4 million and $0.4 million for the years ended December 31, 2023 and 2022, respectively.

For transactions with a government where the Company receives government assistance in performing research and development activities and the accounting for a transaction is not specified within the scope of authoritative GAAP, the Company follows ASC 832, Government Assistance (Topic 832), applying a grant or contribution model by analogy to Subtopic 958-605, Not-for-Profit Entities-Revenue Recognition (“ASC 958-605”).

In 2021, the Company entered into an agreement with the Biomedical Advanced Research and Development Authority (BARDA), part of the Administration for Strategic Preparedness and Response (ASPR) at the U.S. Department of Health and Human Services, to develop MN-166 (ibudilast) as a potential medical countermeasure against chlorine gas-induced lung damage such as ARDS and acute lung injury (ALI). Under the agreement, BARDA agreed to provide federal funding for specified preclinical studies under Contract No. 75A50121C00022. The studies were completed in August 2023, and in September 2023, BARDA paid the Company $0.7 million to partially reimburse the costs of the studies. Contractual arrangements that are not considered an exchange of services are considered contributions under ASC 958-605, and the Company elected to recognize the $0.7 million in funding as an offset to research and development costs for the year ended December 31, 2023.

Leases

The Company determines if an arrangement is a lease at inception and if so, determines whether the lease qualifies as an operating or finance lease. The Company does not recognize right-of-use assets and lease liabilities for leases with a term of 12 months or less and does not separate non-lease components from lease. Operating lease right-of-use assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. Operating lease expense is recognized on a straight-line basis over the lease term and is included in general and administrative expense. As the Company’s operating leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The incremental borrowing rate is the rate that the Company would expect to pay to borrow on a collateralized and fully amortizing basis over a similar term an amount equal to the lease payments in a similar economic environment.

Clinical Trial Accruals and Prepaid Expenses

Costs for preclinical studies, clinical studies and manufacturing activities are recognized as research and development expenses based on an evaluation of the progress by Company vendors towards completion of specific tasks, using data such as patient enrollment, clinical site activations or information provided to the Company by such vendors regarding their actual costs incurred. Payments for these activities are based on the terms of individual contracts and payment timing may differ significantly from the period in which the services are performed. The Company determines accrual estimates through reports from and discussions with applicable personnel and outside service providers as to the progress or state of completion of studies, or the services completed. The Company’s estimates of accrued expenses as of each balance sheet date are based on the facts and circumstances known at the time. Costs that are paid in advance of performance are deferred as a prepaid expense and amortized over the service period as the services are provided. As of December 31, 2023, the Company recorded $1.0 million and$0.0 million in clinical trial accruals and prepaid expenses, respectively. As of December 31, 2022, the Company recorded $1.5 million and $0.3 million in clinical trial accruals and prepaid expenses, respectively.

Share-Based Compensation

The Company estimates the fair value of stock options using the Black-Scholes option pricing model on the date of grant. The fair value of equity instruments expected to vest are recognized and amortized on a straight-line basis over the requisite service period of the award, which is generally three tofour years; however, the Company’s equity compensation plans provide for any vesting schedule as the board may deem appropriate. Forfeitures are recognized as they occur.

The Company issues employee performance-based stock options, the vesting of which is based on a determination made by the board of directors as to the achievement of certain corporate objectives at the end of the performance period. The grant date of such awards is the date on which the board of directors makes its determination. For periods preceding the grant date, the expense related to these awards is measured based on their fair value at each reporting date and the expected number of options based upon the expected performance compared to the performance objectives.

Net Loss Per Share

The Company computes basic net loss per share using the weighted average number of common shares outstanding during the period. Diluted net loss per share is based upon the weighted average number of common shares and potentially dilutive securities (common share equivalents) outstanding during the period. Common share equivalents outstanding, determined using the treasury stock method, are comprised of shares that may be issued under the Company’s outstanding stock option agreements. Common share equivalents are excluded from the diluted net loss per share calculation if their effect is anti-dilutive.

Potentially dilutive outstanding securities of 7,781,749 and 7,985,250 consisting of stock options for the years ended December 31, 2023 and 2022, respectively, were excluded from diluted net loss per common share because of their anti-dilutive effect.

Recently Issued Accounting Pronouncements

In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-13, Financial Instruments— Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). The ASU introduced a new credit loss methodology, the Current Expected Credit Losses (“CECL”) methodology, which requires earlier recognition of credit losses, while also providing additional transparency about credit risk. The CECL methodology utilizes a lifetime “expected credit loss” measurement objective for the recognition of credit losses for loans, held-to maturity debt securities, trade receivables and other receivables measured at amortized cost at the time the financial asset is originated or acquired. Subsequent to the issuance of ASU 2016-13, the FASB issued several additional ASUs to clarify implementation guidance, provide narrow-scope improvements and provide additional disclosure guidance. In November 2019, the FASB issued an amendment making this ASU effective for fiscal years beginning after December 15, 2022 for smaller reporting companies. The new standard was effective for the Company on January 1, 2023. There was no impact on the consolidated financial statements upon adoption of this standard on January 1, 2023.

In August 2020, the FASB issued ASU No. 2020-06, Debt – Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging – Contracts in Entity’s Own Equity (Subtopic 815-40) (“ASU 2020-06”). ASU 2020-06 simplifies the accounting for convertible debt instruments by reducing the number of accounting models and the number of embedded features that could be recognized separately from the host contract. Consequently, more convertible debt instruments will be accounted for as a single liability measured at its amortized cost, as long as no other features require bifurcation and recognition as derivatives. ASU 2020-06 also requires use of the if-converted method in the diluted earnings per share calculation for convertible instruments. ASU 2020-06 is effective for fiscal years beginning after December 15, 2023, and interim periods within those fiscal years for smaller reporting companies, with early adoption permitted. The new standard was effective for the Company on January 1, 2024. There was no impact on the consolidated financial statements upon adoption of this standard on January 1, 2024.

In October 2023, the FASB issued ASU 2023-06, Disclosure Improvements: Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative. ASU 2023-06 modifies the disclosure or presentation requirements of a variety of Topics in the Codification. Specifically, the amendments align the requirements in the Codification with the SEC’s regulations. The amendments apply to all reporting entities within the scope of the affected Topics unless otherwise indicated. For entities subject to the SEC’s existing disclosure requirements and for entities required to file or furnish financial statements with or to the SEC, the effective date for each amendment will be the date on which the SEC’s removal of that related disclosure requirement from Regulation S-X or Regulation S-K becomes effective, with early adoption prohibited. For all other entities, the amendments will be effective two years after the date of such removal. The amendments should be applied prospectively. The Company is currently evaluating the potential impact that this standard will have on its consolidated financial statements and related disclosures.

In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. ASU 2023-07 improves the disclosures about a public entity’s reportable segments and addresses requests from investors for additional, more detailed information about a reportable segment’s expenses. Specifically, it requires that a public entity: 1) disclose, on an annual and interim basis, significant segment expenses that are regularly provided to the chief operating decision maker (CODM) and included within each reported measure of segment profit or loss, 2) disclose, on an annual and interim basis, an amount for other segment items by reportable segment and a description of its composition. The other segment items category is the difference between segment revenue less the segment expenses disclosed under the significant expense principle and each reported measure of segment profit or loss, 3) provide all annual disclosures about a reportable segment’s profit or loss and assets currently required by Topic 280 in interim periods, and 4) disclose the title and position of the CODM and an explanation of how the CODM uses the reported measure(s) of segment profit or loss in assessing segment performance and deciding how to allocate resources. The ASU also requires a public entity that has a single reportable segment to provide all the disclosures required by the amendments in this ASU and all existing segment disclosures in Topic 280. Further, the ASU clarifies that if the CODM uses more than one measure of a segment’s profit or loss in assessing segment performance and deciding how to allocate resources, a public entity may report one or more of those additional measures. However, at least one of the reported segment profit or loss measures should be the measure that is most consistent with the measurement principles used in measuring the corresponding amounts in the public entity’s consolidated financial statements. The amendments are effective for all public entities that are required to report segment information for fiscal years beginning after December 15, 2023 and interim periods beginning after December 15, 2024. Early adoption is permitted. The amendments should be applied retrospectively to all prior periods presented. The Company is currently evaluating the potential impact that this standard will have on its consolidated financial statements and related disclosures.

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. ASU 2023-09 enhances the transparency and decision usefulness of income tax disclosures. Specifically, it requires that a public business entity: 1) disclose, on an annual basis, an income tax rate reconciliation in a tabular form, disclosing specific categories and providing additional information for reconciling items that meet a quantitative threshold, 2) disclose on an annual basis the following information about income taxes paid: i) the amount of income taxes paid (net of refunds received) disaggregated by federal (national), state, and foreign taxes, ii) the amount of income taxes paid (net of refunds received) disaggregated by individual jurisdictions in which income taxes paid (net of refunds received) is equal to or greater than 5 percent of total income taxes paid (net of refunds received), 3) all entities are required to disclose: i) income (or loss) from continuing operations before income tax expense (or benefit) disaggregated between domestic and foreign, and ii) income tax expense (or benefit) from continuing operations disaggregated by federal (national), state, and foreign. For public business entities, the amendments are effective for annual periods beginning after December 15, 2024. For all other entities, the amendments are effective for annual periods beginning after December 15, 2025. Early adoption is permitted for annual financial statements that have not yet been issued or made available for issuance. The amendments in this ASU should be applied on a prospective basis. Retrospective application is permitted. The Company is currently evaluating the potential impact that this standard will have on its consolidated financial statements and related disclosures.

2. Revenue Recognition

Revenue Recognition Policy

Revenues historically have consisted mainly of research and development services performed under a contract with a customer. The Company evaluates the separate performance obligation(s) under each contract, allocates the transaction price to each performance obligation considering the estimated stand-alone selling prices of the services and recognizes revenue upon the satisfaction of such obligations at a point in time or over time dependent on the satisfaction of one of the following criteria: (1) the customer simultaneously receives and consumes the economic benefits provided by the vendor’s performance (2) the vendor creates or enhances an asset controlled by the customer (3) the vendor’s performance does not create an asset for which the vendor has an alternative use, and (4) the vendor has an enforceable right to payment for performance completed to date.

Genzyme Corporation

In December 2005, Avigen, Inc. and Genzyme Corporation (“Genzyme”) entered into an Assignment Agreement (the “Genzyme Agreement”) in which Genzyme acquired certain gene therapy intellectual property, programs and other related assets from Avigen, Inc. in exchange for an upfront payment and potential additional development milestone payments, sublicensing fees, and royalty payments based on the successful development of products by Genzyme utilizing technologies previously developed by Avigen. The Company subsequently acquired Avigen in December 2009 along with Avigen’s rights and obligations under the Genzyme Agreement. If Genzyme fails to diligently pursue the commercialization or marketing of products using the assigned technology, as specified in the Genzyme Agreement, some of the rights assigned could revert back to the Company at a future date.

The development milestones outlined in the Genzyme Agreement did not meet the definition of a substantive milestone obligation under authoritative guidance on revenue recognition for milestone payments, as Genzyme was responsible for the development of the product and there is no further substantive service effort required by the Company. In September 2023, the Company received notice that a gene therapy product based on AAV (adeno-associated virus) vector technology, which was covered under the Genzyme Agreement, achieved one clinical development milestone, triggering a milestone payment of $1.0 million. Accordingly, the Company recognized revenue of $1.0 million for the year ended December 31, 2023.

3. Fair Value Measurements

Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, a three-tier fair value hierarchy has been established, which prioritizes the inputs used in measuring fair value as follows:

The carrying amount and approximate fair value of financial instruments as of December 31, 2023 and 2022, were as follows:

Short-term investments consisting of bank certificates of deposit with an original purchased maturity greater than three months are classified as held-to-maturity and are stated at amortized cost, which approximates fair value due to the short-term maturities and market rates of interest of these instruments.

4. Balance Sheet Details

Property and Equipment

Property and equipment, net, consist of the following:

The Company uses the straight-line method to record depreciation expense with useful lives ofthree tofive years. Leasehold improvements are amortized over a useful life offive years. Depreciation and amortization of property and equipment of $20,295 and $17,707 was recorded for the years ended December 31, 2023 and 2022, respectively.

Accrued Liabilities and Other Current Liabilities

Accrued liabilities and other current liabilities consist of the following:

5. Commitments and Contingencies

Lease Commitments

The Company has operating leases primarily for real estate in the United States and Japan. The United States lease is for the Company’s headquarters in San Diego and has a term offive years ending January 31, 2027, with annual escalations. The Company’s lease in Tokyo, Japan has a term oftwo years ending May 2025 with anauto-renewal, two-year extension. In June 2023, the Company renewed the Japan lease. The auto-renewal was not included in the measurement of the lease liability as renewal at the end of the lease term was not reasonably certain. The real estate operating leases are included in "Right-of-use asset" on the Company's balance sheet and represents the Company’s right to use the underlying assets for the lease term. The Company’s obligation to make lease payments are included in "Operating lease liability" and "Other non-current liabilities" on the Company's consolidated balance sheets.

Information related to the Company’s right-of-use assets and related lease liabilities are as follows:

Product Liability

The Company’s business exposes it to liability risks from its potential drug products. A successful product liability claim or series of claims brought against the Company could result in the payment of significant amounts of money and divert management’s attention from running the business. The Company may not be able to maintain insurance on acceptable terms, or the insurance may not provide adequate protection in the case of a product liability claim. To the extent that product liability insurance, if available, does not cover potential claims, the Company would be required to self-insure the risks associated with such claims. The Company believes it carries reasonably adequate insurance for product liability.

License and Research Agreements

The Company has entered into in-licensing agreements with various pharmaceutical companies. Under the terms of these agreements, the Company has received licenses to research, know-how and technology claimed, in certain patents or patent applications. Under these license agreements, the Company is generally required to make upfront payments and additional payments upon the achievement of milestones and/or royalties on future sales of products until the later of the expiration of the applicable patent or the applicable last date of market exclusivity after the first commercial sale, on a country-by-country basis.

No milestone payments have been made under these agreements during the years ended December 31,2023 and 2022. For products currently in development, future potential milestone payments based on product development of MN-166 (ibudilast) and MN-001 (tipelukast) are $10 million as of December 31,2023. For all other products, future potential milestone payments related to development milestones and commercialization milestones totaled $16.5 million as of December 31,2023. There are no minimum royalties required under any of the license agreements. The Company is unable to estimate with certainty the timing on when these milestone payments will occur as these payments are dependent upon the progress of the Company’s product development programs.

Legal Proceedings

From time to time, the Company may be subject to legal proceedings and claims in the ordinary course of business. The Company is not aware of any such proceedings or claims that it believes will have, individually or in aggregate, a material adverse effect on its business, financial condition or results of operations.

6. Stock-based Compensation

Stock Incentive Plans

In June 2013, the Company adopted the 2013 Equity Incentive Plan, or 2013 Plan, under which the Company granted equity-based awards, including stock options, stock appreciation rights, restricted stock, and restricted stock units to individuals who were then employees, officers, non-employee directors or consultants of the Company or its subsidiaries. A total of 8,700,000 shares of common stock were reserved for issuance under the 2013 Plan. In addition, “returning shares” that may become available from time to time were added back to the plan. “Returning shares” included shares that were subject to outstanding awards granted under the Company's prior 2004 Equity Incentive Plan that expired or terminated prior to exercise or settlement, were forfeited because of the failure to vest, were repurchased, or were withheld to satisfy tax withholding or purchase price obligations in connection with such awards. Although the Company no longer grants equity awards under the 2013 Plan, all outstanding stock awards granted under the 2013 Plan will continue to be subject to the terms and conditions as set forth in the agreements evidencing such stock awards and the terms of the 2013 Plan.

In June 2023, the Company adopted the 2023 Equity Incentive Plan, or 2023 Plan, under which the Company may grant stock options, stock appreciation rights, restricted stock, restricted stock units and other awards to individuals who are then employees, officers, non-employee directors or consultants of the Company or its subsidiaries. The 2023 Plan is the successor to the 2013 Plan. The number of shares of common stock that may be issued under the 2023 Plan is equal to the sum of (a) shares subject to awards granted under the 2013 Plan that were outstanding upon expiration of the 2013 Plan and are subsequently forfeited, expire or lapse unexercised or unsettled and shares issued pursuant to awards granted under the 2013 Plan that were outstanding upon expiration of the 2013 Plan and are subsequently forfeited to or reacquired by the Company and (b) shares reserved under the 2013 Plan that were not issued or subject to outstanding awards under the 2013 Plan upon expiration of the 2013 Plan. While a maximum of 9,934,567 shares may become available for issuance under the 2023 Plan from the 2013 Plan, since this figure assumes that all awards outstanding under the 2013 Plan upon expiration of the 2013 Plan will be forfeited, the Company expects the actual number of shares added to the 2023 Plan to be less. In general, to the extent that awards under the 2023 Plan are forfeited, cancelled or expire for any reason before being exercised or settled in full, the shares subject to such awards will again become available for issuance under the 2023 Plan. If stock appreciation rights are exercised or restricted stock units are settled, then only the number of shares (if any) actually issued to the participant will reduce the number of shares available under the 2023 Plan. If restricted shares or shares issued upon exercise of options are reacquired by the Company pursuant to a forfeiture provision, repurchase right or for any other reason, then such shares shall again become available for issuance under the 2023 Plan. Shares withheld to pay the exercise price of options or satisfy tax withholding obligations related to an award shall again become available for issuance under the 2023 Plan. Further, to the extent an award is settled in cash rather than shares, the cash settlement shall not reduce the number of shares available for issuance under the 2023 Plan.

As of December 31, 2023,2,152,818 shares remain available for future grant under the 2023 Plan.

Certain of the employee stock options granted contain performance conditions, the vesting of which is based on a determination made by the board of directors or its compensation committee as to the achievement of certain corporate objectives at the end of the performance period. The grant date of such awards is the date on which the board of directors or its compensation committee makes its determination. For periods preceding the grant date, the expense related to these awards is measured based on their fair value at each reporting date. The estimated fair value of the performance awards granted and the resulting expense is based upon a certain level of achievement of the corporate objectives and other assumptions in determining fair value. The amount of expense ultimately recognized upon the grant date at completion of the performance period could change from the estimate as a result of various factors, including the level of achievement of the corporate objectives, changes in the assumptions used in the Black-Scholes model in determining fair value or fluctuations in the Company’s stock price during the performance period. As of December 31, 2023, there were a total of 730,350 shares underlying performance options that were subject to vesting based on achievement of corporate objectives for 2023. In January 2024, the compensation committee and the board of directors determined that the performance milestones were achievedat the 70% level and accordingly 511,245 of these options vested and the remaining shares were forfeited.

Stock Options

Options granted under the 2023 Plan and the 2013 Plan have terms often years from the date of grant unless earlier terminated and generally vest over aone tofour-year period.

The exercise price of all options granted during the years ended December 31, 2023 and 2022 was equal to the market value of the Company’s common stock on the date of grant.

A summary of stock option activity and related information for the years ended December 31,2023 and 2022 is as follows:

The aggregate intrinsic value of options exercised was $0 and $1,410 for the years ended December 31, 2023 and 2022, respectively. Options outstanding and exercisable at December 31, 2023 had a weighted average contractual life of 4.47 yearsand 4.89 years, respectively.

As of December 31, 2023 and 2022, the total intrinsic value of options outstanding was $0 and $0, respectively. Total intrinsic value of options exercisable was $0 and $0 as of December 31,2023 and 2022, respectively. Total fair value of options vested was$0.9 million and $2.6 million for the years ended December 31,2023 and 2022, respectively.

Compensation Expense

The estimated fair value of each stock option award was determined on the date of grant using the Black-Scholes option valuation model with the following weighted-average assumptions for stock option grants:

The risk-free interest rate assumption is based upon observed interest rates appropriate for the expected term of employee stock options. The expected volatility is based on the historical volatility of the Company’s common stock. The Company has not paid nor does the Company anticipate paying dividends on its common stock in the foreseeable future. The expected term of employee stock options is based on the simplified method as provided by the authoritative guidance on stock compensation, as the historical stock option exercise experience does not provide a reasonable basis to estimate the expected term.

The weighted-average fair value of each stock option granted during the years ended December 31, 2023 and 2022, estimated as of the grant date using the Black-Scholes option valuation model, was$1.59 per option and $1.47 per option, respectively.

Stock-based compensation expense for stock option awards are reflected in total operating expenses for each respective year. The following table summarizes stock-based compensation expense for the years ended December 31,2023 and 2022:

As of December 31, 2023, there was$0.1 million of unamortized compensation cost related to unvested stock option awards which is expected to be recognized over a remaining weighted-average vesting period of 0.06 years, on a straight-line basis.

7. Stockholders’ Equity

At-The-Market Issuance Sales Agreement

On August 23, 2019, the Company entered into an at the market issuance sales agreement, which was amended on August 26, 2022 (as amended, the “ATM Agreement”) with B. Riley FBR, Inc. (B. Riley FBR) pursuant to which the Company may sell common stock through B. Riley FBR from time to time up to an aggregate offering price of $75.0 million. Sales of the Company’s common stock through B. Riley FBR, if any, will be made by any method that is deemed to be an “at-the-market” equity offering as defined in Rule 415 promulgated under the Securities Act of 1933, as amended, including sales made directly on NASDAQ, on any other existing trading market for the common stock or through a market maker. B. Riley FBR may also sell the common stock in privately negotiated transactions, subject to the Company’s prior approval. The Company agreed to pay B. Riley FBR an aggregate commission rate of up to 3.5% of the gross proceeds of any common stock sold under this agreement. Proceeds from sales of common stock will depend on the number of shares of common stock sold to B. Riley FBR and the per share purchase price of each transaction.

No shares of common stock were sold under the ATM Agreement in the years ended December 31, 2023 and 2022, respectively.

Common Stock Reserved for Future Issuance

The following table summarizes common stock reserved for future issuance at December 31,2023:

8. Income Taxes

A reconciliation of loss before income taxes for domestic and foreign locations for the years ended December 31,2023 and 2022 is as follows:

A reconciliation of income tax expense for the years ended December 31,2023 and 2022 is as follows:

The significant components of deferred income taxes at December 31,2023 and 2022 are as follows:

The Company has established a valuation allowance against net deferred tax assets due to the uncertainty that such assets will be realized. The net change in the valuation allowance during the year ended December 31, 2023 was an increase of $1.0 million. The Company periodically evaluates the recoverability of the deferred tax assets. At such time as it is determined that it is more likely than not that deferred tax assets will be realizable, the valuation allowance will be reduced.

At December 31, 2023, the Company has federal and California net operating loss (NOL) carryforwards of approximately $275.9 million and $190.5 million, respectively. $227.4 million of federal NOL carryforwards begin to expire in 2024, $48.5 million of federal NOL carryforwards can be carried forward indefinitely, and the California NOL carryforwards begin to expire in 2028. At December 31,2023, the Company also had federal and California research tax credit carry-forwards of approximately $8.2 million and $2.4 million, respectively. The federal research tax credit carryforwards begin to expire in 2024, and the California research tax credit carryforward does not expire and can be carried forward indefinitely until utilized.

The above NOL carryforward and the research tax credit carryforwards are subject to an annual limitation under Section 382 and 383 of the Internal Revenue Code of 1986, and similar state provisions due to ownership change limitations that have occurred which will limit the amount of NOL and tax credit carryforwards that can be utilized to offset future taxable income and tax, respectively. In general, an ownership change, as defined by Section 382 and 383, results from transactions increasing ownership of certain stockholders or public groups in the stock of the corporation by more than 50 percentage points over a three-year period. The Company completed an IRC Section 382/383 analysis regarding the limitation of net operating loss and research and development credit carryforwards for a period of inception through December 2022, and did not experience any ownership changes which triggers the limitation. There is a risk that additional changes in ownership have occurred since the completion of the Company’s analysis. If a change in ownership were to have occurred, additional NOL and tax credit carryforwards could be eliminated or restricted. If eliminated, the related asset would be removed from the deferred tax asset schedule with a corresponding reduction in the valuation allowance. Due to the existence of the valuation allowance, limitations created by future ownership changes, if any, related to the Company’s operations in the United States will not impact the Company’s effective tax rate.

A reconciliation of the federal statutory income tax rate to the Company’s effective income tax rate is as follows:

The Company determines its uncertain tax positions based on a determination of whether and how much of a tax benefit taken by the Company in its tax filings is more likely than not to be sustained upon examination by the relevant income tax authorities.

The following table summarizes the activity related to the Company’s unrecognized tax benefits:

If recognized, none of the unrecognized tax benefits as of December 31, 2023 would reduce the annual effective tax rate, primarily due to corresponding adjustments to the valuation allowance.

The Company files income tax returns in the United States, California and foreign jurisdictions. Due to the Company’s losses incurred, the Company is essentially subject to income tax examination by tax authorities from inception to date. The Company’s policy is to recognize interest expense and penalties related to income tax matters as tax expense. At December 31, 2023, there areno significant accruals for interest related to unrecognized tax benefits or tax penalties. The Company does not expect the unrecognized tax benefits to change significantly over the next twelve months.

9. Employee Savings Plan

The Company has an employee savings plan available to substantially all employees. Under the plan, an employee may elect salary reductions which are contributed to the plan. The plan provides for discretionary contributions by the Company, which totaled$115,950 and $75,859 for the years ended December 31,2023 and 2022, respectively.