Basis of Presentation

The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”).

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure at the date of the financial statements and the reported amounts of expenses during the reporting period. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, the accrual of research and development costs and the valuation of common stock (prior to the Company's IPO), derivative warrant and stock-based compensation. Changes in estimates and assumptions are reflected in reported results in the period in which they become known. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from the Company’s estimates.

Liquidity and Capital Resources

As of December 31, 2025, the Company had approximately $295.2 million of cash, cash equivalents and marketable securities and working capital of approximately $301.0 million. As of December 31, 2025, the Company had an accumulated deficit of $129.5 million. During the year ended December 31, 2025, the Company incurred a net loss of $25.2 million and negative cash flows from operations of $35.2 million. The Company has incurred net losses and negative cash flows from operations since its inception and anticipates it will continue to incur net losses for the foreseeable future.

Prior to the IPO, the Company funded its operations primarily through proceeds from issuances of redeemable convertible preferred stock, common stock and convertible notes. In September 2025, the Company completed its IPO as detailed above. The Company believes that its current capital resources, which consist of cash, cash equivalents and marketable securities, will be sufficient to fund operations through at least the next twelve months from the date the accompanying financial statements are issued based on its expected cash needs. As the Company continues to pursue its business plan, it expects to finance its operations through equity offerings, debt financings, or other capital sources, including current or potential future collaborations, licenses, and other similar arrangements. However, there can be no assurance that any additional financing or strategic arrangements will be available to the Company on acceptable terms, if at all.

Concentration of Risk

Financial instruments that potentially subject the Company to concentration of credit risk consist primarily of cash and cash equivalents and marketable securities. To minimize the risks related to cash, cash equivalents and marketable securities, the Company has established guidelines related to credit ratings and maturities intended to safeguard principal balances and maintain liquidity. The Company’s investment portfolio is maintained in accordance with the Company’s investment policy which defines allowable investments, specifies credit quality standards and limits the credit exposure of any single issuer.

The Company relies on third party vendors, including contract research organizations, to conduct and support its research and development activities. A significant disruption in the services provided by these vendors could delay the Company’s clinical development timelines and adversely affect its research and development programs.

As of both December 31, 2025, and 2024, one research and development vendor individually represented more than 10% of the Company’s accounts payable and accrued expenses. This vendor represented approximately 37% and 36% of accounts payable and accrued expenses as of December 31, 2025, and 2024, respectively.

Segment Information

The Company operates as a single reportable segment in the development of novel therapies for the treatment of neuropsychiatric diseases, including schizophrenia. The Company has not generated revenues since inception. The Company’s chief operating decision maker (“CODM”) is its Chief Executive Officer (“CEO”). The CODM reviews the Company’s performance on an aggregate basis, thus the segment’s loss is the Company’s net loss, as reported on accompanying statements of operations, and the segment’s assets are the Company’s total assets, as reported on the accompanying balance sheets. Significant expenses provided to the CODM include research and development and general and administrative expenses, as reported on the accompanying statements of operations.

The CODM uses the information primarily to evaluate the Company’s performance and allocate resources. This includes reviewing key financial metrics such as budget versus actual expenditures and assessing overall cash flow and liquidity to ensure the continuity of operations. This approach allows the CODM to monitor the Company’s performance and make strategic adjustments as needed to support its operational and financial goals.

The Company’s operations and all long-lived assets are located in the United States.

Cash and Cash Equivalents

The Company considers all highly liquid investments with original maturities of three months or less to be cash equivalents. The Company’s cash and cash equivalents primarily consist of balances held at one financial institution and in money market funds. Cash balances may, at times, exceed the Federal Deposit Insurance Corporation (“FDIC”) amounts. Management periodically assesses the financial condition of the banking institution and believes that any potential credit loss is minimal. As of December 31, 2025 and 2024, the Company’s cash balance exceeded the FDIC insured limit of $250,000.

Restricted Cash

Restricted cash primarily consists of certificates of deposit that are held as collateral against the letter of credit that the Company is required to maintain for its operating lease agreement.

Marketable Securities

The Company accounts for marketable securities held as “available-for-sale” in accordance with Accounting Standards Codification (“ASC”) 320, Investments-Debt Securities. The Company classifies these investments as current assets and carries them at fair value. Unrealized gains and losses are recorded as a separate component of stockholders’ deficit as accumulated other comprehensive income. Realized gains or losses on marketable security transactions are reported in the statements of operations. The cost of securities sold is determined on a specific identification basis. Marketable securities are maintained at one financial institution and are governed by the Company’s investment policy, as approved by the Company’s board of directors.

The Company evaluates its marketable securities with unrealized loss positions for impairment by assessing if they are related to deterioration in credit risk and whether the entire amortized cost basis of the security will be recovered, the intent to sell, and whether it is more likely than not that the Company will be required to sell the securities before the recovery of their cost basis. Credit-related impairment losses, not to exceed the amount that fair value is less than the amortized cost basis, are recognized through an allowance for credit losses with changes in the allowance for credit losses recorded in the statements of operations.

No impairment losses related to marketable securities have been recognized during the years ended December 31, 2025 and 2024. Any unrealized losses on available-for-sale debt securities that are attributed to credit risk are recorded to earnings through an allowance for credit losses. Unrealized gains (losses) on available-for-sale debt securities were not material as of December 31, 2025 and 2024, and no allowance for credit losses was recorded.

Property and Equipment

Impairment of Long-Lived Assets

Long-lived assets consist of property and equipment as well as right-of-use assets. Long-lived assets to be held and used are tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. If the sum of the estimated future undiscounted cash flows expected to result from the use and eventual disposition of an asset is less than the carrying amount of the asset, an impairment loss is recognized. Measurement of an impairment loss is based on the fair value of the asset. The Company has not recorded any impairment losses on long-lived assets during the years ended December 31, 2025 and 2024.

Leases

According to ASC 842 Leases, the Company determines if an arrangement is or contains a lease at inception by assessing whether the arrangement contains an identified asset and whether it has the right to control the use of the identified asset over the term of the arrangement.

Right-of-use (“ROU”) assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Lease liabilities are recognized at the lease commencement date based on the present value of future lease payments over the lease term. The interest rate implicit in lease contracts is typically not readily determinable. To the extent that the Company is unable to utilize an interest rate implicit in the lease, the collateralized incremental borrowing rate is used based on the information available at the lease commencement date, in determining the present value of lease payments. ROU assets are based on the measurement of the lease liability and includes any lease payments made prior to or on lease commencement and initial direct costs incurred and excludes lease incentives, as applicable.

The Company has elected not to recognize leases with an original term of one year or less on the balance sheet.

The Company has elected to account for lease and non-lease components together as a single lease component for all underlying assets.

The Company typically only includes an initial lease term in its assessment of a lease arrangement. Options to renew a lease are not included in the Company’s assessment unless there is reasonable certainty that the Company will renew. Assumptions made by the Company at the commencement date are re-evaluated upon occurrence of certain events, including a lease modification. A lease modification results in a separate contract when the modification grants the lessee an additional right of use not included in the original lease and when lease payments increase commensurate with the standalone price for the additional right of use. When a lease modification results in a separate contract, it is accounted for in the same manner as a new lease. If a lease modification is not accounted for as a separate contract, the Company reassesses lease classification as of the effective date of the modification (the date the modification is approved by both the Company and the lessor). The Company reallocates the remaining consideration in the contract and remeasures the lease liability using a discount rate determined at the effective date of the modification, as applicable.

Fair Value Measurements

The Company applies the fair value method under ASC 820 Fair Value Measurements and Disclosure to all financial assets and liabilities and nonfinancial assets and liabilities that are recognized or disclosed at fair value in the financial statements on a recurring basis. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. ASC 820 establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to measurements involving significant unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are as follows:

Level 1 – Observable inputs, such as quoted prices for identical assets and liabilities in active markets.

Level 2 – Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data.

Level 3 – Unobservable inputs supported by little or no market data and requires management to develop its own assumptions based on best estimates of what market participants would use in pricing an asset or liability at the reporting date.

The level in the fair value hierarchy within which a fair value measurement in its entirety falls is based on the lowest-level input that is significant to the fair value measurement in its entirety. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value may require significant

judgment and involve uncertainty. Changes in fair value measurements could have a significant impact on the results of operations in any given period.

The carrying amounts of cash equivalents, marketable securities, accounts payable and accrued expenses approximate the related fair values due to the short-term maturities of these instruments. The Company’s derivative liabilities are carried at fair value based on the fair value hierarchy. The Company invests its excess cash in financial instruments, which are readily convertible into cash, such as money market funds and government securities. Cash equivalents, where applicable, are classified as Level 1 or Level 2, as defined by the fair value hierarchy.

Stock-Based Compensation

The Company uses equity-based compensation programs to provide long-term performance incentives for its employees, directors and consultants. These incentives consist primarily of stock options and restricted stock grants.

The Company measures all stock options and other stock-based awards to employees, directors and non-employees based on the fair value on the date of the grant and recognizes compensation expense of those awards over the requisite service period, which is generally the vesting period of the respective award. The Company records the expense for these awards using the straight-line method over the service period. The Company recognizes adjustments to stock-based compensation expense for forfeitures as they occur. The Company classifies stock-based compensation expenses in its statements of operations in the same manner in which the award recipient’s payroll costs are classified or in which the award recipients’ service payments are classified.

The fair value of each stock option and other stock-based awards are estimated on the date of grant using the Black-Scholes option-pricing model. Inputs used in the Black-Scholes option-pricing model are summarized as follows:

Expected Term: The expected term is calculated using the simplified method. The simplified method calculates the expected term as the average of the vesting and contractual terms of the award. The Company elected to use the simplified method because of its limited history of stock option exercise activity.

Expected Volatility: As the Company does not have sufficient trading history to estimate the volatility of its common stock, the expected volatility was estimated by taking the average historic price volatility for industry peers, consisting of several public companies in the Company’s industry which are either similar in size, stage of life cycle, or financial leverage, over a period equivalent to the expected term of the awards, where available.

Risk-Free Interest Rate: The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award.

Expected Dividend Yield: The Company has never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future. Accordingly, estimated dividend yield is zero.

The fair value for each restricted common stock award and nominal exercise price warrants were estimated on the date of grant based on the most recent calculation of fair value of the Company’s common stock. Subsequent to the Company’s IPO, the fair value is based on the closing price of the Company’s common stock on the grant date.

Common Stock Warrants and Warrant Liability

The Company accounts for common stock warrants issued as freestanding instruments in accordance with applicable accounting guidance as either liabilities or as equity instruments depending on the specific terms of the warrant agreement. Warrants that are classified as liabilities are initially recorded at fair value and remeasured at fair value at each balance sheet date until settlement. Changes in the fair value of warrant liabilities are recorded in change in fair value of derivative instruments in the statements of operations. The Company determines the fair value of warrant liabilities using valuation techniques that maximize the use of observable inputs. For warrant liabilities with nominal or low exercise prices, fair value is generally determined using observable inputs, primarily the quoted closing price of the Company’s common stock at the measurement date, together with fixed contractual terms (including the exercise price). For other warrant liabilities, fair value is estimated using an option pricing model (for example, the Black-Scholes model), which may require inputs such as expected volatility, expected term, risk-free interest rate, and expected dividend yield. Expected volatility may be

estimated using the historical volatilities of comparable public companies when the Company does not have sufficient trading history. Warrant liabilities valued using observable inputs are generally classified within Level 2 of the fair value hierarchy. Warrant liabilities that use significant unobservable inputs are classified within Level 3 of the fair value hierarchy. Different warrant tranches may be classified within different levels of the fair value hierarchy depending on the observability of the significant inputs used in the valuation. See Note 3 Fair Value Measurements for a description of these assumptions.

Redeemable Convertible Preferred Stock

The Company recorded all shares of redeemable convertible preferred stock at their respective fair values on the dates of issuance, net of issuance costs. The redeemable convertible preferred stock were recorded outside of permanent equity because upon the occurrence of certain deemed liquidation events, the majority of the holders could opt to redeem the shares at the liquidation preference and these events, including a merger, acquisition or sale of substantially all of the assets, are considered not solely within the Company’s control. The Company did not adjust the carrying values of the redeemable convertible preferred stock to its redemption value because it was not considered redeemable as of December 31, 2024. During the year ended December 31, 2025, the Company did not accrete the carrying values of the redeemable convertible preferred stock to the liquidation preference, as the IPO triggered automatic conversion to common stock rather than a redemption event. No deemed liquidation events were probable during the period. Immediately prior to the IPO closing, the outstanding shares of redeemable convertible preferred stock were adjusted for the 1-for-27.8874 reverse stock split, and the Series C preferred stock was further adjusted for anti-dilution provisions. Upon closing of the IPO in September 2025, all 78,072,306 shares of redeemable convertible preferred stock (as adjusted) automatically converted into 3,191,334 shares of common stock, including 391,986 shares issued pursuant to anti-dilution adjustments. The conversion was recorded at the aggregate carrying value of $114.3 million, which was reclassified from temporary equity to additional paid-in capital.

Research and Development

Research and development costs include expenditures in connection with clinical trials, employee cash and stock-based compensation, regulatory and scientific consulting fees, contract research for preclinical studies, drug formulation, manufacturing, supply and handling and data collection. Advance payments for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses. The prepaid amounts are expensed as the related goods are delivered or the services are performed.

The value of goods and services received from contract research organizations (“CROs”) and other third parties are accrued each reporting period based on estimates of the level of services performed and progress in the period when invoices have not been received from such organizations. When evaluating the adequacy of the accrued liabilities, the progress of the studies or clinical trials are analyzed, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Accruals are adjusted as actual costs become known or as additional information becomes available.

General and Administrative

General and administrative costs include expenditures that are not directly related to research and development. General and administrative costs include costs for support and administrative functions including salaries and benefits, stock-based compensation and other personnel-related costs. Additional costs include non-personnel costs such as legal and professional fees, rent, audit fees, insurance costs and public company-related expenses.

Patents and Trademarks

The Company expenses external costs, such as filing fees and associated attorney fees, incurred to obtain issued patents and trademarks and patent and trademark applications pending. The Company also expenses costs associated with maintaining and defending patents and trademarks subsequent to their issuance in the period incurred.

Income Taxes

Income taxes have been determined using the asset and liability approach of accounting for income taxes. Under this approach, deferred taxes represent the future tax consequences expected to occur when the reported amounts of assets and liabilities are recovered or paid. Deferred taxes result from differences between the financial statement and tax bases of

LB’s assets and liabilities and are adjusted for changes in tax rates and tax laws when changes are enacted. Valuation allowances are recorded to reduce deferred tax assets when it is more likely than not that a tax benefit will not be realized. The assessment of whether a valuation allowance is required often requires significant judgment.

Net Loss Per Share

The Company follows the two-class method when computing net loss per share, as the Company has issued shares that meet the definition of participating securities. The two-class method determines net loss per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to receive dividends as if all income for the period had been distributed.

Basic net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted average number of shares of common stock outstanding for the period. Diluted net loss attributable to common stockholders is computed by adjusting loss attributable to common stockholders to reallocate undistributed earnings based on the potential impact of dilutive securities, including outstanding stock options. Diluted net loss per share attributable to common stockholders is computed by dividing the diluted net loss attributable to common stockholders by the weighted average number of common shares outstanding for the period, including potential dilutive common shares assuming the dilutive effect of outstanding stock options.

Comprehensive Loss

Comprehensive loss includes net loss, as well as other changes in stockholders’ deficit that result from transactions and economic events other than those with stockholders. For the years ended December 31, 2025 and 2024, the Company’s only element of other comprehensive loss was unrealized gain/loss on marketable securities.

Recently Issued Accounting Pronouncements Not Yet Adopted

In December 2023, the Financial Accounting Standards Board (“FASB”) issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures which requires enhanced income tax disclosures, including a tabular rate reconciliation using specified categories with disaggregated information for significant reconciling items that meet a quantitative threshold, and disclosure of income taxes paid disaggregated by federal, state and foreign jurisdictions. For public business entities, the guidance is effective for annual periods beginning after December 15, 2024. As the Company has elected the extended transition period available to emerging growth companies under the JOBS Act, the guidance is effective for the Company for fiscal years beginning after December 15, 2025, and the Company expects to adopt ASU 2023-09 for its fiscal year ending December 31, 2026. Early adoption is permitted. As the standard impacts disclosure requirements only and does not affect recognition or measurement, the Company does not expect adoption to have a material impact on its financial position or results of operations but does expect expanded income tax disclosures upon adoption.

In November 2024, the FASB issued ASU 2024-03 Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses, which requires public business entities to provide disaggregated disclosures of certain income statement expense line items on an annual and interim basis, including the amounts of employee compensation, depreciation, amortization and depletion, and other specified cost categories included in each relevant expense caption. The guidance applies only to public business entities and is effective for annual reporting periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027. Early adoption is permitted. The Company is evaluating the impact the adoption of this guidance will have on its financial statement disclosures.

In December 2025, the FASB issued ASU 2025-11, Interim Reporting (Topic 270): Narrow-Scope Improvements which reorganizes and clarifies the interim disclosure requirements in ASC 270 to improve usability and clarify when interim reporting guidance applies. The ASU also introduces a disclosure principle requiring entities to describe events occurring after the end of the most recent annual reporting period that have a material impact on the interim period. The standard does not change the fundamental nature or quantity of interim disclosures required under GAAP. For public business

entities, the guidance is effective for interim periods within fiscal years beginning after December 15, 2027. For all other entities, the guidance is effective for interim periods within fiscal years beginning after December 15, 2028. As the Company has elected the extended transition period available to emerging growth companies under the JOBS Act, the Company expects to adopt this guidance for interim periods within fiscal years beginning after December 15, 2028. Early adoption is permitted. The Company does not expect adoption to have a material impact on its financial statements or disclosures.