Summary of Significant Accounting Policies | 2. Summary of Significant Accounting Policies Basis of Presentation The consolidated financial statements and related disclosures have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The functional and reporting currency of the Company and its subsidiaries is the U.S. dollar. The aggregate foreign currency transaction gain (loss) included in determining net loss was not material for the periods presented. 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 disclosures of contingent assets and liabilities at the date of the financial statements as well as the reported amounts of expenses during the reporting periods. Such estimates include lease liability, accruals for research and development activities, share-based compensation and certain other accrued liabilities. Actual results could differ from those estimates. Segments The Company operates and manages its business as one reportable and operating segment, which is the business of research and development of medicines that target chronic diseases with unmet medical need. The Company’s Chief Executive Officer, who is the chief operating decision maker, reviews consolidated financial statements and decides how to allocate resources and evaluate segment performance based on net loss reported in the consolidated statements of operations and comprehensive loss. The Company’s long-lived assets are primarily in China. The table below is a summary of the segment net loss, including significant segment expenses (in thousands): YEAR ENDED DECEMBER 31, 2024 2023 Operating expenses: Discovery research and development $ 64,548 $ 37,512 Clinical research and development 44,266 32,591 General and administrative 49,414 32,672 Total operating expenses 158,228 102,775 Loss from operations (158,228) (102,775) Interest and other income, net 36,012 13,391 Loss before provision for income taxes (122,216) (89,384) Provision for income taxes 310 236 Segment net loss and net loss attributable to ordinary shareholders $ (122,526) $ (89,620) Concentration of Credit Risk The Company is exposed to credit risk from its deposits of cash, cash equivalents and short-term investments in excess of the amount of insurance provided on such deposits. The Company invests its cash, cash equivalents and short-term investments in money market funds, corporate debt securities, U.S. government bonds and U.S. government agency bonds. The Company limits its credit risk associated with cash, cash equivalents and short-term investments by investing in investment-grade securities and using banks and institutions it believes are creditworthy. The Company has not experienced any losses on its deposits of cash, cash equivalents and short-term investments to date. The Company has no off-balance sheet concentrations of credit risk, such as foreign currency exchange contracts, option contracts or other hedging arrangements. Risks and Uncertainties The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, protection of proprietary technology, dependence on key personnel, compliance with government regulations and the need to obtain additional financing to fund operations. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical studies, clinical studies and regulatory approval prior to commercialization. These efforts require significant amounts of additional resources, adequate personnel, infrastructure and extensive compliance and reporting. The Company relies and expects to continue to rely on a small number of vendors to manufacture supplies and materials for use in its clinical trial programs. These programs could be adversely affected by a significant interruption in these manufacturing services. Cash and Cash Equivalents The Company considers all highly-liquid investments purchased with maturities of 90 days or less from the original date of purchase to be cash equivalents. As of December 31, 2024 and 2023, the Company’s cash and cash equivalents consist of cash deposited with banks and investments in money market funds. Short-Term Investments The Company classifies its investments as available-for-sale and records them at fair value based upon market prices at period end. Unrealized gains and losses that are deemed temporary in nature are recorded in accumulated other comprehensive income as a separate component of shareholders’ equity (deficit). Dividend and interest income are recognized when earned. Realized gains and losses are included in earnings and are derived using the specific identification method for determining the cost of investments sold. The Company may sell these securities at any time for use in current operations. Credit Losses For short-term investments in an unrealized loss position, the Company periodically assesses its portfolio for impairment. The assessment first considers the intent or requirement to sell the available-for-sale debt securities. If either of these criteria are met, the amortized cost basis is written down to fair value through earnings. If not met, the Company evaluates whether the decline resulted from credit losses or other factors by considering the extent to which fair value is less than amortized cost, any changes to the rating of the short-term investments by a rating agency, and any adverse conditions specifically related to the short-term investments, among other factors. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the short-term investments is compared to the amortized cost basis of the short-term investments. If the present value of cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit losses is recorded, with a corresponding adjustment to interest and other income, net, limited by the amount that the fair value is less than the amortized cost basis. The Company has elected to exclude accrued interest from both the fair value and the amortized cost basis of the available-for-sale debt securities for the purposes of identifying and measuring an impairment. The Company writes off accrued interest as a reduction of interest income when an issuer has defaulted on interest payments due on a security. Any impairment that has not been recorded through an allowance for credit losses is recognized in other comprehensive loss. At December 31, 2024 and 2023, gross unrealized losses on the Company’s available-for-sale securities were not material and, accordingly, no credit loss reserves were recognized. Fair Value of Financial Instruments The Company establishes the fair value of its assets and liabilities using the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date and established a fair value hierarchy based on the inputs used to measure fair value. The carrying value of cash and cash equivalents, accounts payable and accrued liabilities approximate fair value due to their relatively short maturities. The Company determines the fair value of financial and non-financial assets and liabilities using the fair value hierarchy which establishes three levels of inputs that may be used to measure fair value (see Note 4). Property and Equipment, Net Property and equipment, net is stated at cost less accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets, generally two Impairment of Long-Lived Assets Long-lived assets consist primarily of property and equipment, net and right-of-use assets, and are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If circumstances require that a long-lived asset be tested for possible impairment, the Company compares the undiscounted cash flows expected to be generated by the asset group to the carrying amount of the asset group. If the carrying amount of the long-lived asset is not recoverable on an undiscounted cash flow basis, an impairment is recognized to the extent that the carrying amount exceeds its fair value. During the years ended December 31, 2024 and 2023, the Company did not recognize any such impairment charges. Deferred Offering Costs The Company capitalizes, within other non-current assets, certain legal, accounting and other third-party fees that are directly related to the Company’s in-process equity financings, including its IPO, Private Placement and Follow-On Offering, until such financings are consummated. After consummation of the equity financing, these costs are recorded as a reduction of the proceeds received as a result of the equity financing. Should a planned equity financing be abandoned, terminated or significantly delayed, the deferred offering costs will be immediately written off to general and administrative expenses. Upon closing the IPO, Private Placement and Follow-On Offering, all deferred offering costs were charged against the proceeds from the IPO, Private Placement and Follow-On Offering and recorded in shareholders’ equity as a reduction of additional paid-in capital. As of December 31, 2024 and 2023, there were no deferred offering costs recorded on the consolidated balance sheets. Accrued Research and Development Expenses The Company has entered into various agreements with contract manufacturing organizations (“CMOs”) and contract research organizations (“CROs”). The Company’s research and development accruals are estimated based on the level of services performed, progress of the studies, including the phase or completion of events, and contracted costs. The estimated costs of research and development provided, but not yet invoiced, are included in other current liabilities on the consolidated balance sheets. If the actual timing of the performance of services or the level of effort varies from the original estimates, the Company will adjust the accrual accordingly. Payments made to CMOs and CROs under these arrangements in advance of the performance of the related services are recorded as prepaid expenses and other current assets on the consolidated balance sheets until the services are rendered. Leases The Company determines if an arrangement is, or contains, a lease at inception and then classifies the lease as operating or financing based on the underlying terms and conditions of the contract. Operating leases with terms greater than one year are initially recognized on the consolidated balance sheets as right-of-use assets and lease liabilities based on the present value of lease payments over the expected lease term. The Company has also elected to not apply the recognition requirement to any leases within its existing classes of assets with a term of 12 months or less and does not include any options to purchase the underlying asset that the Company is reasonably certain to exercise. As most of the Company’s 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 future payments. Lease expense for lease payments is recognized on a straight-line basis over the lease term. Variable lease payments are excluded from the right-of-use assets and operating lease liabilities and are recognized in the period in which the obligation for those payments is incurred. The Company elected the practical expedient not to separate non-lease components from lease components for the Company’s facility leases and to account for the lease and non-lease components as a single lease component. Research and Development Expenses Research and development expenses include costs directly attributable to the conduct of research and development programs, including payroll and related expenses, costs for CMOs, costs for CROs, materials, supplies, consulting costs, and the allocated portions of facility costs, such as rent, utilities, insurance, information technology costs and general support services. Research and development costs are expensed within the consolidated statements of operations and comprehensive loss as incurred. The Company estimates research and development accruals based on the level of services performed, progress of the studies, including the phase or completion of events, and contracted costs. The estimated costs of research and development provided, but not yet invoiced, are included in accrued expenses and other current liabilities on the consolidated balance sheets. If the actual timing of the performance of services or the level of effort varies from the original estimates, the Company adjusts the accrual accordingly. Payments made to CMOs and CROs under these arrangements in advance of the performance of the related services are recorded as prepaid expenses and other current assets on the consolidated balance sheets until the services are rendered. Share-Based Compensation The Company accounts for share-based compensation arrangements with employees and non-employees using a fair value method which requires the recognition of compensation expense for costs related to all share-based payments including share options. The fair value method requires the Company to estimate the fair value of share-based payment awards on the date of grant using an option-pricing model. The Company uses the Black-Scholes option-pricing model to estimate the fair value of options granted that are expensed on a straight-line basis over the requisite service period, which is generally the vesting period. The Company accounts for forfeitures as they occur. Option valuation models, including the Black-Scholes option-pricing model, require the input of several assumptions. The assumptions are as follows: ● Expected term. The expected term represents the period that the share-based awards are expected to be outstanding. The expected term is calculated using the simplified method which is used when there is insufficient historical data about exercise patterns and post-vesting employment termination behavior. The simplified method is based on the vesting period and the contractual term for each grant, or for each vesting-tranche for awards with graded vesting. The mid-point between the vesting date and the maximum contractual expiration date is used as the expected term under this method. ● Expected volatility. The Company estimated the volatility data based on a study of publicly traded industry peer companies as it did not have any trading history for its ordinary shares. For purposes of identifying these peer companies, the Company considered the industry, stage of development, size and financial leverage of potential comparable companies. For each grant, the Company measured historical volatility over a period equivalent to the expected term. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own share price becomes available. ● Risk-free interest rate. The risk-free interest rate is based on the U.S. Treasury yield in effect at the time of grant for zero-coupon U.S. Treasury notes with remaining terms similar to the expected term of the options. ● Expected Dividend yield. The expected dividend is assumed to be zero as the Company has never paid dividends and has no current plans to do so. The Company has granted share options to employees based in China. The exercise of share options granted to such employees was conditioned on a liquidity event, such as an IPO or change in control, which was not considered probable until consummated. The liquidity event condition was satisfied upon the closing of the IPO, and the Company recognized cumulative share-based compensation expense for share options granted to employees based in China. The Company has granted restricted share units with service and performance conditions to certain employees. The awards are divided into three equal tranches, and the vesting of each tranche is contingent on the occurrence of certain milestone events and fulfilment of service condition. As a result, the related compensation cost is recognized as an expense when achievement of the milestones is considered probable. The expense to be recognized for these awards is based on the grant date fair value of the Company’s ordinary shares multiplied by the number of units granted. Income Taxes The Company uses the asset and liability method of accounting for income taxes, in which deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the consolidated financial statement carrying amounts of existing assets and liabilities and their respective tax bases. The Company measures deferred tax assets and liabilities using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be reversed. The Company recognizes the effect on deferred tax assets and liabilities of a change in tax rates as income and expense in the period that includes the enactment date. A valuation allowance is established if it is more likely than not that all or a portion of the deferred tax asset will not be realized. In determining the need for a valuation allowance, we consider future growth, forecasted earnings, future taxable income, the mix of earnings in the jurisdictions in which the Company operates, historical earnings, taxable income in prior years, if carryback is permitted under the law, carryforward periods and prudent and feasible tax planning strategies. Due to cumulative losses over recent years and based on all available positive and negative evidence, the Company has determined that it is more likely than not that its U.S. and certain foreign deferred tax assets will not be realizable as of December 31, 2024. To the extent sufficient positive evidence becomes available, the Company may release a portion, or all, of its valuation allowance in one or more future periods. A release of the valuation allowance, if any, would result in the recognition of certain deferred tax assets and a potentially material income tax benefit for the period in which such release is recorded. The Company’s tax positions are subject to income tax audits by multiple tax jurisdictions throughout the world. The Company recognizes the tax benefit of an uncertain tax position only if it is more likely than not the position is sustainable upon examination by the taxing authority, based on the technical merits. The Company measures the tax benefit recognized as the largest amount of benefit which is more likely than not to be realized upon settlement with the taxing authority. Significant judgment is required to evaluate uncertain tax positions. The Company’s evaluations are based upon a number of factors, including changes in facts or circumstances, changes in tax law or guidance, correspondence with tax authorities during the course of audits and effective settlement of audit issues. Changes in the recognition or measurement of uncertain tax positions could result in material increases or decreases in our income tax expense in the period in which we make the change, which could have a material impact on our effective tax rate and operating results. The Company calculates the current and deferred income tax provision based on estimates and assumptions that could differ from the actual results reflected in income tax returns filed in subsequent years and record adjustments based on filed income tax returns when identified. The amount of income taxes paid is subject to examination by U.S. federal, state and foreign tax authorities. The estimate of the potential outcome of any uncertain tax issue is subject to management’s assessment of relevant risks, facts and circumstances existing at that time. To the extent the assessment of such tax position changes, we record the change in estimate in the period in which we make the determination. Net Loss Per Share Attributable to Ordinary Shareholders Basic net loss per ordinary share is calculated by dividing the net loss attributable to ordinary shareholders by the weighted-average number of ordinary shares, including non-voting ordinary shares, outstanding during the period, without consideration of potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss attributable to ordinary shareholders by the weighted-average number of ordinary shares, including non-voting ordinary shares, and potentially dilutive securities outstanding for the period. For purposes of the diluted net loss per share calculation, the unvested restricted share units, ordinary shares committed under the employee share purchase plan and share options are considered to be potentially dilutive securities. Because the Company has reported a net loss for all periods presented, diluted net loss per ordinary share is the same as basic net loss per ordinary share for those periods. Comprehensive Income (Loss) Comprehensive income (loss) is defined as a change in equity of a business enterprise during a period, resulting from transactions from non-owner sources. Other comprehensive income (loss) represents unrealized gains or losses on short-term investments that are reported as a component of shareholders’ equity on the consolidated balance sheets. Recent Accounting Pronouncements Recently Adopted Accounting Pronouncements In November 2023, the Financial Accounting Standards Board (“FASB”) issued Account Standards Update (“ASU”) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures Accounting Pronouncements Not Yet Adopted In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures 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 |