Summary of Significant Accounting Policies | 2. Summary of Significant Accounting Policies Basis of Presentation The financial statements and accompanying notes have been prepared in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”) and include all adjustments necessary for the fair presentation of the Company’s financial position for the periods presented. Certain prior period amounts in the balance sheet and the statement of cash flows have been reclassified to conform to the current period presentation. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and expenses as well as related disclosure of contingent assets and liabilities. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, accrued research and development expenses, revenue recognition, stock-based compensation, and uncertain tax positions. The Company bases its estimates on its historical experience and on assumptions that it believes are reasonable; however, actual results could significantly differ from those estimates. Risks and Uncertainties Any product candidates developed by the Company will require approvals from the U.S. Food and Drug Administration (“FDA”) or foreign regulatory agencies prior to commercial sales. There can be no assurance that the Company’s current and future product candidates will meet desired efficacy and safety requirements to obtain the necessary approvals. If approval is denied or delayed, it may have a material adverse impact on the Company’s business and its financial statements. The Company is subject to a number of risks similar to other late-stage biopharmaceutical companies including, but not limited to, dependency on the clinical success of the Company’s product candidate, tildacerfont, ability to obtain regulatory approval of tildacerfont, the need for substantial additional financing to achieve its goals, uncertainty of broad adoption of its approved products, if any, by physicians and consumers, significant competition, untested manufacturing capabilities, and dependence on key individuals and sole source suppliers. Global economic and business activities continue to face widespread macroeconomic and geopolitical uncertainties, including recent and potential future disruptions in access to bank deposits or lending commitments due to bank failures, labor shortages, inflation and monetary supply shifts, recession risks and potential disruptions from the ongoing wars in Ukraine and Israel and related sanctions. The Company continues to actively monitor the impact of these macroeconomic and geopolitical factors on its financial condition, liquidity, operations, and workforce. The extent of the impact of these factors on the Company’s operational and financial performance, including its ability to execute its business strategies and initiatives in the expected time frame, will depend on future developments, which are uncertain and cannot be predicted; however, any continued or renewed disruption resulting from these factors could negatively impact the Company’s business. Concentration of Credit Risk Financial instruments, which potentially subject the Company to significant concentration of credit risk, consist primarily of cash and cash equivalents. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash and cash equivalents to the extent recorded in the balance sheets. Segment Reporting The Company operates and manages its business as one operating segment, which is the business of developing and commercializing novel therapies for rare endocrine disorders with significant unmet medical need. The Company’s chief executive officer, who is the chief operating decision maker, reviews financial information on an aggregate basis for allocating and evaluating financial performance. All long-lived assets are maintained in the United States of America. Cash and Cash Equivalents The Company considers all highly liquid investments with remaining maturities at the date of purchase of three months or less to be cash equivalents. Cash equivalents, which consist of amounts invested in money market funds, are stated at fair value. Restricted Cash The Company had $ 35 thousand and $ 0.2 million of restricted cash as of December 31, 2023 and 2022 , respectively, which is related to collateralized cash in connection with letters of credit issued on behalf of the Company for the security deposits required under operating leases. Short-term restricted cash is included in other current assets on the balance sheets and long-term restricted cash is included in other assets on the balance sheets. Fair Value of Financial Instruments Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability, or an exit price, in the principal or most advantageous market for that asset or liability in an orderly transaction between market participants on the measurement date. Fair value measurement establishes a fair value hierarchy that requires an entity to maximize the use of observable inputs, where available, and minimize the use of unobservable inputs when measuring fair value. The Company determined the fair value of financial assets and liabilities using the fair value hierarchy that describes three levels of inputs that may be used to measure fair value, as follows: ▪ Level 1—Quoted prices in active markets for identical assets and liabilities; ▪ Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and ▪ Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The Company’s financial instruments primarily consist of cash and cash equivalents, prepaid expenses, accounts payable, term loan, and accrued expenses. The carrying value of cash and cash equivalents, prepaid expenses, accounts payable, and accrued expenses are generally considered to be representative of their respective fair values because of the short-term nature of those instruments. The estimated fair value of the term loan is based on market observable interest rates, which is considered a Level 2 fair value measurement. Investments The Company adopted Accounting Standards Update (“ASU”) 2016-13, Measurement of Credit Losses on Financial Instruments , on January 1, 2023. The Company’s investments are classified as available-for-sale and carried at estimated fair values and reported in cash equivalents, short-term investments, or long-term investments. Management determines the appropriate classification of the investments at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date. Investments with contractual maturities greater than 12 months are considered long-term investments. For available-for-sale debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value and recognized in interest and other income, net in the statement of operations and comprehensive loss. If neither criteria is met, the Company evaluates whether the decline in fair value is related to credit-related factors or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. Credit-related impairment losses, limited by the amount that the fair value is less than the amortized cost basis, are recorded through an allowance for credit losses in interest and other income, net. Any unrealized losses from declines in fair value below the amortized cost basis as a result of non-credit factors are recognized in accumulated other comprehensive loss, net of tax as a separate component of stockholders’ equity, along with unrealized gains. Realized gains and losses and declines in fair value, if any, on available-for-sale securities are included in interest and other income, net in the statement of operations and comprehensive loss. For purposes of identifying and measuring credit-related impairments, the Company’s policy is to exclude applicable accrued interest from both the fair value and amortized cost basis of the related security. The Company has elected to write-off uncollectible accrued interest receivable balances in a timely manner, which is defined by the Company as when interest due becomes 90 days delinquent. The accrued interest write-off will be recorded by reversing interest income. Accrued interest receivable is recorded in other current assets on the balance sheets. Leases The Company determines if an arrangement includes a lease at inception. Right-of-use assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at the commencement date. The right-of-use asset includes any lease payments made on or before the lease commencement date, less lease incentives received. The incremental borrowing rate is used in determining the present value of future payments. The Company utilizes its incremental borrowing rate, which is the rate incurred to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment. The lease terms may include options to extend or terminate the lease. Lease expense for operating leases is recognized on a straight-line basis over the non-cancelable lease term. Variable lease expense relates primarily to office lease common area maintenance, insurance, and property taxes, is expensed as incurred, and is excluded from the calculation of the lease liability and right-of-use-asset. The Company does not have any finance leases. The Company has elected not to recognize a right-of-use asset and lease liability for short-term leases. A short-term lease is a lease with an expected lease term of 12 months or less and which does not include an option to purchase the underlying asset that the lessee is reasonably certain to exercis e. Lease agreements that include lease and non-lease components are accounted for as a single lease component. Property and Equipment, Net Property and equipment are stated at cost less accumulated depreciation and are included in other assets on the balance sheets. Depreciation expense is calculated using the straight-line method over the estimated useful life of the respective asset and begins at the time the asset is placed into service. Maintenance and repairs are charged to expense as incurred, and improvements are capitalized. The useful lives of property and equipment are as follows: Computer and office equipment 3 years Computer software 3 years Furniture and fixtures 5 years Manufacturing machinery and equipment 7 years Leasehold improvements Lesser of lease term or 15 years Long-Lived Assets Long-lived assets, such as property and equipment are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be fully recoverable. If circumstances require a long-lived asset or asset group to be tested for possible impairment, the Company first compares undiscounted cash flows expected to be generated by that asset or asset group to its carrying value. If the carrying value of the long-lived asset or asset group is not recoverable on an undiscounted cash flow basis, an impairment is recognized to the extent that the carrying value exceeds its fair value. Fair value is determined through various valuation techniques including discounted cash flow models, quoted market values and third-party independent appraisals, as considered necessary. There were no such impairment losses during the years ended December 31, 2023 and 2022 . Accrued Research and Development Expenses Clinical trial costs are charged to research and development expense as incurred. The Company accrues for expenses resulting from contracts with clinical research organizations (“CROs”), consultants, and clinical site agreements in connection with conducting clinical trials. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided to us under such contracts. The Company’s policy is to reflect the appropriate expense in the financial statements by matching the appropriate expenses with the period in which services and efforts are expended. The CRO contracts generally include pass-through fees including, but not limited to, regulatory expenses, investigator fees, laboratory fees and other miscellaneous costs. The Company determines accrual estimates through reports from and discussion with clinical personnel and outside service providers as to the progress or state of completion of trials, or the services completed. The Company estimates accrued expenses as of each balance sheet date based on the facts and circumstances known at that time. The clinical trial accrual is dependent, in part, upon the receipt of timely and accurate reporting from the CROs and other third-party vendors. 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 associated with licensing agreements to acquire exclusive licenses to develop, use, manufacture and commercialize products that have not reached technological feasibility and do not have alternate commercial use are expensed as incurred. Payments made to third parties under these arrangements in advance of the performance of the related services by the third parties are recorded as prepaid expenses until the services are rendered. Revenue Recognition The Company recognizes revenues when, or as, the promised goods or services are transferred to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those services. To determine revenue recognition for arrangements, the Company performs the following five steps: (1) identify the contract(s) with a customer; (2) identify the performance obligation(s) in the contract; (3) determine the transaction price; (4) allocate the transaction price to the performance obligation(s) in the contract; and (5) recognize revenue when (or as) the performance obligation(s) are satisfied. The Company has entered into a licensing and collaboration agreement that primarily includes the following: (i) upfront cash consideration; (ii) payments associated with achieving certain milestones; and (iii) royalties based on specified percentages of net product sales, if any. At the initiation of an agreement, the Company analyzes each unit of account within the contract to determine if the counterparty is a customer in the context of the unit of account. At contract inception, the Company assesses the goods or services promised and enforceable in a contract with a customer and identifies those distinct goods and services that represent a performance obligation. If a promised good or service is not distinct, the Company combines that good or service with other promised goods or services until it identifies a bundle of goods or services that is distinct. Promised goods and services that are not material in the context of the contract are not considered performance obligations. Additional goods or services that are exercisable at a customer’s discretion are assessed to determine if they provide a material right to the customer and if so, they are considered performance obligations. The transaction price is the amount of consideration to which the Company expects to be entitled in exchange for transferring promised goods or services to a customer. The consideration promised in a contract with a customer may include fixed amounts, variable amounts, or both. Non-refundable upfront payments are considered fixed consideration and included in the transaction price. At the inception of arrangements that include variable consideration, the Company uses judgment to estimate the amount of variable consideration to include in the transaction price using the most likely method. If it is probable that a significant revenue reversal will not occur, then the estimated amount is included in the transaction price. Milestone payments that are not within the Company’s or the licensee’s control, such as regulatory approvals, are not included in the transaction price until those approvals are received. For arrangements with licenses of intellectual property that include sales-based royalties, including milestone payments based on the level of sales, and if the license is deemed to be the predominant item to which the royalties relate, the Company recognizes royalty revenue and sales-based milestones at the later of (i) when the related sales occur, or (ii) when the performance obligation to which the royalty has been allocated has been satisfied. At the end of each reporting period, the Company re-evaluates the estimated variable consideration included in the transaction price and any related constraint and, as necessary, adjusts the estimate of the overall transaction price. Any adjustments will be recorded on a cumulative catch-up basis, which would affect revenues and earnings in the period of adjustment. If it is determined that multiple performance obligations exist, the transaction price is allocated at the inception of the agreement to all identified performance obligations based on the relative standalone selling prices, unless the consideration is variable and meets the criteria to be allocated entirely to one or more, but not all, performance obligations in the contract. Other components of the transaction price are allocated based on the relative standalone selling price, over which the Company applies significant judgment. The Company develops assumptions that require judgment to determine the standalone selling price for license-related performance obligations under the adjusted market assessment approach, which may include forecasted revenues, development timelines, discount rates and probabilities of success. Revenue is recognized when, or as, the Company satisfies a performance obligation. The Company recognizes revenue over time by measuring the progress toward complete satisfaction of the relevant performance obligation using an appropriate input method based on the nature of the good or service promised to the customer. The Company uses judgment to assess the nature of the performance obligation to determine whether the performance obligation is satisfied over time or at a point in time. The selection of the method to measure progress towards completion requires judgment and is based on the nature of the products or services to be provided. If a customer pays consideration, or the Company has an unconditional right to the consideration, before the satisfaction of the revenue recognition criteria, the amounts are recorded as deferred revenue in the Company’s balance sheet. The current portion of deferred revenue represents the amount of the performance obligation that is expected to be satisfied within the next twelve months. Amounts recognized as revenue prior to receipt or before they are due are recorded as contract assets in the Company’s balance sheet, excluding any amounts presented as accounts receivable. If the Company has an unconditional right to receive consideration, the contract assets are accounted for as accounts receivable and presented separately from contract assets. A net contract asset or liability is presented for each contract with a customer. Research and Development Expenses Research and development costs are expensed as incurred. Research and development expenses include, but are not limited to, personnel costs, fees paid to external entities that conduct certain non-clinical and clinical development activities on our behalf, manufacturing costs, outside service and consulting costs, and allocated overhead, including rent. Assets acquired that are utilized in research and development that have no alternative future use are also expensed as incurred. Stock-Based Compensation The Company accounts for stock-based compensation using a fair value-based method, which requires the recognition of compensation expense for costs related to all stock-based payments including stock options, restricted stock units (“RSUs”) and purchase rights under the Employee Stock Purchase Plan (“ESPP”). The Company estimates the fair value of stock options and purchase rights granted under the ESPP on the date of grant using the Black-Scholes option pricing model, which is impacted by the fair value of the Company’s common stock, as well as changes in assumptions regarding a number of highly complex and subjective variables. The model requires management to make a number of assumptions which include the following: ▪ Expected Term . The expected term is based on the simplified method, as the Company’s stock options have the following characteristics: (i) granted at-the-money; (ii) exercisability is conditioned upon service through the vesting date; (iii) termination of service prior to vesting results in forfeiture; (iv) limited exercise period following termination of service; and (v) options are non-transferable and non-hedgeable, or “plain vanilla” options, and the Company has limited history of exercise data. For the ESPP, the expected term is based on the term of the purchase period. ▪ Expected Volatility . The expected volatility is estimated using a combination of historical volatilities of the Company's stock and that of comparable publicly traded biopharmaceutical companies. In evaluating similarity, the Company considered factors such as market capitalization, stage of development, area of specialty, and stock-specific attributes. The Company will continue to apply this process and analyze the historical stock price volatility and expected term assumptions as more historical data for the Company’s common stock becomes available. ▪ Risk-Free Interest Rate . The risk-free interest rate is based on U.S. Treasury constant maturity rates with remaining terms similar to the expected term of the options. ▪ Expected Dividend Rate . The Company has never paid any dividends and does not plan to pay dividends in the foreseeable future, and, therefore, used an expected dividend rate of zero in the valuation model. ▪ Forfeitures . The Company accounts for forfeitures as they occur. The fair value of RSUs, including RSUs subject to performance-based vesting conditions, is based on the grant-date fair value of the Company's stock price. The Company recognizes compensation expense on a straight-line basis over the requisite service period of the award, which is generally the vesting period. The Company accounts for forfeitures as they occur. For options and RSUs that vest upon the satisfaction of certain performance conditions, the Company recognizes compensation expense when it becomes probable that the performance conditions will be met. When the criteria are deemed probable of being met, the Company records cumulative compensation expense in the period the performance criteria are deemed probable of being met and recognizes the remaining compensation expense on a straight-line basis over the remaining period for which the performance criteria are expected to be completed . Income Taxes The Company accounts for income taxes under the asset and liability method. The Company estimates actual current tax exposure together with assessing temporary differences resulting from differences in accounting for reporting purposes and tax purposes for certain items, such as accruals and allowances not currently deductible for tax purposes. These temporary differences result in deferred tax assets and liabilities. In general, deferred tax assets represent future tax benefits to be received when certain expenses previously recognized in the Company’s statements of operations and comprehensive loss become deductible expenses under applicable income tax laws or when net operating loss or credit carryforwards are utilized. Accordingly, realization of the Company’s deferred tax assets is dependent on future taxable income against which these deductions, losses and credits can be utilized. The Company assesses the likelihood that the Company’s deferred tax assets will be recovered from future taxable income, and to the extent the Company believes that recovery is not likely, the Company establishes a valuation allowance. The assessment of whether or not a valuation allowance is required often requires significant judgment, including the forecast of future taxable income and on-going prudent and feasible tax planning initiatives. Based upon the weight of available evidence, the Company has determined that net deferred tax assets should be fully offset by a valuation allowance. When the Company establishes or reduces the valuation allowance against its net deferred tax assets, its provision for income taxes will increase or decrease, respectively, in the period such determination is made. The Company accounts for uncertainty in income taxes in accordance with Accounting Standards Codification 740. Tax positions are evaluated in a two-step process, whereby the Company first determines whether it is more likely than not that a tax position will be sustained upon examination by tax authorities, including resolutions of any related appeals or litigation processes, based on technical merit. If a tax position meets the more-likely-than-not recognition threshold, it is then measured to determine the amount of benefit to be recognized in the financial statements. The tax position is measured as the largest amount of benefit that is greater than 50 % likely of being realized upon ultimate settlement. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit. To date, there have been no interest or penalties charged in relation to unrecognized tax benefits. Comprehensive loss Comprehensive loss represents the net loss for the period and other comprehensive income. Other comprehensive loss reflects certain gains and losses that are recorded as a component of stockholders’ equity and are not reflected in the statements of operations. The Company’s other comprehensive loss consists of changes in unrealized gains and losses on available-for-sale investments, net of tax. There was no income tax effect related to unrealized gains and losses during the years ended December 31, 2023 and 2022 . Net Loss per Share Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period, without consideration for potentially dilutive securities. Diluted 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 common stock and potentially dilutive securities outstanding for the period. For purposes of the diluted net loss per share calculation, outstanding stock options, RSUs, and shares expected to be issued pursuant to the ESPP are considered to be potentially dilutive securities. Because the Company has reported a net loss for all periods presented, diluted net loss per share is the same as basic net loss per share for those periods. Emerging Growth Company Status The Company is an emerging growth company (“EGC”) as defined in the Jumpstart Our Business Startups Act of 2012 (“JOBS Act” ) and may take advantage of reduced reporting requirements that are otherwise applicable to public companies. Section 107 of the JOBS Act exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies are required to comply with those standards. The Company has elected to use the extended transition period for complying with new or revised accounting standards. Recent Accounting Pronouncements Adopted In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update 2016-13, Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). ASU 2016-13 requires that financial assets measured at amortized cost be presented at the net amount expected to be collected. The measurement of expected credit losses is based on historical experience, current conditions, and reasonable and supportable forecasts that affect collectability. ASU 2016-13 also eliminates the concept of “other-than-temporary” impairment when evaluating available-for-sale debt securities and instead focuses on determining whether any impairment is a result of a credit loss or other factors. An entity will recognize an allowance for credit losses on available-for-sale debt securities rather than an other-than-temporary impairment that reduces the cost basis of the investment. The Company adopted ASU 2016-13 on January 1, 2023 and the adoption did not have any impact on the Company’s financial statements . Recent Accounting Pronouncements - Not Yet Adopted In December 2023, the FASB issued Accounting Standards Update 2023-09, Income Taxes - Improvements to Income Tax Disclosures (“ASU 2023-09”) requiring enhancements and further transparency to certain income tax disclosures, most notably the tax rate reconciliation and income taxes paid. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024 on a prospective basis and retrospective application is permitted. The Company is currently evaluating the impact of the adoption of this standard on the Company’s financial statements and related disclosures. In November 2023, the FASB issued ASU 2023-07, Improvements to Reportable Segment Disclosures (“ASU 2023-07”) which is intended to improve reportable segment disclosure requirements, primarily through additional disclosures about significant segment expenses, including for single reportable segment entities. The standard is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. The amendments should be applied retrospectively to all prior periods presented in the financial statements. We are evaluating the disclosure requirements related to the new standard. |