Summary of Significant Accounting Policies and Use of Estimates | SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND USE OF ESTIMATES (i) Basis of Presentation The Company’s Condensed Financial Statements have been prepared in conformity with generally accepted accounting principles ("GAAP") in the United States ("U.S.") for interim financial information and pursuant to Form 10-Q and with the rules and regulations of the Securities and Exchange Commission ("SEC"). Accordingly, the accompanying Condensed Financial Statements do not include all of the information and footnotes required by GAAP for complete financial statements. The interim Condensed Balance Sheet as of June 30, 2022, the interim Condensed Statements of Operations and Comprehensive (Loss) Income, and Stockholders’ Equity for the three and six months ended June 30, 2022 and 2021, and the interim Condensed Cash Flows for the six months ended June 30, 2022 and 2021 are unaudited. These unaudited interim financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments, which consist of only normal and recurring adjustments for the fair presentation of its financial information. The financial data and other information disclosed in these notes related to the three and six-month periods are also unaudited. The Condensed Balance Sheet as of December 31, 2021 has been derived from the audited financial statements at that date but does not include all information and footnotes required by GAAP for annual financial statements. The condensed interim operating results for three and six months ended June 30, 2022 are not necessarily indicative of results to be expected for the year ending December 31, 2022 or any other interim or annual period. The accompanying interim unaudited Condensed Financial Statements should be read in conjunction with the audited financial statements and the related notes thereto in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021, as filed with the SEC on March 14, 2022. The preparation of financial statements in conformity with GAAP and with the rules and regulations of the SEC requires management to make informed estimates and assumptions that affect the amounts reported in these financial statements and accompanying notes. These estimates and assumptions involve judgments with respect to numerous factors that are difficult to forecast and may materially differ from the amounts ultimately realized and reported due to the inherent uncertainty of any estimate or assumption. There have been no significant changes in the Company’s significant accounting policies during the three and six months ended June 30, 2022, as compared with those disclosed in its Annual Report on Form 10-K for the year ended December 31, 2021, filed with the SEC on March 14, 2022. The accounting policies and estimates that most significantly impact the presented amounts within the accompanying Condensed Financial Statements are further described below. (ii) Cash and Cash Equivalents Cash and cash equivalents consist of bank deposits and highly liquid investments, including money market fund accounts, that are readily convertible into cash without penalty, with original maturities of three months or less from the purchase date. (iii) Marketable Securities and Long-Term Investments As of December 31, 2021, "marketable securities" represents LianBio common stock (see Note 7 ). These shares are reported within "long-term investments" on the Condensed Balance Sheet as of June 30, 2022, reflecting the intent to hold these shares for at least one year from the balance sheet date. These securities are designated as "available-for-sale" with associated gains or losses reported in "other expense, net" within the Condensed Statements of Operations and Comprehensive (Loss) Income for each reported period. (iv) Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents in deposits at financial institutions that exceed federally insured limits. In March 2020, the World Health Organization declared a pandemic related to the global novel coronavirus disease 2019 (“COVID-19”) outbreak. The COVID-19 pandemic continues to evolve and its impact on the Company’s business will depend on several factors that are highly uncertain and unpredictable, including the efficacy and adoption of vaccines, future resurgences of the virus and its variants, and the speed at which government restrictions are lifted. To date, the Company’s operations have not been significantly impacted by the COVID-19 pandemic, though the Company continues to monitor the potential impact COVID-19 may have on its ongoing and planned clinical trials. However, the Company cannot at this time predict the specific extent, duration, or full impact that the COVID-19 outbreak may have on these activities or its financial condition. The Company’s results of operations involve numerous risks and uncertainties. Factors that could adversely impact the Company’s operating results and business objectives include, but are not limited to, (1) uncertainty of results of clinical trials, (2) uncertainty of regulatory approval of the Company’s potential product candidates, (3) uncertainty of market acceptance of its product candidates, (4) competition from substitute products and other companies, (5) securing and protecting proprietary technology and strategic relationships, and (6) dependence on key individuals and sole source suppliers. The Company’s product candidates require approvals from the U.S. Food and Drug Administration (“FDA”) and comparable foreign regulatory agencies prior to commercial sales in their respective jurisdictions. There can be no assurance that any product candidates will receive the necessary approvals. If the Company is denied approval, approval is delayed, or the Company is unable to maintain approval for any product candidate, it could have a materially adverse impact on its business. (v) Revenue Recognition for Out-License Arrangements Overview The Company currently has one out-license arrangement that allows the third-party licensee to market the TP-03 product candidate (representing "functional intellectual property") in certain territories for a certain field of use and for a stated term - see Note 9 . The accounting and reporting of revenue for out-license arrangements requires significant judgment for: (a) identification of the number of performance obligations within the contract, (b) the contract’s transaction price for allocation (including variable consideration), (c) the stand-alone selling price for each identified performance obligation, and (d) the timing and amount of revenue recognition in each period. The Company's out-license arrangement, as described in Note 9 , was analyzed under GAAP to determine whether the promised goods or services (which include the license, and know-how, data, and information necessary or reasonably useful for the research, development, manufacture, or commercialization of any licensed product, and governance committee services) are distinct or must be accounted for as part of a combined performance obligation. In making these assessments, the Company considers factors such as the stage of development of the underlying intellectual property and the capabilities of the customer to develop the intellectual property on their own, and/or whether the required expertise is readily available. If the license is considered to not be distinct, the license is combined with other promised goods or services as a combined performance obligation for revenue recognition. The Company's out-license arrangement includes the following forms of consideration: (i) non-refundable upfront license payments, (ii) equity-based consideration, (iii) sales-based royalties, (iv) sales threshold milestones, (v) development milestone payments, and (vi) regulatory milestone payments. Revenue is recognized in proportion to the allocated transaction price when (or as) the respective performance obligation is satisfied. The Company evaluates the progress related to each milestone at each reporting period and, if necessary, also adjusts the probability of achievement and related revenue recognition. The measure of progress, and thereby periods over which revenue is recognized, is subject to estimates by management and may change over the course of the respective agreement. Contractual Terms for Receipt of Payments The contractual terms that establish the Company’s right to collect specified amounts from its customers and that require contemporaneous evaluation and documentation under GAAP for the corresponding timing and amount of revenue recognition, are as follows: (1) Upfront License Fees: The Company determines whether non-refundable license fee consideration is recognized at the time of contract execution (i.e., when the license is transferred to the customer and the customer is able to use and benefit from the license) or over the actual (or implied) contractual period of the out-license. The Company also evaluates whether it has any other requirements to provide substantive services that are inseparable from the performance obligation of the license transfer to determine whether any combined performance obligation is satisfied over time or at a point in time. Upfront payments may require deferral of revenue recognition to a future period until the Company performs obligations under these arrangements. (2) Development Milestones: The Company utilizes the “most likely amount” method to estimate the amount of consideration to which it will be entitled for achievement of development milestones as these represent variable consideration. For those payments based on development milestones (e.g., patient dosing in a clinical study or the achievement of statistically significant clinical results), the Company assesses the probability that the milestone will be achieved, including its ability to control the timing or likelihood of achievement, and any associated revenue constraint. Given the high degree of uncertainty around the occurrence of these events, the Company determines the milestone and other contingent amounts to be "constrained" until the uncertainty associated with these payments is resolved. At each reporting period, the Company re-evaluates this associated revenue recognition constraint. Any resulting adjustments are recorded to revenue on a cumulative catch-up basis, and reflected in the financial statements in the period of adjustment. (3) Regulatory Milestones: The Company utilizes the “most likely amount” method to estimate the consideration to which it will be entitled and recognizes revenue in the period regulatory approval occurs (the performance obligation is satisfied) as these represent variable consideration. Amounts constrained as variable consideration are included in the transaction price to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. The Company evaluates whether the milestones are considered probable of being reached and not otherwise "constrained." Accordingly, due to the inherent uncertainty of achieving regulatory approval, associated milestones are deemed constrained for revenue recognition until achievement. (4) Royalties: Under the "sales-or-usage-based royalty exception" the Company recognizes revenue based on the contractual percentage of the licensee’s sale of products to its customers at the later of (i) the occurrence of the related product sales or (ii) the date upon which the performance obligation to which some or all of the royalty has been allocated has been satisfied or partially satisfied. To date, the Company has not recognized any royalty revenue from its out-licensing arrangements. (5) Sales Threshold Milestones: Similar to royalties, applying the "sales-or-usage-based royalty exception", the Company recognizes revenue from sales threshold milestones at the later of (i) the period the licensee achieves the one-time annual product sales levels in their territories for which the Company is contractually entitled to a specified lump-sum receipt, or (ii) the date upon which the performance obligation to which some or all of the milestone has been allocated has been satisfied or partially satisfied. To date, the Company has not recognized any sales threshold milestone revenue from out-licensing arrangements. The Company re-evaluates the measure of progress to each performance obligation in each reporting period as uncertain events are resolved and other changes in circumstances occur. A "performance obligation" is a promise in a contract to transfer a distinct good or service and is the unit of accounting. A contract’s "transaction price" is allocated among each distinct performance obligation based on relative standalone selling price and recognized when, or as, the applicable performance obligation is satisfied. (vi) Research and Development Costs Research and development costs are expensed as incurred or as certain upfront or milestone payments become contractually due to licensors upon the achievement of clinical or regulatory events. These expenses also include internal costs directly attributable to in-development programs, including cost of certain salaries, payroll taxes, employee benefits, and stock-based compensation expense, as well as laboratory and clinical supplies, pre-clinical and clinical trial related expenses, clinical manufacturing costs, and the cost of services provided by outside contractors. The Company recognizes expense for pre-clinical studies and clinical trial activities performed by these third parties. This is typically based upon estimates of the proportion of work completed over the term of the individual study or trial, as well as patient enrollment and dosing events in accordance with agreements established with clinical research organizations (CROs) and clinical trial or pre-clinical study sites. The Company has entered, and may continue to enter into, license agreements to access and utilize intellectual property for drug development. In each case, the Company evaluates if the assets acquired in a transaction represent the acquisition of an as set or a business, as defined under applicable GAAP. The Company’s executed in-license agreements (see Note 8 (b) ) were evaluated and determined to represent asset acquisitions. Because these assets have not yet received regulatory approval and have no alternative future use, the purchase price for each was immediately recognized as research and development expense. In addition, any future milestone payments (whether in the form of cash or stock) made before product regulatory approval (that do not meet the definition of a derivative) will also be immediately recognized as research and development expense when paid or becomes payable, provided there is no alternative future use of the rights in other research and development projects. (vii) Stock-Based Compensation The Company recognizes stock-based compensation expense for equity awards granted to employees, consultants, and members of its Board of Directors. The Black-Scholes pricing model is used to estimate the fair value of stock option awards as of the date of grant. The fair value of restricted stock units is representative of the closing share price preceding the date of grant. For stock-based awards that vest subject to the satisfaction of a service requirement, the related expense is recognized on a straight-line basis over each award’s actual or implied vesting period. For stock-based awards that vest subject to a performance condition, the Company recognizes related expense on an accelerated attribution method, if and when it concludes that it is highly probable that the performance condition will be achieved. As applicable, the Company reverses previously recognized expense for unvested awards in the same period of forfeiture. The measurement of the fair value of stock option awards and recognition of stock-based compensation expense requires assumptions to be estimated by management that involve inherent uncertainties and the application of management’s judgment, including (a) the fair value of the Company’s common stock on the date of the option grant for all awards granted prior to its October 2020 Initial Public Offering ("IPO"), (b) the expected term of the stock option until its exercise by the recipient, (c) stock price volatility over the expected term, (d) the prevailing risk-free interest rate over the expected term, and (e) expected dividend payments over the expected term. Management estimates the expected term of awarded stock options utilizing the “simplified method” for awards as the Company does not yet have sufficient exercise history since its November 2016 corporate formation. Additionally, the Company lacks company-specific historical and implied volatility information of its stock since its IPO. Accordingly, management estimated this expected volatility based on a designated peer-group of publicly-traded companies for a look-back period, as of the date of grant, that corresponded with the expected term of the awarded stock option. The Company estimates the risk-free interest rate based upon the U.S. Department of the Treasury yield curve in effect at award grant for time periods that correspond with the expected term of the awarded stock option. The Company’s expected dividend yield is zero because it has never paid cash dividends and does not expect to for the foreseeable future. The fair value of the Company’s common stock is based on the closing quoted market price of its common stock as reported by the Nasdaq Global Select Market on the date of grant. All stock-based compensation expense is reported in the Statements of Operations and Comprehensive (Loss) Income within "research and development" expense or "general and administrative" expense, based upon the assigned department of the award recipient. (viii) Net (Loss) Income per Share Basic net (loss) income per share is calculated by dividing the net (loss) income by the weighted-average number of shares of common stock outstanding for the period, without consideration for potential dilutive shares of common stock. Diluted net (loss) income per share is computed by dividing the net (loss) income by the weighted-average number of common stock equivalents outstanding for the period determined using the "treasury-stock method" and "if-converted method" as applicable. The Company’s "participating securities" include unvested common stock awards issued upon early exercise of certain stock options, as early exercised unvested common stock awards have a non-forfeitable right to dividends. The Company’s participating securities do not have a contractual obligation to share in the Company’s losses, so in periods of net losses, the "two-class method" of calculating basic and diluted earnings per share is not required. In periods of net income, basic and diluted net loss per share attributable to common stockholders is presented in conformity with the two-class method required for participating securities. Also, net income is attributed to both common stockholders and participating security holders, and therefore, net income is allocated to shares of common stock and participating securities, as if all of the earnings for the period had been distributed. Diluted earnings per share under the two-class method is calculated using the more dilutive of the treasury stock or the two-class method. Due to a net loss for the three and six months ended June 30, 2022, all otherwise potentially dilutive securities are antidilutive, and accordingly, the reported basic net loss per share equals the reported diluted net loss per share in this period. (ix) Fair Value Measurements Assets and liabilities recorded at fair value on a recurring basis in the balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. 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. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: • Level 1: Quoted prices (unadjusted) in active markets for identical assets or liabilities that are publicly accessible at the measurement date. • Level 2: Observable prices that are based on inputs not quoted on active markets, but that are corroborated by market data. These inputs may include quoted prices for similar assets or liabilities or quoted market prices in markets that are not active to the general public. • 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 carrying amounts for financial instruments consisting of cash and cash equivalents, accounts payable and accrued liabilities approximate fair value due to the short maturities for each. The Company's equity warrant holdings are carried at fair value based on unobservable market inputs (see Note 7 ). Assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurements. The Company reviews the fair value hierarchy classification on a quarterly basis. Changes in the ability to observe valuation inputs may result in a reclassification of levels for certain assets or liabilities within the fair value hierarchy. The Company did not have any transfers of assets and liabilities between the levels of the fair value measurement hierarchy during the years presented. (x) Comprehensive (Loss) Income Comprehensive (loss) income represents all changes in stockholders’ equity, except those resulting from distributions to stockholders. For all periods presented in the accompanying Condensed Financial Statements, comprehensive (loss) income was the same as reported net (loss) income. (xi) Recently Issued or Effective Accounting Standards Recently issued or effective accounting pronouncements that impact, or may have an impact, on the Company’s financial statements have been discussed within the footnote to which each relates. Other recent accounting pronouncements not disclosed in these Condensed Financial Statements have been determined by the Company’s management to have no impact, or an immaterial impact, on its current and expected future financial position, results of operations, or cash flows. |