Summary of Significant Accounting Policies | 2. Summary of Significant Accounting Policies Unaudited Interim Consolidated Financial Statements The condensed consolidated balance sheet as of September 30, 2022, the condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2022 and 2021, the condensed consolidated statements of stockholders’ equity for the three and nine months ended September 30, 2022 and 2021, and the condensed consolidated statements of cash flows for the nine months ended September 30, 2022 and 2021 are unaudited. The unaudited condensed consolidated financial statements have been prepared on the same basis as the annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal, recurring adjustments that are necessary to present fairly our consolidated financial position as of September 30, 2022, our results of operations for the three and nine months ended September 30, 2022 and 2021 and our cash flows for the nine months ended September 30, 2022 and 2021. The financial data and the other financial information contained in these notes to the condensed consolidated financial statements related to the three- and nine- month periods are also unaudited. The condensed balance sheet as of December 31, 2021, is derived from our audited consolidated financial statements. The results of operations for the three and nine months ended September 30, 2022, are not necessarily indicative of the results to be expected for the year ending December 31, 2022, or for any other future annual or interim period. These condensed consolidated financial statements are not complete and are to be read in conjunction with our audited financial statements and the related notes for the year ended December 31, 2021. The audited financial statements and related notes for the year ended December 31, 2021 was filed in the Form S-1 and Form S-1/A on August 12, 2022 and September 1, 2022, respectively, with the U.S. Securities and Exchange Commission. Basis of Presentation We prepare our consolidated financial statements and accompanying notes in accordance with accounting principles generally accepted in the United States of America (“GAAP”). Principles of Consolidation The unaudited condensed consolidated financial statements include the accounts of Apexigen and its wholly owned subsidiary. All significant inter-company transactions and balances have been eliminated in consolidation. Emerging Growth Company We are an “emerging growth company,” as defined in Section 2(a) of the Securities Act, as modified by the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”), and may take advantage of certain exemptions from various reporting requirements that are applicable to public companies that are not emerging growth companies. Section 102(b)(1) of the JOBS Act exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies (that is, those that have not had a Securities Act registration statement declared effective or do not have a class of securities registered under the Securities Exchange Act of 1934 (the "Exchange Act")) are required to comply with the new or revised financial accounting standards. The JOBS Act provides that an emerging growth company can elect to opt out of the extended transition period and comply with the requirements that apply to non-emerging growth companies but any such election to opt out is irrevocable. We have elected not to opt out of such extended transition period which means that when a standard is issued or revised and it has different application dates for public or private companies, we, as an emerging growth company, can adopt the new or revised standard at the time private companies adopt the new or revised standard. This may make comparison of our consolidated financial statements with another public company, which is neither an emerging growth company nor an emerging growth company that has opted out of using the extended transition period, difficult or impossible because of the potential differences in accounting standards used. Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts expensed during the reporting period. On an ongoing basis, management evaluates its estimates, including those related to accruals for research and development costs, stock-based compensation, uncertain tax positions and fair values of common stock and preferred stock. We adjust such estimates and assumptions when facts and circumstances dictate. Changes in those estimates resulting from continuing changes in the economic environment will be reflected in the consolidated financial statements in future periods. As future events and their effects cannot be determined with precision, actual results could materially differ from those estimates and assumptions. Segment Reporting We have one operating segment, which is the business of researching, developing and commercializing antibody therapeutics for oncology. Our chief operating decision maker, Chief Executive Officer, manages our operations on an aggregated basis for the purposes of allocating resources and evaluating financial performance. Cash and Cash Equivalents We consider all highly liquid investments purchased with original maturities of three months or less from the purchase date to be cash equivalents. Cash equivalents consist primarily of amounts invested in money market funds and corporate debt securities. The carrying amount of cash equivalents approximates their fair value. Short-Term Investments Short-term investments consist of debt securities with original maturities of greater than three months from the date of purchase but less than one year from the balance sheet date. Such investments are considered available-for-sale and reported at fair value with unrealized gains and losses included as a component of stockholders’ deficit. The amortized cost of debt securities is adjusted for amortization of premiums and accretion of discounts to maturity, which is included as other income, net in the consolidated statements of operations and comprehensive loss. Realized gains and losses and declines in fair value determined to be other-than-temporary, if any, on investments are included in other income, net. We determine the cost of securities sold using the specific identification method. Fair Value Measurements We apply fair value accounting to all financial assets and liabilities and non-financial assets and liabilities that are recognized or disclosed at fair value in the consolidated financial statements on a recurring basis. The carrying amount of our financial assets and liabilities, including accounts payable and accrued expenses, approximate their fair values due to their short-term maturities. Concentrations of Credit and Other Risks Financial instruments that potentially subject us to a concentration of credit risk consist primarily of cash and cash equivalents and short-term investments. We hold our bank deposits at accredited financial institutions and these deposits may at times exceed insured limits. We are exposed to credit risk in the event of a default by the financial institutions holding our cash and cash equivalents to the extent of the amounts held in excess of federally insured limits. We limit our credit risk associated with cash and cash equivalents by placing them with financial institutions we believe are of high quality. We have not experienced any losses on our deposits of cash. Our investment policy limits investments to certain types of securities issued by the U.S. government, its agencies and institutions with investment-grade credit ratings and places restrictions on maturities and concentration by type and issuer. As of September 30, 2022 and 2021 , we had no off-balance sheet concentrations of credit risk. We are subject to a number of risks similar to other early-stage biopharmaceutical companies, including the need to obtain adequate additional funding, possible failure of clinical trials, the need to obtain marketing approval for our product candidates, competitors developing new technological innovations, the need to successfully commercialize and gain market acceptance of our products, and protection of proprietary technology. If we do not successfully develop, obtain regulatory approval for, commercialize or partner our product candidates, we will be unable to generate revenue from product sales or achieve profitability. Property and Equipment, Net Property and equipment are stated at cost, less accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the related assets. The estimated useful life of laboratory equipment, furniture and fixtures, office equipment, and software ranges from two to five years . We expense maintenance, repair and calibration costs as incurred. Impairment of Long-Lived Assets Our long-lived assets are comprised principally of our property and equipment and right-of-use lease assets. We periodically evaluate our long-lived assets for impairment whenever events or changes in business circumstances indicate that the carrying amount of the assets or group of assets may not be fully recoverable. We deem a long-lived asset impaired when the undiscounted future cash flows expected to be generated by the asset or group of assets is less than the carrying amount of the assets. If there is an impairment, we would reduce the carrying amount of the assets through an impairment charge, to their estimated fair values based on a discounted cash flow approach or, when available and appropriate, to comparable market values. We recorded no impairment of long-lived assets during the three and nine months ended September 30, 2022 . Deferred Transaction Costs Deferred transaction costs consist of direct legal, accounting, filing and other fees and costs directly attributable to the Transaction (see Note 3). We capitalized deferred transaction costs prior to the close of the Transaction and included in prepaid expenses and other current assets. We reclassified the deferred transaction costs related to the Transaction to additional paid-in capital to offset the proceeds received upon closing of the Transaction. There were deferred transaction costs of $ 0.5 million on the consolidated balance sheet as of December 31, 2021 . Upon the close of the Transaction, we reclassified transaction costs of $ 9.2 million to additional paid-in capital to offset the proceeds received, where we paid transaction costs of approximately $ 11,000 in 2021, paid $ 8.7 million in 2022, and accrued $ 0.5 million as of September 30, 2022 (see Note 3). Deferred Financing Costs Deferred financing costs consist of direct costs and commitment fees directly attributable to the commencement of the equity line of credit from Lincoln Park Capital Fund, LLC upon closing of the Transaction (see Note 7). We capitalize deferred financing costs and amortize these costs over 24 months of the equity line of credit. As of September 30, 2022, deferred financing costs totaled $ 3.3 million . Amortization expense for deferred financing costs was $ 0.3 million for the three and nine months ended September 30, 2022 . Revenue Recognition Under Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 606, Revenue from Contracts with Customers , we recognize revenue when we transfer promised goods or services to customers in an amount that reflects the consolidated balance sheets to which we expect to be entitled in exchange for those goods or services. We have not commenced sales of our drug candidates and did not have a product approved for marketing as of September 30, 2022. We may also earn contingent fees, including milestone payments based on counterparty performance and royalties on sales, from collaborations and other out-license arrangements. We will recognize milestone payments as revenue once the underlying events are probable of being met and there is not a significant risk of reversal. We will recognize sales-based royalties as revenue when the underlying sales occur. In October 2019, Novartis’ Beovu ® product, which is covered by one of our license agreements, was approved for commercial product sale. Under this agreement, Novartis is obligated to pay us a very low single-digit royalty on net sales of the Beovu product. However, Novartis has disputed its obligation to pay us royalties on Beovu sales under this agreement. As a result, we have determined that any sales-based Beovu product royalty revenue that we may earn under this agreement is currently fully constrained. We have recorded the royalty proceeds as deferred revenue in the consolidated balance sheets. As of September 30, 2022 and December 31, 2021, deferred revenue totaled $ 5.1 million and $ 3.6 million , respectively. Lease We determine if an arrangement is a lease at inception and if so, we determine whether the lease qualifies as an operating or a finance lease. We include operating lease in operating lease right-of-use (“ROU”) assets and lease liabilities in our consolidated balance sheets. We did not have any finance leases as of September 30, 2022 or December 31, 2021 . ROU assets represent the right to use an underlying asset for the lease term and lease liabilities represent the obligation to make lease payments arising from the lease. We recognize operating lease ROU assets and liabilities at the lease commencement date based on the present value of lease payments over the lease term. When a lease does not provide an implicit rate, we use an incremental borrowing rate based on the information available at the commencement date to determine the present value of lease payments. We use the implicit rate when readily determinable. The operating lease ROU assets also include any lease payments made and exclude lease incentives when paid by us or on our behalf. Our lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. We recognize lease expense for lease payments on a straight-line basis over the lease term. We also made an accounting policy election to recognize lease expense for short-term leases with a term of 12 months or less on a straight-line basis over the lease term and not to recognize ROU assets or lease liabilities for such leases. We lease our facility under a non-cancelable operating lease agreement and recognize related rent expense on a straight-line basis over the terms of the leases. As an implicit interest rate is not readily determinable in our lease, the incremental borrowing rate is based on information available on the adoption date in determining the present value of lease payments. The lease term for our operating lease includes the non-cancellable period of the lease plus any additional periods covered by its option to extend the lease that we are reasonably certain to exercise. Research and Development Expenses Research and development costs are expensed as incurred. Research and development expenses are primarily for the development of sotiga, our lead product candidate, as well as APX601 and other product candidates. Research and development costs consist primarily of external costs related to clinical development, contract manufacturing, preclinical development and discovery as well as personnel costs and allocated overhead, such as rent, equipment, depreciation, and utilities. Personnel costs consist of salaries, employee benefits and stock-based compensation. We estimate external research and development expenses based on the services performed, pursuant to contracts with commercial and academic institutions that conduct and manage research and development services on our behalf. We record the costs of research and development activities based upon the estimated amount of services provided but not yet invoiced and include these costs in accrued liabilities in the consolidated balance sheets. These costs are a component of our research and development expenses. We accrue these costs based on factors such as the number of patient visits, the number of active patients, the number of patients enrolled, estimates of the work completed and other measures in accordance with agreements established with our third-party service providers under the service agreements. As actual costs become known, we adjust our accrued liabilities. We have not experienced any significant differences between accrued costs and actual costs incurred. However, the status and timing of actual services performed may vary from our estimates, resulting in adjustments to expense in future periods. Changes in these estimates that result in significant changes to our accruals could significantly affect our results of operations. Nonrefundable advance payments for goods or services to be received in the future for use in research and development activities are capitalized and then expensed as the related goods are delivered or the services are performed. We evaluate such payments for current or long-term classification based on when they will be realized. Preferred Stock Warrant Liability We record at fair value freestanding puttable or redeemable warrants, or warrants which are not considered to be indexed to our stock and include this amount in accrued expenses on our consolidated balance sheets. On the Closing of the Transaction, the preferred stock warrant that was outstanding immediately before the Closing became a common stock warrant. We adjusted the carrying value of such warrant to its estimated fair value at the Closing based upon the value of our common stock warrant and reclassified from accrued expenses to additional paid-in capital on the date of Closing. Derivative Warrant Liabilities We account for the private placement warrants issued in connection with the initial public offering as derivative warrant liabilities in accordance with FASB ASC Topic 815, “ Derivative and Hedging ”. Accordingly, we recognize the private placement warrants as liabilities at fair value and adjust the instruments to fair value at each reporting period. The liabilities are subject to re-measurement at each balance sheet date until exercised, and any change in fair value is recognized and included as other income, net in the condensed consolidated statements of operations and comprehensive loss. We measured the fair value of the private placement warrants using a Black-Scholes option-pricing model. The determination of the fair value of the warrant liabilities may be subject to change as more current information becomes available and accordingly the actual results could differ significantly. As of September 30, 2022, deferred warrant liabilities were approximately $ 28,000 . Change in fair value of derivative warrant liabilities was approximately $ 62,000 for the three and nine months ended September 30, 2022 . Stock-Based Compensation We measure all stock-based awards granted to employees and non-employees based on the estimated grant date fair value. For awards subject to service-based vesting conditions, we recognize stock-based compensation expense on a straight-line basis over the requisite service period, which is generally the vesting term. For awards subject to performance-based vesting conditions, we recognize stock-based compensation expense using the accelerated attribution method when it is probable that the performance condition will be achieved. We recognize forfeitures as they occur. We use the Black-Scholes option-pricing model to estimate the fair value of stock option awards and recognize expense using the straight-line attribution approach. The Black-Scholes option-pricing model requires assumptions to be made related to the fair value of our common stock, the expected term of the awards, expected stock priced volatility, risk-free rate for a period that approximates the expected term of the awards and the expected dividend yield. Income Taxes We account for income taxes under the asset and liability method. Under this method, we recognize deferred tax assets and liabilities for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. We measure deferred tax assets and liabilities using enacted tax rates applied to taxable income in the years in which we expect to realize those temporary differences. We recognize the effect on deferred tax assets and liabilities of a change in tax rates as income or loss in the period that includes the enactment date. We establish a valuation allowance, when necessary, to reduce deferred tax assets to the amount we expect to realize. We recognize the financial statement effects of uncertain tax positions when it is more-likely-than-not, based on the technical merits of the position, that it will be sustained upon examination. We include interest and penalties related to unrecognized tax benefits within the provision of income tax. To date, there have been no interest or penalties charged in relation to the unrecognized tax benefits. Comprehensive Loss Comprehensive loss includes net loss and certain changes in stockholders’ deficit that are excluded from net loss, primarily unrealized gains or losses on our marketable securities. Net Loss per Share We calculate basic net loss per share by dividing the net loss 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 is the same as basic net loss per share for each period presented, since the effects of potentially dilutive securities are antidilutive given our net loss. Recent Accounting Pronouncements The adoption dates discussed below reflect the election as an emerging growth company. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , as clarified in subsequent amendments. The standard changes the impairment model for certain financial instruments. The new model is a forward-looking expected loss model and will apply to financial assets subject to credit losses and measured at amortized cost and certain off-balance sheet credit exposures. This includes loans, held-to-maturity debt securities, loan commitments, financial guarantees and net investments in leases, as well as trade receivables. For available-for-sale debt securities with unrealized losses, credit losses will be measured in a manner similar to the existing standard, except that the losses will be recognized as allowances rather than reductions in the amortized cost of the securities. The standard is effective for Apexigen for fiscal years and interim periods beginning January 1, 2023. Early adoption is permitted. We have not yet assessed the effect of adopting the standard on our consolidated financial statements. |