CASTLE BIOSCIENCES INC 10-Q

Item 1. Financial Statements. CASTLE BIOSCIENCES, INC. CONDENSED CONSOLIDATED BALANCE SHEETS (in thousands, except share and per share data) March 31, 2024 December 31, 2023 ASSETS (unaudited) Current Assets Cash and cash equivalents $ 82,949 $ 98,841 Marketable investment securities 156,264 144,258 Accounts receivable, net 42,699 38,302 Inventory 7,645 7,942 Prepaid expenses and other current assets 6,221 6,292 Total current assets 295,778 295,635 Long-term accounts receivable, net 1,056 1,191 Property and equipment, net 32,904 25,433 Operating lease assets 11,961 12,306 Goodwill and other intangible assets, net 115,088 117,335 Other assets – long-term 1,720 1,440 Total assets $ 458,507 $ 453,340 LIABILITIES AND STOCKHOLDERS’ EQUITY Current Liabilities Accounts payable $ 9,318 $ 10,268 Accrued compensation 14,708 28,945 Operating lease liabilities 1,189 1,137 Other accrued and current liabilities 6,744 7,317 Total current liabilities 31,959 47,667 Long-term debt 10,000 — Noncurrent operating lease liabilities 13,864 14,173 Deferred tax liability 206 206 Other liabilities 16 25 Total liabilities 56,045 62,071 Commitments and Contingencies (Note 11) Stockholders’ Equity Preferred stock, $ 0.001 par value per share; 10,000,000 shares authorized as of March 31, 2024 and December 31, 2023; no shares issued and outstanding as of March 31, 2024 and December 31, 2023 — — Common stock, $ 0.001 par value per share; 200,000,000 shares authorized as of March 31, 2024 and December 31, 2023; 27,585,669 and 27,410,532 shares issued and outstanding as of March 31, 2024 and December 31, 2023, respectively 28 27 Additional paid-in capital 623,450 609,477 Accumulated deficit ( 220,905 ) ( 218,371 ) Accumulated other comprehensive (loss) income ( 111 ) 136 Total stockholders’ equity 402,462 391,269 Total liabilities and stockholders’ equity $ 458,507 $ 453,340 The accompanying notes are an integral part of these unaudited condensed consolidated financial statements. 1 Table of Contents CASTLE BIOSCIENCES, INC. CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) (in thousands, except per share data) Three Months Ended March 31, 2024 2023 NET REVENUES $ 72,974 $ 42,037 OPERATING EXPENSES Cost of sales (exclusive of amortization of acquired intangible assets) 13,894 10,182 Research and development 13,809 14,393 Selling, general and administrative 48,495 46,762 Amortization of acquired intangible assets 2,247 2,222 Total operating expenses, net 78,445 73,559 Operating loss ( 5,471 ) ( 31,522 ) Interest income 2,996 2,336 Interest expense ( 14 ) ( 4 ) Loss before income taxes ( 2,489 ) ( 29,190 ) Income tax expense 45 14 Net loss $ ( 2,534 ) $ ( 29,204 ) Loss per share, basic and diluted $ ( 0.09 ) $ ( 1.10 ) Weighted-average shares outstanding, basic and diluted 27,485 26,607 The accompanying notes are an integral part of these unaudited condensed consolidated financial statements. 2 Table of Contents CASTLE BIOSCIENCES, INC. CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (UNAUDITED) (in thousands) Three Months Ended March 31, 2024 2023 Net loss $ ( 2,534 ) $ ( 29,204 ) Other comprehensive (loss) income: Net unrealized (loss) gain on marketable investment securities ( 247 ) 245 Comprehensive loss $ ( 2,781 ) $ ( 28,959 ) The accompanying notes are an integral part of these unaudited condensed consolidated financial statements. 3 Table of Contents CASTLE BIOSCIENCES, INC. CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (UNAUDITED) (in thousands, except share data) Preferred Stock Common Stock Additional Paid-in Capital Accumulated Deficit Accumulated Other Comprehensive (Loss) income Total Stockholders’ Equity Shares Amount Shares Amount BALANCE, JANUARY 1, 2023 — $ — 26,553,681 $ 27 $ 560,409 $ ( 160,905 ) $ ( 381 ) $ 399,150 Stock-based compensation expense — — — — 13,525 — — 13,525 Exercise of common stock options — — 30,495 — 95 — — 95 Issuance of common stock from vested restricted stock units and payment of employees’ taxes — — 24,835 — ( 314 ) — — ( 314 ) Issuance of common stock under the employee stock purchase plan — — 77,190 — 1,652 — — 1,652 Net unrealized gain on marketable investment securities — — — — — — 245 245 Net loss — — — — — ( 29,204 ) — ( 29,204 ) BALANCE, MARCH 31, 2023 — $ — 26,686,201 $ 27 $ 575,367 $ ( 190,109 ) $ ( 136 ) $ 385,149 BALANCE, JANUARY 1, 2024 — $ — 27,410,532 $ 27 $ 609,477 $ ( 218,371 ) $ 136 $ 391,269 Stock-based compensation expense — — — — 12,675 — — 12,675 Exercise of common stock options — — 19,066 — 65 — — 65 Issuance of common stock from vested restricted stock units and payment of employees’ taxes — — 44,830 — ( 474 ) — — ( 474 ) Issuance of common stock under the employee stock purchase plan — — 111,241 1 1,707 — — 1,708 Net unrealized gain on marketable investment securities — — — — — — ( 247 ) ( 247 ) Net loss — — — — — ( 2,534 ) — ( 2,534 ) BALANCE, MARCH 31, 2024 — $ — 27,585,669 $ 28 $ 623,450 $ ( 220,905 ) $ ( 111 ) $ 402,462 The accompanying notes are an integral part of these unaudited condensed consolidated financial statements. 4 Table of Contents CASTLE BIOSCIENCES, INC. CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (in thousands) Three Months Ended March 31, 2024 2023 OPERATING ACTIVITIES Net loss $ ( 2,534 ) $ ( 29,204 ) Adjustments to reconcile net loss to net cash used in operating activities: Depreciation and amortization 3,340 2,892 Stock-based compensation expense 12,675 13,525 Deferred income taxes — 13 Accretion of discounts on marketable investment securities ( 1,699 ) ( 1,229 ) Other 179 211 Change in operating assets and liabilities: Accounts receivable ( 4,262 ) ( 4,383 ) Prepaid expenses and other current assets ( 103 ) ( 654 ) Inventory 297 ( 540 ) Operating lease assets 338 331 Other assets ( 230 ) 319 Accounts payable ( 422 ) 3,896 Operating lease liabilities ( 250 ) ( 68 ) Accrued compensation ( 14,237 ) ( 11,562 ) Other accrued and current liabilities 73 1,014 Net cash used in operating activities ( 6,835 ) ( 25,439 ) INVESTING ACTIVITIES Purchases of property and equipment ( 9,152 ) ( 3,338 ) Proceeds from sale of property and equipment 5 5 Purchases of marketable investment securities ( 60,754 ) ( 30,083 ) Proceeds from maturities of marketable investment securities 50,200 50,000 Net cash (used in) provided by investing activities ( 19,701 ) 16,584 FINANCING ACTIVITIES Proceeds from exercise of common stock options 65 95 Payment of employees’ taxes on vested restricted stock units ( 474 ) ( 314 ) Proceeds from contributions to the employee stock purchase plan 1,089 982 Repayment of principal portion of finance lease liabilities ( 36 ) ( 35 ) Proceeds from issuance of term debt 10,000 — Net cash provided by financing activities 10,644 728 NET CHANGE IN CASH AND CASH EQUIVALENTS ( 15,892 ) ( 8,127 ) Beginning of period 98,841 122,948 End of period $ 82,949 $ 114,821 The accompanying notes are an integral part of these unaudited condensed consolidated financial statements. 5 Table of Contents CASTLE BIOSCIENCES, INC. CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (CONTINUED) (UNAUDITED) (in thousands) Three Months Ended March 31, 2024 2023 DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES: Accrued purchases of property and equipment $ 699 $ 2,730 Decrease in operating lease assets with corresponding change in lease liabilities $ ( 7 ) $ — Property and equipment acquired with tenant improvement allowance $ — $ 89 The accompanying notes are an integral part of these unaudited condensed consolidated financial statements. 6 Table of Contents CASTLE BIOSCIENCES, INC. NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED) 1. Organization and Description of Business Castle Biosciences, Inc. (the ‘‘Company”, “we”, “us” or “our”) was incorporated in the state of Delaware on September 12, 2007. We are a commercial-stage diagnostics company focused on providing clinicians and their patients with personalized, clinically actionable information to inform treatment decisions and improve health outcomes. We are based in Friendswood, Texas (a suburb of Houston, Texas) and our laboratory operations are conducted at our facilities located in Phoenix, Arizona and Pittsburgh, Pennsylvania. 2. Summary of Significant Accounting Policies Basis of Presentation Our unaudited condensed consolidated financial statements include the accounts of Castle Biosciences, Inc. and our wholly owned subsidiaries and have been prepared in conformity with accounting principles generally accepted in the United States of America (‘‘U.S. GAAP’’). All intercompany accounts and transactions have been eliminated in consolidation. We have a history of recurring net losses and negative cash flows and as of March 31, 2024, we had an accumulated deficit of $ 220.9 million. We believe our $ 82.9 million of cash and cash equivalents and $ 156.3 million of marketable investment securities as of March 31, 2024, and anticipated revenue from our test reports, will be sufficient to meet our cash requirements through at least the 12-month period following the date that these unaudited condensed consolidated financial statements were issued. Unaudited Interim Financial Information The accompanying condensed consolidated balance sheet as of March 31, 2024; the condensed consolidated statements of operations, the condensed consolidated statements of comprehensive loss and the condensed consolidated statements of stockholders’ equity, each for the three months ended March 31, 2024 and 2023; and the condensed consolidated statements of cash flows for the three months ended March 31, 2024 and 2023 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of our consolidated financial position as of March 31, 2024, the results of our consolidated operations for the three months ended March 31, 2024 and 2023 and our consolidated cash flows for the three months ended March 31, 2024 and 2023. The financial data and other information disclosed in these notes related to the three months ended March 31, 2024 and 2023 are also unaudited. The results for the three months ended March 31, 2024 are not necessarily indicative of results to be expected for the year ending December 31, 2024, any other interim periods, or any future year or period. The balance sheet as of December 31, 2023 included herein was derived from the audited financial statements as of that date. Certain disclosures have been condensed or omitted from the unaudited interim consolidated financial statements. These unaudited condensed consolidated financial statements should be read in conjunction with our audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2023 filed with the Securities and Exchange Commission (“SEC”) on February 28, 2024 (the "2023 Form 10-K"). Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Significant items subject to such estimates include revenue recognition, the valuation of stock-based compensation, assessing future tax exposure and the realizability of deferred tax assets, the useful lives and recoverability of long-lived assets, the goodwill impairment test, the valuation of acquired intangible assets and the valuation of contingent consideration and other contingent liabilities. We base these estimates on historical and anticipated results, trends, and various other assumptions that we believe are reasonable under the circumstances, including assumptions as to future events. These estimates form the basis for making judgments about the carrying values of assets and liabilities and recorded revenues and expenses that are not readily apparent from other sources. Actual results could differ from those estimates and assumptions. 7 Table of Contents CASTLE BIOSCIENCES, INC. NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Continued) (UNAUDITED) Cash and Cash Equivalents including Concentrations of Credit Risk Cash equivalents consist of short-term, highly liquid investments with original maturities of three months or less. Our cash equivalents consist of money market funds, which are not insured by the Federal Deposit Insurance Corporation (“FDIC”), that are primarily invested in short-term U.S. government obligations. Cash deposits at financial institutions may exceed the amount of insurance provided by the FDIC. Management believes that we are not exposed to significant credit risk on our cash deposits due to the financial position of the financial institutions in which deposits are held. Marketable Investment Securities All debt securities are recognized in accordance with Financial Accounting Standards Board (‘‘FASB’’) Accounting Standards Codification (‘‘ASC’’) Topic 320, Investments-Debt Securities (‘‘ASC 320’’). Management determines the appropriate classification of securities at the time of purchase and re-evaluates such determination at each balance sheet date. All debt securities are classified as available-for-sale and are recorded at fair value in accordance with ASC 320. We recognize the unrealized gains and losses related to changes in fair value as a separate component of accumulated other comprehensive loss within total stockholders’ equity, net of any related deferred income tax effects, on our condensed consolidated balance sheets. Premiums or discounts from par value are amortized to interest income over the life of the underlying investment. Realized gains and losses on available-for-sale securities are calculated at the individual security level and included in interest income in the condensed consolidated statements of operations. Impairments of available-for-sale debt securities, if any, are recorded in our unaudited condensed consolidated statements of operations. See Notes 5 and 10 for further details. Revenue Recognition In accordance with ASC Topic 606, Revenue from Contracts with Customers (“ASC 606”), we follow a five-step process to recognize revenues: (1) identify the contract with the customer, (2) identify the performance obligations, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations and (5) recognize revenues when the performance obligations are satisfied. We have determined that we have a contract with the patient when the treating clinician orders the test. Our contracts generally contain a single performance obligation, which is the delivery of the test report, and we satisfy our performance obligation at a point in time upon the delivery of the test report to the treating clinician, at which point we can bill for the report. The amount of revenue recognized reflects the amount of consideration to which we expect to be entitled, or the transaction price, and considers the effects of variable consideration. See Note 3 for further details. Accounts Receivable and Allowance for Credit Losses We classify accounts receivable balances that are expected to be paid more than one year from the consolidated balance sheet date as noncurrent assets. The estimated timing of payment utilized as a basis for classification as noncurrent is determined by analyses of historical payor-specific payment experience, adjusted for known factors that are expected to change the timing of future payments. We accrue an allowance for credit losses against our accounts receivable based on management’s current estimate of amounts that will not be collected. Management’s estimates are typically based on historical loss information adjusted for current conditions. We generally do not perform evaluations of customers’ financial condition and generally do not require collateral. Historically, our credit losses have not been significant given our application of the constraint to variable consideration. The allowance for credit losses was zero as of March 31, 2024 and December 31, 2023. Adjustments for implicit price concessions attributable to variable consideration, as discussed below, are incorporated into the measurement of the accounts receivable balances and are not part of the allowance for credit losses. Goodwill Goodwill represents the excess of the purchase price over the fair value of the net tangible and intangible assets acquired in a business combination. In accordance with ASC Topic 350, Intangibles—Goodwill and Other , our goodwill is not amortized but is tested for impairment on an annual basis or whenever events or changes in circumstances indicate that it may be impaired. We perform annual impairment reviews of our goodwill balance during the fourth quarter of each fiscal year. We may perform a qualitative assessment to determine if it is necessary to perform a quantitative impairment test. If we determine that a quantitative impairment test is necessary, we apply the guidance in Accounting Standards Update (“ASU”) No. 2017-04, Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment, by comparing the fair value of the reporting unit to 8 Table of Contents CASTLE BIOSCIENCES, INC. NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Continued) (UNAUDITED) its carrying value, including the goodwill. If the carrying value exceeds the fair value, we recognize an impairment loss for the amount by which the carrying value exceeds fair value, up to the total amount of goodwill allocated to the reporting unit. We did not incur any goodwill impairment losses in any of the periods presented. Factors that could result in a future impairment of goodwill include declines in the price of our common stock, increased competition, changes in macroeconomic developments, unfavorable government or regulatory developments and changes in coverage or reimbursement conditions. Accrued Compensation We accrue for liabilities under discretionary employee and executive bonus plans. Our estimated compensation liabilities are based on progress against corporate objectives approved by our board of directors, compensation levels of eligible individuals and target bonus percentage levels. Our board of directors reviews and evaluates the performance against these objectives and ultimately determines the actual achievement levels attained. We also accrue for liabilities under employee sales incentive bonus plans with accruals based on performance achieved to date compared to established targets. As of March 31, 2024 and December 31, 2023, we accrued approximately $ 6,574,000 and $ 21,706,000 , respectively, for liabilities associated with these bonus plans. These amounts are classified as current or noncurrent accrued liabilities in the unaudited condensed consolidated balance sheets based on the expected timing of payment. Stock-Based Compensation Stock-based compensation expense for equity instruments issued to employees is measured based on the grant-date fair value of the awards. The fair value of employee stock options and offerings under the 2019 Employee Stock Purchase Plan (the “ESPP”) are estimated on the date of grant using the Black-Scholes option-pricing valuation model. For restricted stock units (“RSUs”) and performance-based restricted stock units (“PSUs”), the fair value is equal to the closing price of our common stock on the date of grant. For awards with graded vesting and only service conditions, we recognize compensation costs on a straight-line basis over the requisite service period of the awards. For options and RSUs, the requisite service period is generally the award’s vesting period (typically four years ). PSUs vest upon the achievement of certain performance conditions and the provision of service with us through a specified period. Accruals of compensation cost for PSUs are based on the probable outcome of the performance conditions and are reassessed each reporting period. We recognize compensation cost for PSUs separately for each vesting tranche on a ratable basis over the requisite service period. The requisite service period for PSUs is based on an analysis of vesting requirements and performance conditions for the particular award. Certain employees are entitled to acceleration of vesting of a portion of their awards upon retirement, subject to age, service and notice requirements. In these cases, the requisite service period takes into consideration the employee’s retirement eligibility, and is reassessed at each reporting date. For the ESPP, the requisite service period is generally the period of time from the offering date to the purchase date. Forfeitures are accounted for as they occur. Comprehensive Loss Comprehensive loss is defined as a change in equity during a period from transactions and other events and circumstances from non-owner sources. Comprehensive loss is made up of net loss plus net unrealized gain (loss) on marketable investment securities, which is our only other item of other comprehensive income (loss). Accounting Pronouncements Yet to be Adopted In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740)—Improvements to Income Tax Disclosures ("ASU 2023-09"), which is intended to enhance the transparency and decision usefulness of income tax disclosures. The amendments in ASU 2023-09 provide for enhanced income tax information primarily through changes to the rate reconciliation and income taxes paid information. ASU 2023-09 is effective for the Company prospectively to all annual periods beginning after December 15, 2024. Early adoption is permitted. We are currently evaluating the impact this update will have on our consolidated financial statements and disclosures. In November 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280)—Improvements to Reportable Segment Disclosures (“ASU 2023-07”), which require public companies disclose significant segment expenses and other segment items on an annual and interim basis and to provide in interim periods all disclosures about a reportable segment’s profit or loss and assets that are currently required annually. The guidance is effective for public entities for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted. The guidance is applied retrospectively to all 9 Table of Contents CASTLE BIOSCIENCES, INC. NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Continued) (UNAUDITED) periods presented in the financial statements, unless it is impracticable. We are currently evaluating the impact this update will have on our consolidated financial statements and disclosures. We have evaluated all other recently issued, but not yet effective, accounting pronouncements and do not believe that these accounting pronouncements will have any material impact on our consolidated financial statements or disclosures upon adoption. 3. Revenue All of our revenues from contracts with customers are associated with the provision of testing services. Our revenues are primarily attributable to our DecisionDx ® -Melanoma test for cutaneous melanoma. We also provide a test for patients with cutaneous squamous cell carcinoma, DecisionDx ® -SCC, a test for use in patients with suspicious pigmented lesions, MyPath ® Melanoma, a test for uveal melanoma, DecisionDx ® -UM, a test for patients diagnosed with Barrett’s esophagus, the TissueCypher ® Barrett’s Esophagus Test and a pharmacogenomics testing service focused on mental health, IDgenetix ® . We previously offered a second test for patients with suspicious pigmented lesions, DiffDx ® -Melanoma, which we suspended in February 2023. Information on the disaggregation of revenues is included below. Once we satisfy our performance obligations and bill for the service, the timing of the collection of payments may vary based on the payment practices of the third-party payor and the existence of contractually established reimbursement rates. The payments for our services are primarily made by third-party payors, including Medicare and commercial health insurance carriers. Certain contracts contain a contractual commitment of a reimbursement rate that differs from our list prices. However, absent a positive coverage policy, with or without a contractually committed reimbursement rate, with a commercial carrier or governmental program, our diagnostic tests may or may not be paid by these entities. In addition, patients do not enter into direct agreements with us that commit them to pay any portion of the cost of the tests in the event that their insurance provider declines to reimburse us. We may pursue, on a case-by-case basis, reimbursement from such patients in the form of co-payments and co-insurance, in accordance with the contractual obligations that we have with the insurance carrier or health plan. These situations may result in a delay in the collection of payments. The Medicare claims that are covered by Medicare are generally paid at a rate established on Medicare’s Clinical Laboratory Fee Schedule or by the respective Medicare contractor within 30 days from receipt. Medicare claims that were either submitted to Medicare prior to the local coverage determination or other coverage commencement date or are not covered but meet the definition of being medically reasonable and necessary pursuant to the controlling Section 1862(a)(1)(A) of the Social Security Act are generally appealed and may ultimately be paid at the first (termed ‘‘redetermination’’), second (termed ‘‘reconsideration’’) or third level of appeal ( de novo hearing with an Administrative Law Judge). A successful appeal at any of these levels may result in prompt payment. In the absence of Medicare coverage, contractually established reimbursements rates or other coverage, we have concluded that our contracts include variable consideration because the amounts paid by Medicare or commercial health insurance carriers may be paid at less than our standard rates or not paid at all, with such differences considered implicit price concessions. Variable consideration attributable to these price concessions is measured at the expected value using the ‘‘most likely amount’’ method under ASC 606. The amounts are estimated using historical average collection rates by test type and payor category taking into consideration the range of possible outcomes, the predictive value of our past experiences, the time period of when uncertainties expect to be resolved and the amount of consideration that is susceptible to factors outside of our influence, such as the judgment and actions of third parties. Such variable consideration is included in the transaction price only to the extent it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainties with respect to the amount are resolved. Variable consideration may be constrained and excluded from the transaction price in situations where there is no contractually agreed upon reimbursement coverage or in the absence of a predictable pattern and history of collectability with a payor. Accordingly, in such situations revenues are recognized on the basis of actual cash collections. Variable consideration for Medicare claims that are not covered by Medicare, including those claims undergoing appeal, is deemed to be fully constrained due to factors outside our influence (e.g., judgment or actions of third parties) and the uncertainty of the amount to be received is not expected to be resolved for a long period of time. Variable consideration is evaluated each reporting period and adjustments are recorded as increases or decreases in revenues. Included in revenues for the three months ended March 31, 2024 and 2023 were $ 1,656,000 of net positive revenue adjustments and $ 1,336,000 of net negative revenue adjustments, respectively, associated with changes in estimated variable consideration related to performance obligations satisfied in previous periods. These amounts include (i) adjustments for actual 10 Table of Contents CASTLE BIOSCIENCES, INC. NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Continued) (UNAUDITED) collections versus estimated amounts and (ii) cash collections and the related recognition of revenue in current period for tests delivered in prior periods due to the release of the constraint on variable consideration. Because our contracts with customers have an expected duration of one year or less, we have elected the practical expedient in ASC 606 to not disclose information about our remaining performance obligations. Any incremental costs to obtain contracts are recorded as selling, general and administrative expenses as incurred due to the short duration of our contracts. Contract balances consisted solely of accounts receivable (both current and noncurrent) as of March 31, 2024 and December 31, 2023. Disaggregation of Revenues The table below provides the disaggregation of revenue by type (in thousands): Three Months Ended March 31, 2024 2023 Dermatologic (1) $ 59,334 $ 35,911 Non-Dermatologic (2) 13,640 6,126 Total net revenues $ 72,974 $ 42,037 (1) Consists of DecisionDx-Melanoma, DecisionDx-SCC and our Diagnostic Gene Expression Profile offering (MyPath Melanoma and DiffDx-Melanoma). (2) Consists of TissueCypher Barrett’s Esophagus Test, DecisionDx-UM and IDgenetix. Payor Concentration We rely upon reimbursements from third-party government payors (primarily Medicare) and private-payor insurance companies to collect accounts receivable related to sales of our tests. Our significant third-party payors and their related revenues as a percentage of total revenues and accounts receivable balances are as follows: Percentage of Revenues Three Months Ended March 31, Percentage of Accounts Receivable (current) as of Percentage of Accounts Receivable (noncurrent) as of 2024 2023 March 31, 2024 December 31, 2023 March 31, 2024 December 31, 2023 Medicare 49 % 49 % 20 % 20 % * * Payor A 14 % 15 % 21 % 19 % 15 % 15 % Payor B * * * 10 % 11 % 11 % * Less than 10% There were no other third-party payors that individually accounted for more than 10% of our total revenue or accounts receivable for the periods shown in the table above. 4. Loss Per Share Basic loss per share is computed by dividing net loss for the period by the weighted-average number of common shares outstanding during the period. Diluted loss per share reflects the additional dilution from potential issuances of common stock, such as stock issuable pursuant to the exercise of stock options, vesting of RSUs and PSUs or purchases under the ESPP. The treasury stock method is used to calculate the potential dilutive effect of these common stock equivalents. Contingently issuable PSU awards are included in the computation of diluted loss per share when the applicable performance criteria would be met and the common shares would be issuable if the end of the reporting period were the end of the contingency period. However, potentially dilutive shares are excluded from the computation of diluted loss per share when their effect is antidilutive. 11 Table of Contents CASTLE BIOSCIENCES, INC. NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Continued) (UNAUDITED) Because we reported a net loss for all periods presented, all potentially dilutive securities are antidilutive and are excluded from the computation of diluted loss per share for such periods. The table below provides the weighted-average number of potential common shares associated with outstanding securities not included in our calculation of diluted loss per share for the three months ended March 31, 2024 and 2023 because to do so would be antidilutive or, in the case of PSUs, the applicable performance conditions have not yet been met (in thousands): Three Months Ended March 31, 2024 2023 Stock options 3,192 3,389 RSUs and PSUs 3,131 3,420 ESPP 333 279 Total 6,656 7,088 In addition, in connection with our acquisition of AltheaDx, Inc. (“AltheaDx”) in April 2022, we may be required to issue shares of our common stock to satisfy the contingent consideration obligations, pending the outcome of certain commercial and regulatory milestones, as required by the definitive agreement to acquire AltheaDx. For purposes of calculating diluted loss per share, no such shares were assumed to have been issued because none of the applicable conditions have been met to date. See Note 10 for additional information. 5. Marketable Investment Securities The following tables present our available-for-sale debt securities (in thousands): March 31, 2024 Amortized Cost Unrealized Estimated Fair Value Gains Losses U.S. government securities $ 156,374 $ 15 $ ( 125 ) $ 156,264 Total $ 156,374 $ 15 $ ( 125 ) $ 156,264 December 31, 2023 Amortized Cost Unrealized Estimated Fair Value Gains Losses U.S. government securities $ 144,122 $ 143 $ ( 7 ) $ 144,258 Total $ 144,122 $ 143 $ ( 7 ) $ 144,258 Although available to be sold to meet operating needs or otherwise, securities are generally held through maturity. We classify all investments as current assets, as these are readily available for use in current operations. The cost of securities sold is determined based on the specific identification method for purposes of recording gains and losses. There were no realized gains or losses on sales of investments for the three months ended March 31, 2024 and 2023. We evaluated our investment portfolio under the available-for-sale debt securities impairment model guidance and determined our investment portfolio is comprised of low-risk, investment grade securities. As of March 31, 2024, unrealized losses on our available-for-sale investments are not attributed to credit risk. We believe that an allowance for credit losses is unnecessary because the unrealized losses on certain of our marketable investment securities are due to market factors. No credit-related or noncredit-related impairment losses were recorded for the three months ended March 31, 2024 and 2023. The allowance for credit losses was zero as of March 31, 2024 and December 31, 2023. 12 Table of Contents CASTLE BIOSCIENCES, INC. NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Continued) (UNAUDITED) As of March 31, 2024, all of our available-for-sale debt securities had contractual maturities of one year or less. Accrued interest receivable is included in prepaid expenses and other current assets in our unaudited condensed consolidated balance sheets. As of March 31, 2024 and December 31, 2023, the accrued interest receivable balance was immaterial. Additional information relating to the fair value of marketable investment securities can be found in Note 10. 6. Property and Equipment, Net Property and equipment, net consisted of the following (in thousands): March 31, 2024 December 31, 2023 Land (1) $ 7,245 $ — Lab equipment (2) 16,651 16,472 Leasehold improvements 10,127 9,990 Computer equipment 4,264 4,060 Furniture and fixtures 2,484 2,385 Construction-in-progress 1,320 637 Total 42,091 33,544 Less accumulated depreciation (2) ( 9,187 ) ( 8,111 ) Property and equipment, net $ 32,904 $ 25,433 (1) On February 9, 2024, we purchased approximately 23 acres of land in Friendswood, Texas for purpose of developing a commercial office building to be used as our future corporate headquarters. (2) As of March 31, 2024 and December 31, 2023, includes lab equipment under finance lease of $ 369 thousand and accumulated depreciation of $ 313 thousand and $ 278 thousand, respectively. Depreciation expense was recorded in the unaudited condensed consolidated statements of operations as follows (in thousands): Three Months Ended March 31, 2024 2023 Cost of sales (exclusive of amortization of acquired intangible assets) $ 655 $ 295 Research and development 84 79 Selling, general and administrative 354 296 Total $ 1,093 $ 670 7. Goodwill and Other Intangible Assets, Net Goodwill The balance of our goodwill was $ 10.7 million as of March 31, 2024 and December 31, 2023. There were no accumulated impairments of goodwill as of March 31, 2024 or December 31, 2023. 13 Table of Contents CASTLE BIOSCIENCES, INC. NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Continued) (UNAUDITED) Other Intangible Assets, Net Our other intangible assets, net consist of the following (in thousands): March 31, 2024 Gross carrying value Accumulated amortization Net Weighted-Average Remaining Life (in years) Developed technology $ 125,317 $ ( 21,222 ) $ 104,095 11.9 Assembled workforce 563 ( 262 ) 301 2.7 Total other intangible assets, net $ 125,880 $ ( 21,484 ) $ 104,396 December 31, 2023 Gross carrying value Accumulated amortization Net Weighted-Average Remaining Life (in years) Developed technology $ 125,317 $ ( 19,003 ) $ 106,314 12.2 Assembled workforce 563 ( 234 ) 329 2.9 Total other intangible assets, net $ 125,880 $ ( 19,237 ) $ 106,643 Amortization expense of intangible assets was $ 2.2 million for the three months ended March 31, 2024 and the three months ended March 31, 2023 . 8. Other Accrued and Current Liabilities Other accrued and current liabilities consisted of the following (in thousands): March 31, 2024 December 31, 2023 Accrued service fees $ 3,358 $ 2,097 Clinical studies 2,344 3,475 ESPP contributions 276 896 Other 766 849 Total $ 6,744 $ 7,317 9. Long-Term Debt We had no debt as of December 31, 2023. Our long-term debt as of March 31, 2024 is presented in the table below (in thousands): March 31, 2024 Term debt $ 10,200 Unamortized discount ( 200 ) Total long-term debt 10,000 Less: Current portion of long-term debt — Total $ 10,000 14 Table of Contents CASTLE BIOSCIENCES, INC. NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Continued) (UNAUDITED) Future maturities of principal amounts on long-term debt as of March 31, 2024 are as follows (in thousands): Years Ending December 31, 2024 $ — 2025 278 2026 3,333 2027 3,333 2028 3,056 Total $ 10,000 2024 Loan and Security Agreement On March 26, 2024 (the ‘‘Closing Date’’), we entered into a Loan and Security Agreement (the ‘‘2024 LSA”), by and between us, our wholly owned subsidiary, Castle Narnia Real Estate Holding 1, LLC and Silicon Valley Bank, a division of First-Citizens Bank & Trust Company (the “Lender’’). The 2024 LSA provides for (i) on the Closing Date, $ 10.0 million aggregate principal amount of term loans (discussed in the ‘‘2024 Term Loan’’ section below), and (ii) from the Closing Date until March 31, 2025, an additional line of credit of $ 25.0 million with the same interest rate and maturity as the term debt available (discussed in the ‘‘2024 Credit Line’’ section below) at our option. The obligations under the 2024 LSA are secured by substantially all of our assets, excluding intellectual property, the real property held by us, and are subject to certain other exceptions and limitations. We have the right to prepay the 2024 LSA in whole, subject to a prepayment fee of approximately 1.50 % if prepaid prior to March 26, 2026. Amounts repaid under the 2024 LSA may not be reborrowed. In addition, the 2024 LSA contains customary conditions of borrowing, events of default and covenants, including covenants that restrict our ability to dispose of assets, merge with or acquire other entities, incur indebtedness and make distributions to holders of our capital stock. Should an event of default occur, including the occurrence of a material adverse change, we could be liable for immediate repayment of all obligations under the 2024 LSA. Should we seek to amend the terms of the 2024 LSA, the consent of the Lender would be required. As of March 31, 2024, we were in compliance with this covenant. The 2024 LSA bears interest at a floating rate equal to the greater of (a) the WSJ Prime Rate plus 0.25 % or (b) 6.00 % per annum. The Term Loans are interest only from the Closing Date through November 30, 2025, which may be extended at our option through November 30, 2026 as long as no event of default under the 2024 LSA has occurred. After the end of the interest only period, we are required to pay equal monthly installments of principal through the maturity date of November 1, 2028. We are also obligated to make an additional final payment of 2.00 % of the aggregate original principal amounts of Term Loans advanced by the Lender, due at the earlier of the maturity date or date the Term Loans are repaid in full. 2024 Term Loan On March 26, 2024, we drew $ 10.0 million in Term Loans under the terms and provisions of the 2024 LSA. We are obligated to make a final payment of $ 200,000 under the terms of the 2024 LSA final payment provisions. A discount on debt equal to this obligation was recorded on the draw date and is being amortized as additional interest expense using the effective interest method over the term of the debt. As of March 31, 2024, the effective interest rate for all outstanding debt under the 2024 Term Loan was 9.03 %. 2024 Credit Line We have a $ 25.0 million line of credit under the terms and provisions of the 2024 LSA available from the Closing Date until March 31, 2025. Amounts repaid under the 2024 Credit Line may not be reborrowed. As of March 31, 2024, no draws had been made on the line of credit. Interest Expense on Long-Term Debt During the three months ended March 31, 2024, we recorded interest expense of $ 12,000 on long-term debt. During the three months ended March 31, 2023, no long-term debt was outstanding and no interest expense incurred. 15 Table of Contents CASTLE BIOSCIENCES, INC. NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Continued) (UNAUDITED) 10. Fair Value Measurements Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market in an orderly transaction between market participants at the measurement date. The fair value hierarchy prioritizes the inputs to valuation techniques used in measuring fair value. There are three levels to the fair value hierarchy based on the reliability of inputs, as follows: Level 1 – Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets. Level 2 – Inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. Level 3 – Unobservable inputs in which little or no market data exists, therefore requiring us to develop our own assumptions. Financial instruments measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the asset or liability. The use of different assumptions and/or estimation methodologies may have a material effect on estimated fair values. Accordingly, the fair value estimates disclosed, or amounts recorded, may not be indicative of the amount that we or holders of the instruments could realize in a current market exchange. The table below provides information, by level within the fair value hierarchy, of our financial assets and liabilities that are accounted for at fair value on a recurring basis as of March 31, 2024 and December 31, 2023 (in thousands): As of March 31, 2024 Quoted Prices in Active Markets for Identical Items (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Assets Money market funds (1) $ 72,141 $ — $ — $ 72,141 U.S. government securities (2) $ 156,264 $ — $ — $ 156,264 Liabilities Contingent consideration (3) $ — $ — $ — $ — As of December 31, 2023 Quoted Prices in Active Markets for Identical Items (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Assets Money market funds (1) $ 89,308 $ — $ — $ 89,308 U.S. government securities (2) $ 144,258 $ — $ — $ 144,258 Liabilities Contingent consideration (3) $ — $ — $ — $ — (1) Classified as “Cash and cash equivalents” in the unaudited condensed consolidated balance sheets. (2) Classified as “Marketable investment securities” in the unaudited condensed consolidated balance sheets. (3) Current portion, if any, classified as “Other accrued and current liabilities” in the unaudited condensed consolidated balance sheets. 16 Table of Contents CASTLE BIOSCIENCES, INC. NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Continued) (UNAUDITED) Contingent Consideration In connection with our acquisition of AltheaDx, we agreed to pay contingent consideration of up to $ 75.0 million of commercial milestone payments based on the achievement of certain net revenue targets relating to the years ending December 31, 2022, 2023 and 2024 (“AltheaDx Earnout Payments”). The portion of the AltheaDx Earnout Payments associated with the commercial milestones for the year ended December 31, 2023 was $ 37.5 million and was not paid since the applicable commercial milestones were not met. The AltheaDx Earnout Payments included a 2022 catch-up provision for additional payment of up to $ 17.5 million that expired in 2023. Therefore, as of March 31, 2024, we have a potential payment obligation of up to $ 20.0 million with respect to the remaining commercial milestones for 2024. If the settlement of the remaining portion of the AltheaDx Earnout Payments would have occurred on March 31, 2024, no amounts would have been due because no commercial milestones had been achieved as of such date. The contingent consideration was classified as a Level 3 fair value measurement due to the use of significant unobservable inputs and a Monte Carlo simulation to determine its fair value. The Monte Carlo simulation uses projections of the commercial milestones for the applicable period as well as the corresponding targets and approximate timing of payment based on the terms of the arrangement. The valuation of the AltheaDx contingent consideration was zero as of March 31, 2024 and December 31, 2023, and no gains or losses were recorded associated with changes in fair value during the three months ended March 31, 2024 and 2023. The contingent consideration liability is remeasured at fair value at each reporting period taking into account any updated assumptions or changes in circumstances. Any changes in the fair value are recorded as gains or losses in our unaudited condensed consolidated statement of operations. 11. Commitments and Contingencies From time to time, we may be involved in legal proceedings arising in the ordinary course of business. We believe there is no threatened litigation or litigation pending that could have, individually or in the aggregate, a material adverse effect on our financial position, results of operations or cash flows. On February 1, 2024, we received a Subpoena from the Department of Health and Human Services, Office of Inspector General, seeking documents and information concerning claims submitted for payment under federal healthcare programs. The Subpoena requested that we produce documents relating primarily to interactions with medical providers and billing to government-funded healthcare programs for our tests. The time period covered by the Subpoena is January 1, 2015 through February 1, 2024. We are continuing to cooperate with the government’s request and are in the process of responding to the Subpoena. We are unable to predict what action, if any, might be taken in the future by the Department of Health and Human Services, Office of Inspector General, or any other governmental authority as a result of the matters related to this Subpoena. No claims have been made against us at this time. This inquiry, and any potential resulting claim asserted against us, with or without merit, could be time-consuming, expensive to address and divert management’s attention and other resources. These claims also could subject us to significant liability for damages and harm our reputation. Our insurance and indemnities may not cover all claims that may be asserted against us. We are unable to predict the outcome and are unable to make a meaningful estimate of the amount or range of loss, if any, that could result from any unfavorable outcome. 12. Stock Incentive Plans and Stock-Based Compensation Stock Incentive Plans Effective January 1, 2024, an additional 1,370,526 shares became available under our 2019 Equity Incentive Plan (the “2019 Plan”) pursuant to an automatic annual increase. The 2019 Plan provides for automatic annual increases to the number of shares authorized for issuance, equal to 5 % of our common shares outstanding as of the immediately preceding year end, through January 1, 2029. As of March 31, 2024, 386,932 shares remained available for grant under the 2019 Plan. On December 22, 2022, our board of directors approved the 2022 Inducement Plan (the “Inducement Plan”). Our Inducement Plan provides for the grant of RSU awards and other stock awards made as an inducement material to the grantee’s entering into employment with us to the extent such grantee was not previously an employee of ours or is entering into employment following a bona fide period of non-employment with us. As of March 31, 2024, there were 414,842 shares available for grant under the Inducement Plan. 17 Table of Contents CASTLE BIOSCIENCES, INC. NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Continued) (UNAUDITED) Stock Options Stock option activity under our stock plans for the three months ended March 31, 2024 is set forth below: Weighted-Average Stock Options Outstanding Exercise Price Remaining Contractual Term (Years) Aggregate Intrinsic Value (in thousands) Balance as of December 31, 2023 3,208,979 $ 35.38 Granted — $ — Exercised ( 19,066 ) $ 3.40 Forfeited/Cancelled ( 17,783 ) $ 42.09 Balance as of March 31, 2024 3,172,130 $ 35.54 6.3 $ 9,814 Exercisable at March 31, 2024 2,703,995 $ 33.70 6.1 $ 9,764 Restricted Stock Units RSUs represent the right to receive shares of our common stock at a specified future date, subject to vesting. Our RSUs generally vest annually from the grant date in four equal installments subject to the holder’s continued service with us. We issue new shares of common stock upon the vesting of RSUs. The following table summarizes our RSU activity for the three months ended March 31, 2024: Restricted Stock Units Outstanding Weighted-Average Grant Date Fair Value Balance as of December 31, 2023 2,805,075 $ 25.48 Granted 1,240,265 $ 21.16 Vested (1) ( 67,486 ) $ 29.74 Forfeited/Cancelled ( 39,547 ) $ 21.80 Balance as of March 31, 2024 3,938,307 $ 24.08 (1) The aggregate number of shares withheld upon vesting for employee tax obligations was 22,656 for the three months ended March 31, 2024. Performance-Based Restricted Stock Units PSUs represent the right to receive shares of our common stock contingent upon the achievement of certain financial performance measures. We issue new shares of common stock upon the vesting of PSUs. The following table summarizes our PSU activity for the three months ended March 31, 2024: Performance-Based Restricted Stock Units Outstanding Weighted-Average Grant Date Fair Value Balance as of December 31, 2023 196,033 $ 23.23 Granted 177,513 $ 21.23 Vested — $ — Forfeited/Cancelled — $ — Balance as of March 31, 2024 373,546 $ 22.28 18 Table of Contents CASTLE BIOSCIENCES, INC. NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Continued) (UNAUDITED) Retirement Policy In January 2023, our board of directors approved a retirement policy (the “Retirement Policy”) that provides for acceleration of a portion of unvested awards that were granted to certain eligible employees upon meeting age, service and notice requirements. We considered the adoption of the Retirement Policy to be a modification of existing awards under ASC Topic 718 , Compensation – Stock Compensation . The modification did not result in any incremental compensation cost. However, the adoption of the of the policy resulted in a new estimate of the requisite service period for certain awards, which we reassess at each balance sheet date. In connection with the Retirement Policy, we accelerated the recognition of compensation expense of $ 0.2 million and $ 0.7 million during the three months ended March 31, 2024 and 2023, respectively. Employee Stock Purchase Plan The ESPP provides for certain automatic increases in the number of shares of common stock reserved for issuance, which resulted in an additional 274,105 shares becoming available under the ESPP effective January 1, 2024. During the three months ended March 31, 2024, we issued 111,241 shares of common stock pursuant to scheduled purchases under the ESPP. As of March 31, 2024, 1,103,127 shares remained available for issuance under the ESPP. Determining Fair Value - Summary of Assumptions We use the Black-Scholes option pricing model to estimate the fair value of each option grant on the date of grant or any other measurement date. The following table sets forth the assumptions used to determine the fair value of stock options: Three Months Ended March 31, 2024 2023 Average expected term (years) 5.0 5.8 Expected stock price volatility 75.57 % - 76.01 % 68.34 % - 76.01 % Risk-free interest rate 3.57 % - 3.57 % 1.54 % - 4.21 % Dividend yield — % — % The following table sets forth assumptions used to determine the fair value of the purchase rights issued under the ESPP: Three Months Ended March 31, 2024 2023 Average expected term (years) 1.3 1.3 Expected stock price volatility 72.04 % - 130.95 % 72.80 % - 82.61 % Risk-free interest rate 4.43 % - 5.33 % 4.77 % - 5.07 % Dividend yield — % — % We use the closing price of our common stock on the date of grant to determine the fair value of RSUs and PSUs. 19 Table of Contents CASTLE BIOSCIENCES, INC. NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (Continued) (UNAUDITED) Stock-Based Compensation Expense Stock-based compensation expense is included in the unaudited condensed consolidated statements of operations as follows (in thousands): Three Months Ended March 31, 2024 2023 Cost of sales (exclusive of amortization of acquired intangible assets) $ 1,314 $ 1,272 Research and development 2,629 2,587 Selling, general and administrative 8,732 9,666 Total stock-based compensation expense $ 12,675 $ 13,525 For the three months ended March 31, 2023, the weighted-average grant date fair value of stock options granted was $ 17.39 per option. There were no stock options granted for the same period in 2024. For the three months ended March 31, 2024 and 2023, the weighted-average grant date fair value of the purchase rights granted under the ESPP was $ 11.17 and $ 11.00 per share, respectively. As of March 31, 2024, the total unrecognized stock-based compensation cost related to outstanding awards was $ 103,100,000 , which is expected to be recognized over a weighted-average period of 2.5 years. The total unrecognized compensation cost will be adjusted for forfeitures in future periods as they occur. 13. Income Taxes Our effective income tax rate was 11.0 % for the three months ended March 31, 2024, and was immaterial for the three months ended March 31, 2023. The effective rate for the the three months ended March 31, 2024 differed from our federal statutory rate of 21% primarily due to t he tax impact from the valuation allowance for current year activity, state income taxes and the non-deductibility of other permanent items. 20 Table of Contents