Summary of Significant Accounting Policies	9 Months Ended
Sep. 30, 2022
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	Note 2. Summary of Significant Accounting Policies Basis of Presentation The unaudited interim condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All material intercompany balances and transactions have been eliminated in consolidation. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and the instructions to Form 10-Q. Accordingly, certain information and footnote disclosures normally included in consolidated financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. In the opinion of management, all adjustments, consisting of normal recurring adjustments, and disclosures considered necessary for a fair presentation of interim period results have been included. Interim results for the nine months ended September 30, 2022 are not necessarily indicative of results that may be expected for the year ending December 31, 2022. For further information, refer to the consolidated financial statements and footnotes thereto included in the Company’s 2021 Form 10-K. Use of Estimates The preparation of the Company’s unaudited condensed consolidated financial statements in conformity with GAAP requires the Company 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 unaudited condensed consolidated financial statements and reported amounts of revenues and expenses during the reporting period. The Company bases its estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances and are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ from these estimates. Estimates that are critical to the accompanying unaudited condensed consolidated financial statements include the estimated fair value of the net assets acquired in connection with the Acquisition of Aceragen, the estimated fair value of the liability classified warrants issued to Aceragen warrant holders and accrued clinical trial expenses. Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of 90 days or less when purchased to be cash equivalents. Cash and cash equivalents at September 30, 2022 and December 31, 2021 consisted of cash and money market funds. Financial Instruments At September 30, 2022 and December 31, 2021, the Company’s financial instruments included accounts payable, accrued expenses, stockholder notes and debt. The carrying amount of cash and cash equivalents, accounts receivable, accounts payable and accrued expenses approximates fair value due to the short-term maturities of these instruments. Each of the carrying values of the preferred stock warrant liabilities and Series X preferred stock liability issued to Aceragen stockholders and the acquisition obligation assumed in connection with the Acquisition of Aceragen are recorded at their estimated fair values. As of September 30, 2022, the Company did not have any derivatives, hedging instruments or other similar financial instruments. Accounts Receivable Accounts receivables are recorded net of an estimated expected credit losses. The Company’s measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. To date, there have been no expected credit losses as the Company’s customer is the U.S. government. Unbilled accounts receivable at September 30, 2022 which is included in accounts receivables is $1.1 million and relates to revenue recognized for work that has been performed but the invoicing has not yet occurred. Foreign Currency Upon completion of the Acquisition of Aceragen in September 2022, the Company has a wholly-owned subsidiary in Switzerland and the functional currency is the Swiss Franc. The results of the Company’s non-US dollar based functional currency operations are translated to US dollars at the average exchange rates during the period. Assets and liabilities are translated at the exchange rate prevailing at the balance sheet date. Equity is translated at the prevailing exchange rate at the date of the equity transaction. Translation adjustments are included in stockholders' equity, as a component of accumulated other comprehensive income. The Company realizes foreign currency transaction gains (losses) in the normal course of business based on movements in the applicable exchange rates. These gains (losses) are included as a component of other (expense) income, net. Business Combinations The Company evaluates acquisitions of assets and other similar transactions to assess whether or not the transaction should be accounted for as a business combination or asset acquisition by first applying a screen to determine if substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets. If the screen is met, the transaction is accounted for as an asset acquisition. If the screen is not met, further determination is required as to whether or not the Company has acquired inputs and processes that have the ability to create outputs, which would meet the requirements of a business. If determined to be a business combination, the Company accounts for the transaction under the acquisition method of accounting as indicated in Accounting Standard Update (“ASU”) 2017-01, Business Combinations, which requires the acquiring entity in a business combination to recognize the fair value of all assets acquired, liabilities assumed, and any non-controlling interest in the acquiree and establishes the acquisition date as the fair value measurement point. Accordingly, the Company recognizes assets acquired and liabilities assumed in business combinations based on the fair value estimates as of the date of acquisition. In accordance with ASC 805, Business Combinations, the Company recognizes and measures goodwill as of the acquisition date, as the excess of the fair value of the consideration paid over the fair value of the identified net assets acquired. Goodwill Goodwill represents the amount of consideration paid in excess of the fair value of net assets acquired as a result of the Company’s business acquisitions accounted for using the acquisition method of accounting. The intangible assets acquired represented the fair value of in-process research and development (IPR&D) which has been recorded on the accompanying condensed consolidated balance sheet as indefinite-lived intangible assets. A deferred tax liability was recorded for the difference between the fair value of the acquired IPR&D and its tax basis which was recognized as goodwill in applying the purchase method of accounting. Goodwill is not amortized and is subject to impairment testing at a reporting unit level on an annual basis or when a triggering event occurs that may indicate the carrying value of the goodwill is impaired. An entity is permitted to first assess qualitative factors to determine if a quantitative impairment test is necessary. Further testing is only required if the entity determines, based on the qualitative assessment, that it is more likely than not that the fair value of the reporting unit is less than its carrying amount. We evaluate goodwill for impairment at least annually on October 1 and whenever facts and circumstances indicate that their carrying amounts may not be recoverable. For the nine months ended September 30, 2022, the Company determined that there was no impairment to goodwill. Indefinite-Lived Intangible Assets Indefinite-lived intangible assets consist of In-Process Research and Development(“IPR&D”). The fair values of IPR&D project assets acquired in business combinations are capitalized. The Company generally utilizes the Multi-Period Excess Earning Method to determine the estimated fair value of the IPR&D assets acquired in a business combination. The projections used in this valuation approach are based on many factors, such as relevant market size and share, probabilities of success, anticipated patent protection, and expected pricing. The estimated future net cash flows are then discounted to the present value using an appropriate discount rate. These assets are treated as indefinite-lived intangible assets until completion or abandonment of the projects, at which time the assets are amortized over the remaining useful life or written off, as appropriate. Intangible assets with indefinite lives, including IPR&D, are tested for impairment if impairment indicators arise and, at a minimum, annually. However, an entity is permitted to first assess qualitative factors to determine if a quantitative impairment test is necessary. Further testing is only required if the entity determines, based on the qualitative assessment, that it is more likely than not that an indefinite-lived intangible asset’s fair value is less than its carrying amount. Otherwise, no further impairment testing is required. The indefinite-lived intangible asset impairment test consists of a one-step analysis that compares the fair value of the intangible asset with its carrying amount. If the carrying amount of an intangible asset exceeds its fair value, an impairment loss is recognized in an amount equal to that excess. We consider many factors in evaluating whether the value of our intangible assets with indefinite lives may not be recoverable, including, but not limited to, expected growth rates, the cost of equity and debt capital, general economic conditions, our outlook and market performance of our industry and recent and forecasted financial performance. We evaluate indefinite-lived intangible assets for impairment at least annually on October 1 and whenever facts and circumstances indicate that their carrying amounts may not be recoverable. For the nine months ended September 30, 2022, the Company determined that there was no impairment to IPR&D. Concentration of Credit Risk Financial instruments that subject the Company to credit risk primarily consist of cash and cash equivalents. The Company’s credit risk is managed by investing in highly rated money market instruments, U.S. treasury bills, corporate bonds, commercial paper and/or other debt securities. Due to these factors, no significant additional credit risk is believed by management to be inherent in the Company’s assets. As of September 30, 2022, all the Company’s cash and cash equivalents were held at five high credit-quality financial institutions. Operating Lease Right-of-Use Assets and Lease Liability The Company accounts for leases under ASC 842, Leases. Operating leases are included in “Operating lease right-of-use assets” within the Company’s consolidated balance sheets and represent the Company’s right to use an underlying asset for the lease term. The Company’s related obligation to make lease payments are included in “Operating lease liability” and “Operating lease liability, net of current portion” within the Company’s consolidated balance sheets. Operating lease right-of-use (“ROU”) assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rates, which are the rates incurred to borrow on a collateralized basis over a similar term, an amount equal to the lease payments in a similar economic environment. Lease expense for lease payments is recognized on a straight-line basis over the lease term. The ROU assets are tested for impairment according to ASC 360, Property, Plant, and Equipment. Leases with an initial term of 12 months or less are not recorded on the balance sheet and are recognized as lease expense on a straight-line basis over the lease term. As of September 30, 2022 and December 31, 2021, the Company’s operating lease ROU assets and corresponding short-term and long-term lease liabilities primarily relate to its existing Exton, PA facility operating lease which expires on May 31, 2025. In connection with the Aceragen Acquisition, as defined and described in Note 4, the Company acquired an operating lease for an office in Basel, Switzerland which expires on March 31, 2023. Acquisition-Related Costs Acquisition-related costs include direct expenses incurred in connection with the Acquisition of Aceragen as well as integration-related professional fees and other incremental costs directly associated to the acquisition. Restructuring and Other Charges The Company accounts for exit or disposal activities in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 420, Exit or Disposal Cost Obligations (“ASC 420”). A business restructuring is defined as an exit or disposal activity that includes, but is not limited to, a program that is planned and controlled by management and materially changes either the scope of a business or the manner in which that business is conducted. Business restructuring charges include (i) one-time termination benefits related to employee separations (i.e. severance costs), (ii) contract termination costs, and (iii) other related costs associated with exit or disposal activities. In the third quarter of 2022, the Company implemented a restructuring plan to streamline the organization, reduce costs, and direct resources to advance the Company’s primary operating goals. The Company recognizes and measures a liability for one-time termination benefits, for which no future service is required, once the plan of termination meets all of the following criteria for an established communication date: (i) management commits to a plan of termination, (ii) the plan identifies the number of employees to be terminated and their job classifications or functions, locations and the expected completion date, (iii) the plan establishes the terms of the benefit arrangement, and (iv) it is unlikely that significant changes to the plan will be made or the plan will be withdrawn. For one-time termination benefits for which future service is required, a liability is measured at the communication date based on its value as of the termination date and recognized ratably over the future service period. The Company recognizes and measures a liability for other related costs in the period in which the liability is incurred. Series X Preferred Stock Liability In conjunction with the Acquisition of Aceragen, the Company evaluated the newly issued Series X preferred stock and determined its revised terms represents a sale of future revenues and is classified as a liability under ASC 470, Debt and the Company has elected to account for the Series X preferred stock liability under the fair value option. The fair value of the Series X preferred stock liability represents the present value of estimated future payments, including royalty payments, as well as estimated payments that are contingent upon the achievement of specified milestones. The fair value of the Series X preferred stock liability is based on the cumulative probability of the various estimated payments. The fair value measurement is based on significant Level 3 unobservable inputs such as the probability of achieving the milestones, anticipated timelines, probability and timing of an early redemption of all obligations under Series X preferred liability and the discount rate. Any changes in the fair value of the liability in each reporting period are recognized in the consolidated statement of operations until it is settled. Warrant Liability In connection with the Aceragen Acquisition, a portion of the consideration paid to Aceragen warrant holders was in the form of warrants to purchase shares of Series Z (the “Series Z warrants”). The Series Z warrants were classified as a liability on the condensed consolidated balance sheet at September 30, 2022 because the underlying Series Z are contingently redeemable. The fair value of the Series Z warrants on the date of issuance was recorded as a component to the carrying value of the shares Series Z and as a long-term liability in the condensed consolidated balance sheet. The warrants are remeasured to fair value at each balance sheet date until the warrants are exercised, reclassified, expire or otherwise settled. Changes in the fair values of the Series Z warrants are recognized as other income or expense in the consolidated statements of operations and comprehensive loss. The Company used the Black-Scholes option pricing model, which incorporated assumptions and estimates, to value the Series Z warrants. Estimates and assumptions impacting the fair value measurement of the Series Z warrants included the remaining contractual term of the warrants, risk-free interest rate, expected dividend yield and expected volatility of the price of the underlying shares of Series Z. The estimated the expected stock volatility based on the Company’s historical volatility for a term equal to the remaining contractual term of the warrants at the time of issuance and again at the remeasurement date. The risk-free interest rate was determined by reference to the US Treasury yield curve for time periods approximately equal to the remaining contractual term of the warrants. Expected dividend yield was determined based on the fact that the Company had never paid cash dividends and did not expect to pay any cash dividends in the foreseeable future. Redeemable Preferred Stock The Company applies ASC 480 when determining the classification and measurement of its preferred stock. Preferred shares subject to mandatory redemption are classified as liability instruments and are measured at fair value. Conditionally redeemable preferred shares (including preferred shares that feature redemption rights that are either within the control of the holder or subject to redemption upon the occurrence of uncertain events not solely within the Company’s control) are classified as temporary equity. At all other times, preferred shares are classified as stockholders’ equity. The carrying value of the shares of Series Z is accreted to redemption value using the estimated fair value of the redemption value at each reporting period until the redeemable convertible preferred stock cease to be outstanding or the redemption right has expired. The accretion for the three and nine months ended September 30, 2022 was immaterial. Revenue Recognition The Company recognizes revenue when the Company's customers obtain control of promised goods or services, in an amount that reflects the consideration which the Company expects to receive in exchange for those goods or services by analyzing the following five steps: (i) identify the contract with a customer(s); (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. Revenues from reimbursable contracts are recognized as costs are incurred, generally based on allowable direct costs incurred during the period, plus allocable overheads together with any recognizable earned fee. The Company uses this input method to measure progress as the customer has access to the development research under these projects and benefits incrementally as R&D activities occur. Income Taxes In accordance with ASC 270, Interim Reporting, and ASC 740, Income Taxes, the Company is required at the end of each interim period to determine the best estimate of its annual effective tax rate and then apply that rate in providing for income taxes on a current year-to-date (interim period) basis. At September 30, 2022, the Company evaluated the realizability of its deferred tax assets and determined that the valuation allowance should be decreased by approximately $6.0 million in consideration of positive and negative evidence bearing upon its ability to realize certain of its deferred tax assets. Such is reflected as an income tax benefit for the three and nine months ended September 30, 2022 in the condensed consolidated statement of operations. As of September 30, 2022 and December 31, 2021, the Company had no uncertain tax positions. As a result of the Aceragen Acquisition, the Company will have a significant change in ownership. In general, if the Company experiences a greater than 50% aggregate change in ownership of certain significant stockholders over a three-year period (a “Section 382 ownership change”), utilization of its pre-change net operating loss and credit carryforwards is subject to an annual limitation under Section 382 of the Internal Revenue Code of 1986, as amended (the “Code”) (and similar state laws). The annual limitation generally is determined by multiplying the value of the Company’s stock at the time of such Section 382 ownership change (subject to certain adjustments) by the applicable long-term tax-exempt rate. Such limitations may result in expiration of a portion of the net operating loss and credit carryforwards before utilization and may be substantial. The ability of the Company to use its net operating loss and credit carryforwards may be limited or lost if the Company experiences a Section 382 ownership change in connection with offerings or as a result of future changes in its stock ownership. Losses from a specific period may be subject to multiple limitations and would generally be limited by the lowest of those limitations. As of September 30, 2022, the Company had not completed a Section 382 ownership change assessment to determine the amount of any potential limitations. A formal analysis of ownership changes and associated tax impacts will be completed prior to utilization of any tax net operating losses or other tax credits. New Accounting Pronouncements From time to time, new accounting pronouncements are issued by the FASB and rules are issued by the SEC that the Company has or will adopt as of a specified date. Unless otherwise noted, management does not believe that any other recently issued accounting pronouncements issued by the FASB or guidance issued by the SEC had, or is expected to have, a material impact on the Company’s present or future consolidated financial statements. Recently Adopted Accounting Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity (“ASU 2020-06”), which simplifies the guidance on an issuer’s accounting for convertible instruments and contracts in its own equity. The Company adopted ASU 2020-06 in the first quarter of 2021. The adoption of ASU 2020-06 did not have a material effect on the Company’s consolidated financial statements.

Summary of Significant Accounting Policies

9 Months Ended

Sep. 30, 2022

Summary of Significant Accounting Policies

Summary of Significant Accounting Policies

Note 2. Summary of Significant Accounting Policies

Basis of Presentation

The unaudited interim condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All material intercompany balances and transactions have been eliminated in consolidation. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and the instructions to Form 10-Q. Accordingly, certain information and footnote disclosures normally included in consolidated financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. In the opinion of management, all adjustments, consisting of normal recurring adjustments, and disclosures considered necessary for a fair presentation of interim period results have been included. Interim results for the nine months ended September 30, 2022 are not necessarily indicative of results that may be expected for the year ending December 31, 2022. For further information, refer to the consolidated financial statements and footnotes thereto included in the Company’s 2021 Form 10-K.

Use of Estimates

The preparation of the Company’s unaudited condensed consolidated financial statements in conformity with GAAP requires the Company 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 unaudited condensed consolidated financial statements and reported amounts of revenues and expenses during the reporting period. The Company bases its estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances and are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ from these estimates. Estimates that are critical to the accompanying unaudited condensed consolidated financial statements include the estimated fair value of the net assets acquired in connection with the Acquisition of Aceragen, the estimated fair value of the liability classified warrants issued to Aceragen warrant holders and accrued clinical trial expenses.

Cash and Cash Equivalents

The Company considers all highly liquid investments with maturities of 90 days or less when purchased to be cash equivalents. Cash and cash equivalents at September 30, 2022 and December 31, 2021 consisted of cash and money market funds.

Financial Instruments

At September 30, 2022 and December 31, 2021, the Company’s financial instruments included accounts payable, accrued expenses, stockholder notes and debt. The carrying amount of cash and cash equivalents, accounts receivable, accounts payable and accrued expenses approximates fair value due to the short-term maturities of these instruments. Each of the carrying values of the preferred stock warrant liabilities and Series X preferred stock liability issued to Aceragen stockholders and the acquisition obligation assumed in connection with the Acquisition of Aceragen are recorded at their estimated fair values. As of September 30, 2022, the Company did not have any derivatives, hedging instruments or other similar financial instruments.

Accounts Receivable

Accounts receivables are recorded net of an estimated expected credit losses. The Company’s measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. To date, there have been no expected credit losses as the Company’s customer is the U.S. government. Unbilled accounts receivable at September 30, 2022 which is included in accounts receivables is $1.1 million and relates to revenue recognized for work that has been performed but the invoicing has not yet occurred.

Foreign Currency

Upon completion of the Acquisition of Aceragen in September 2022, the Company has a wholly-owned subsidiary in Switzerland and the functional currency is the Swiss Franc. The results of the Company’s non-US dollar based functional currency operations are translated to US dollars at the average exchange rates during the period. Assets and liabilities are translated at the exchange rate prevailing at the balance sheet date. Equity is translated at the prevailing exchange rate at the date of the equity transaction. Translation adjustments are included in stockholders' equity, as a component of accumulated other comprehensive income.

The Company realizes foreign currency transaction gains (losses) in the normal course of business based on movements in the applicable exchange rates. These gains (losses) are included as a component of other (expense) income, net.

Business Combinations

The Company evaluates acquisitions of assets and other similar transactions to assess whether or not the transaction should be accounted for as a business combination or asset acquisition by first applying a screen to determine if substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets. If the screen is met, the transaction is accounted for as an asset acquisition. If the screen is not met, further determination is required as to whether or not the Company has acquired inputs and processes that have the ability to create outputs, which would meet the requirements of a business. If determined to be a business combination, the Company accounts for the transaction under the acquisition method of accounting as indicated in Accounting Standard Update (“ASU”) 2017-01, Business

Combinations, which requires the acquiring entity in a business combination to recognize the fair value of all assets acquired, liabilities assumed, and any non-controlling interest in the acquiree and establishes the acquisition date as the fair value measurement point. Accordingly, the Company recognizes assets acquired and liabilities assumed in business combinations based on the fair value estimates as of the date of acquisition. In accordance with ASC 805, Business Combinations, the Company recognizes and measures goodwill as of the acquisition date, as the excess of the fair value of the consideration paid over the fair value of the identified net assets acquired.

Goodwill

Goodwill represents the amount of consideration paid in excess of the fair value of net assets acquired as a result of the Company’s business acquisitions accounted for using the acquisition method of accounting. The intangible assets acquired represented the fair value of in-process research and development (IPR&D) which has been recorded on the accompanying condensed consolidated balance sheet as indefinite-lived intangible assets. A deferred tax liability was recorded for the difference between the fair value of the acquired IPR&D and its tax basis which was recognized as goodwill in applying the purchase method of accounting. Goodwill is not amortized and is subject to impairment testing at a reporting unit level on an annual basis or when a triggering event occurs that may indicate the carrying value of the goodwill is impaired. An entity is permitted to first assess qualitative factors to determine if a quantitative impairment test is necessary. Further testing is only required if the entity determines, based on the qualitative assessment, that it is more likely than not that the fair value of the reporting unit is less than its carrying amount.

We evaluate goodwill for impairment at least annually on October 1 and whenever facts and circumstances indicate that their carrying amounts may not be recoverable. For the nine months ended September 30, 2022, the Company determined that there was no impairment to goodwill.

Indefinite-Lived Intangible Assets

Indefinite-lived intangible assets consist of In-Process Research and Development(“IPR&D”). The fair values of IPR&D project assets acquired in business combinations are capitalized. The Company generally utilizes the Multi-Period Excess Earning Method to determine the estimated fair value of the IPR&D assets acquired in a business combination. The projections used in this valuation approach are based on many factors, such as relevant market size and share, probabilities of success, anticipated patent protection, and expected pricing. The estimated future net cash flows are then discounted to the present value using an appropriate discount rate. These assets are treated as indefinite-lived intangible assets until completion or abandonment of the projects, at which time the assets are amortized over the remaining useful life or written off, as appropriate.

Intangible assets with indefinite lives, including IPR&D, are tested for impairment if impairment indicators arise and, at a minimum, annually. However, an entity is permitted to first assess qualitative factors to determine if a quantitative impairment test is necessary. Further testing is only required if the entity determines, based on the qualitative assessment, that it is more likely than not that an indefinite-lived intangible asset’s fair value is less than its carrying amount. Otherwise, no further impairment testing is required. The indefinite-lived intangible asset impairment test consists of a one-step analysis that compares the fair value of the intangible asset with its carrying amount. If the carrying amount of an intangible asset exceeds its fair value, an impairment loss is recognized in an amount equal to that excess. We consider many factors in evaluating whether the value of our intangible assets with indefinite lives may not be recoverable, including, but not limited to, expected growth rates, the cost of equity and debt capital, general economic conditions, our outlook and market performance of our industry and recent and forecasted financial performance.

We evaluate indefinite-lived intangible assets for impairment at least annually on October 1 and whenever facts and circumstances indicate that their carrying amounts may not be recoverable. For the nine months ended September 30, 2022, the Company determined that there was no impairment to IPR&D.

Concentration of Credit Risk

Financial instruments that subject the Company to credit risk primarily consist of cash and cash equivalents. The Company’s credit risk is managed by investing in highly rated money market instruments, U.S. treasury bills, corporate bonds, commercial paper and/or other debt securities. Due to these factors, no significant additional

credit risk is believed by management to be inherent in the Company’s assets. As of September 30, 2022, all the Company’s cash and cash equivalents were held at five high credit-quality financial institutions.

Operating Lease Right-of-Use Assets and Lease Liability

The Company accounts for leases under ASC 842, Leases. Operating leases are included in “Operating lease right-of-use assets” within the Company’s consolidated balance sheets and represent the Company’s right to use an underlying asset for the lease term. The Company’s related obligation to make lease payments are included in “Operating lease liability” and “Operating lease liability, net of current portion” within the Company’s consolidated balance sheets. Operating lease right-of-use (“ROU”) assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rates, which are the rates incurred to borrow on a collateralized basis over a similar term, an amount equal to the lease payments in a similar economic environment. Lease expense for lease payments is recognized on a straight-line basis over the lease term. The ROU assets are tested for impairment according to ASC 360, Property, Plant, and Equipment. Leases with an initial term of 12 months or less are not recorded on the balance sheet and are recognized as lease expense on a straight-line basis over the lease term.

As of September 30, 2022 and December 31, 2021, the Company’s operating lease ROU assets and corresponding short-term and long-term lease liabilities primarily relate to its existing Exton, PA facility operating lease which expires on May 31, 2025. In connection with the Aceragen Acquisition, as defined and described in Note 4, the Company acquired an operating lease for an office in Basel, Switzerland which expires on March 31, 2023.

Acquisition-Related Costs

Acquisition-related costs include direct expenses incurred in connection with the Acquisition of Aceragen as well as integration-related professional fees and other incremental costs directly associated to the acquisition.

Restructuring and Other Charges

The Company accounts for exit or disposal activities in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 420, Exit or Disposal Cost Obligations (“ASC 420”). A business restructuring is defined as an exit or disposal activity that includes, but is not limited to, a program that is planned and controlled by management and materially changes either the scope of a business or the manner in which that business is conducted. Business restructuring charges include (i) one-time termination benefits related to employee separations (i.e. severance costs), (ii) contract termination costs, and (iii) other related costs associated with exit or disposal activities. In the third quarter of 2022, the Company implemented a restructuring plan to streamline the organization, reduce costs, and direct resources to advance the Company’s primary operating goals.

The Company recognizes and measures a liability for one-time termination benefits, for which no future service is required, once the plan of termination meets all of the following criteria for an established communication date: (i) management commits to a plan of termination, (ii) the plan identifies the number of employees to be terminated and their job classifications or functions, locations and the expected completion date, (iii) the plan establishes the terms of the benefit arrangement, and (iv) it is unlikely that significant changes to the plan will be made or the plan will be withdrawn. For one-time termination benefits for which future service is required, a liability is measured at the communication date based on its value as of the termination date and recognized ratably over the future service period. The Company recognizes and measures a liability for other related costs in the period in which the liability is incurred.

Series X Preferred Stock Liability

In conjunction with the Acquisition of Aceragen, the Company evaluated the newly issued Series X preferred stock and determined its revised terms represents a sale of future revenues and is classified as a liability under ASC 470, Debt and the Company has elected to account for the Series X preferred stock liability under the fair value option. The fair value of the Series X preferred stock liability represents the present value of estimated future payments, including royalty payments, as well as estimated payments that are contingent upon the achievement of

specified milestones. The fair value of the Series X preferred stock liability is based on the cumulative probability of the various estimated payments. The fair value measurement is based on significant Level 3 unobservable inputs such as the probability of achieving the milestones, anticipated timelines, probability and timing of an early redemption of all obligations under Series X preferred liability and the discount rate. Any changes in the fair value of the liability in each reporting period are recognized in the consolidated statement of operations until it is settled.

Warrant Liability

In connection with the Aceragen Acquisition, a portion of the consideration paid to Aceragen warrant holders was in the form of warrants to purchase shares of Series Z (the “Series Z warrants”). The Series Z warrants were classified as a liability on the condensed consolidated balance sheet at September 30, 2022 because the underlying Series Z are contingently redeemable. The fair value of the Series Z warrants on the date of issuance was recorded as a component to the carrying value of the shares Series Z and as a long-term liability in the condensed consolidated balance sheet. The warrants are remeasured to fair value at each balance sheet date until the warrants are exercised, reclassified, expire or otherwise settled. Changes in the fair values of the Series Z warrants are recognized as other income or expense in the consolidated statements of operations and comprehensive loss.

The Company used the Black-Scholes option pricing model, which incorporated assumptions and estimates, to value the Series Z warrants. Estimates and assumptions impacting the fair value measurement of the Series Z warrants included the remaining contractual term of the warrants, risk-free interest rate, expected dividend yield and expected volatility of the price of the underlying shares of Series Z. The estimated the expected stock volatility based on the Company’s historical volatility for a term equal to the remaining contractual term of the warrants at the time of issuance and again at the remeasurement date. The risk-free interest rate was determined by reference to the US Treasury yield curve for time periods approximately equal to the remaining contractual term of the warrants. Expected dividend yield was determined based on the fact that the Company had never paid cash dividends and did not expect to pay any cash dividends in the foreseeable future.

Redeemable Preferred Stock

The Company applies ASC 480 when determining the classification and measurement of its preferred stock. Preferred shares subject to mandatory redemption are classified as liability instruments and are measured at fair value. Conditionally redeemable preferred shares (including preferred shares that feature redemption rights that are either within the control of the holder or subject to redemption upon the occurrence of uncertain events not solely within the Company’s control) are classified as temporary equity. At all other times, preferred shares are classified as stockholders’ equity.

The carrying value of the shares of Series Z is accreted to redemption value using the estimated fair value of the redemption value at each reporting period until the redeemable convertible preferred stock cease to be outstanding or the redemption right has expired.

The accretion for the three and nine months ended September 30, 2022 was immaterial.

Revenue Recognition

The Company recognizes revenue when the Company's customers obtain control of promised goods or services, in an amount that reflects the consideration which the Company expects to receive in exchange for those goods or services by analyzing the following five steps: (i) identify the contract with a customer(s); (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation.

Revenues from reimbursable contracts are recognized as costs are incurred, generally based on allowable direct costs incurred during the period, plus allocable overheads together with any recognizable earned fee. The Company uses this input method to measure progress as the customer has access to the development research under these projects and benefits incrementally as R&D activities occur.

Income Taxes

In accordance with ASC 270, Interim Reporting, and ASC 740, Income Taxes, the Company is required at the end of each interim period to determine the best estimate of its annual effective tax rate and then apply that rate in providing for income taxes on a current year-to-date (interim period) basis. At September 30, 2022, the Company evaluated the realizability of its deferred tax assets and determined that the valuation allowance should be decreased by approximately $6.0 million in consideration of positive and negative evidence bearing upon its ability to realize certain of its deferred tax assets. Such is reflected as an income tax benefit for the three and nine months ended September 30, 2022 in the condensed consolidated statement of operations. As of September 30, 2022 and December 31, 2021, the Company had no uncertain tax positions.

As a result of the Aceragen Acquisition, the Company will have a significant change in ownership. In general, if the Company experiences a greater than 50% aggregate change in ownership of certain significant stockholders over a three-year period (a “Section 382 ownership change”), utilization of its pre-change net operating loss and credit carryforwards is subject to an annual limitation under Section 382 of the Internal Revenue Code of 1986, as amended (the “Code”) (and similar state laws). The annual limitation generally is determined by multiplying the value of the Company’s stock at the time of such Section 382 ownership change (subject to certain adjustments) by the applicable long-term tax-exempt rate. Such limitations may result in expiration of a portion of the net operating loss and credit carryforwards before utilization and may be substantial. The ability of the Company to use its net operating loss and credit carryforwards may be limited or lost if the Company experiences a Section 382 ownership change in connection with offerings or as a result of future changes in its stock ownership. Losses from a specific period may be subject to multiple limitations and would generally be limited by the lowest of those limitations. As of September 30, 2022, the Company had not completed a Section 382 ownership change assessment to determine the amount of any potential limitations. A formal analysis of ownership changes and associated tax impacts will be completed prior to utilization of any tax net operating losses or other tax credits.

New Accounting Pronouncements

From time to time, new accounting pronouncements are issued by the FASB and rules are issued by the SEC that the Company has or will adopt as of a specified date. Unless otherwise noted, management does not believe that any other recently issued accounting pronouncements issued by the FASB or guidance issued by the SEC had, or is expected to have, a material impact on the Company’s present or future consolidated financial statements.

Recently Adopted Accounting Pronouncements

In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity (“ASU 2020-06”), which simplifies the guidance on an issuer’s accounting for convertible instruments and contracts in its own equity. The Company adopted ASU 2020-06 in the first quarter of 2021. The adoption of ASU 2020-06 did not have a material effect on the Company’s consolidated financial statements.