Summary of Significant Accounting Policies | 2. Summary of Significant Accounting Policies Basis of Presentation The accompanying financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and, in the opinion of management, include all adjustments necessary for a fair presentation of the Company’s financial position, results of operations, and cash flows for each period presented. Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. To date, we have viewed our operations and managed our business as one segment. Use of estimates The preparation of financial statements in conformity with U.S. GAAP and U.S. Securities and Exchange Commission (“SEC”), requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amount of revenues and expenses during the reporting periods. Actual results could differ from those estimates. Cash and cash equivalents Cash consists of funds held in bank accounts. Cash equivalents consist of short-term, highly liquid investments with original maturities of 90 days or less at the time of purchase and generally include money market accounts. Investments The Company’s investments consist of certificates of deposit and debt securities classified as held-to-maturity. Management held-to-maturity maturity. Held-to-maturity held-to-maturity The Company uses the specific identification method to determine the cost basis of securities sold. Investments are considered to be impaired when a decline in fair value is judged to be other-than-temporary. The Company evaluates an investment for impairment by considering the length of time and extent to which market value has been less than cost or amortized cost, the financial condition and near-term prospects of the issuer as well as specific events or circumstances that may influence the operations of the issuer and the Company’s intent to sell the security or the likelihood that it will be required to sell the security before recovery of the entire amortized cost. Once a decline in fair value is determined to be other-than-temporary, an impairment charge is recorded to other income/(expense) and a new cost basis in the investment is established. Concentrations of Credit Risk The Company maintains its cash and cash equivalents and certificates of deposit with two financial institutions that are federally insured. Some of these financial instruments are in excess of federally insured limits and as a result, could potentially expose the Company to significant concentrations of credit risk. To date, the Company has not experienced any losses associated with this credit risk and continues to believe that this exposure is not significant. The Company invests its excess cash primarily in money market funds, certificates of deposit, and debt instruments of corporations and U.S. government agencies. These investments generally mature within a two-year Inventory Purchases of clinical materials stored for master and working viral banks that remain at the sites in anticipation of their future use at that site are charged to expense when they are incurred. Since the Company can use each of the raw materials in only a single product, each raw material is deemed to have no future economic value independent of the development status of that single drug. Fair value of financial instruments The Company is required to disclose information on all assets and liabilities reported at fair value that enables an assessment of the inputs used in determining the reported fair values. The Financial Accounting Standards Board (“FASB”) Accounting Standard Codification (“ASC”) Topic 820, Fair Value Measurements and Disclosures (“ASC 820”), establishes a hierarchy of inputs used when available. Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are those that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances. The fair value hierarchy applies only to the valuation inputs used in determining the reported fair value of financial instruments and is not a measure of the investment credit quality. The three levels of the fair value hierarchy are described below: Level 1—Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2—Valuations based on quoted prices for similar assets or liabilities in markets that are not active or for which all significant inputs are observable, either directly or indirectly. Level 3—Valuations that require inputs that reflect the Company’s own assumptions that are both significant to the fair value measurement and are unobservable. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Property and equipment Property and equipment, consisting of laboratory equipment, furniture and fixtures, computer equipment and leasehold improvements, are recorded at cost. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, which are generally three to ten 6.8 Intangible assets Intangible assets primarily include licenses and patents. The Company obtains licenses from third parties and capitalizes the costs related to exclusive licenses that have alternative future use in multiple potential programs. The Company also capitalizes costs related to filing, issuance, and prosecution of patents. The Company reviews its capitalized costs periodically to determine that such costs relate to patent applications that have future value and an alternative future use and writes off any costs associated with patents that are no longer being actively pursued or that have no future benefit. Amortization expense is computed using the straight-line method over the estimated useful lives of the assets, which are generally eight to twenty 8.6 in-licensed Impairment of long-lived assets The Company reviews its long-lived assets for impairment when impairment indicators are present. If impairment indicators exist, management determines whether impairment in value has occurred by comparing the estimated undiscounted cash flows from future operations with the carrying values of the assets. Management considers several indicators in assessing impairment, including trends and prospects, as well as the effects of obsolescence, demand, competition and other economic factors. No impairment charges were recorded for each of the fiscal years ended June 30, 2019 and 2018. Revenue recognition Effective July 1, 2018, the Company adopted the provisions of ASC 606, Revenue from Contracts with Customers, The adoption of the new revenue recognition guidance resulted in an increase of $22.6 million in deferred revenue and accumulated deficit as of July 1, 2018. For the year ended June 30, 2019, revenue increased by $25.4 million, net income increased by $25.4 million and basic and diluted earnings per share increased by $1.40 based on revenue recognition under Topic 606 as compared to the Company’s prior revenue recognition methodology under ASC 605, Revenue Recognition Under Topic 606, an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine the appropriate amount of revenue to be recognized for arrangements determined to be within the scope of Topic 606, the Company performs the following five steps: (i) identification of the contract; (ii) determination of whether the promised goods or services are performance obligations; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations; and (v) recognition of revenue when (or as) the Company satisfies each performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect consideration it is entitled to in exchange for the goods or services it transfers to the customer. Performance obligations are promises to transfer distinct goods or services to the customer. Promised goods or services are considered distinct when (i) the customer can benefit from the good or service on its own or together with other readily available resources and (ii) the promised good or service is separately identifiable from other promises in the contract. In assessing whether promised goods or services are distinct, the Company considers factors such as the stage of development of the underlying intellectual property, the capabilities of the customer to develop the intellectual property on their own or whether the required expertise is readily available. The Company estimates the transaction price based on the amount expected to be received for transferring the promised goods or services in the contract. The consideration may include both fixed consideration or variable consideration. At the inception of an arrangement that includes variable consideration and at each reporting period, the Company evaluates the amount of potential payment and the likelihood that the payments will be received. The Company utilizes either the most likely amount method or expected amount method to estimate the amount to be received based on which method better predicts the amount expected to be received. If it is probable that a significant revenue reversal would not occur, the variable consideration is included in the transaction price. The Company will assess its revenue generating arrangements in order to determine whether a significant financing component exists and conclude that a significant financing component does not exist in any of its arrangements if: (a) the promised consideration approximates the cash selling price of the promised goods and services or any significant difference is due to factors other than financing; and (b) timing of payment approximates the transfer of goods and services and performance is over a relatively short period of time within the context of the entire term of the contract. The Company’s contracts will often include development and regulatory milestone payments. At contract inception and at each reporting period, the Company evaluates whether the milestones are considered probable of being reached and estimate the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s control or the customer’s control, such as regulatory approvals, are not included in the transaction price. At the end of each subsequent reporting period, the Company re-evaluates catch-up For arrangements that may include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any royalty revenue resulting from any of the Company’s collaboration arrangements. The Company allocates the transaction price based on the estimated standalone selling price of the underlying performance obligations or in the case of certain variable consideration to one or more performance obligations. The Company must develop assumptions that require judgment to determine the stand-alone selling price for each performance obligation identified in the contract. The Company utilizes key assumptions to determine the stand-alone selling price, which may include other comparable transactions, pricing considered in negotiating the transaction and the estimated costs to complete the respective performance obligation. Certain variable consideration is allocated specifically to one or more performance obligations in a contract when the terms of the variable consideration relate to the satisfaction of the performance obligation and the resulting amounts allocated to each performance obligation are consistent with the amounts the Company would expect to receive for each performance obligation. For performance obligations consisting of licenses and other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front non-refundable, up-front The Company receives payments from its customers based on billing terms established in each contract. Such billings generally have 30-day Collaboration revenue To date, the Company’s collaboration revenue has been generated from its collaboration arrangement with Biogen as further described in Note 7, “ Collaboration Agreements The Company analyzes its collaboration arrangements to assess whether they are within the scope of ASC 808, Collaborative Arrangements Income taxes The Company uses the asset and liability method for accounting for income taxes. Under this method, deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective income tax bases. Deferred tax assets and liabilities are measured using enacted rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The Tax Cut and Jobs Act (the “Tax Act”) was enacted on December 22, 2017. The Tax Act contains several key provisions including, among other things, reducing the U.S. federal corporate tax rate from 35% to 21%. In addition, federal net operating losses (“NOLs”) will be carried forward indefinitely but will be subject to an 80% utilization against taxable income. For the fiscal year ended June 30, 2019, the Company recorded an income tax provision, as a result of uncertainties related to state income tax. For the fiscal year ended June 30, 2018, the Company recorded an income tax provision, related to the Company’s Federal alternative minimum tax credit and uncertainties related to state income taxes. As required by U.S. GAAP, the Company recognizes the financial statement benefit of a tax position only after determining that the relevant tax authority would more likely than not sustain the position following an audit. For tax positions meeting the more-likely-than-not The uncertain tax position liability for years ended June 30, 2019 and 2018, was $2,035,000 and $1,959,000, respectively. Research and development expenses Research and development costs include costs incurred in identifying, developing and testing product candidates and generally comprise compensation and related benefits and non-cash pre-clinical As part of the process of preparing financial statements, the Company is required to estimate its accrued expenses. This process involves reviewing quotations and contracts, identifying services that have been performed on its behalf and estimating the level of service performed and the associated cost incurred for the service when the Company has not yet been invoiced or otherwise notified of the actual cost. The majority of the Company’s service providers invoice the Company monthly in arrears for services performed or when contractual milestones are met. The Company makes estimates of its accrued expenses as of each balance sheet date in its financial statements based on facts and circumstances known to it at that time. The significant estimates in the Company’s accrued research and development expenses are related to expenses incurred with respect to academic research centers, contract research organizations (“CROs”), and other vendors in connection with research and development activities for which it has not yet been invoiced. There may be instances in which the Company’s service providers require advance payments at the inception of a contract or in which payments made to these vendors will exceed the level of services provided, resulting in a prepayment of the research and development expense. Such prepayments are charged to research and development expense as and when the service is provided or when a specific milestone outlined in the contract is reached. Prepayments related to research and development activities were approximately $0.7 million and $1.0 million at June 30, 2019 and 2018, respectively, and are included within the prepaid and other current assets line item on the balance sheets. Share-based compensation The Company accounts for share-based awards issued to employees in accordance with ASC Topic 718, Compensation—Stock Compensation non-employees 505-50, Equity-Based Payments to Non-employees 505-50”). 505-50, non-employees re-measurement For purposes of calculating stock-based compensation, the Company estimates the fair value of stock options using a Black-Scholes option-pricing model. The determination of the fair value of share-based payment awards utilizing the Black-Scholes model is affected by the Company’s stock price and a number of assumptions, including expected volatility, expected life, risk-free interest rate and expected dividends. The expected volatility is primarily based on the historical volatility of peer company data while the expected life of the stock options is based on historical and other economic data trended into the future. The risk-free interest rate assumption is based on observed interest rates appropriate for the expected terms of the Company’s stock options. The dividend yield assumption is based on the Company’s history and expectation of no dividend payouts. If factors change and the Company employs different assumptions, stock-based compensation expense may differ significantly from what has been recorded in the past. If there is a difference between the assumptions used in determining stock-based compensation expense and the actual factors which become known over time, specifically with respect to anticipated forfeitures, the Company may change the input factors used in determining stock-based compensation costs for future grants. These changes, if any, may materially impact the Company’s results of operations in the period such changes are made. Net loss per share Basic net loss per share is calculated by dividing net loss by the weighted average shares outstanding during the period, without consideration for common stock equivalents. Diluted net loss per share is calculated by adjusting weighted average shares outstanding for the dilutive effect of common stock equivalents outstanding for the period, determined using the treasury-stock method. For purposes of the diluted net loss per share calculations, stock options are considered to be common stock equivalents if they are dilutive. The dilutive impact of stock options for the years ended June 30, 2019 and 2018 was 0.2 million. The dilutive impact of stock options has been excluded from the calculation of diluted net loss per share for the year ended June 30, 2019 and 2018 as their effect would be anti-dilutive. Therefore, for the years ended June 30, 2019 and 2018 basic and diluted net loss per share were the same. Comprehensive loss Comprehensive loss consists of net loss and changes in equity during a period from transactions and other equity and circumstances generated from non-owner sources. The Company’s net loss equals comprehensive loss for all periods presented. New Accounting Pronouncements Adopted in the current period Revenue recognition In May 2014, Topic 606, replaced the existing accounting standards for revenue recognition with a single comprehensive five-step model. The core principle is to recognize revenue upon the transfer of goods or services to customers at an amount that reflects the consideration expected to be received. It also requires enhanced disclosures about revenue, provides guidance for transactions that were not previously addressed comprehensively, and improves guidance for multiple-element arrangements. The guidance was effective for public companies for annual periods beginning after December 15, 2017 as well as interim periods within those annual periods using either the full retrospective approach or modified retrospective approach. The Company adopted the new standard effective July 1, 2018 using the modified retrospective approach. Refer to Note 7 for the impact of adoption. Share-Based Compensation In May 2017, the FASB issued Accounting Standards Update (“ASU”) No. 2017-09, Financial Instrument Accounting In January 2016, the FASB issued ASU No. 2016-01, (Subtopic 825-10): No. 2016-01 To be adopted in future periods Leases In February 2016, the FASB issued ASU No. 2016-02, right-of-use right-of-use right-of-use Financial Instruments—Credit Losses In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The new standard requires financial assets measured at amortized cost basis to be presented at the net amount expected to be collected and separately measure an allowance for credit losses that is deducted from the amortized cost basis of the financial assets. This standard will be effective for the Company on July 1, 2020. Early adoption is permitted. The adoption of this guidance is not expected to have a significant impact on the Company’s financial statements. Share-Based Compensation In June 2018, the FASB issued ASU No. 2018-07, Fair Value Measurement In August 2018, the FASB issued ASU No. 2018-13, Collaborative Arrangements In November 2018, the FASB issued ASU No. 2018-18, unit-of-account |