2. Significant Accounting Policies	9 Months Ended
Sep. 30, 2019
Accounting Policies [Abstract]
Significant Accounting Policies	2. Significant Accounting Policies Basis of Presentation The accompanying condensed consolidated financial statements are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). Certain information and footnote disclosures included in the Company’s annual financial statements have been condensed or omitted. The year-end condensed balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. In the opinion of management, all adjustments (including normal recurring accruals) considered necessary for a fair presentation of the condensed consolidated financial statements have been included. Interim results are not necessarily indicative of results for a full year. Principles of Consolidation The consolidated financial statements include the accounts of Phio and its wholly-owned subsidiary, MirImmune, LLC. All material intercompany accounts have been eliminated in consolidation. Uses of Estimates in Preparation of Financial Statements The preparation of financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ materially from these estimates. Restricted Cash Restricted cash consists of certificates of deposit held by financial institutions as collateral for the Company’s corporate credit cards. Leases The Company follows the provisions of the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 842, “Leases” (“ASC 842”). At the inception of a contract, the Company determines whether the contract is or contains a lease based on all relevant facts and circumstances. For contracts that contain a lease, the Company identifies the lease and non-lease components, determines the consideration in the contract and recognizes the classification of the lease as operating or financing. At the commencement date of the lease, the Company recognizes a liability to make lease payments and an asset representing the right to use the underlying asset during the lease term. The Company has elected not to recognize leases with a term less than one year on the balance sheet. Lease liabilities and the corresponding right of use assets are recorded based on the present value of lease payments to be made over the lease term. The discount rate used to calculate the present value is the rate implicit in the lease, or if not readily determinable, the Company’s incremental borrowing rate. The Company’s incremental borrowing rate is the rate of interest that the Company would have to pay to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment. Certain adjustments to the right of use asset may be required for items such as initial direct costs or incentives received. Lease payments on operating leases are recognized on a straight-line basis over the expected term of the lease. Lease payments on financing leases are recognized using the effective interest method. Derivative Financial Instruments The Company follows the provisions of the FASB ASC Topic 815, “Derivatives and Hedging.” Financial instruments that meet the definition of a derivative are classified as an asset or liability and measured at fair value on the issuance date and are revalued on each subsequent balance sheet date. The changes in fair value are recognized as current period income or loss. Financial instruments that do not meet the definition of a derivative are classified as equity and measured at fair value and recorded as additional paid in capital in stockholders’ equity at the date of issuance. No further adjustments to their valuation are made. Fair Value of Financial Instruments The carrying amounts reported in the balance sheet for restricted cash, accounts payable and accrued expenses approximate their fair values due to their short-term nature. Research and Development Expenses Research and development costs relate to compensation and benefits for research and development personnel, facility-related expenses, supplies, external services, costs to acquire technology licenses, expenses associated with preclinical and clinical development activities and other operating costs. Research and development expenses are charged to expense as incurred. Payments made by the Company in advance for research and development services not yet provided and/or for materials not yet received are recorded as prepaid expenses and expensed when the service has been performed or when the goods have been received. Accrued liabilities are recorded related to those expenses for which vendors have not yet billed the Company with respect to services provided and/or materials that it has received. The Company contracts with third parties to perform various preclinical and clinical activities on its behalf for the continued development of its product candidates. Accruals and expenses are recorded during the period incurred based on such estimates and assumptions as expected cost, passage of time, the achievement of milestones and other information available to us and are assessed on a quarterly basis. Actual results may differ from these estimates and could have a material impact on the Company’s reported results. The Company’s historical accrual estimates have not been materially different from its actual costs. Stock-based Compensation The Company follows the provisions of the FASB ASC Topic 718, “Compensation — Stock Compensation” (“ASC 718”), which requires the measurement and recognition of compensation expense for all stock-based payment awards. Stock compensation expense is based on the grant date fair value estimated in accordance with the provisions of ASC 718 and is recognized as an expense over the requisite service period. Comprehensive Loss The Company’s comprehensive loss is equal to its net loss for all periods presented. Net Loss per Share The Company accounts for and discloses net loss per share in accordance with the FASB ASC Topic 260, “Earnings per Share.” Basic and diluted net loss per share is computed by dividing net loss by the weighted average number of common shares outstanding. Diluted earnings per share is computed by dividing the Company’s net loss by the weighted average number of common shares outstanding and the impact of all dilutive potential common shares.

2. Significant Accounting Policies

9 Months Ended

Sep. 30, 2019

2. Significant Accounting Policies

Basis of Presentation

The accompanying condensed consolidated financial statements are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). Certain information and footnote disclosures included in the Company’s annual financial statements have been condensed or omitted. The year-end condensed balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. In the opinion of management, all adjustments (including normal recurring accruals) considered necessary for a fair presentation of the condensed consolidated financial statements have been included. Interim results are not necessarily indicative of results for a full year.

Principles of Consolidation

The consolidated financial statements include the accounts of Phio and its wholly-owned subsidiary, MirImmune, LLC. All material intercompany accounts have been eliminated in consolidation.

Uses of Estimates in Preparation of Financial Statements

The preparation of financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ materially from these estimates.

Restricted Cash

Restricted cash consists of certificates of deposit held by financial institutions as collateral for the Company’s corporate credit cards.

Leases

The Company follows the provisions of the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 842, “Leases” (“ASC 842”). At the inception of a contract, the Company determines whether the contract is or contains a lease based on all relevant facts and circumstances. For contracts that contain a lease, the Company identifies the lease and non-lease components, determines the consideration in the contract and recognizes the classification of the lease as operating or financing. At the commencement date of the lease, the Company recognizes a liability to make lease payments and an asset representing the right to use the underlying asset during the lease term. The Company has elected not to recognize leases with a term less than one year on the balance sheet.

Lease liabilities and the corresponding right of use assets are recorded based on the present value of lease payments to be made over the lease term. The discount rate used to calculate the present value is the rate implicit in the lease, or if not readily determinable, the Company’s incremental borrowing rate. The Company’s incremental borrowing rate is the rate of interest that the Company would have to pay to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment. Certain adjustments to the right of use asset may be required for items such as initial direct costs or incentives received. Lease payments on operating leases are recognized on a straight-line basis over the expected term of the lease. Lease payments on financing leases are recognized using the effective interest method.

Derivative Financial Instruments

The Company follows the provisions of the FASB ASC Topic 815, “Derivatives and Hedging.” Financial instruments that meet the definition of a derivative are classified as an asset or liability and measured at fair value on the issuance date and are revalued on each subsequent balance sheet date. The changes in fair value are recognized as current period income or loss. Financial instruments that do not meet the definition of a derivative are classified as equity and measured at fair value and recorded as additional paid in capital in stockholders’ equity at the date of issuance. No further adjustments to their valuation are made.

Fair Value of Financial Instruments

The carrying amounts reported in the balance sheet for restricted cash, accounts payable and accrued expenses approximate their fair values due to their short-term nature.

Research and Development Expenses

Research and development costs relate to compensation and benefits for research and development personnel, facility-related expenses, supplies, external services, costs to acquire technology licenses, expenses associated with preclinical and clinical development activities and other operating costs. Research and development expenses are charged to expense as incurred. Payments made by the Company in advance for research and development services not yet provided and/or for materials not yet received are recorded as prepaid expenses and expensed when the service has been performed or when the goods have been received. Accrued liabilities are recorded related to those expenses for which vendors have not yet billed the Company with respect to services provided and/or materials that it has received.

The Company contracts with third parties to perform various preclinical and clinical activities on its behalf for the continued development of its product candidates. Accruals and expenses are recorded during the period incurred based on such estimates and assumptions as expected cost, passage of time, the achievement of milestones and other information available to us and are assessed on a quarterly basis. Actual results may differ from these estimates and could have a material impact on the Company’s reported results. The Company’s historical accrual estimates have not been materially different from its actual costs.

Stock-based Compensation

The Company follows the provisions of the FASB ASC Topic 718, “Compensation — Stock Compensation” (“ASC 718”), which requires the measurement and recognition of compensation expense for all stock-based payment awards. Stock compensation expense is based on the grant date fair value estimated in accordance with the provisions of ASC 718 and is recognized as an expense over the requisite service period.

Comprehensive Loss

The Company’s comprehensive loss is equal to its net loss for all periods presented.

Net Loss per Share

The Company accounts for and discloses net loss per share in accordance with the FASB ASC Topic 260, “Earnings per Share.” Basic and diluted net loss per share is computed by dividing net loss by the weighted average number of common shares outstanding. Diluted earnings per share is computed by dividing the Company’s net loss by the weighted average number of common shares outstanding and the impact of all dilutive potential common shares.