Phio Pharmaceuticals (PHIO) 10-K 25 Mar 21 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Mar. 18, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Trading Symbol	PHIO
Security Exchange Name	NASDAQ
Security 12b title	Common Stock, par value, $0.0001 per share
Entity Registrant Name	Phio Pharmaceuticals Corp.
Entity Central Index Key	0001533040
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		13,531,941
Entity Small Business	true
Entity Emerging Growth	false
Entity Shell company	false
Entity File Number	001-36304
Entity Interactive Data Current	Yes
Entity Incorporation Country Code	DE
Entity Current Reporting Status	Yes
Entity Well Known Seasoned Issuer	No
Entity Voluntary Filer	No
Entity Public Float			$ 12,583,469

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash	$ 14,244	$ 6,934
Restricted cash	50	50
Prepaid expenses and other current assets	870	316
Total current assets	15,164	7,300
Right of use asset, net	400	511
Property and equipment, net of accumulated depreciation of $1,122 and $1,048 in 2020 and 2019, respectively	157	210
Other assets	18	18
Total assets	15,739	8,039
Current liabilities:
Accounts payable	728	809
Accrued expenses and other current liabilities	1,352	964
Lease Liability	116	107
Total current liabilities	2,196	1,880
Lease Liability, net of current portion	295	411
Long-term debt	231	0
Total Liabilities	2,722	2,291
Commitments and contingencies (Note 8)
Stockholders' equity:
Preferred stock, $0.0001 par value, 10,000,000 shares authorized	0	0
Common stock, $0.0001 par value, 100,000,000 shares authorized; 5,780,973 and 669,433 shares issued and outstanding at December 31, 2020 and December 31, 2019, respectively	1	1
Additional paid-in capital	116,629	100,566
Accumulated deficit	(103,613)	(94,819)
Total stockholders' equity	13,017	5,748
Total liabilities and stockholders' equity	$ 15,739	$ 8,039

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Accumulated depreciation	$ 1,122	$ 1,048
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred Stock, shares issued	0	0
Preferred Stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	5,780,973	669,433
Common stock, shares outstanding	5,780,973	669,433

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Revenues	$ 0	$ 21
Operating expenses:
Research and development	4,431	4,300
General and administrative	4,362	4,708
Total operating expenses	8,793	9,008
Operating loss	(8,793)	(8,987)
Total other (expense) income, net	(1)	79
Loss before income taxes	(8,794)	(8,908)
Provision for income taxes	0	0
Net loss	$ (8,794)	$ (8,908)
Net loss per common share: Basic and diluted	$ (1.92)	$ (19.33)
Weighted average number of common shares outstanding: Basic and diluted	4,587,346	460,809

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-In Capital	Accumulated Deficit	Total
Beginning balance, shares at Dec. 31, 2018	342,578
Beginning balance, value at Dec. 31, 2018		$ 99,489	$ (85,911)	$ 13,578
Issuance of common stock upon the exercise of warrants, shares	130,338
Issuance of common stock upon the exercise of warrants, value		72		72
Issuance of common stock under Lincoln Park Capital, LLC purchase agreement, shares	9,090
Issuance of common stock under Lincoln Park Capital, LLC purchase agreement, value		(58)		(58)
Issuance of restricted stock, shares	4,419
Issuance of restricted stock, value
Issuance of common stock under the employee stock purchase plan, shares	36
Issuance of common stock under the employee stock purchase plan, value		1		1
Issuance of common stock in connection with registered direct public offering, net of offering costs of $234, shares	181,818
Issuance of common stock in connection with registered direct public offering, net of offering costs of $234, value	$ 1	765		766
Issuance of common stock upon vesting of restricted stock units, shares	1,154
Issuance of common stock upon vesting of restricted stock units, value		(3)		(3)
Stock-based compensation expense		300		300
Net Loss			(8,908)	(8,908)
Ending balance, shares at Dec. 31, 2019	669,433
Ending balance, value at Dec. 31, 2019	$ 1	100,566	(94,819)	5,748
Issuance of common stock upon the exercise of warrants, shares	2,205,663
Issuance of common stock upon the exercise of warrants, value		3,856		3,856
Cash in lieu of fractional shares for 1:55 reverse stock split, shares	(1,364)
Cash in lieu of fractional shares for 1:55 reverse stock split, value		(15)		(15)
Issuance of common stock under the employee stock purchase plan, shares	153
Issuance of common stock under the employee stock purchase plan, value		1		1
Issuance of common stock and warrants in connection with registered direct and private placement offerings, net of offering costs of $746, shares	1,910,120
Issuance of common stock and warrants in connection with registered direct and private placement offerings, net of offering costs of $746, value		4,994		4,994
Issuance of common stock, pre-funded warrants and warrants in connection with underwritten public offering, net of offering costs of $906, shares	993,633
Issuance of common stock, pre-funded warrants and warrants in connection with underwritten public offering, net of offering costs of $906, value		7,093		7,093
Issuance of common stock upon vesting of restricted stock units, shares	3,335
Issuance of common stock upon vesting of restricted stock units, value		(2)		(2)
Stock-based compensation expense		136		136
Net Loss			(8,794)	(8,794)
Ending balance, shares at Dec. 31, 2020	5,780,973
Ending balance, value at Dec. 31, 2020	$ 1	$ 116,629	$ (103,613)	$ 13,017

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Common Stock And Warrant [Member]
Payment of offering costs	$ 746
Stock Pre-funded Warrants and Warrants [Member]
Payment of offering costs	$ 906
Common Stock [Member]
Payment of offering costs		$ 234

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net loss	$ (8,794)	$ (8,908)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	72	67
Non-cash lease expense	111	109
Non-cash stock-based compensation expense	136	300
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(554)	(113)
Accounts payable	(81)	259
Accrued expenses and other liabilities	415	(257)
Lease Liability	(107)	(102)
Net cash used in operating activities	(8,802)	(8,645)
Cash flows from investing activities:
Cash paid for purchase of property and equipment	(19)	(72)
Net cash used in investing activities	(19)	(72)
Cash flows from financing activities:
Net proceeds from the issuance of common stock and warrants	12,087	708
Net proceeds from the exercise of warrants	3,856	72
Cash paid in lieu of fractional shares for 1:55 reverse stock split	(15)	0
Payment of taxes for net share settled restricted stock unit issuances	(2)	(3)
Proceeds from debt	231	0
Proceeds from the issuance of common stock in connection with the employee stock purchase plan	1	1
Payments for capital lease obligations less than one year	(27)	(6)
Net cash provided by financing activities	16,131	772
Net (decrease) increase in cash and restricted cash	7,310	(7,945)
Cash and restricted cash at the beginning of period	6,984	14,929
Cash and restricted cash at the end of period	14,294	6,984
Supplemental disclosure of cash flow information:
Interest paid	6	5
Supplemental disclosure of non-cash investing and financing activities:
Right of use asset obtained in exchange for operating lease liability	0	620
Purchase of property and equipment through short-term financing lease included in accrued expenses and other current liabilities	$ 0	$ 33

1. Nature of Operations

1. Nature of Operations	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations	1. Nature of Operations Phio Pharmaceuticals Corp. (“ Phio we our Company INTASYL™ In December 2019, a novel strain of coronavirus that causes COVID-19 was reported to have surfaced in Wuhan, China and has since spread to other parts of the world, including the United States. In March 2020, the World Health Organization (the “ WHO As a result of the coronavirus pandemic, certain of our third-party suppliers and service providers on which we rely have seen impacts to their operations. If the impact to their operations continue or extend, it may in turn affect our operations. We previously had been able to engage with third-party service providers in areas with limited or no impact (e.g. countries with limited or no restrictions), but with the global spread of the virus and associated restrictions, this has been no longer possible. The Company does not expect a material impact to its program’s anticipated timelines as a result of potential delays from our third-party service providers and believes that it has a sufficient supply of our INTASYL compounds to conduct its ongoing preclinical studies and initial clinical activities. The Company has also undertaken efforts to mitigate potential future impact by identifying and engaging alternative third-party service providers and suppliers. However, the ultimate impact to these third parties on which we rely is highly uncertain and subject to change. If the measures to contain the outbreak are extended or further expanded, it could reduce or delay the availability of supplies and services that we purchase and outsource, which may in turn slow or delay our preclinical and clinical activities, and/or result in higher costs. We believe that the coronavirus pandemic has not had a significant impact on our operations and financial condition thus far, however a variety of factors, including current and future restrictions and the length of the pandemic, may further impact our operations and may slow or diminish our research and development activities. The extent to which the coronavirus pandemic impacts our results will depend on future developments, which are highly uncertain and cannot be predicted.

2. Significant Accounting Polic

2. Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“ GAAP Reverse Stock Split Effective January 15, 2020, the Company completed a 1-for-55 reverse stock split of the Company’s outstanding common stock. All share and per share amounts in the financial statements have been retroactively adjusted for all periods presented to give effect to the reverse stock split, including reclassifying an amount equal to the reduction in par value to additional paid-in capital. Unless otherwise noted, shares of common stock issued and outstanding, shares underlying warrants and stock awards, shares reserved, conversion price of convertible securities, exercise prices of warrants and stock awards and loss per share have been proportionately adjusted to reflect the reverse stock split. The reverse stock split did not reduce the number of authorized shares of the Company’s common stock or preferred stock. 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. The areas subject to significant estimates and judgement include, among others, those related to the fair value of equity awards, research and development expenses, useful lives of property and equipment, income taxes, and our valuation allowance on our deferred tax assets. On an ongoing basis we evaluate our estimates and base our estimates on historical experience and other relevant assumptions that we believe are reasonable under the circumstances, including as a result of new information that may emerge concerning the coronavirus pandemic. We have made estimates of the impact of the coronavirus pandemic within our financial statements and there may be changes to those estimates in future periods. 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. Concentrations of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash. The Company maintains cash balances in several accounts with a financial institution that management believes is creditworthy, which at times are in excess of federally insured limits. These accounts are insured by the Federal Deposit Insurance Corporation (FDIC) for up to $250,000 per institution. Property and Equipment Property and equipment are stated at cost and depreciated using the straight-line method based on the estimated useful lives of the related assets. The Company provides for depreciation over the assets’ estimated useful lives as follows: Computer equipment 3 years Machinery & equipment 5 years Furniture & fixtures 5 years Leasehold improvements 5 years Depreciation and amortization expense for the years ended December 31, 2020 and 2019 was $72,000 and $67,000, respectively. Impairment of Long-Lived Assets The Company reviews long-lived assets for impairment whenever an event occurs or change in circumstances that the related carrying amounts may not be recoverable. An impairment loss would be recognized based on the difference between the carrying value of the asset and its estimated fair value, which would be determined based on either discounted future cash flows or other appropriate fair value methods. The Company believes no impairment existed as of December 31, 2020 or 2019. 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. Leases 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. For leases with a term greater than one year, the Company recognizes a liability to make lease payments and an asset representing the right to use the underlying asset during the lease term at the commencement date of the lease. 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. Debt On March 27, 2020, the United States enacted the Coronavirus Aid, Relief, and Economic Security Act (the “ CARES Act PPP Debt ASC 470 Derivative Financial Instruments 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. Research and Development Expenses Research and development expenses 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. Accrued liabilities for the services provided by contract research organizations 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 Financial Accounting Standards Board (the “ FASB ASC Compensation — Stock Compensation ASC 718 Stock-based compensation expense recognized in the financial statements is based on awards that are ultimately expected to vest. Accordingly, we are also required to estimate forfeitures at the time of grant, and to revise those estimates in subsequent periods if actual forfeitures differ from estimates. We use historical data to estimate pre-vesting option forfeitures and record stock-based compensation expense only for those awards that are expected to vest. Our forfeiture rate estimates are based on an analysis of our actual forfeiture experience, employee turnover behavior, and other factors. The impact of any adjustments to our forfeiture rates would be recorded as a cumulative adjustment in the period of adjustment. To the extent that actual forfeitures differ from our estimates, the difference is recorded as a cumulative adjustment in the period the estimates were revised. Income Taxes The Company recognizes assets or liabilities for the deferred tax consequences of temporary differences between the tax basis of assets or liabilities and their reported amounts in the financial statements in accordance with the FASB ASC Topic 740, “Accounting for Income Taxes” ASC 740 . ASC 740 requires that a valuation allowance be established when management determines that it is more likely than not that all or a portion of a deferred asset will not be realized. The Company evaluates the realizability of its net deferred income tax assets and valuation allowances as necessary, at least on an annual basis. During this evaluation, the Company reviews its forecasts of income in conjunction with other positive and negative evidence surrounding the realizability of its deferred income tax assets to determine if a valuation allowance is required. Adjustments to the valuation allowance will increase or decrease the Company’s income tax provision or benefit. The recognition and measurement of benefits related to the Company’s tax positions requires significant judgment, as uncertainties often exist with respect to new laws, new interpretations of existing laws, and rulings by taxing authorities. The Company follows a more-likely-than not threshold for financial statement recognition and measurement of a tax position taken, or expected to be taken in a tax return. The guidance relates to, amongst other things, classification, accounting for interest and penalties associated with tax positions, and disclosure requirements. Any interest and penalties accrued related to uncertain tax positions are recorded as tax expense. Differences between actual results and the Company’s assumptions or changes in the Company’s assumptions in future periods are recorded in the period they become known. Comprehensive Loss The Company’s comprehensive loss is equal to its net loss for all periods presented. Net Loss per Share Basic net loss per share is computed by dividing net loss by the weighted average number of common shares outstanding. Diluted net loss per share is computed by dividing the Company’s net less by the weighted average number of common shares outstanding and the impact of all dilutive potential common shares outstanding, except where such dilutive potential common shares would be anti-dilutive. Dilutive potential common shares primarily consist of warrants, restricted stock units and stock options.

3. Liquidity and Going Concern

3. Liquidity and Going Concern	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Liquidity and Going Concern	3. Liquidity and Going Concern The Company has reported recurring losses from operations since inception and expects that the Company will continue to have negative cash flows from operations for the foreseeable future. Historically, the Company’s primary source of funding has been the sale of its securities. The Company’s ability to continue to fund its operations is dependent on obtaining funding from third parties, such as proceeds from the issuance of debt, sale of equity, or strategic opportunities, in order to maintain its operations. This is dependent on a number of factors, including the market demand or liquidity of the Company’s common stock. There is no guarantee that debt, additional equity or other funding will be available to us on acceptable terms, or at all. If we fail to obtain additional funding when needed, we would be forced to scale back or terminate our operations or seek to merge with or to be acquired by another company. While we believe that the coronavirus pandemic has not had a significant impact on our financial condition and results of operations at this time, the potential economic impact brought by, and the duration of, the coronavirus pandemic is difficult to assess or predict. There may be developments outside of our control that require us to adjust our operating plans and given the nature of the situation, we cannot reasonably estimate the impact of the coronavirus pandemic on our financial conditions, results of operations or cash flows in the future. The Company believes that its existing cash and the net proceeds received from the Company’s financing activities subsequent to the balance sheet date, discussed further in Note 14, should be sufficient to fund operations for at least the next 12 months from the date of the release of these financial statements

4. Recent Accounting Pronouncem

4. Recent Accounting Pronouncements	12 Months Ended
	Dec. 31, 2020
Accounting Standards Update and Change in Accounting Principle [Abstract]
Recent Accounting Pronouncements	4. Recent Accounting Pronouncements In November 2018, the FASB issued Accounting Standards Update (“ ASU Collaborative Arrangements (Topic 808) Topic 808 Revenue from Customers Topic 606 adopted ASU 2018-18 in the first quarter of 2020. The Company also elected to apply ASU 2018-18 only to contracts that were not completed at the date of initial application of Topic 606. Since the Company has no significant revenue, this ASU has no immediate impact on the Company’s consolidated financial statements. In December 2019, the FASB issued ASU 2019-12, “ Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes The amendments also clarify and simplify other aspects of the accounting for income taxes. The amendments in ASU 2019-12 are effective for public entities for fiscal years, and the interim periods within those fiscal years, beginning after December 20, 2020. Early adoption is permitted. In August 2020, the FASB issued ASU 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)” ASU 2020-06 For contracts in an entity’s own equity, ASU 2020-06 simplifies the settlement assessment by removing the requirements to (1) to consider whether the contract would be settled in registered shares, (2) to consider whether collateral is required to be posted, and (3) to assess shareholder rights. ASU 2020-06 is effective for fiscal years beginning after December 15, 2023, and interim periods within those fiscal years. Early adoption is permitted, but no earlier than fiscal years beginning after December 15, 2020, and interim periods within those fiscal years. The Company does not expect the adoption of ASU 2020-06 to have a material impact on its consolidated financial statements.

5. Accrued Expenses and Other C

5. Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2020
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	5. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consist of the following, in thousands: December 31, 2020 2019 Compensation and benefits $ 618 $ 524 Professional fees 81 171 Research and development costs 549 242 Other 104 27 Total accrued expenses and other current liabilities $ 1,352 $ 964

6. Leases

6. Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	6. Leases On January 22, 2019, the Company amended the lease for its corporate headquarters and primary research facility in Marlborough, Massachusetts. The Company leases 7,581 square feet of office and laboratory space, which will expire on March 31, 2024. The lease contains an option to terminate the lease after two years or three years by providing advance written notice of termination pursuant to the terms of the agreement. The exercise of this option was not determined to be reasonably certain and thus is not included in the lease liability on the Company’s balance sheet. Additionally, the lease agreement did not contain information to determine the rate implicit in the lease. As such, the Company calculated its incremental borrowing rate based on what the Company would have to pay to borrow on a collateralized basis over the lease term for an amount equal to the remaining lease payments taking into consideration such assumptions as, but not limited to, the U.S. treasury yield rate and borrowing rates from a creditworthy financial institution using the above lease factors. The lease for our corporate headquarters represents substantially all of our significant lease obligations. The amounts reported in the consolidated balance sheets for operating leases in which the Company is the lessee and other supplemental balance sheet information is set forth as follows, in thousands, except lease term and discount rate: December 31, 2020 December 31, 2019 Assets Right of use asset $ 400 $ 511 Liabilities Lease liability, current 116 107 Lease liability, non-current 295 411 Total lease liability $ 411 $ 518 Lease Term and Discount Rate Weighted average remaining lease term 3.71 4.43 Weighted average discount rate 4.70% 4.64% Operating lease cost included in operating expense was $132,000 and $127,000 for the years ended December 31, 2020 and 2019, respectively. Short-term lease costs were not material for the years ended December 31, 2020 and 2019. Cash paid for the amounts included in the measurement of the operating lease liability on the Company’s consolidated balance sheets and included within changes in the lease liability in the operating activities of our consolidated statement of cash flows was $127,800 and $121,000 for the years ended December 31, 2020 and 2019, respectively. Future lease payments for our non-cancellable operating leases and a reconciliation to the carrying amount of the operating lease liability presented in the consolidated balance sheet as of December 31, 2020 is as follows, in thousands: 2021 $ 132 2022 135 2023 140 2024 35 Total lease payments 442 Less: Imputed interest (31 ) Total operating lease liabilities (includes current portion) $ 411

7. Debt

7. Debt	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Debt	7. Debt On May 11, 2020, the Company received loan proceeds in the amount of $231,252 from Bank of America, N.A., as lender, pursuant to the PPP under the CARES Act. The PPP loan matures on May 11, 2022, bears interest at a rate of 1% per year and monthly principal and interest payments are deferred to the date that the Small Business Administration remits the borrower’s loan forgiveness amount to the lender. The loan may be forgiven if used for eligible purposes, including payroll, benefits, rent and utilities. The Company believes it has used the loan proceeds for the eligible purposes allowed and applied for full loan forgiveness. On February 18, 2021, the Small Business Administration determined that the Company’s application for full loan forgiveness was fully approved and the full amount of the PPP loan was remitted to the lender for forgiveness. When applying for the PPP loan, the Company carefully assessed the requirements for application under the program and believed that the loan was necessary to support its operations. As loan forgiveness had not yet been determined at December 31, 2020, the Company followed the guidance under ASC 470 in assessing the accounting for the PPP loan proceeds. Per ASC 470, the Company recorded a liability on the balance sheet for the full amount of PPP loan proceeds received and is accruing interest over the term of the loan. As of December 31, 2020, the PPP loan proceeds have been classified as long-term debt on the balance sheet.

8. Commitments and Contingencie

8. Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	8. Commitments and Contingencies License Commitments The Company acquires assets under development and enters into research and development arrangements with third parties that often require milestone and royalty payments based on the progress of the asset through development stages. Milestone payments may be required, for example, upon approval of the product for marketing by a regulatory agency. In certain agreements, the Company is required to make royalty payments based upon a percentage of the sales of the products licensed pursuant to such agreements. Because of the contingent nature of these payments, they are not included in the table of contractual obligations shown below. During the years ended December 31, 2020 and 2019, the Company did not trigger any milestone payments. The Company’s contractual license obligations that will require future cash payments as of December 31, 2020 are as follows, in thousands: Year Ending December 31, 2021 165 2022 100 2023 100 2024 100 2025 100 Thereafter 400 Total $ 965 The Company applies the disclosure provisions of the FASB ASC Topic 460, “ Guarantor’s Accounting and Disclosure Requirements for Guarantees, Including Indirect Guarantees of Indebtedness of Others ASC 460 Litigation From time to time, the Company is party to legal proceedings. There are none deemed to be material at this time. Accordingly, the Company has not accrued any liabilities in its consolidated financial statements related to proceedings.

9. Stockholders' Equity

9. Stockholders' Equity	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Stockholders' Equity	9. Stockholders’ Equity November 2019 Registered Public Offering— November 2019 Offering November 2019 Placement Agent Warrants HCW Concurrent with the close of the November 2019 Offering, the Company unilaterally reduced the per share exercise price of all of the outstanding common stock warrants issued in October 2018 to an exercise price of $10.45 per share, which was equal to the closing price of the Company’s common stock on November 15, 2019, and to $13.06 per share for the warrants issued to HCW, which was equal to 125% of the closing price of the Company’s common stock on November 15, 2019. The modification resulted in an increase in fair value of approximately $800,000. This amount was recorded as a cost of capital of the November 2019 Offering and recorded in additional paid-in capital as the modification was required to complete the capital raise. February 2020 Registered Direct Offering and Private Placement February 2020 Registered Offering February 2020 Registered Direct Warrants February 2020 Placement Agent Warrants February 2020 Underwritten Public Offering 2020 Pre-Funded Warrants February 2020 Warrants February 2020 Underwritten Offering In connection with the February 2020 Underwritten Offering, the Company also granted to the underwriter, HCW, a 30-day option to purchase up to an additional 300,000 shares of the Company’s common stock at a purchase price of $3.999 per such share and/or warrants to purchase up to 300,000 shares of the Company’s common stock at a purchase price of $0.001 per such warrant. Such warrants have the same terms as the February 2020 Warrants. On February 12, 2020, HCW exercised its option to purchase warrants to purchase an aggregate of 300,000 shares of the Company’s common stock. February 2020 Underwriter Warrants Net proceeds from the February 2020 Underwritten Offering were $7,093,000 after deducting underwriting discounts and commissions and offering expenses paid by the Company. April 2020 Registered Direct Offering and Private Placement April 2020 Offering April 2020 Warrants April 2020 Placement Agent Warrants Warrants The Company first assesses the warrants it issues under the FASB ASC Topic 480, “ Distinguishing Liabilities from Equity ASC 480 The Company then applies and follows the applicable accounting guidance in ASC 815. Financial instruments are accounted for as either derivative liabilities or as equity instruments depending on the specific terms of the agreement. The Company’s outstanding warrants do not meet the definition of a derivative instrument as they are indexed to the Company’s common stock and classified within stockholders’ equity. Based on this determination, all of the Company’s outstanding warrants issued are classified within stockholders’ equity. The following table summarizes warrant activity and the shares of common stock underlying the Company’s outstanding equity-classified warrants for the year ended December 31, 2020: Exercise Expiration Balance December 31, Warrants Warrants Warrants Balance December 31, Description Price Date 2019 Issued Exercised Expired 2020 June 2015 Warrants $ 2,860.00 6/2/2020 2,364 – – (2,364 ) – December 2016 Warrants $ 495.00 12/21/2021 23,233 – – – 23,233 April 2018 Warrants $ 173.25 5/31/2023 20,599 – – – 20,599 April 2018 Placement Agent Warrants $ 223.00 4/9/2023 1,373 – – – 1,373 October 2018 Warrants $ 10.45 10/3/2025 389,610 – – – 389,610 October 2018 Underwriter Warrants $ 13.06 10/1/2023 29,220 – – – 29,220 November 2019 Placement Agent Warrants $ 6.875 11/18/2024 13,636 – – – 13,636 February 2020 Registered Direct Warrants $ 8.71 8/6/2025 – 197,056 – – 197,056 February 2020 Placement Agent Warrants $ 11.0375 2/4/2025 – 14,779 – – 14,779 February 2020 Underwritten Offering Warrants $ 4.00 2/13/2025 – 2,300,000 (973,500 ) – 1,326,500 February 2020 Pre-funded Warrants $ 0.001 No expiration – 1,006,367 (1,006,367 ) – – February 2020 Underwriter Warrants $ 5.00 2/11/2025 – 150,000 – – 150,000 April 2020 Warrants $ 2.21 10/2/2025 – 1,713,064 (428,266 ) – 1,284,798 April 2020 Placement Agent Warrants $ 2.9188 3/31/2025 – 128,480 – – 128,480 480,035 5,509,746 (2,408,133 ) (2,364 ) 3,579,284 During the year ended December 31, 2020, the Company received net proceeds of $3,856,000 from the exercise of warrants. During the year ended December 31, 2019, the Company received net proceeds of $72,000 from the exercise warrants. Of the warrants exercised during the year ended December 31, 2020, 428,266 of the Company’s April 2020 Warrants were exercised via a cashless exercise transaction and as a result a total of 225,796 shares of common stock were issued. There were no cashless exercises of warrants during the year ended December 31, 2019.

10. Net Loss per Share

10. Net Loss per Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Net Loss per Share	10. Net Loss per Share The following table sets forth the potential common shares excluded from the calculation of net loss per share because their inclusion would be anti-dilutive: December 31, 2020 2019 Options to purchase common stock 2,570 2,659 Nonvested restricted stock units 9,699 14,945 Warrants to purchase common stock 3,579,284 480,035 Total 3,591,553 497,639

11. Stock-based Compensation

11. Stock-based Compensation	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock-based Compensation	11. Stock-based Compensation Stock Plans The Company’s approved equity plans include the Phio Pharmaceuticals Corp. 2020 Long Term Incentive Plan (the “ 2020 Plan 2012 Plan As of December 31, 2020, there were an aggregate of 1,267,675 shares of common stock reserved under the 2020 Plan, including 2,570 shares subject to outstanding stock options and 9,699 shares subject to unvested restricted stock units (“ RSUs Restricted Stock Units RSUs are issued under the 2020 Plan or as inducement grants issued outside of the plan to new employees. RSUs are generally subject to graded vesting and the satisfaction of service requirements. Upon vesting, each outstanding RSU will be exchanged for one share of the Company’s common stock. Employee RSU recipients may elect to net share settle upon vesting, in which case the Company pays the employee’s income taxes due upon vesting and withholds a number of shares of equal value. The fair value of the RSUs awarded are based upon the Company’s closing stock price at the grant date and are expensed over the requisite service period. The following table summarizes the activity of the Company’s RSUs for the year ended December 31, 2020: Number Weighted- Unvested units at December 31, 2019 14,945 $ 20.50 Granted – – Vested (4,282 ) 22.18 Forfeited (964 ) 18.33 Unvested units at December 31, 2020 9,699 $ 19.97 Stock-based compensation expense related to RSUs was $85,000 and $125,000 for the years ended December 31, 2020 and 2019, respectively. As of December 31, 2020, the compensation expense for all unvested RSUs in the amount of approximately $151,000 will be recognized in the Company’s results of operations over a weighted average period of 2.35 years. Stock Options Stock options are issued under the 2020 Plan or as inducement grants issued outside of the plan to new employees. Stock options are generally subject to graded vesting and the satisfaction of service requirements. Upon the exercise of a stock option, the Company issues new shares and delivers them to the recipient. The Company does not expect to repurchase shares to satisfy stock option exercises. December 31, 2019 Risk-free interest rate 1.85 – 2.58% Expected volatility 97.67 – 98.87% Expected lives (in years) 5.31 Expected dividend yield 0.00% The weighted-average fair value of options granted during the year ended December 31, 2019 was $16.50 per share. The Company uses the Black-Scholes option-pricing model to determine the fair value of all its option grants. The risk-free interest rate used for each grant was based upon the yield on zero-coupon U.S. Treasury securities with a term similar to the expected life of the related option. The Company’s expected stock price volatility assumption is based upon the Company’s own implied volatility. As the Company has limited stock option exercise information, the expected life assumption used for option grants is based upon the simplified method provided for under ASC 718. The dividend yield assumption is based upon the fact that the Company has never paid cash dividends and presently has no intention of paying cash dividends. The following table summarizes the activity of the Company’s stock option plan for the year ended December 31, 2020: Total Number Weighted- Weighted- Aggregate Balance at December 31, 2019 2,659 $ 3,298.90 Granted – – Exercised – – Cancelled (89 ) 2,671.45 Balance at December 31, 2020 2,570 $ 3,334.06 6.22 years $ – Exercisable at December 31, 2020 1,855 $ 4,578.01 5.70 years $ – Stock-based compensation expense related to stock options for the years ended December 31, 2020 and 2019 was $51,000 and $69,000, respectively. As of December 31, 2020, the compensation expense for all unvested stock options in the amount of approximately $58,000 will be recognized in the Company’s results of operations over a weighted average period of 1.47 years. There is no income tax benefit as the Company is currently operating at a loss and an actual income tax benefit may not be realized. Restricted Stock During the period of from September 15, 2018 to February 28, 2019, the Company’s former Chief Executive Officer elected the right to receive, in lieu cash, up to 50% of his base salary and cash bonuses, if any, (collectively, the “ Compensation Compensation Expense Related to Equity Awards The following table sets forth total stock-based compensation expense for the years ended December 31, 2020 and 2019, in thousands: December 31, 2020 2019 Research and development $ 22 $ 21 General and administrative 114 279 Total stock-based compensation $ 136 $ 300

12. Income Taxes

12. Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	12. Income Taxes For the years ended December 31, 2020 and 2019, all of the Company’s loss before income taxes was generated in the United States. The components of federal and state income tax expense (benefit) are as follows, in thousands: Years Ended December 31, 2020 2019 Current Federal $ – $ – State – – Total current – – Deferred Federal (1,873 ) (1,773 ) State (768 ) (759 ) Total deferred (2,641 ) (2,532 ) Valuation allowance 2,641 2,532 Total income tax expense (benefit) $ – $ – Reconciliation of the effective income tax rate to the U.S. statutory rate is as follows: Years Ended December 31, 2020 2019 Federal statutory rate 21.0 % 21.0 % State income taxes, net of federal benefit 6.7 6.7 Non-deductible expenses (0.5 ) (0.2 ) Income tax credits 2.1 1.5 Valuation allowance (29.3 ) (29.0 ) Effective tax rate – – The components of the Company’s deferred tax assets are as follows, in thousands: Years Ending December 31, 2020 2019 Deferred tax assets: Net operating loss carryforwards $ 22,307 $ 19,647 Tax credit carryforwards 2,017 1,710 Stock-based compensation 1,374 1,391 Licensing deduction deferral 2,376 2,717 Other timing differences 196 165 Lease liability 111 140 Deferred tax assets 28,381 25,770 Deferred tax liabilities: Right of use asset (108 ) (138 ) Deferred tax liability (108 ) (138 ) Valuation allowance (28,273 ) (25,632 ) Net deferred tax asset $ – $ – The Company’s deferred tax assets at December 31, 2020 and 2019 consisted primarily of its net operating loss carryforwards, tax credit carryforwards, deferred compensation and intangible assets capitalized for federal income tax purposes. The valuation allowance increased $2,641,000 and $2,532,000 for the years ended December 31, 2020 and 2019, respectively, and is primarily attributable to an increase in net operating losses and tax credits. The Company has incurred net operating losses since inception. At December 31, 2020, the Company had federal and state net operating loss carryforwards of approximately $83,600,000 and $75,300,000, respectively, which will begin to expire in 2031. Approximately, $55,300,000 of the federal net operating loss carryforwards will begin to expire in 2031, unless previously utilized, and approximately $28,300,000 of the federal net operating loss carryforwards will carryforward indefinitely. The Company’s state tax loss carryforwards will begin to expire in 2031, unless previously utilized. In general, an ownership change, as defined by Section 382 of the Internal Revenue Code, results from transactions increasing the ownership of certain shareholders or public groups in the stock of a corporation by more than 50% over a three-year period. The Company has not conducted a study to assess whether a change of control has occurred or whether there have been multiple changes of control since inception due to their history of losses. If the Company has experienced a change of control, as defined by Section 382, at any time since inception, utilization of the net operating loss carryforwards or research and development tax credit carryforwards would be subject to an annual limitation under Section 382 and 383. Any limitation may result in expiration of a portion of the net operating loss carryforwards or research and development tax credit carryforwards before utilization. Further, until a study is completed and any limitation is known, no adjustments have been reflected in the deferred tax asset for net operating loss carryforwards. The Company files income tax returns in the United States, Massachusetts and New Jersey. The Company is subject to tax examinations for federal and state purposes for tax years 2012 through 2020. The Company has not recorded any uncertain tax positions as of December 31, 2020 or 2019. The Company does not believe there will be any material changes in its unrecognized tax positions over the next 12 months. The Company has not incurred any interest or penalties. In the event that the Company is assessed interest or penalties at some point in the future, they will be classified in the financial statements as general and administrative expenses.

13. License Agreements

13. License Agreements	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
License Agreements	13. License Agreements As part of its business, the Company enters into licensing agreements with third parties that often require milestone and royalty payments based on the progress of the asset through development stages. Milestone payments may be required, for example, upon approval of the product for marketing by a regulatory agency. In certain agreements, the Company is required to make royalty payments based upon a percentage of the sales of the products licensed pursuant to such agreements. The expenditures required under these arrangements may be material individually in the event that the Company develops product candidates covered by the intellectual property licensed under any such arrangement, and in the unlikely event that milestones for multiple products covered by these arrangements were reached in the same period, the aggregate charge to expense could be material to the results of operations. In addition, these arrangements often give the Company discretion to unilaterally terminate development of the product, which would allow the Company to avoid making the contingent payments; however, the Company is unlikely to cease development if the compound successfully achieves clinical testing objectives. Advirna LLC. Advirna Our rights under the Advirna agreement will expire upon the later of: (i) the expiration of the last-to-expire of the “patent rights” (as defined therein) included in the Advirna agreement; or (ii) the abandonment of the last-to-be abandoned of such patents, unless earlier terminated in accordance with the provisions of the agreement.

14. Subsequent Events

14. Subsequent Events	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	14. Subsequent Events January 2021 Private Placement — The Company is currently reviewing the accounting for the pre-funded warrants and warrants issued in the January 2021 private placement. February 2021 Registered Direct Offering — Warrant Exercises —

2. Significant Accounting Pol_2

2. Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“ GAAP
Reverse Stock Split	Reverse Stock Split Effective January 15, 2020, the Company completed a 1-for-55 reverse stock split of the Company’s outstanding common stock. All share and per share amounts in the financial statements have been retroactively adjusted for all periods presented to give effect to the reverse stock split, including reclassifying an amount equal to the reduction in par value to additional paid-in capital. Unless otherwise noted, shares of common stock issued and outstanding, shares underlying warrants and stock awards, shares reserved, conversion price of convertible securities, exercise prices of warrants and stock awards and loss per share have been proportionately adjusted to reflect the reverse stock split. The reverse stock split did not reduce the number of authorized shares of the Company’s common stock or preferred stock.
Principles of Consolidation	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	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. The areas subject to significant estimates and judgement include, among others, those related to the fair value of equity awards, research and development expenses, useful lives of property and equipment, income taxes, and our valuation allowance on our deferred tax assets. On an ongoing basis we evaluate our estimates and base our estimates on historical experience and other relevant assumptions that we believe are reasonable under the circumstances, including as a result of new information that may emerge concerning the coronavirus pandemic. We have made estimates of the impact of the coronavirus pandemic within our financial statements and there may be changes to those estimates in future periods. Actual results could differ materially from these estimates.
Restricted Cash	Restricted Cash Restricted cash consists of certificates of deposit held by financial institutions as collateral for the Company’s corporate credit cards.
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash. The Company maintains cash balances in several accounts with a financial institution that management believes is creditworthy, which at times are in excess of federally insured limits. These accounts are insured by the Federal Deposit Insurance Corporation (FDIC) for up to $250,000 per institution.
Property and Equipment	Property and Equipment Property and equipment are stated at cost and depreciated using the straight-line method based on the estimated useful lives of the related assets. The Company provides for depreciation over the assets’ estimated useful lives as follows: Computer equipment 3 years Machinery & equipment 5 years Furniture & fixtures 5 years Leasehold improvements 5 years Depreciation and amortization expense for the years ended December 31, 2020 and 2019 was $72,000 and $67,000, respectively.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company reviews long-lived assets for impairment whenever an event occurs or change in circumstances that the related carrying amounts may not be recoverable. An impairment loss would be recognized based on the difference between the carrying value of the asset and its estimated fair value, which would be determined based on either discounted future cash flows or other appropriate fair value methods. The Company believes no impairment existed as of December 31, 2020 or 2019.
Fair Value of Financial Instruments	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.
Leases	Leases 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. For leases with a term greater than one year, the Company recognizes a liability to make lease payments and an asset representing the right to use the underlying asset during the lease term at the commencement date of the lease. 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.
Debt	Debt On March 27, 2020, the United States enacted the Coronavirus Aid, Relief, and Economic Security Act (the “ CARES Act PPP Debt ASC 470
Derivative Financial Instruments	Derivative Financial Instruments 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.
Research and Development Expenses	Research and Development Expenses Research and development expenses 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. Accrued liabilities for the services provided by contract research organizations 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	Stock-based Compensation The Company follows the provisions of the Financial Accounting Standards Board (the “ FASB ASC Compensation — Stock Compensation ASC 718 Stock-based compensation expense recognized in the financial statements is based on awards that are ultimately expected to vest. Accordingly, we are also required to estimate forfeitures at the time of grant, and to revise those estimates in subsequent periods if actual forfeitures differ from estimates. We use historical data to estimate pre-vesting option forfeitures and record stock-based compensation expense only for those awards that are expected to vest. Our forfeiture rate estimates are based on an analysis of our actual forfeiture experience, employee turnover behavior, and other factors. The impact of any adjustments to our forfeiture rates would be recorded as a cumulative adjustment in the period of adjustment. To the extent that actual forfeitures differ from our estimates, the difference is recorded as a cumulative adjustment in the period the estimates were revised.
Income Taxes	Income Taxes The Company recognizes assets or liabilities for the deferred tax consequences of temporary differences between the tax basis of assets or liabilities and their reported amounts in the financial statements in accordance with the FASB ASC Topic 740, “Accounting for Income Taxes” ASC 740 . ASC 740 requires that a valuation allowance be established when management determines that it is more likely than not that all or a portion of a deferred asset will not be realized. The Company evaluates the realizability of its net deferred income tax assets and valuation allowances as necessary, at least on an annual basis. During this evaluation, the Company reviews its forecasts of income in conjunction with other positive and negative evidence surrounding the realizability of its deferred income tax assets to determine if a valuation allowance is required. Adjustments to the valuation allowance will increase or decrease the Company’s income tax provision or benefit. The recognition and measurement of benefits related to the Company’s tax positions requires significant judgment, as uncertainties often exist with respect to new laws, new interpretations of existing laws, and rulings by taxing authorities. The Company follows a more-likely-than not threshold for financial statement recognition and measurement of a tax position taken, or expected to be taken in a tax return. The guidance relates to, amongst other things, classification, accounting for interest and penalties associated with tax positions, and disclosure requirements. Any interest and penalties accrued related to uncertain tax positions are recorded as tax expense. Differences between actual results and the Company’s assumptions or changes in the Company’s assumptions in future periods are recorded in the period they become known.
Comprehensive Loss	Comprehensive Loss The Company’s comprehensive loss is equal to its net loss for all periods presented.
Net Loss per Share	Net Loss per Share Basic net loss per share is computed by dividing net loss by the weighted average number of common shares outstanding. Diluted net loss per share is computed by dividing the Company’s net less by the weighted average number of common shares outstanding and the impact of all dilutive potential common shares outstanding, except where such dilutive potential common shares would be anti-dilutive. Dilutive potential common shares primarily consist of warrants, restricted stock units and stock options.

2. Significant Accounting Pol_3

2. Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Schedule of useful lives of property and equipment	The Company provides for depreciation over the assets’ estimated useful lives as follows: Computer equipment 3 years Machinery & equipment 5 years Furniture & fixtures 5 years Leasehold improvements 5 years

5. Accrued Expenses and Other_2

5. Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2020
Payables and Accruals [Abstract]
Schedule of Accrued expenses and other current liabilities	Accrued expenses and other current liabilities consist of the following, in thousands: December 31, 2020 2019 Compensation and benefits $ 618 $ 524 Professional fees 81 171 Research and development costs 549 242 Other 104 27 Total accrued expenses and other current liabilities $ 1,352 $ 964

6. Leases (Tables)

6. Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Schedule of lease amounts recorded in balance sheet	The amounts reported in the consolidated balance sheets for operating leases in which the Company is the lessee and other supplemental balance sheet information is set forth as follows, in thousands, except lease term and discount rate: December 31, 2020 December 31, 2019 Assets Right of use asset $ 400 $ 511 Liabilities Lease liability, current 116 107 Lease liability, non-current 295 411 Total lease liability $ 411 $ 518 Lease Term and Discount Rate Weighted average remaining lease term 3.71 4.43 Weighted average discount rate 4.70% 4.64%
Aggregate future minimum lease payments	Future lease payments for our non-cancellable operating leases and a reconciliation to the carrying amount of the operating lease liability presented in the condensed consolidated balance sheet as of December 31, 2020 is as follows, in thousands: 2021 $ 132 2022 135 2023 140 2024 35 Total lease payments 442 Less: Imputed interest (31 ) Total operating lease liabilities (includes current portion) $ 411

8. Commitments and Contingenc_2

8. Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Future Cash Payments Under Contractual License Obligations	The Company’s contractual license obligations that will require future cash payments as of December 31, 2020 are as follows, in thousands: Year Ending December 31, 2021 165 2022 100 2023 100 2024 100 2025 100 Thereafter 400 Total $ 965

9. Stockholders' Equity (Tables

9. Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Summary of outstanding warrants	The following table summarizes warrant activity and the shares of common stock underlying the Company’s outstanding equity-classified warrants for the year ended December 31, 2020: Exercise Expiration Balance December 31, Warrants Warrants Warrants Balance December 31, Description Price Date 2019 Issued Exercised Expired 2020 June 2015 Warrants $ 2,860.00 6/2/2020 2,364 – – (2,364 ) – December 2016 Warrants $ 495.00 12/21/2021 23,233 – – – 23,233 April 2018 Warrants $ 173.25 5/31/2023 20,599 – – – 20,599 April 2018 Placement Agent Warrants $ 223.00 4/9/2023 1,373 – – – 1,373 October 2018 Warrants $ 10.45 10/3/2025 389,610 – – – 389,610 October 2018 Underwriter Warrants $ 13.06 10/1/2023 29,220 – – – 29,220 November 2019 Placement Agent Warrants $ 6.875 11/18/2024 13,636 – – – 13,636 February 2020 Registered Direct Warrants $ 8.71 8/6/2025 – 197,056 – – 197,056 February 2020 Placement Agent Warrants $ 11.0375 2/4/2025 – 14,779 – – 14,779 February 2020 Underwritten Offering Warrants $ 4.00 2/13/2025 – 2,300,000 (973,500 ) – 1,326,500 February 2020 Pre-funded Warrants $ 0.001 No expiration – 1,006,367 (1,006,367 ) – – February 2020 Underwriter Warrants $ 5.00 2/11/2025 – 150,000 – – 150,000 April 2020 Warrants $ 2.21 10/2/2025 – 1,713,064 (428,266 ) – 1,284,798 April 2020 Placement Agent Warrants $ 2.9188 3/31/2025 – 128,480 – – 128,480 480,035 5,509,746 (2,408,133 ) (2,364 ) 3,579,284

10. Net Loss per Share (Tables)

10. Net Loss per Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Schedule of antidilutive stock	December 31, 2020 2019 Options to purchase common stock 2,570 2,659 Nonvested restricted stock units 9,699 14,945 Warrants to purchase common stock 3,579,284 480,035 Total 3,591,553 497,639

11. Stock-based Compensation (T

11. Stock-based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Summary of RSU activity	The following table summarizes the activity of the Company’s RSUs for the year ended December 31, 2020: Number Weighted- Unvested units at December 31, 2019 14,945 $ 20.50 Granted – – Vested (4,282 ) 22.18 Forfeited (964 ) 18.33 Unvested units at December 31, 2020 9,699 $ 19.97
Fair value assumptions used	December 31, 2019 Risk-free interest rate 1.85 – 2.58% Expected volatility 97.67 – 98.87% Expected lives (in years) 5.31 Expected dividend yield 0.00%
Summary of Stock Option Activity	The following table summarizes the activity of the Company’s stock option plan for the year ended December 31, 2020: Total Number Weighted- Weighted- Aggregate Balance at December 31, 2019 2,659 $ 3,298.90 Granted – – Exercised – – Cancelled (89 ) 2,671.45 Balance at December 31, 2020 2,570 $ 3,334.06 6.22 years $ – Exercisable at December 31, 2020 1,855 $ 4,578.01 5.70 years $ –
Details of Stock-based Compensation Expense Recorded	December 31, 2020 2019 Research and development $ 22 $ 21 General and administrative 114 279 Total stock-based compensation $ 136 $ 300

12. Income Taxes (Tables)

12. Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Components of Federal and State Income Tax Expense	The components of federal and state income tax expense (benefit) are as follows, in thousands: Years Ended December 31, 2020 2019 Current Federal $ – $ – State – – Total current – – Deferred Federal (1,873 ) (1,773 ) State (768 ) (759 ) Total deferred (2,641 ) (2,532 ) Valuation allowance 2,641 2,532 Total income tax expense (benefit) $ – $ –
Effect Income Tax Rate Reconciliation	Reconciliation of the effective income tax rate to the U.S. statutory rate is as follows: Years Ended December 31, 2020 2019 Federal statutory rate 21.0 % 21.0 % State income taxes, net of federal benefit 6.7 6.7 Non-deductible expenses (0.5 ) (0.2 ) Income tax credits 2.1 1.5 Valuation allowance (29.3 ) (29.0 ) Effective tax rate – –
Components of Net Deferred Tax Assets	Years Ending December 31, 2020 2019 Deferred tax assets: Net operating loss carryforwards $ 22,307 $ 19,647 Tax credit carryforwards 2,017 1,710 Stock-based compensation 1,374 1,391 Licensing deduction deferral 2,376 2,717 Other timing differences 196 165 Lease liability 111 140 Deferred tax assets 28,381 25,770 Deferred tax liabilities: Right of use asset (108 ) (138 ) Deferred tax liability (108 ) (138 ) Valuation allowance (28,273 ) (25,632 ) Net deferred tax asset $ – $ –

2. Property and Equipment Usefu

2. Property and Equipment Useful Lives (Details)	12 Months Ended
	Dec. 31, 2020
Computer Equipment [Member]
Property and equipment useful life	3 years
Machinery and equipment [Member]
Property and equipment useful life	5 years
Furniture And Fixtures [Member]
Property and equipment useful life	5 years
Leasehold Improvements [Member]
Property and equipment useful life	5 years

2. Significant Accounting Pol_4

2. Significant Accounting Policies (Details Narrative) - USD ($) $ in Thousands	Jan. 15, 2020	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Reverse stock split	Effective January 15, 2020, the Company completed a 1-for-55 reverse stock split	1:55 reverse stock split
Depreciation and amortization expense		$ 72	$ 67
Impairment of Long-Lived Assets		$ 0	$ 0

5. Accrued Expenses and Other_3

5. Accrued Expenses and Other Current Liabilities - (Details - Schedule of Accrued Expenses) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accrued Liabilities and Other Liabilities [Abstract]
Compensation and benefits	$ 618	$ 524
Professional fees	81	171
Research and development costs	549	242
Other	104	27
Total accrued expenses and other current liabilities	$ 1,352	$ 964

6. Leases (Details - Balance sh

6. Leases (Details - Balance sheet lease items) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Right of use asset	$ 400	$ 511
Lease liability, current	116	107
Lease liability, non-current	295	411
Total lease liability	$ 411	$ 518
Weighted average remaining lease term	3 years 8 months 16 days	4 years 5 months 5 days
Weighted average discount rate	4.70%	4.64%

6. Leases (Details - Future lea

6. Leases (Details - Future lease payments) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
2021	$ 132
2022	135
2023	140
2024	35
Total lease payments	442
Less: Imputed interest	(31)
Total operating lease liabilities (includes current portion)	$ 411	$ 518

6. Leases (Details Narrative)

6. Leases (Details Narrative)	12 Months Ended
	Dec. 31, 2020USD ($)ft²	Dec. 31, 2019USD ($)
Operating lease cost	$ 132,000	$ 127,000
Operating lease payments	$ 127,800	$ 121,000
Office and Laboratory Space [Member]
Lease expiration date	Mar. 31, 2024
Operating lease footage | ft²	7,581

7. Debt (Details Narrative)

7. Debt (Details Narrative) - USD ($)	4 Months Ended	12 Months Ended
	May 11, 2020	Dec. 31, 2020	Dec. 31, 2019
Proceeds from debt		$ 231,000	$ 0
PPP Loan [Member]
Proceeds from debt	$ 231,252
Debt maturity date	May 11, 2022
Debt interest rate	1.00%

8. Commitments and Contingenc_3

8. Commitments and Contingencies - (Details - Future Cash Payments) $ in Thousands	Dec. 31, 2020USD ($)
Commitments and Contingencies Disclosure [Abstract]
2021	$ 165
2022	100
2023	100
2024	100
2025	100
Thereafter	400
Total	$ 965

9. Stockholders' Equity (Detail

9. Stockholders' Equity (Details - Warrants outstanding) - Warrants [Member] - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Class of Warrant or Right [Line Items]
Warrants outstanding	3,579,284	480,035
Warrants issued	5,509,746
Warrants exercised	(2,408,133)
Warrants expired	(2,364)
June 2015 Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant exercise price	$ 2,860
Warrant expiration date	Jun. 2, 2020
Warrants outstanding	0	2,364
Warrants issued	0
Warrants exercised	0
Warrants expired	(2,364)
December 2016 Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant exercise price	$ 495
Warrant expiration date	Dec. 21, 2021
Warrants outstanding	23,233	23,233
Warrants issued	0
Warrants exercised	0
Warrants expired	0
April 2018 Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant exercise price	$ 173.25
Warrant expiration date	May 31, 2023
Warrants outstanding	20,599	20,599
Warrants issued	0
Warrants exercised	0
Warrants expired	0
April 2018 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant exercise price	$ 223
Warrant expiration date	Apr. 9, 2023
Warrants outstanding	1,373	1,373
Warrants issued	0
Warrants exercised	0
Warrants expired	0
October 2018 Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant exercise price	$ 10.45
Warrant expiration date	Oct. 3, 2025
Warrants outstanding	389,610	389,610
Warrants issued	0
Warrants exercised	0
Warrants expired	0
October 2018 Underwriter Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant exercise price	$ 13.06
Warrant expiration date	Oct. 1, 2023
Warrants outstanding	29,220	29,220
Warrants issued	0
Warrants exercised	0
Warrants expired	0
November 2019 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant exercise price	$ 6.875
Warrant expiration date	Nov. 18, 2024
Warrants outstanding	13,636	13,636
Warrants issued	0
Warrants exercised	0
Warrants expired	0
February 2020 Registered Direct Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant exercise price	$ 8.71
Warrant expiration date	Aug. 6, 2025
Warrants outstanding	197,056	0
Warrants issued	197,056
Warrants exercised	0
Warrants expired	0
February 2020 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant exercise price	$ 11.0375
Warrant expiration date	Feb. 4, 2025
Warrants outstanding	14,779	0
Warrants issued	14,779
Warrants exercised	0
Warrants expired	0
February 2020 Underwritten Offering Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant exercise price	$ 4
Warrant expiration date	Feb. 13, 2025
Warrants outstanding	1,326,500	0
Warrants issued	2,300,000
Warrants exercised	(973,500)
Warrants expired	0
February 2020 Pre-funded Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant exercise price	$ 0.001
Warrants outstanding	0	0
Warrants issued	1,006,367
Warrants exercised	(1,006,367)
Warrants expired	0
February 2020 Underwriter Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant exercise price	$ 5
Warrant expiration date	Feb. 11, 2025
Warrants outstanding	150,000	0
Warrants issued	150,000
Warrants exercised	0
Warrants expired	0
April 2020 Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant exercise price	$ 2.21
Warrant expiration date	Oct. 2, 2025
Warrants outstanding	1,284,798	0
Warrants issued	1,713,064
Warrants exercised	(428,266)
Warrants expired	0
April 2020 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Warrant exercise price	$ 2.9188
Warrant expiration date	Mar. 31, 2025
Warrants outstanding	128,480	0
Warrants issued	128,480
Warrants exercised	0
Warrants expired	0

9. Stockholders' Equity (Deta_2

9. Stockholders' Equity (Details Narrative) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		3 Months Ended	11 Months Ended	12 Months Ended
	Feb. 13, 2020	Feb. 06, 2020	Apr. 02, 2020	Nov. 19, 2019	Dec. 31, 2020	Dec. 31, 2019
Proceeds from issuance of stock and warrants					$ 12,087	$ 708
Proceeds from exercise of warrants					$ 3,856	$ 72
February 2020 Registered Offering [Member]
Stock issued during period, shares		197,056
Stock price per share		$ 8.705
Proceeds from issuance of stock and warrants		$ 1,467
February 2020 Registered Direct Warrants [Member]
Stock price per share		$ 0.125
Warrants issued		197,056
Warrant exercise price		$ 8.71
February 2020 Placement Agent Warrants [Member]
Warrants issued		14,779
Warrant exercise price		$ 11.0375
November 2019 Offering [Member]
Stock issued during period, shares				181,818
Proceeds from the issuance of common stock				$ 766
Stock price per share				$ 5.50
Increase in fair value due to modification of price				$ 800
November 2019 Offering [Member] | H.C. Wainwright [Member]
Warrants issued				13,636
Warrant exercise price				$ 6.875
October 2018 Offering [Member]
Warrant exercise price				10.45
October 2018 Offering [Member] | H.C. Wainwright [Member]
Warrant exercise price				$ 13.06
February 2020 Underwritten Public Offering [Member]
Stock issued during period, shares	993,633
Stock price per share	$ 4
Proceeds from issuance of stock and warrants	$ 7,093
February 2020 Underwritten Public Offering [Member] | 2020 Pre-Funded Warrants [Member]
Stock price per share	$ 3.999
Warrants issued	1,006,367
Warrant exercise price	$ 0.001
February 2020 Underwritten Public Offering [Member] | February 2020 Warrants [Member]
Stock price per share	$ 4
Warrants issued	2,000,000
February 2020 Underwritten Public Offering [Member] | February 2020 Underwriter Warrants [Member]
Warrants issued	150,000
Warrant exercise price	$ 5
February 2020 Underwritten Public Offering [Member] | Underwriter [Member] | February 2020 Warrants [Member]
Stock price per share	$ 0.001
Warrants issued	300,000
Option to purchase shares of common stock, shares	300,000
Option to purchase shares of common stock, price per share	$ 3.999
April 2020 Offering [Member]
Stock issued during period, shares			1,713,064
Stock price per share			$ 2.21
Proceeds from issuance of stock and warrants			$ 3,527
Warrants converted, shares converted					428,266
Warrants converted, common stock issued					225,796
April 2020 Offering [Member] | April 2020 Warrants [Member]
Stock price per share			$ 0.125
Warrants issued			1,713,064
Warrant exercise price			$ 2.21
April 2020 Offering [Member] | April 2020 Placement Agent Warrants [Member]
Warrants issued			128,480
Warrant exercise price			$ 2.9188

10. Net Loss per Share (Details

10. Net Loss per Share (Details - Antidilutive shares) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total amount of anti-dilutive securities excluded from computation of earnings per share	3,591,553	497,639
Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total amount of anti-dilutive securities excluded from computation of earnings per share	2,570	2,659
Nonvested Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total amount of anti-dilutive securities excluded from computation of earnings per share	9,699	14,945
Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total amount of anti-dilutive securities excluded from computation of earnings per share	3,579,284	480,035

11. Stock-based Compensation (D

11. Stock-based Compensation (Details - RSU activity) - Restricted Stock Units R S U [Member]	12 Months Ended
	Dec. 31, 2020$ / sharesshares
RSU's unvested units, beginning balance | shares	14,945
RSU's granted | shares	0
RSU's vested | shares	(4,282)
RSU's forfeited | shares	(964)
RSU's unvested units, ending balance | shares	9,699
RSU beginning balance, price per share | $ / shares	$ 20.5
RSU's granted, price per share | $ / shares
RSU's vested, price per share | $ / shares	22.18
RSU's forfeited, price per share | $ / shares	18.33
RSU ending balance, price per share | $ / shares	$ 19.97

11. Stock-based Compensation _2

11. Stock-based Compensation (Details - Assumptions) - Options [Member]	12 Months Ended
	Dec. 31, 2020
Risk-free interest rate, minimum	1.85%
Risk-free interest rate, maximum	2.58%
Expected volatility, minimum	97.67%
Expected volatility, maximum	98.87%
Expected lives (in years)	5 years 3 months 22 days
Expected dividend yield	0.00%

11. Stock-based Compensation _3

11. Stock-based Compensation (Details - Option activity) - Options [Member] $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares
Total Number of Options, Beginning Balance | shares	2,659
Total Number of Options, Granted | shares	0
Total Number of Options, Exercised | shares	0
Total Number of Options, Cancelled | shares	(89)
Total Number of Options, Ending Balance | shares	2,570
Total Number of Options, Exercisable | shares	1,855
Weighted-Average Exercise Price Per Share, Beginning Balance | $ / shares	$ 3,298.90
Weighted-Average Exercise Price Per Share, Granted | $ / shares
Weighted-Average Exercise Price Per Share, Exercised | $ / shares
Weighted-Average Exercise Price Per Share, Cancelled | $ / shares	2,671.45
Weighted-Average Exercise Price Per Share, Ending Balance | $ / shares	3,334.06
Weighted-Average Exercise Price Per Share, Exercisable | $ / shares	$ 4,578.01
Weighted-Average Contractual Term, Outstanding	6 years 2 months 19 days
Weighted-Average Contractual Term, Exercisable	5 years 8 months 12 days
Aggregate Intrinsic Value, Ending Balance | $	$ 0
Aggregate Intrinsic Value, Exercisable | $	$ 0

11. Stock-based Compensation _4

11. Stock-based Compensation (Details - Share-based compensation) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 136	$ 300
Research and Development Expense [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	22	21
General and Administrative Expense [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 114	$ 279

11. Stock-based Compensation _5

11. Stock-based Compensation (Details Narrative) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based compensation expense	$ 136	$ 300
2020 Long-Term Incentive Plan [Member]
Shares reserved for issuance	1,267,675
Shares available for future grants	1,254,906
Restricted Stock [Member] | Dr. Cauwenbergh [Member]
Share-based compensation expense		$ 106
Issuance of restricted stock, shares		4,419
Restricted Stock Units R S U [Member]
Share-based compensation expense	$ 85	$ 125
Unrecognized compensation expense - other than options	$ 151
Unrecognized compensation expense weighted average period	2 years 4 months 6 days
Other than options, nonvested	9,699	14,945
Options [Member]
Weighted average grant date fair value per share of options granted		$ 16.50
Share-based compensation expense	$ 51	$ 69
Unrecognized compensation expense - options	$ 58
Unrecognized compensation expense weighted average period	1 year 5 months 20 days
Options outstanding	2,570	2,659
Options [Member] | 2020 Long-Term Incentive Plan [Member]
Options outstanding	2,570

12. Income Taxes - (Details -

12. Income Taxes - (Details - Components of Federal and State Income Tax Expense) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Current
Federal	$ 0	$ 0
State	0	0
Total current	0	0
Deferred
Federal	(1,873)	(1,773)
State	(768)	(759)
Total deferred	(2,641)	(2,532)
Valuation allowance	2,641	2,532
Total income tax expense (benefit)	$ 0	$ 0

12. Income Taxes - (Details - E

12. Income Taxes - (Details - Effect Income Tax Rate Reconciliation)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Federal statutory rate	21.00%	21.00%
State income taxes, net of federal benefit	6.70%	6.70%
Non-deductible expenses	(0.50%)	(0.20%)
Income tax credits	(2.10%)	1.50%
Valuation allowance	(29.30%)	(29.00%)
Effective tax rate	0.00%	0.00%

12. Income Taxes - (Details - C

12. Income Taxes - (Details - Components of Net Deferred Tax Assets) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating loss carryforwards	$ 22,307	$ 19,647
Tax credit carryforwards	2,017	1,710
Stock-based compensation	1,374	1,391
Licensing deduction deferral	2,376	2,717
Other timing differences	196	165
Lease liability	111	140
Deferred tax assets	28,381	25,770
Deferred tax liabilities:
Right of use asset	(108)	(138)
Deferred tax liability	(108)	(138)
Valuation allowance	(28,273)	(25,632)
Net deferred tax asset	$ 0	$ 0

12. Income Taxes (Details Narra

12. Income Taxes (Details Narrative) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Line Items]
Increase (decrease) in valuation allowance	$ 2,641	$ 2,532
NOL beginning expiration date	Dec. 31, 2031
Research tax credit beginning expiration date	Dec. 31, 2031
Income tax benefit	$ 0	0
Uncertain tax positions	0	$ 0
Federal [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	83,600
NOL carryforward with expiration	55,300
NOL carryforward indefinitely	28,300
Research tax credits	1,430
State [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	75,300
Research tax credits	$ 742

14. Subsequent Events (Details

14. Subsequent Events (Details Narrative) - USD ($)	1 Months Ended		3 Months Ended	12 Months Ended
	Feb. 12, 2021	Jan. 25, 2021	Mar. 23, 2021	Dec. 31, 2020	Dec. 31, 2019
Proceeds from sale of equity				$ 12,087,000	$ 708,000
Proceeds from warrant exercises				$ 3,856,000	$ 72,000
Warrants [Member]
Warrants issued, shares				5,509,746
Subsequent Event [Member]
Proceeds from warrant exercises			$ 2,146,000
Stock issued from exercise of warrants, shares			1,083,321
Subsequent Event [Member] | Jan 2021 Private Placement [Member] | Common Stock [Member]
Stock issued new, shares		4,420,863
Stock price per share		$ 3.07
Proceeds from sale of equity		$ 12,700,000
Subsequent Event [Member] | Jan 2021 Private Placement [Member] | Pre Funded Warrants [Member]
Stock price per share		$ 3.069
Warrants issued, shares		140,065
Subsequent Event [Member] | Jan 2021 Private Placement [Member] | Warrants [Member]
Warrants issued, shares		3,420,696
Warrant per share issue price		$ 3
Subsequent Event [Member] | Jan 2021 Private Placement [Member] | Warrants [Member] | Placement Agent [Member]
Warrants issued, shares		342,070
Warrant per share issue price		$ 3.8375
Subsequent Event [Member] | February 2021 Registered Direct Offering [Member]
Proceeds from sale of equity	$ 6,900,000
Subsequent Event [Member] | February 2021 Registered Direct Offering [Member] | Common Stock [Member]
Stock issued new, shares	2,246,784
Stock price per share	$ 3.42
Subsequent Event [Member] | February 2021 Registered Direct Offering [Member] | Warrants [Member] | Placement Agent [Member]
Warrants issued, shares	168,509
Warrant per share issue price	$ 4.275