Opus Genetics (IRD) 10-Q 7 May 20 2020 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2020	May 07, 2020
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2020
Entity Registrant Name	REXAHN PHARMACEUTICALS, INC.
Entity Central Index Key	0001228627
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Entity Current Reporting Status	Yes
Entity Small Business	true
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		4,019,141

Condensed Balance Sheet

Condensed Balance Sheet - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Current Assets:
Cash and cash equivalents	$ 10,998,096	$ 9,219,547
Marketable securities		2,997,220
Prepaid expenses and other current assets	290,756	447,206
Total Current Assets	11,288,852	12,663,973
Security Deposits	25,681	25,681
Operating Lease Right-of-Use Assets	171,870	203,348
Equipment, Net	66,515	75,770
Total Assets	11,552,918	12,968,772
Current Liabilities:
Accounts payable and accrued expenses	1,237,007	1,265,731
Deferred revenue	600,000	1,500,000
Operating lease liabilities, current	144,610	139,765
Total Current Liabilities	1,981,617	2,905,496
Operating Lease Liabilities, non-current	25,790	63,605
Warrant Liabilities	100,109	41,717
Total Liabilities	2,107,516	3,010,818
Commitments and Contingencies (note 11)
Stockholders' Equity:
Preferred stock, par value $0.0001, 10,000,000 authorized shares, none issued and outstanding
Common stock, par value $0.0001, 75,000,000 authorized shares, 4,019,141 issued and outstanding	402	402
Additional paid-in capital	173,354,446	173,278,144
Accumulated other comprehensive income		2,084
Accumulated deficit	(163,909,446)	(163,322,676)
Total Stockholders' Equity	9,445,402	9,957,954
Total Liabilities and Stockholders' Equity	$ 11,552,918	$ 12,968,772

Condensed Balance Sheet (Parent

Condensed Balance Sheet (Parenthetical) - $ / shares	Mar. 31, 2020	Dec. 31, 2019
Condensed Balance Sheet [Abstract]
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	75,000,000	75,000,000
Common Stock, Shares, Issued	4,019,141	4,019,141
Common Stock, Shares, Outstanding	4,019,141	4,019,141

Condensed Statement Of Operatio

Condensed Statement Of Operations - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Condensed Statement Of Operations [Abstract]
Revenues:	$ 1,150,000
Expenses:
General and administrative	1,256,006	1,695,523
Research and development	456,790	2,242,229
Total Expenses	1,712,796	3,937,752
Loss from Operations	(562,796)	(3,937,752)
Other Income
Interest income	34,418	81,385
Unrealized (loss) gain on fair value of warrants	(58,392)	1,513,371
Total Other (Loss) Income	(23,974)	1,594,756
Net Loss Before Provision for Income Taxes	(586,770)	(2,342,996)
Provision for Income Taxes
Net Loss	$ (586,770)	$ (2,342,996)
Net loss per share, basic and diluted	$ (0.15)	$ (0.62)
Weighted average number of shares outstanding, basic and diluted	4,019,141	3,779,953

Condensed Statement Of Comprehe

Condensed Statement Of Comprehensive Loss - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Condensed Statement Of Comprehensive Loss [Abstract]
Net Loss	$ (586,770)	$ (2,342,996)
Unrealized (loss) gain on available-for-sale securities	(2,084)	5,234
Comprehensive Loss	$ (588,854)	$ (2,337,762)

Condensed Statement Of Stockhol

Condensed Statement Of Stockholders' Equity - USD ($)	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance at Dec. 31, 2018	$ 312	$ 165,267,656	$ (154,687,242)	$ (17,836)	$ 10,562,890
Balance, shares at Dec. 31, 2018	3,122,843
Issuance of common stock and units, net of issuance costs	$ 90	7,553,738			7,553,828
Issuance of common stock and units, net of issuance costs, Shares	895,834
Common stock issued from vested restricted stock units, shares	464
Stock-based compensation		161,000			161,000
Net Loss			(2,342,996)		(2,342,996)
Other Comprehensive income (loss)				5,234	5,234
Balance at Mar. 31, 2019	$ 402	172,982,394	(157,030,238)	(12,602)	15,939,956
Balance, shares at Mar. 31, 2019	4,019,141
Balance at Dec. 31, 2019	$ 402	173,278,144	(163,322,676)	2,084	$ 9,957,954
Balance, shares at Dec. 31, 2019	4,019,141				4,019,141
Stock-based compensation		76,302			$ 76,302
Net Loss			(586,770)		(586,770)
Other Comprehensive income (loss)				$ (2,084)	(2,084)
Balance at Mar. 31, 2020	$ 402	$ 173,354,446	$ (163,909,446)		$ 9,445,402
Balance, shares at Mar. 31, 2020	4,019,141				4,019,141

Condensed Statement Of Cash Flo

Condensed Statement Of Cash Flows - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash Flows from Operating Activities:
Net loss	$ (586,770)	$ (2,342,996)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	9,255	11,533
Loss on sale of equipment		9,594
Amortization of premiums and discounts on marketable securities, net	(4,864)	(18,499)
Stock-based compensation	76,302	161,000
Unrealized loss (gain) on fair value of warrants	58,392	(1,513,371)
Changes in assets and liabilities:
Prepaid expenses and other assets	156,450	73,367
Accounts payable and accrued expenses	(28,724)	(906,350)
Deferred revenue	(900,000)	150,000
Other, net	(1,492)	(4,373)
Net Cash Used in Operating Activities	(1,221,451)	(4,380,095)
Cash Flows from Investing Activities:
Purchase of equipment		(13,181)
Sale of equipment		5,500
Purchase of marketable securities		(8,887,566)
Redemption of marketable securities	3,000,000	3,000,000
Net Cash Provided by (Used in) Investing Activities	3,000,000	(5,895,247)
Cash Flows from Financing Activities:
Issuance of common stock and units, net of issuance costs		7,653,828
Net Cash Provided by Financing Activities		7,653,828
Net Increase (Decrease) in Cash and Cash Equivalents	1,778,549	(2,621,514)
Cash and Cash Equivalents - beginning of period	9,219,547	8,744,301
Cash and Cash Equivalents - end of period	10,998,096	6,122,787
Supplemental Cash Flow Information
Operating cash flows paid for amounts included in the measurement of lease liabilities	$ 38,262	84,651
Non-cash financing and investing activties:
Warrants issued		4,735,913
Operating lease right-of-use assets obtained in exchange for lease obligations:		$ 380,935

Operations And Organization

Operations And Organization	3 Months Ended
	Mar. 31, 2020
Operations And Organization [Abstract]
Operations And Organization	1. Operations and Organization Operations Rexahn Pharmaceuticals, Inc. (the “Company”), a Delaware corporation, is a biopharmaceutical company whose principal operations are the development of innovative treatments for cancer. The Company had an accumulated deficit of $163,909,446 at March 31, 2020 and anticipates incurring losses in the foreseeable future. In September 2019, the Company commenced a process to explore and evaluate strategic alternatives to enhance shareholder value and engaged a financial advisory firm to assist in the process.  The Company believes that its cash and cash equivalents of approximately $11.0 million as of March 31, 2020 will be sufficient to cover its cash flow requirements for its current activities for at least the next 12 months from the date these financial statements were issued.  Basis of Presentation The accompanying unaudited condensed financial statements of the Company have been prepared pursuant to the rules and regulations of the U.S. Securities and Exchange Commission for interim financial information. Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States (“U.S. GAAP”) for complete financial statements. In the opinion of the Company’s management, all adjustments (consisting of only normal recurring accruals) considered necessary for a fair presentation of the Company’s financial position as of March 31, 2020 and December 31, 2019 and of the results of operations, comprehensive loss, stockholders’ equity and cash flows for the three months ended March 31, 2020 and 2019 have been included. Operating results for the three months ended March 31, 2020 are not necessarily indicative of results that may be expected for any other interim period or the full fiscal year ending December 31, 2020. The accompanying unaudited condensed financial statements should be read in conjunction with the audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019 (the “2019 Form 10-K”). Information included in the condensed balance sheet as of December 31, 2019 has been derived from the Company’s audited financial statements for the year ended December 31, 2019 included in the 2019 Form 10-K. The unaudited condensed financial statements have been prepared on a basis that assumes the Company will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business.  Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the 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. These estimates are based on management’s best knowledge of current events and actions the Company may undertake in the future. Actual results may ultimately differ from these estimates. These estimates are reviewed periodically, and as adjustments become necessary, they are reported in earnings in the period in which they become available. COVID-19 Pandemic The outbreak of the COVID-19 disease, which the World Health Organization declared a pandemic in March 2020, has led to disruption in the global economy and the biopharmaceutical industry. The extent of the COVID-19 pandemic’s impact on the Company’s business, financial condition and results of operations, as well as the Company’s ability to enter into and complete a strategic transaction, is highly uncertain and will depend on various factors, including the duration and scope of the pandemic, restrictions on business and social distancing guidelines that may be requested or mandated by governmental authorities, other actions taken to contain the impact of the pandemic, and impacts on the Company’s ability or the ability of potential strategic partners to access the markets on favorable terms, or at all.  

Marketable Securities

Marketable Securities	3 Months Ended
	Mar. 31, 2020
Marketable Securities [Abstract]
Marketable Securities	2. Marketable Securities  Marketable securities are considered “available-for-sale” in accordance with Financial Accounting Standards Board Accounting Standards Codification (“ASC”) 320, “Debt and Equity Securities,” and thus are reported at fair value in the Company’s accompanying balance sheet, with unrealized gains and losses excluded from earnings and reported as a separate component of stockholders’ equity. Amounts reclassified out of accumulated other comprehensive income (loss) into realized gains and losses are accounted for on the basis of specific identification and are included in other income or expense in the statement of operations. The Company classifies such investments as current on the balance sheet as the investments are readily marketable and available for use in current operations.  The Company had no marketable securities as of March 31, 2020. The following table shows the Company’s marketable securities’ adjusted cost, gross unrealized gains and losses, and fair value by significant investment category as of December 31, 2019:    December 31, 2019   Cost Gross Unrealized Gross Unrealized Fair  Basis Gains Losses Value  Commercial Paper $ 1,996,216 $ 1,184 $ - $ 1,997,400  Corporate Bonds 998,920 900 - 999,820  Total Marketable Securities $ 2,995,136 $ 2,084 $ - $ 2,997,220 

Equipment, Net

Equipment, Net	3 Months Ended
	Mar. 31, 2020
Equipment, Net [Abstract]
Equipment, Net	3. Equipment, Net    March 31, December 31,  2020 2019   Furniture and fixtures $ 67,650 $ 67,650  Office and computer equipment 163,440 163,440  Leasehold improvements 116,403 116,403   Total equipment 347,493 347,493  Less: Accumulated depreciation and amortization (280,978) (271,723)   Net carrying amount $ 66,515 $ 75,770

Accounts Payable And Accrued Ex

Accounts Payable And Accrued Expenses	3 Months Ended
	Mar. 31, 2020
Accounts Payable And Accrued Expenses [Abstract]
Accounts Payable And Accrued Expenses	4. Accounts Payable and Accrued Expenses     March 31, December 31,  2020 2019   Trade payables $ 891,419 $ 488,285  Accrued expenses 165,931 471,700  Accrued research and development contract costs 125,992 221,170  Payroll liabilities 53,665 84,576   $ 1,237,007 $ 1,265,731 

License Agreements

License Agreements	3 Months Ended
	Mar. 31, 2020
License Agreements [Abstract]
License Agreements	 5. License Agreements  BioSense Global LLC On March 10, 2020 , t he Company entered into a n amendment to its collaboration and license agreement , ( as amended, the “License and Assignment Agreement”) with BioSense Global LLC (“BioSense”) to advance the development and commercialization of RX-3117 for all human uses in the Republic of Singapore, China, Hong Kong, Macau , and Taiwan (the “Territory”). Under the terms of the License and Assignment Agreement, upon payment in full of an upfront payment, the Company will (i) grant BioSense an exclusive license to develop and commercialize pharma ceutical products containing RX-3117 as a single agent for all human uses in the Territ or y and (ii) assign and transfer all of the Company’s patents and patent applications related to RX-3117 in the Territory. The upfront payment consists of an aggregate of $1,650,000 , of which $1,500,000 has been received to date. Under the License and Assignment Agreement, the Company is eligible to receive milestone payments in an aggregate of up to $84.5 million upon the achievement of development, regulatory and commercial goals and will also be eligible to receive tiered royalties in the mid-single digits to low tens on annual net sales in the Territory. The Company has evaluated the License and Assignment Agreement under ASC 606, “Revenue from Contracts with Customers , ” to determine the appropriate amount of revenue to be recognized as the Company fulfills its obligations under the License and Assignment Agreement. The Company identified the exclusive license to develop RX-3117 and the supply of RX-3117 drug product, drug substance and intermediate materials (collectively, the “Transferred Materials”) as the distinct performance obligations in the contract. The Company has determined that it will recognize revenue related to the exclusive license to develop RX-3117 and the supply of the Transferred Materials transfers to BioSense at a point in time when the exclusive license is conveyed and the Transferred Materials are made available f o r delivery to BioSense , respectively . The Company has determined the transaction price contains both fixed and variable consideration. The fixed consideration is equal to the upfront payment of $1,650,000 . The variable consideration relates to the milestone payments and future sales-based royalty payments. The Company estimates the variable consideration in the contract using the most likely amount method. The Company determined at the contract outset and as of March 31 , 20 20 that all milestone payments should be fully constrained, as it is not probable that a significant reversal of revenue will not occur in a future period, given the significance of the milestone payments and that the payments are earned based upon the achievement of events that are highly susceptible to factors outside of the Company’s control. Future sales-based royalties related to the exclusive license to develop RX-3117 will be recognized in the period the underlying sales transaction occurs. The $1,650,000 upfront payment has been allocated to the performance obligations on the basis of the relative standalone selling price estimated for each performance obligation. The Company has determined the standalon e selling price of the exclusive license to develop RX-3117 using the adjusted market approach, which represents the price the market will bear based on the license rights granted and the state of the intellectual property, and has determined the standalone selling price of the supply of the Transferred Materials using a cost approach. Accordingly, the Company has allocated $750,000 of the upfront transaction price to the exclusive license to develop RX-3117 and $900,000 to the supply of the Transferred Materials. Additional transaction price recognized in future periods related to milestone payments and royalties will be allocated solely to the exclusive license to develop RX-3117, as these amounts relate to efforts associated with the development and commercialization of products related to the exclusive license to develop RX-3117. As of March 31, 2020, $1,500,000 of the upfront payment had been paid, and the remaining $150,000 remained unpaid. As of March 31, 2020, the Company had satisfied the performance obligation related to the Transferred Materials and therefore recognized $900,000 in revenue which was previously classified as deferred revenue. As of March 31, 2020, the exclusive license had not been transferred and no revenue was recognized related to that performance obligation. Therefore, the Company has recorded the additional $600,000 of transaction consideration received as of March 31, 2020 as deferred revenue on the Company’s balance sheet. Zhejiang HaiChang Biotechnology Co., Ltd. On February 8, 2020, the Company entered into an exclusive license agreement (the “HaiChang License Agreement”) with Zhejiang HaiChang Biotechnology Co., Ltd. (“HaiChang”) pursuant to which the Company granted HaiChang an exclusive (even as to the Company), royalty-bearing, sublicensable worldwide license to research, develop and commercialize pharmaceutical products comprising RX-0201 (subject to and limited by the exclusive rights of NEXT BT Co. Ltd (“Next BT”) with respect to RX-0201 in Asia), the nano-liposomal formulation of RX-0201 known as RX-0301, and RX-0047, a proprietary compound currently in preclinical development. HaiChang has agreed to use commercially reasonable efforts to develop, seek regulatory approval for, and commercialize one product comprising RX-0301 and one product comprising RX-0047.  HaiChang paid a one-time upfront payment of $250,000 to the Company for certain materials to be transferred by the Company to HaiChang . HaiChang will pay the Company development milestone payments in an aggregate of up to $63,000,000 with respect to RX-0201 and RX-0301 and up to $33,000,000 with respect to RX-0047, and royalties based on percentages of net sales in the low tens with respect to RX-0201 and RX-0301 and the mid-single digits with respect to RX-0047. However, if HaiChang exclusively sublicenses its rights to a third party with respect to RX-0201 and RX-0301 or RX-0047 in a particular jurisdiction, instead of the foregoing milestones and royalties to the extent relating to such compound(s) and jurisdiction, HaiChang will pay the Company a percentage of any sublicensing revenue received by HaiChang , provided that in any event HaiChang will pay a milestone payment on initiation of a Phase 3 clinical trial that is subject to reduction by the amount of any sublicensing revenue paid with respect to the applicable compound(s) as of the time of initiation of the trial.  The Company accounts for the HaiChang License Agreement under ASC 606. The Company has determined the performance obligations under the contract relate to the transfer of materials and the license of intellectual property. Revenue associated with the materials and license are recognized at a point in time. The Company has determined the transaction price contains both fixed and variable consideration. The fixed consideration is equal to the upfront payment of $250,000 . At the outset of the contract, the value of the license was determined to be de minimis given the early stage of clinical development of the intellectual property, and allocated the entire fixed consideration to the materials. The Company transferred the materials during the three months ended March 31, 2020 and therefore recognized the entire fixed consideration as revenue. The variable consideration relates to the milestone payments , sublicense fees and future sales-based royalty payments . The Company estimates variable consideration under the contract using the expected value method. Given the early stage and the uncertain success of the development work to be performed by HaiChang, the Company has determined that the variable consideration in the contract should be fully constrained at the contract outset and as of March 31, 2020.

Leases

Leases	3 Months Ended
	Mar. 31, 2020
Leases [Abstract]
Leases	6. Leases  The Company leases 5,466 square feet of office space in Rockville, Maryland, with a lease term ending June 30, 2024. Under the lease agreement, the Company pays its allocable portion of real estate taxes and common area operating charges, which are recorded as variable lease costs. The lease has escalating rent payments for which the Company records lease expense on a straight-line basis over the lease term, and an option to terminate the leased premises, without penalty, on June 30, 2021. The Company is reasonably certain that it will not remain in these leased premises after the optional termination date, and therefore, is using the optional termination date in assessing the lease term.  The following table summarizes the right of use lease assets and lease liabilities as of March 31, 2020:     Right-of-Use Assets $ 171,870   Operating Lease Liabilities  Current $ 144,610  Long Term 25,790  Total Operating Lease Liabilities $ 170,400  The components of lease expense were as follows:    For the Three Months Ended March 31,  2020 2019  Operating lease cost $ 36,771 $ 80,279  Variable lease cost 5,693 16,012   Total Lease Cost $ 42,464 $ 96,291  The right-of-use asset and lease liability were calculated using an estimated incremental borrowing rate of 11% . At March 31, 2020, the weighted average lease term was 1.3 years. The table below summarizes the Company’s scheduled future minimum lease payments recorded on the balance sheet, as of March 31, 2020:     Year Ending December 31:  2020 (excluding the three months ended March 31, 2020) $ 117,018  2021 65,364  Minimum lease payments 182,382  Less: Imputed interest (11,982)  Present value of minimum lease payments 170,400  Less: current maturities of lease obligations (144,610)  Long-term lease obligations $ 25,790 

Net Loss Per Common Share

Net Loss Per Common Share	3 Months Ended
	Mar. 31, 2020
Net Loss Per Common Share [Abstract]
Net Loss Per Common Share	7. Net Loss per Common Share Basic loss per common share is computed by dividing net loss by the weighted average number of shares of common stock outstanding for the period. Diluted loss per common share is computed by dividing net loss by the weighted average number of shares of common stock outstanding, plus the number of common share equivalents that would be dilutive. As of March 31, 2020 and December 31, 2019, there were stock options and warrants to acquire, in the aggregate , 2,070,511 and 2,126,063 shares of the Company’s common stock, respectively, that are potentially dilutive. However, diluted loss per share is the same as basic loss per share for all periods presented because the inclusion of common share equivalents would be anti-dilutive.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2020
Stock-Based Compensation [Abstract]
Stock-Based Compensation	8. Stock-Based Compensation As of March 31, 2020, the Company had 149,022 options to purchase common stock outstanding. In June 2013, the Company’s shareholders voted to approve the Rexahn Pharmaceuticals, Inc. 2013 Stock Option Plan (the “2013 Plan”). Under the 2013 Plan, the Company grants equity awards to key employees, directors and consultants of the Company. The Company has reserved 283,333 shares of common stock for issuance pursuant to the 2013 Plan. As of March 31 , 20 20 , there were 144,366 options outstanding under the 2013 Plan, and 136,936 shares were available for issuance . In addition, as of March 31, 2020, there were 4,656 options outstanding under a previously established stock option plan under which no new stock options may be granted. Accounting for Awards Stock-based compensation expense is the estimated fair value of options granted amortized on a straight-line basis over the requisite vesting service period for the entire portion of the award. Total stock-based compensation recognized by the Company for the three months ended March 3 1 , 20 20 and 201 9 is as follows:    For the Three Months Ended March 31,  2020 2019  Statement of operations line item:  General and administrative $ 72,420 $ 116,679  Research and development 3,882 44,321   Total $ 76,302 $ 161,000  No income tax benefit has been recognized in the statement of operations for stock-based compensation arrangements as the Company has provided for a 100 % valuation allowance on its deferred tax assets. Summary of Stock Option Transactions  A summary of stock option activity for the three months ended March 31, 2020 is as follows:     Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value  Outstanding, January 1, 2020 204,574 $ 35.60 7.3 years $ -  Granted - $ -  Exercised - $ -  Expired (2,498) $ 159.60  Cancelled (53,054) $ 60.40   Outstanding, March 31, 2020 149,022 $ 24.69 7.8 years $ -  Exercisable, March 31, 2020 75,304 $ 37.16 7.0 years $ -  A summary of the Company’s unvested options as of March 31, 2020 and changes during the three months ended March 31, 2020 is presented below:     2020  Number of Options Weighted Average Fair Value at Grant Date  Unvested at January 1, 2020 81,311 $ 7.90  Granted - $ -  Vested (7,593) $ 8.34  Cancelled - $ -   Unvested at March 31, 2020 73,718 $ 7.85 As of March 31, 2020, there was $501,655 of total unrecognized compensation cost related to unvested stock options, which is expected to be recognized over a weighted average vesting period of 1.7 years.

Warrants

Warrants	3 Months Ended
	Mar. 31, 2020
Warrants [Abstract]
Warrants	9. Warrants The following table summarizes the Company’s outstanding warrants to purchase common stock as of March 31, 2020 and December 31, 2019:     Number of Warrants:  Warrant Issuance March 31, 2020 December 31, 2019 Exercise Price Expiration Date  Liability-classified Warrants  November 2015 Investors 104,168 104,168 $ 63.60 May 2021  November 2015 Placement Agent 279 279 $ 63.60 Nov. 2020  March 2016 Investors 50,651 50,651 $ 50.40 Sept. 2021  September 2016 Investors 67,084 67,084 $ 36.00 Mar. 2022  June 2017 Investors 126,264 126,264 $ 48.00 Dec. 2022  June 2017 Placement Agent 15,153 15,153 $ 49.50 June 2022  October 2017 Investors 136,058 136,058 $ 34.20 Apr. 2023  October 2017 Placement Agent 16,327 16,327 $ 36.72 Oct. 2022  Total liability classified warrants 515,984 515,984   Equity-classified Warrants  October 2018 Investors 480,771 480,771 $ 20.04 Apr. 2024  October 2018 Placement Agent 28,848 28,848 $ 19.50 Oct. 2023  January 2019 Investors 895,886 895,886 $ 9.60 Jan. 2024  Total equity-classified warrants 1,405,505 1,405,505   Total outstanding warrants 1,921,489 1,921,489  The following table summarizes the Company’s warrant activity for the three months ended March 31, 2020:      Number of Warrants  Liability-classified Equity- classified Total Weighted average exercise price  Balance, January 1, 2020 515,984 1,405,505 1,921,489 $ 22.10  Issued during the period - - - $ -  Exercised during the period - - - $ -  Expired during the period - - $ -   Balance, March 31, 2020 515,984 1,405,505 1,921,489 $ 22.10 At March 31, 2020, the weighted average remaining contractual life of the outstanding warrants was 3.4 years. The following table summarizes the fair value of the liability-classified warrants as of the respective balance sheet dates:    Fair Value as of:  Warrant Issuance: March 31, 2020 December 31, 2019  November 2015 Investors $ 971 $ 55  November 2015 Placement Agent - -  March 2016 Investor 1,240 439  September 2016 Investors 14,639 3,196  June 2017 Investors 30,364 11,736  June 2017 Placement Agent 2,574 845  October 2017 Investors 46,178 23,772  October 2017 Placement Agent 4,143 1,674  Total: $ 100,109 $ 41,717  The assumptions used in calculating the fair values of the liability-classified warrants are as follows:     March 31, 2020 December 31, 2019  Trading market prices $ 1.80 $ 1.91  Estimated future volatility 100 % 102 %  Dividend - -  Estimated future risk-free rate 0.20 -0.41 % 1.57 -1.72 %  Equivalent volatility 113-129 % 85-94 %  Equivalent risk-free rate 0.13 -0.19 % 1.57 -1.59 %  Fundamental transaction likelihood 50 % 50 %  Fundamental transaction timing July 2020 April 2020  . Changes in the fair value of the warrant liabilities, carried at fair value, reported as “unrealized (loss) gain on fair value of warrants” in the statement of operations:     For the Three Months Ended March 31,  2020 2019  November 2015 Investors $ (916) $ 197,084  November 2015 Placement Agent - 380  March 2016 Investors (801) 114,799  September 2016 Investors (11,443) 217,869  June 2017 Investors (18,628) 388,391  June 2017 Placement Agent (1,729) 41,911  October 2017 Investors (22,406) 496,501  October 2017 Placement Agent (2,469) 56,436  Total: $ (58,392) $ 1,513,371 

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2020
Income Taxes [Abstract]
Income Taxes	10. Income Taxes No provision for federal and state income taxes was required for the three months ended March 31, 2020 and 2019 due to the Company’s operating losses and increased deferred tax asset valuation allowance. At March 31, 2020 and December 31, 2019, the Company had unused net operating loss carry-forwards of approximately $157,964,000 and $ 156,586 ,000 respectively, which portions of expire at various dates beginning in 2021. Some of this amount may be subject to annual limitations under certain provisions of the Internal Revenue Code related to “changes in ownership.” As of March 31, 2020 and December 31, 2019, the deferred tax assets related to the aforementioned carry-forwards have been fully offset by valuation allowances, because significant utilization of such amounts is not presently expected in the foreseeable future. Deferred tax assets and valuation allowances consist of:     March 31, December 31,  2020 2019   Net Operating Loss Carryforwards $ 44,230,000 $ 43,844,000  Stock Compensation Expense 551,000 1,191,000  Book Tax Differences on Assets and Liabilities 163,000 464,000  Valuation Allowance (44,944,000) (45,499,000)   Net Deferred Tax Assets $ - $ - The Company files income tax returns in the U.S. federal and Maryland state jurisdictions. Tax years for fiscal 2016 through 2019 are open and potentially subject to examination by the federal and Maryland state taxing authorities.

Commitments And Contingencies

Commitments And Contingencies	3 Months Ended
	Mar. 31, 2020
Commitments And Contingencies [Abstract]
Commitments And Contingencies	11. Commitments and Contingencies a) The Company has contracted with various vendors for services, with terms that require payments over the terms of the agreements, usually ranging from two to 36 months. The costs to be incurred are estimated and are subject to revision. As of March 31, 2020, the total estimated cost to complete these agreements was approximately $800,000 . All of these agreements may be terminated by either party upon appropriate notice as stipulated in the respective agreements. b) On June 22, 2009, the Company entered into a License Agreement with Korea Research Institute of Chemical Technology (“KRICT”) to acquire the rights to all intellectual property related to quinoxaline-piperazine derivatives that were synthesized under a Joint Research Agreement. The agreement with KRICT calls for a one-time milestone payment of $ 1,000,000 within 30 days after the first achievement of marketing approval of the first commercial product arising out of or in connection with the use of KRICT’s intellectual property. As of March 31, 2020, the milestone has not occurred. c) The Company has established a 401(k) plan for its employees. The Company has elected to match 100% of the first 3% of an employee’s compensation plus 50% of an additional 2% of the employee’s deferral. Expense related to this matching contribution aggregated to $11,229 and $27,879 for the three months ended March 31, 2020 and 2019, respectively. d) On February 5, 2018, the Company and Next BT terminated a research collaboration agreement between the Company and Rexgene Biotech Co., Ltd, a predecessor in interest to Next BT. The Company agreed to pay Next BT a royalty in the low single digits of any net sales of RX-0201 the Company makes in Asia and 50% of the Company’s licensing revenue related to licensing of RX-0201 in Asia, up to an aggregate of $5,000,000 . As of March 31, 2020, the Company has not made any royalty payments to Next BT. 

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2020
Fair Value Measurements [Abstract]
Fair Value Measurements	12. Fair Value Measurements ASC 820 defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date, not adjusted for transaction costs. ASC 820 also establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels giving the highest priority to quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3).  The three levels are described below:  Level 1 Inputs — Unadjusted quoted prices in active markets for identical assets or liabilities that are accessible by the Company; Level 2 Inputs — Quoted prices in markets that are not active or financial instruments for which all significant inputs are observable, either directly or indirectly; Level 3 Inputs — Unobservable inputs for the asset or liability including significant assumptions of the Company and other market participants.  The following tables present assets and liabilities that are measured at fair value on a recurring basis and are categorized using the fair value hierarchy. de    Fair Value Measurements at March 31, 2020  Total Level 1 Level 2 Level 3  Liabilities:  Warrant Liabilities $ 100,109 $ - $ - $ 100,109     Fair Value Measurements at December 31, 2019  Total Level 1 Level 2 Level 3  Assets:  Commercial Paper $ 1,997,400 $ - $ 1,997,400 $ -  Corporate Bonds 999,820 - 999,820 -  Total Assets: $ 2,997,220 $ - $ 2,997,220 $ -   Liabilities:  Warrant Liabilities $ 41,717 $ - $ - $ 41,717  There have been no changes in the methodologies used at March 31, 2020 and December 31, 2019, and no transfers between Level 1, 2 and 3 during the three months ended March 31, 2020.  The reconciliation of changes to the fair value of the Company’s warrant liabilities for the three months ended March 31, 2020 is as follows:     Warrant Liabilities  Balance at January 1, 2020 $ 41,717  Unrealized losses, net 58,392  Balance at March 31, 2020 $ 100,109

Subsequent Event

Subsequent Event	3 Months Ended
	Mar. 31, 2020
Subsequent Event [Abstract]
Subsequent Event	13. Subsequent Event  On April 7 , 2020, the Company notified Merck Sharp & Dohme B.V. (“Merck”) that it was terminating the Clinical Trial Collaboration and Supply Agreement dated as of August 16, 2018, by and between the Company and Merck, effective immediately, in connection with the Company’s determination to discontinue development of RX-5902 for the treatment of metastatic triple negative breast cancer.

Operations And Organization (Po

Operations And Organization (Policies)	3 Months Ended
	Mar. 31, 2020
Operations And Organization [Abstract]
Operations	Operations Rexahn Pharmaceuticals, Inc. (the “Company”), a Delaware corporation, is a biopharmaceutical company whose principal operations are the development of innovative treatments for cancer. The Company had an accumulated deficit of $163,909,446 at March 31, 2020 and anticipates incurring losses in the foreseeable future. In September 2019, the Company commenced a process to explore and evaluate strategic alternatives to enhance shareholder value and engaged a financial advisory firm to assist in the process.  The Company believes that its cash and cash equivalents of approximately $11.0 million as of March 31, 2020 will be sufficient to cover its cash flow requirements for its current activities for at least the next 12 months from the date these financial statements were issued.
Basis Of Presentation	Basis of Presentation The accompanying unaudited condensed financial statements of the Company have been prepared pursuant to the rules and regulations of the U.S. Securities and Exchange Commission for interim financial information. Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States (“U.S. GAAP”) for complete financial statements. In the opinion of the Company’s management, all adjustments (consisting of only normal recurring accruals) considered necessary for a fair presentation of the Company’s financial position as of March 31, 2020 and December 31, 2019 and of the results of operations, comprehensive loss, stockholders’ equity and cash flows for the three months ended March 31, 2020 and 2019 have been included. Operating results for the three months ended March 31, 2020 are not necessarily indicative of results that may be expected for any other interim period or the full fiscal year ending December 31, 2020. The accompanying unaudited condensed financial statements should be read in conjunction with the audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019 (the “2019 Form 10-K”). Information included in the condensed balance sheet as of December 31, 2019 has been derived from the Company’s audited financial statements for the year ended December 31, 2019 included in the 2019 Form 10-K. The unaudited condensed financial statements have been prepared on a basis that assumes the Company will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business. 
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the 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. These estimates are based on management’s best knowledge of current events and actions the Company may undertake in the future. Actual results may ultimately differ from these estimates. These estimates are reviewed periodically, and as adjustments become necessary, they are reported in earnings in the period in which they become available.
COVID-19 Pandemic	COVID-19 Pandemic The outbreak of the COVID-19 disease, which the World Health Organization declared a pandemic in March 2020, has led to disruption in the global economy and the biopharmaceutical industry. The extent of the COVID-19 pandemic’s impact on the Company’s business, financial condition and results of operations, as well as the Company’s ability to enter into and complete a strategic transaction, is highly uncertain and will depend on various factors, including the duration and scope of the pandemic, restrictions on business and social distancing guidelines that may be requested or mandated by governmental authorities, other actions taken to contain the impact of the pandemic, and impacts on the Company’s ability or the ability of potential strategic partners to access the markets on favorable terms, or at all.

Marketable Securities (Tables)

Marketable Securities (Tables)	3 Months Ended
	Mar. 31, 2020
Marketable Securities [Abstract]
Schedule Of Cost And Fair Value Of Marketable Securities	  December 31, 2019   Cost Gross Unrealized Gross Unrealized Fair  Basis Gains Losses Value  Commercial Paper $ 1,996,216 $ 1,184 $ - $ 1,997,400  Corporate Bonds 998,920 900 - 999,820  Total Marketable Securities $ 2,995,136 $ 2,084 $ - $ 2,997,220 

Equipment, Net (Tables)

Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2020
Equipment, Net [Abstract]
Schedule Of Equipment, Net	  March 31, December 31,  2020 2019   Furniture and fixtures $ 67,650 $ 67,650  Office and computer equipment 163,440 163,440  Leasehold improvements 116,403 116,403   Total equipment 347,493 347,493  Less: Accumulated depreciation and amortization (280,978) (271,723)   Net carrying amount $ 66,515 $ 75,770 

Accounts Payable And Accrued _2

Accounts Payable And Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2020
Accounts Payable And Accrued Expenses [Abstract]
Schedule Of Accounts Payable And Accrued Expenses	  March 31, December 31,  2020 2019   Trade payables $ 891,419 $ 488,285  Accrued expenses 165,931 471,700  Accrued research and development contract costs 125,992 221,170  Payroll liabilities 53,665 84,576   $ 1,237,007 $ 1,265,731 

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2020
Leases [Abstract]
Summary Of Right Of Use Lease Assets And Lease Liabilities	  Right-of-Use Assets $ 171,870   Operating Lease Liabilities  Current $ 144,610  Long Term 25,790  Total Operating Lease Liabilities $ 170,400 
Components Of Lease Expense	  For the Three Months Ended March 31,  2020 2019  Operating lease cost $ 36,771 $ 80,279  Variable lease cost 5,693 16,012   Total Lease Cost $ 42,464 $ 96,291 
Scheduled Future Minimum Lease Payments	  Year Ending December 31:  2020 (excluding the three months ended March 31, 2020) $ 117,018  2021 65,364  Minimum lease payments 182,382  Less: Imputed interest (11,982)  Present value of minimum lease payments 170,400  Less: current maturities of lease obligations (144,610)  Long-term lease obligations $ 25,790 

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2020
Stock-Based Compensation [Abstract]
Summary Of Stock Compensation Expense	  For the Three Months Ended March 31,  2020 2019  Statement of operations line item:  General and administrative $ 72,420 $ 116,679  Research and development 3,882 44,321   Total $ 76,302 $ 161,000 
Summary Of Share-Based Transactions	   Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value  Outstanding, January 1, 2020 204,574 $ 35.60 7.3 years $ -  Granted - $ -  Exercised - $ -  Expired (2,498) $ 159.60  Cancelled (53,054) $ 60.40   Outstanding, March 31, 2020 149,022 $ 24.69 7.8 years $ -  Exercisable, March 31, 2020 75,304 $ 37.16 7.0 years $ - 
Summary Of Unvested Shares	   2020  Number of Options Weighted Average Fair Value at Grant Date  Unvested at January 1, 2020 81,311 $ 7.90  Granted - $ -  Vested (7,593) $ 8.34  Cancelled - $ -   Unvested at March 31, 2020 73,718 $ 7.85 

Warrants (Tables)

Warrants (Tables)	3 Months Ended
	Mar. 31, 2020
Warrants [Abstract]
Summary Of Warrants Outstanding	  Number of Warrants:  Warrant Issuance March 31, 2020 December 31, 2019 Exercise Price Expiration Date  Liability-classified Warrants  November 2015 Investors 104,168 104,168 $ 63.60 May 2021  November 2015 Placement Agent 279 279 $ 63.60 Nov. 2020  March 2016 Investors 50,651 50,651 $ 50.40 Sept. 2021  September 2016 Investors 67,084 67,084 $ 36.00 Mar. 2022  June 2017 Investors 126,264 126,264 $ 48.00 Dec. 2022  June 2017 Placement Agent 15,153 15,153 $ 49.50 June 2022  October 2017 Investors 136,058 136,058 $ 34.20 Apr. 2023  October 2017 Placement Agent 16,327 16,327 $ 36.72 Oct. 2022  Total liability classified warrants 515,984 515,984   Equity-classified Warrants  October 2018 Investors 480,771 480,771 $ 20.04 Apr. 2024  October 2018 Placement Agent 28,848 28,848 $ 19.50 Oct. 2023  January 2019 Investors 895,886 895,886 $ 9.60 Jan. 2024  Total equity-classified warrants 1,405,505 1,405,505   Total outstanding warrants 1,921,489 1,921,489 
Summary Of Changes In Warrants Outstanding During The Period	  Number of Warrants  Liability-classified Equity- classified Total Weighted average exercise price  Balance, January 1, 2020 515,984 1,405,505 1,921,489 $ 22.10  Issued during the period - - - $ -  Exercised during the period - - - $ -  Expired during the period - - $ -   Balance, March 31, 2020 515,984 1,405,505 1,921,489 $ 22.10 
Schedule Of Fair Value Of Warrants Issued	  Fair Value as of:  Warrant Issuance: March 31, 2020 December 31, 2019  November 2015 Investors $ 971 $ 55  November 2015 Placement Agent - -  March 2016 Investor 1,240 439  September 2016 Investors 14,639 3,196  June 2017 Investors 30,364 11,736  June 2017 Placement Agent 2,574 845  October 2017 Investors 46,178 23,772  October 2017 Placement Agent 4,143 1,674  Total: $ 100,109 $ 41,717 
Schedule Of Assumptions Used In Calculating Fair Value Of Warrants	   March 31, 2020 December 31, 2019  Trading market prices $ 1.80 $ 1.91  Estimated future volatility 100 % 102 %  Dividend - -  Estimated future risk-free rate 0.20 -0.41 % 1.57 -1.72 %  Equivalent volatility 113-129 % 85-94 %  Equivalent risk-free rate 0.13 -0.19 % 1.57 -1.59 %  Fundamental transaction likelihood 50 % 50 %  Fundamental transaction timing July 2020 April 2020 
Schedule Of Unrealized Gain/(Loss) On Fair Value Of Warrants	  For the Three Months Ended March 31,  2020 2019  November 2015 Investors $ (916) $ 197,084  November 2015 Placement Agent - 380  March 2016 Investors (801) 114,799  September 2016 Investors (11,443) 217,869  June 2017 Investors (18,628) 388,391  June 2017 Placement Agent (1,729) 41,911  October 2017 Investors (22,406) 496,501  October 2017 Placement Agent (2,469) 56,436  Total: $ (58,392) $ 1,513,371 

Income Taxes (Tables)

Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2020
Income Taxes [Abstract]
Schedule Of Deferred Tax Assets And Valuation Allowance	   March 31, December 31,  2020 2019   Net Operating Loss Carryforwards $ 44,230,000 $ 43,844,000  Stock Compensation Expense 551,000 1,191,000  Book Tax Differences on Assets and Liabilities 163,000 464,000  Valuation Allowance (44,944,000) (45,499,000)   Net Deferred Tax Assets $ - $ - 

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2020
Fair Value Measurements [Abstract]
Schedule Of Assets And Liabilities Measured At Fair Value On A Recurring Basis	   Fair Value Measurements at March 31, 2020  Total Level 1 Level 2 Level 3  Liabilities:  Warrant Liabilities $ 100,109 $ - $ - $ 100,109     Fair Value Measurements at December 31, 2019  Total Level 1 Level 2 Level 3  Assets:  Commercial Paper $ 1,997,400 $ - $ 1,997,400 $ -  Corporate Bonds 999,820 - 999,820 -  Total Assets: $ 2,997,220 $ - $ 2,997,220 $ -   Liabilities:  Warrant Liabilities $ 41,717 $ - $ - $ 41,717 
Reconciliation Of Changes In The Fair Value Of Liabilities	  Warrant Liabilities  Balance at January 1, 2020 $ 41,717  Unrealized losses, net 58,392  Balance at March 31, 2020 $ 100,109 

Operations And Organization (De

Operations And Organization (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Operations And Organization [Abstract]
Cash, cash equivalents and marketable securities	$ 11,000,000
Accumulated deficit	$ 163,909,446	$ 163,322,676

Marketable Securities (Details)

Marketable Securities (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Schedule of Available-for-sale Securities [Line Items]
Cost Basis		$ 2,995,136
Gross Unrealized Gains		2,084
Fair Value	$ 0	2,997,220
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis		1,996,216
Gross Unrealized Gains		1,184
Fair Value		1,997,400
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis		998,920
Gross Unrealized Gains		900
Fair Value		$ 999,820

Equipment, Net (Details)

Equipment, Net (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total equipment	$ 347,493	$ 347,493
Less: Accumulated depreciation and amortization	(280,978)	(271,723)
Net carrying amount	66,515	75,770
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total equipment	67,650	67,650
Office And Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Total equipment	163,440	163,440
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total equipment	$ 116,403	$ 116,403

Accounts Payable And Accrued _3

Accounts Payable And Accrued Expenses (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Accounts Payable And Accrued Expenses [Abstract]
Trade payables	$ 891,419	$ 488,285
Accrued expenses	165,931	471,700
Accrued research and development contract costs	125,992	221,170
Payroll liabilities	53,665	84,576
Total accounts payable and accrued expenses	$ 1,237,007	$ 1,265,731

License Agreements (Details)

License Agreements (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Deferred revenue	$ 600,000	$ 1,500,000
BioSense Global LLC [Member]
Upfront payment	1,650,000
Amount received from upfront payment	1,500,000
Deferred revenue	600,000
Amount due	150,000
Milestone payment	84,500,000
Zhejiang HaiChang Biotechnology Co., Ltd. [Member]
Upfront payment	250,000
Fixed consideration	250,000
RX-3117 License [Member] | BioSense Global LLC [Member]
Upfront payment	750,000
Revenue recognized	0
RX-3117 Material [Member] | BioSense Global LLC [Member]
Revenue recognized	900,000
RX-0201 [Member] | Zhejiang HaiChang Biotechnology Co., Ltd. [Member]
Milestone payment	63,000,000
RX-0047 [Member] | Zhejiang HaiChang Biotechnology Co., Ltd. [Member]
Milestone payment	$ 33,000,000

Leases (Narrative) (Details)

Leases (Narrative) (Details)	Mar. 31, 2020ft²
Lessee, Lease, Description [Line Items]
Discount rate	11.00%
Weighted average lease term	1 year 3 months 18 days
Office Space Rental [Member]
Lessee, Lease, Description [Line Items]
Area	5,466

Leases (Summary Of Right Of Use

Leases (Summary Of Right Of Use Lease Assets And Lease Liabilities) (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Right-of-Use Assets	$ 171,870	$ 203,348
Current	144,610	139,765
Long Term	25,790	$ 63,605
Present value of minimum lease payments	$ 170,400

Leases (Components Of Lease Exp

Leases (Components Of Lease Expense) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Leases [Abstract]
Operating lease cost	$ 36,771	$ 80,279
Variable lease cost	5,693	16,012
Total Lease Cost	$ 42,464	$ 96,291

Leases (Scheduled Future Minimu

Leases (Scheduled Future Minimum Lease Payments) (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Leases [Abstract]
2020 (excluding the three months ended March 31, 2020)	$ 117,018
2021	65,364
Minimum lease payments	182,382
Less: Imputed interest	(11,982)
Present value of minimum lease payments	170,400
Less: current maturities of lease obligations	(144,610)	$ (139,765)
Long-term lease obligations	$ 25,790	$ 63,605

Net Loss Per Common Share (Deta

Net Loss Per Common Share (Details) - shares	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Stock Options, Restricted Stock Units And Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities	2,070,511	2,126,063

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Income tax benefit from share-based compensation	$ 0
Valuation allowance on deferred tax assets	100.00%
Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options outstanding	149,022	204,574
Unrecognized compensation cost	$ 501,655
Weighted average vesting period, years	1 year 8 months 12 days
The 2013 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options authorized for issuance	283,333
Shares available for issuance	136,936
The 2013 Plan [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options outstanding	144,366
The 2003 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance	0
The 2003 Plan [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options outstanding	4,656

Stock-Based Compensation (Summa

Stock-Based Compensation (Summary Of Stock Compensation Expense) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share Based Compensation	$ 76,302	$ 161,000
General and administrative [Member]
Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share Based Compensation	72,420	116,679
Research and development [Member]
Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share Based Compensation	$ 3,882	$ 44,321

Stock-Based Compensation (Sum_2

Stock-Based Compensation (Summary Of Share-Based Transactions ) (Details) - Stock Option [Member] - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Number of Options, Oustanding	204,574
Number of Options, Granted
Number of Options, Exercised
Number of Options, Expired	(2,498)
Number of Options, Cancelled	(53,054)
Number of Options, Oustanding	149,022	204,574
Weighted Average Exercise Price, Outstanding	$ 35.60
Weighted Average Exercise Price, Granted
Weighted Average Exercise Price, Exercised
Weighted Average Exercise Price, Expired	159.60
Weighted Average Exercise Price, Cancelled	60.40
Weighted Average Exercise Price, Outstanding	$ 24.69	$ 35.60
Weighted Average Remaining Contractual Term, Outstanding	7 years 9 months 18 days	7 years 3 months 18 days
Aggregate Intrinsic Value, Outstanding
Number of Options, Exercisable	75,304
Weighted Average Exercise Price, Exercisable	$ 37.16
Weighted Average Remaining Contractual Term, Exercisable	7 years
Aggregate Intrinsic Value, Exercisable

Stock-Based Compensation (Sum_3

Stock-Based Compensation (Summary Of Unvested Shares) (Details) - Stock Option [Member]	3 Months Ended
	Mar. 31, 2020$ / sharesshares
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of Options, Unvested | shares	81,311
Number of Options, Granted | shares
Number of Options, Vested | shares	(7,593)
Number of Options, Cancelled | shares
Number of Options, Unvested | shares	73,718
Weighted Average Fair Value at Grant Date, Unvested | $ / shares	$ 7.90
Weighted Average Fair Value at Grant Date, Granted | $ / shares
Weighted Average Fair Value at Grant Date, Vested | $ / shares	8.34
Weighted Average Fair Value at Grant Date, Cancelled | $ / shares
Weighted Average Fair Value at Grant Date, Unvested | $ / shares	$ 7.85

Warrants (Narrative) (Details)

Warrants (Narrative) (Details)	3 Months Ended
	Mar. 31, 2020
Warrants [Abstract]
Average remaining contractual life of warrants outstanding	3 years 4 months 24 days

Warrants (Summary Of Warrants O

Warrants (Summary Of Warrants Outstanding) (Details) - $ / shares	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Class of Warrant or Right [Line Items]
Number of Warrants	1,921,489	1,921,489
Liability-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of Warrants	515,984	515,984
Equity-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of Warrants	1,405,505	1,405,505
November 2015 Investor Warrants [Member] | Liability-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of Warrants	104,168	104,168
Exercise Price	$ 63.60
Expiration Date	2021-05
November 2015 Placement Agent Warrants [Member] | Liability-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of Warrants	279	279
Exercise Price	$ 63.60
Expiration Date	2020-11
March 2016 Investor Warrants [Member] | Liability-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of Warrants	50,651	50,651
Exercise Price	$ 50.40
Expiration Date	2021-09
September 2016 Investor Warrants [Member] | Liability-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of Warrants	67,084	67,084
Exercise Price	$ 36
Expiration Date	2022-03
June 2017 Investor Warrants [Member] | Liability-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of Warrants	126,264	126,264
Exercise Price	$ 48
Expiration Date	2022-12
June 2017 Placement Agent Warrants [Member] | Liability-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of Warrants	15,153	15,153
Exercise Price	$ 49.50
Expiration Date	2022-06
October 2017 Investor Warrants [Member] | Liability-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of Warrants	136,058	136,058
Exercise Price	$ 34.20
Expiration Date	2023-04
October 2017 Placement Agent Warrants [Member] | Liability-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of Warrants	16,327	16,327
Exercise Price	$ 36.72
Expiration Date	2022-10
October 2018 Investor Warrants [Member] | Equity-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of Warrants	480,771	480,771
Exercise Price	$ 20.04
Expiration Date	2024-04
October 2018 Placement Agent Warrants [Member] | Equity-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of Warrants	28,848	28,848
Exercise Price	$ 19.50
Expiration Date	2023-10
January 2019 Investor Warrants [Member] | Equity-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of Warrants	895,886	895,886
Exercise Price	$ 9.60
Expiration Date	2024-01

Warrants (Summary Of Changes In

Warrants (Summary Of Changes In Warrants Outstanding During The Period) (Details)	3 Months Ended
	Mar. 31, 2020$ / sharesshares
Class of Warrant or Right [Line Items]
Number of warrants, Outstanding	1,921,489
Number of warrants, issued
Number of warrants, Exercised
Number of warrants, Expired
Number of warrants, Outstanding	1,921,489
Weigted average exercise price, Outstanding | $ / shares	$ 22.10
Weighted average exercise price, Issued | $ / shares
Weighted average exercise price, Exercised | $ / shares
Weighted average exercise price, Expired | $ / shares
Weigted average exercise price, Outstanding | $ / shares	$ 22.10
Liability-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of warrants, Outstanding	515,984
Number of warrants, issued
Number of warrants, Exercised
Number of warrants, Expired
Number of warrants, Outstanding	515,984
Equity-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of warrants, Outstanding	1,405,505
Number of warrants, issued
Number of warrants, Exercised
Number of warrants, Expired
Number of warrants, Outstanding	1,405,505

Warrants (Schedule Of Fair Valu

Warrants (Schedule Of Fair Value Of Warrants Issued) (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Class of Warrant or Right [Line Items]
Fair value	$ 100,109	$ 41,717
November 2015 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	971	55
March 2016 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	1,240	439
September 2016 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	14,639	3,196
June 2017 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	30,364	11,736
June 2017 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	2,574	845
October 2017 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	46,178	23,772
October 2017 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	$ 4,143	$ 1,674

Warrants (Schedule Of Assumptio

Warrants (Schedule Of Assumptions Used In Calculating Fair Value Of Warrants) (Details) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Class of Warrant or Right [Line Items]
Trading market prices	$ 1.80	$ 1.91
Estimated future volatility	100.00%	102.00%
Dividend
Fundamental transaction likelihood	50.00%	50.00%
Fundamental transaction timing	2020-07	2020-04
Minimum [Member]
Class of Warrant or Right [Line Items]
Estimated future risk-free rate	0.20%	1.57%
Equivalent volatility	113.00%	85.00%
Equivalent risk-free rate	0.13%	1.57%
Maximum [Member]
Class of Warrant or Right [Line Items]
Estimated future risk-free rate	0.41%	1.72%
Equivalent volatility	129.00%	94.00%
Equivalent risk-free rate	0.19%	1.59%

Warrants (Schedule Of Unrealize

Warrants (Schedule Of Unrealized Gain/(Loss) On Fair Value Of Warrants) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Class of Warrant or Right [Line Items]
Unrealized (loss) gain on fair value of warrants	$ (58,392)	$ 1,513,371
November 2015 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized (loss) gain on fair value of warrants	(916)	197,084
November 2015 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized (loss) gain on fair value of warrants		380
March 2016 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized (loss) gain on fair value of warrants	(801)	114,799
September 2016 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized (loss) gain on fair value of warrants	(11,443)	217,869
June 2017 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized (loss) gain on fair value of warrants	(18,628)	388,391
June 2017 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized (loss) gain on fair value of warrants	(1,729)	41,911
October 2017 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized (loss) gain on fair value of warrants	(22,406)	496,501
October 2017 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized (loss) gain on fair value of warrants	$ (2,469)	$ 56,436

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Provision for Income Taxes
Operating loss carry-forward	157,964,000		$ 156,586,000
Federal And State [Member]
Operating Loss Carryforwards [Line Items]
Provision for Income Taxes	$ 0	$ 0

Income Taxes (Schedule Of Defer

Income Taxes (Schedule Of Deferred Tax Assets And Valuation Allowance) (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Income Taxes [Abstract]
Net Operating Loss Carryforwards	$ 44,230,000	$ 43,844,000
Stock Compensation Expense	551,000	1,191,000
Book Tax Differences on Assets and Liabilities	163,000	464,000
Valuation Allowance	(44,944,000)	(45,499,000)
Net Deferred Tax Assets

Commitments And Contingencies (

Commitments And Contingencies (Details) - USD ($)	Jun. 22, 2009	Mar. 31, 2020	Mar. 31, 2019	Feb. 05, 2018
Commitments And Contingencies [Line Items]
Estimated cost to complete contracts		$ 800,000
One-time milestone payment	$ 1,000,000
Employer matching contribution		100.00%
Maximum percentage of employee's gross pay		3.00%
Employer matching contribution on deferral		50.00%
Percentage of employee's gross pay		2.00%
Expense related to matching contribution		$ 11,229	$ 27,879
Percentage of licensing revenue				50.00%
Maximum [Member]
Commitments And Contingencies [Line Items]
Contract term, months		36 months
Licensing revenue agreement				$ 5,000,000
Minimum [Member]
Commitments And Contingencies [Line Items]
Contract term, months		2 months

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details)	Mar. 31, 2020USD ($)
Fair Value Measurements [Abstract]
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount	$ 0
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount	0
Fair Value, Liabilities, Level 1 to Level 2 Transfers, Amount	0
Fair Value, Liabilities, Level 2 to Level 1 Transfers, Amount	$ 0

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule Of Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:		$ 2,997,220
Warrant Liabilities	$ 100,109	41,717
Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:		999,820
Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:		1,997,400
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant Liabilities
Level 1 [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:		2,997,220
Warrant Liabilities
Level 2 [Member] | Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:		999,820
Level 2 [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:		1,997,400
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant Liabilities	$ 100,109	41,717
Level 3 [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:

Fair Value Measurements (Reconc

Fair Value Measurements (Reconciliation Of Changes In The Fair Value Of Liabilities) (Details) - Warrant Liabilities [Member]	3 Months Ended
	Mar. 31, 2020USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance	$ 41,717
Unrealized losses, net	58,392
Balance	$ 100,109