Opus Genetics (IRD) 10-Q 7 Aug 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Aug. 07, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2019
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	2019
Document Fiscal Period Focus	Q2
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 ($)	Jun. 30, 2019	Dec. 31, 2018
Current Assets:
Cash and cash equivalents	$ 7,310,049	$ 8,744,301
Marketable securities	8,950,120	5,981,520
Prepaid expenses and other current assets	1,033,041	1,173,847
Total Current Assets	17,293,210	15,899,668
Security Deposits	25,681	30,785
Operating Lease Right-of-Use Assets	263,658
Equipment, Net	94,685	112,473
Total Assets	17,677,234	16,042,926
Current Liabilities:
Accounts payable and accrued expenses	1,920,734	3,152,550
Deferred revenue	1,500,000
Operating lease liabilities, current	130,466
Total Current Liabilities	3,551,200	3,152,550
Operating Lease Liabilities, non-current	136,196
Warrant Liabilities	366,732	2,307,586
Other Liabilities		19,900
Total Liabilities	4,054,128	5,480,036
Commitments and Contingencies (note 14)
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 and 3,122,843 issued and outstanding	402	312
Additional paid-in capital	173,110,047	165,267,656
Accumulated other comprehensive income (loss)	7,179	(17,836)
Accumulated deficit	(159,494,522)	(154,687,242)
Total Stockholders' Equity	13,623,106	10,562,890
Total Liabilities and Stockholders' Equity	$ 17,677,234	$ 16,042,926

Condensed Balance Sheet (Parent

Condensed Balance Sheet (Parenthetical) - $ / shares	Jun. 30, 2019	Dec. 31, 2018
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	3,122,843
Common Stock, Shares, Outstanding	4,019,141	3,122,843

Condensed Statement Of Operatio

Condensed Statement Of Operations - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Condensed Statement Of Operations [Abstract]
Revenues:
Expenses:
General and administrative	1,340,016	1,568,848	3,035,538	3,396,170
Research and development	1,648,401	3,432,593	3,890,631	7,491,126
Total Expenses	2,988,417	5,001,441	6,926,169	10,887,296
Loss from Operations	(2,988,417)	(5,001,441)	(6,926,169)	(10,887,296)
Other Income
Interest income	96,650	67,473	178,035	143,209
Other income				368,750
Unrealized gain on fair value of warrants	427,483	1,095,700	1,940,854	4,462,196
Total Other Income	524,133	1,163,173	2,118,889	4,974,155
Net Loss Before Provision for Income Taxes	(2,464,284)	(3,838,268)	(4,807,280)	(5,913,141)
Provision for income taxes
Net Loss	$ (2,464,284)	$ (3,838,268)	$ (4,807,280)	$ (5,913,141)
Net loss per share, basic and diluted	$ (0.61)	$ (1.45)	$ (1.23)	$ (2.24)
Weighted average number of shares outstanding, basic and diluted	4,019,141	2,640,927	3,900,208	2,640,391

Condensed Statement Of Comprehe

Condensed Statement Of Comprehensive Loss - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Condensed Statement Of Comprehensive Loss [Abstract]
Net Loss	$ (2,464,284)	$ (3,838,268)	$ (4,807,280)	$ (5,913,141)
Unrealized gain (loss) on available-for-sale securities	19,781	24,421	25,015	(8,069)
Comprehensive Loss	$ (2,444,503)	$ (3,813,847)	$ (4,782,265)	$ (5,921,210)

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, 2017	$ 264	$ 157,143,930	$ (140,318,712)	$ (56,886)	$ 16,768,596
Balance, shares at Dec. 31, 2017	2,639,319
Common stock issued in exchange for services		12,150			12,150
Common stock issued in exchange for services, shares	625
Common stock issued from vested restricted stock units, shares	983
Stock-based compensation		563,728			563,728
Net Loss			(5,913,141)		(5,913,141)
Other Comprehensive income (loss)				(8,069)	(8,069)
Balance at Jun. 30, 2018	$ 264	157,719,808	(146,231,853)	(64,955)	11,423,264
Balance, shares at Jun. 30, 2018	2,640,927
Balance at Mar. 31, 2018	$ 264	157,452,657	(142,393,585)	(89,376)	14,969,960
Balance, shares at Mar. 31, 2018	2,640,927
Stock-based compensation		267,151			267,151
Net Loss			(3,838,268)		(3,838,268)
Other Comprehensive income (loss)				24,421	24,421
Balance at Jun. 30, 2018	$ 264	157,719,808	(146,231,853)	(64,955)	11,423,264
Balance, shares at Jun. 30, 2018	2,640,927
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				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		288,653			288,653
Net Loss			(4,807,280)		(4,807,280)
Other Comprehensive income (loss)				25,015	25,015
Balance at Jun. 30, 2019	$ 402	173,110,047	(159,494,522)	7,179	$ 13,623,106
Balance, shares at Jun. 30, 2019	4,019,141				4,019,141
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
Stock-based compensation		127,653			127,653
Net Loss			(2,464,284)		(2,464,284)
Other Comprehensive income (loss)				19,781	19,781
Balance at Jun. 30, 2019	$ 402	$ 173,110,047	$ (159,494,522)	$ 7,179	$ 13,623,106
Balance, shares at Jun. 30, 2019	4,019,141				4,019,141

Condensed Statement Of Cash Flo

Condensed Statement Of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash Flows from Operating Activities:
Net loss	$ (4,807,280)	$ (5,913,141)
Adjustments to reconcile net loss to net cash used in operating activities:
Compensatory stock		12,150
Depreciation and amortization	22,077	27,188
Loss on sale of equipment	9,594
Amortization of premiums and discounts on marketable securities, net	(56,019)	26,504
Stock-based compensation	288,653	563,728
Amortization and termination of deferred research and development arrangement		(375,000)
Unrealized gain on fair value of warrants	(1,940,854)	(4,462,196)
Amortization of deferred lease incentive		(6,222)
Deferred rent		(10,927)
Changes in assets and liabilities:
Prepaid expenses and other assets	22,308	(61,237)
Accounts payable and accrued expenses	(1,231,816)	147,767
Deferred revenue	1,500,000
Other, net	6,706
Net Cash Used in Operating Activities	(6,186,631)	(10,051,386)
Cash Flows from Investing Activities:
Purchase of equipment	(19,383)	(3,493)
Sale of equipment	5,500
Purchase of marketable securities	(8,887,566)
Redemption of marketable securities	6,000,000	6,250,000
Net Cash (Used In) Provided by Investing Activities	(2,901,449)	6,246,507
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 Decrease in Cash and Cash Equivalents	(1,434,252)	(3,804,879)
Cash and Cash Equivalents - beginning of period	8,744,301	8,899,154
Cash and Cash Equivalents - end of period	7,310,049	$ 5,094,275
Supplemental Cash Flow Information
Operating cash flows paid for amounts included in the measurement of lease liabilities	120,700
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	6 Months Ended
	Jun. 30, 2019
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 $159,494,522 at June 30 , 2019 and anticipates incurring losses through fiscal year 2019 and beyond. The Company has not yet generated commercial revenues and has funded its operations to date through the sale of shares of its common stock and warrants, exercises of stock warrants, interest income from cash, cash equivalents and marketable securities, and proceeds from reimbursed research and development costs. The Company believes that its cash, cash equivalents and marketable securities, will be sufficient to cover its cash flow requirements for its current activities for at least for the next 12 months from the date these financial statements were issued. Management believes it has the capability of managing the Company’s operations within existing cash available by focusing on select research and development activities, selecting projects in conjunction with potential financings and milestones, and efficiently managing its general and administrative affairs.  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 June 30 , 2019 and December 31, 2018 and of the results of operations, comprehensive loss and stockholders’ equity for the three and six months ended June 30 , 2019 and 2018 , and cash flows for the six months ended June 30, 2019 and 2018 have been included. Operating results for the three and six months ended June 30 , 2019 are not necessarily indicative of results that may be expected for any other interim period or the full fiscal year ending December 31, 2019. 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, 2018 (the “2018 Form 10-K”). Information included in the condensed balance sheet as of December 31, 2018 has been derived from the Company’s audited financial statements for the year ended December 31, 2018 included in the 2018 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. 

Recent Accounting Pronouncement

Recent Accounting Pronouncements Affecting The Company	6 Months Ended
	Jun. 30, 2019
Recent Accounting Pronouncements Affecting The Company [Abstract]
Recent Accounting Pronouncements Affecting The Company	2. Recent Accounting Pronouncements Affecting the Company Leases  In February 2016, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (“ASU 2016-02”). ASU 2016-02 requires the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous GAAP. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company adopted the standard on January 1, 2019. The Company elected the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allows carryforward of the historical lease classification. The Company is not electing the hindsight practical expedient. The Company made an accounting policy election to keep leases with an initial term of 12 months or less off the balance sheet. The Company will recognize those lease payments in the consolidated statements of operations on a straight-line basis over the lease term.  Adoption of this standard resulted in recognition of additional net right-of-use assets and lease liabilities, both of which were not quantitatively material to the Company’s financial statements, and there was no impact to the Company’s accumulated deficit. Adoption of this standard did not have a notable impact on the Company’s liquidity.  See Note 8 for additional discussion on the Company’s leases and the adoption of ASU 2016-02.   

Marketable Securities

Marketable Securities	6 Months Ended
	Jun. 30, 2019
Marketable Securities [Abstract]
Marketable Securities	 3. Marketable Securities  Marketable securities are considered “available-for-sale” in accordance with FASB 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 following table shows the Company’s marketable securities’ adjusted cost, gross unrealized gains and losses, and fair value by significant investment category as of June 30, 2019 and December 31, 2018:    June 30, 2019  Cost Gross Unrealized Gross Unrealized Fair  Basis Gains Losses Value  Commercial Paper $ 5,940,729 $ 4,831 $ - $ 5,945,560  Corporate Bonds 3,002,212 2,348 - 3,004,560  Total Marketable Securities $ 8,942,941 $ 7,179 $ - $ 8,950,120   December 31, 2018  Cost Gross Unrealized Gross Unrealized Fair  Basis Gains Losses Value  Corporate Bonds $ 5,999,356 $ - $ (17,836) $ 5,981,520  The Company typically invests in highly-rated securities, with the primary objective of minimizing the potential risk of principal loss. As of June 30, 2019, all of the Company’s marketable securities are due to mature in less than one year.

Prepaid Expenses And Other Curr

Prepaid Expenses And Other Current Assets	6 Months Ended
	Jun. 30, 2019
Prepaid Expenses And Other Current Assets [Abstract]
Prepaid Expenses And Other Current Assets	4. Prepaid Expenses and Other Current Assets    June 30, December 31,  2019 2018   Deposits on contracts $ 370,942 $ 618,417  Prepaid expenses and other current assets 662,099 555,430   $ 1,033,041 $ 1,173,847 Deposits on contracts consist of deposits on research and development contracts for services that had not been incurred as of the balance sheet date. Prepaid expenses and other assets include prepaid general and administrative expenses, such as insurance, rent, investor relations fees and compensatory stock issued for services not yet incurred as of the balance sheet date.

Equipment, Net

Equipment, Net	6 Months Ended
	Jun. 30, 2019
Equipment, Net [Abstract]
Equipment, Net	5. Equipment, Net    June 30, December 31,  2019 2018   Furniture and fixtures $ 67,650 $ 82,686  Office and computer equipment 178,872 159,489  Lab equipment - 447,653  Leasehold improvements 116,403 131,762   Total equipment 362,925 821,590  Less: Accumulated depreciation and amortization (268,240) (709,117)   Net carrying amount $ 94,685 $ 112,473 During the six months ended June 30, 2019, the Company sold its lab equipment prior to terminating its laboratory lease. The Company recorded a loss of $9,594 on the sale, which is included in general and administrative expense in the Company’s statement of operations.

Accounts Payable And Accrued Ex

Accounts Payable And Accrued Expenses	6 Months Ended
	Jun. 30, 2019
Accounts Payable And Accrued Expenses [Abstract]
Accounts Payable And Accrued Expenses	6. Accounts Payable and Accrued Expenses     June 30, December 31,  2019 2018   Trade payables $ 945,829 $ 547,519  Accrued expenses 89,000 140,637  Accrued research and development contract costs 623,266 1,782,131  Payroll liabilities 262,639 682,263   $ 1,920,734 $ 3,152,550 

Collaboration Agreement

Collaboration Agreement	6 Months Ended
	Jun. 30, 2019
Collaboration Agreement [Abstract]
Collaboration Agreement	 7. Collaboration Agreements  BioSense Global LLC On February 25, 2019, t he Company entered into a collaboration and license agreement (the “Collaboration and License Agreement”) with BioSense Global LLC (“BioSense”) to advance the development and commercialization of RX-3117 for pancreatic and other cancers in the Republic of Singapore, China, Hong Kong, Macau and Taiwan (the “Territory”). Under the terms of the Collaboration and License Agreement, the Company will grant BioSense an exclusive license to develop and commercialize pharma ceutical products containing RX-3117 as a single agent for the prevention or treatment of metastatic pancreatic cancer and other forms of cancer in the Territory that is effective upon paym ent in full of an upfront payment. The upfront payment consists of an aggregate of $3,000,000 , $1,500,000 of which had been paid by June 30, 2019, and the remaining $1,500,000 of which is due on August 24, 2019. Under the Collaboration and License Agreement, the Company is also eligible to receive milestone payments (i) in an aggregate of up to $126,000,000 for the achievement of development and regulatory goals in China and (ii) in an aggregate of up to $100,000,000 for the achievement of annual sales goals in the Republic of Singapore, China, Hong Kong, Macau and Taiwan with respect to each pharmaceutical product containing RX-3117 as a single agent. The Company will also be eligible to receive tiered royalties in the low double digits to mid-teens on annual net sales in the Territory. The Company has evaluated the Collaboration and License 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 Collaboration and License Agreement. The Company identified the exclusive license to develop RX-3117 and the supply RX-3117 clinical material for clinical trials 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 RX-3117 clinical material transfers to BioSense at a point in time when the exclusive license is conveyed and RX-3117 clinical material is delivered to BioSense , respectively . The Company determined the transaction price contains both fixed and variable consideration. The fixed consideration is equal to the upfront payment of $3,000,000 . 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 has determined at the contract outset and as of June 30, 2019 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 $3,000,000 upfront payment will be allocated to the performance obligations on the basis of the relative stand-alone 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 RX-3117 clinical material using a cost plus a margin approach. Accordingly, the Company has allocated $2,500,000 of the upfront transaction price to the exclusive license to develop RX-3117 and $500,000 to the supply of RX-3117 clinical material. 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. Neither performance obligation has been satisfied as of June 30, 2019. Accordingly, no revenue has been recognized for the three and six months ended June 30, 2019. The Company has recorded the $1,500,000 of transaction consideration received as of June 30, 2019 as deferred revenue on the Company’s balance sheet. Zhejiang Haichang Biotechnology Co., Ltd. On February 8, 2018, the Company entered into a research and development collaboration agreement with Zhejiang Haichang Biotechnology Co., Ltd. (“Haichang”) under which Haichang will develop RX-0301, a nano-liposomal formulation of RX-0201, using its proprietary QTsome™ technology and will conduct certain preclinical and clinical activities through completion of a Phase 2a proof-of-concept clinical trial in hepatocellular carcinoma in China.  The Company accounts for this contract under ASC 606. The Company has determined the sole performance obligation under the contract with Haichang relates to the license of intellectual property in exchange for variable, non-cash consideration in the form of the rights to the enhanced intellectual property developed by Haichang under the contract. Revenue associated with this license is recognized at a point in time. 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. Because the consideration in the contract varies based upon the success of the research and development efforts of Haichang, the Company has determined that the non-cash consideration in the contract represents variable consideration. 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 June 30, 2019. The Company has not recorded revenue for this contract for the three and six months ended June 30, 2019.  

Leases

Leases	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Leases	8. Leases  The Company adopted ASU 2016-02 on January 1, 2019. Upon adoption, leases classified as operating leases under previous U.S. GAAP are recognized as right of use lease assets and lease liabilities. The classification criteria for distinguishing between finance leases and operating leases pursuant to ASU 2016-02 are substantially similar to the classification criteria for distinguishing between capital leases and operating leases in the previous leases guidance. Upon adoption, the Company did not have any finance leases, and the Company’s operating leases were as follows:  Office Space Lease  The Company leases 5,466 square feet of office space in Rockville Maryland, with a lease term ending June 30, 2024. Prior to the amendment of this lease on March 18, 2019, the lease covered 7,193 square feet and had a lease term ending June 30, 2019. Under the lease agreement, the Company pays its allocable portion of real estate taxes and common area operating charges. The lease has escalating rent payments for which the Company records rent 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.  Laboratory Lease  The Company previously leased 2,552 square feet of laboratory space with a lease term due to end on June 30, 2020. The Company terminated its laboratory lease agreement on February 4, 2019 and surrendered the premises on February 28, 2019.  The following table summarizes the right of use lease assets and lease liabilities as of June 30, 2019:     Right-of-Use Assets $ 263,658   Operating Lease Liabilities  Current $ 130,466  Long Term 136,196  Total Operating Lease Liabilities $ 266,662  Lease expense for the three months ended June 30, 2019 was $53,788 , which includes $47,129 in operating lease costs and $6,659 in variable lease costs. Lease expense for the six months ended June 30, 2019 was $150,079 , which includes $127,407 in operating lease costs and $22,672 in variable lease costs. The right-of-use asset and lease liability were calculated using an estimated incremental borrowing rate of 11% . At June 30, 2019, the weighted average lease term was 2.0 years. The table below summarizes the Company’s scheduled future minimum lease payments recorded on the balance sheet, as of June 30, 2019:     Year Ending December 31:  2019 (excluding the six months ended June 30, 2019) $ 63,770  2020 154,961  2021 78,437  Minimum lease payments 297,168  Less: Imputed interest (30,506)  Present value of minimum lease payments 266,662  Less: current maturities of lease obligations (130,466)  Long-term lease obligations $ 136,196 

Net Loss Per Common Share

Net Loss Per Common Share	6 Months Ended
	Jun. 30, 2019
Net Loss Per Common Share [Abstract]
Net Loss Per Common Share	9. 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 June 30, 2019 and December 31, 2018, there were stock options, restricted stock units and warrants to acquire, in the aggregate , 2,160,106 and 1,322,602 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.

Common Stock

Common Stock	6 Months Ended
	Jun. 30, 2019
Common Stock [Abstract]
Common Stock	10. Common Stock The following transactions occurred during the six months ended June 30, 2019:  Reverse Stock Split On April 12, 2019 the Company effected a 1 -for- 12 reverse stock split of the outstanding shares of the Company’s common stock. Each 12 shares of the Company’s common stock, par value $0.0001 per share, issued and outstanding at the effective time of the reverse stock split were reclassified and combined into one share of common stock par value $0.0001 per share. The number of shares of common stock and preferred stock the Company is authorized to issue remained unchanged at 75,000,000 and 10,000,000 , respectively. All share and per share amounts have been restated for all periods to give retroactive effect to the reverse stock split. Accordingly, an amount equal to the par value of the decreased shares resulting from the reverse stock split was reclassified from “Common stock” to “Additional paid-in capital.”  January 2019 Public Offering On January 25, 2019, the Company closed an underwritten public offering of 895,834 shares of common stock and warrants to purchase up to 895,886 shares of common stock, resulting in gross proceeds to the Company of approximately $8,600,000 . The common stock and warrants were sold in units, consisting of a share of common stock and a warrant to purchase a share of common stock, at a price of $9.60 per unit, with an exercise price for the warrants of $9.60 per share . The warrants were immediately exercisable and will remain exercisable until January 25, 2024. The warrants issued are classified as equity instruments. The closing costs of this offering were $1,046,172 in underwriter’s and other professional fees that are recorded as a reduction in the gross proceeds of the offering.  Restricted Stock Units During the six months ended June 30, 2019, the Company issued 464 shares resulting from the vesting of restricted stock units (“RSUs”). 

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2019
Stock-Based Compensation [Abstract]
Stock-Based Compensation	11. Stock-Based Compensation As of June 30, 2019, the Company had 238,346 options to purchase common stock and 271 RSUs outstanding. At the Company’s Annual Meeting of Shareholders held on June 10, 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 June 30 , 201 9 , there were 219,526 options and 271 RSUs outstanding under the 2013 Plan, and 61,505 shares were available for issuance. On August 5, 2003, the Company established a stock option plan (the “2003 Plan”). With the adoption of the 2013 Plan, no new stock options may be issued under the 2003 Plan, but previously issued options under the 2003 Plan remain outstanding until their expiration. As of June 30, 2019, there were 18,820 options outstanding under the 2003 Plan. Accounting for Awards Stock-based compensation expense is the estimated fair value of options and RSUs 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 and six months ended June 3 0 , 2019 and 2018 is as follows:    For the Three Months Ended June 30, For the Six Months Ended June 30,  2019 2018 2019 2018  Statement of operations line item:  General and administrative $ 119,719 $ 174,589 $ 236,398 $ 391,004  Research and development 7,934 92,562 52,255 172,724   Total $ 127,653 $ 267,151 $ 288,653 $ 563,728  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 There were 52,465 stock options granted at exercise prices ranging from $5.23 to $7.45 with an aggregate fair value of $220,540 during the six months ended June 30 , 201 9 . The fair value of options at the date of grant was estimated using the Black-Scholes option pricing model. The Company took into consideration guidance under ASC 718, “Compensation-Stock Compensation,” and Staff Accounting Bulletin No. 107 (“SAB 107”) when reviewing and updating assumptions. The expected volatility is based upon historical volatility of the Company’s stock. The expected term is based upon the simplified method as allowed under SAB 107.  The assumptions made in calculating the fair values of options are as follows:     For the Six Months Ended June 30,  2019 2018  Black-Scholes assumptions  Expected dividend yield 0 % 0 %  Expected volatility 74-75 % 69-72 %  Risk-free interest rate 1.9 -2.6 % 2.3 -2.8 %  Expected term (in years) 5.5 -6 years 5.5 -6 years A summary of stock option activity for the six months ended June 30, 2019 is as follows:     Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value  Outstanding, January 1, 2019 255,922 $ 41.88 7.8 years $ -  Granted 52,465 $ 6.41  Exercised - $ -  Expired (2,080) $ 97.78  Cancelled (67,961) $ 39.02   Outstanding, June 30, 2019 238,346 $ 34.36 7.8 years $ -  Exercisable, June 30, 2019 119,953 $ 55.44 6.3 years $ -  There were no stock options exercised during the three and six months ended June 30, 2019 and 2018. The weighted average fair value of the options granted was $4.20 and $ 15.24 for the six months ended June 30 , 201 9 and 201 8 , respectively. A summary of the Company’s unvested options as of June 30, 2019 and changes during the six months ended June 30, 2019 is presented below:     2019  Number of Options Weighted Average Fair Value at Grant Date  Unvested at January 1, 2019 131,531 $ 13.19  Granted 52,465 $ 4.20  Vested (32,503) $ 16.16  Cancelled (33,100) $ 12.73   Unvested at June 30, 2019 118,393 $ 8.52 As of June 30, 2019, there was $908,838 of total unrecognized compensation cost related to unvested stock options, which is expected to be recognized over a weighted average vesting period of 2.6 years. Summary of Restricted Stock Unit Transactions The fair value of an RSU award is the closing price of the Company’s common stock on the date of grant. A summary of RSU activity for the six months ended June 30, 2019 is as follows:    Number of RSUs Weighted Average Grant Date Fair Value  Outstanding, January 1, 2019 1,394 $ 22.08  Granted - $ -  Vested and Released (464) $ 22.08  Cancelled (659) $ 22.08   Outstanding, June 30, 2019 271 $ 22.08 As of June 30, 2019, there was $4,884 of total unrecognized compensation cost related to unvested RSUs which is expected to be recognized over a weighted average vesting period of 1.7 years.

Warrants

Warrants	6 Months Ended
	Jun. 30, 2019
Warrants [Abstract]
Warrants	12. Warrants The following table summarizes the Company’s outstanding warrants to purchase common stock as of June 30, 2019 and December 31, 2018:     Number of Warrants:  Warrant Issuance June 30, 2019 December 31, 2018 Exercise Price Expiration Date  Liability-classified Warrants  January 2014 Investors - 39,683 $ 153.60 Jan. 2019  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 Jun. 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 515,984 555,667   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 - $ 9.60 Jan. 2024  Total equity-classified warrants 1,405,505 509,619   Total outstanding warrants 1,921,489 1,065,286  The following table summarizes the Company’s warrant activity for the six months ended June 30, 2019:      Number of Warrants  Liability-classified Equity- classified Total Weighted average exercise price  Balance, January 1, 2019 555,667 509,619 1,065,286 $ 37.52  Issued during the period - 895,886 895,886 $ 9.60  Exercised during the period - - - $ -  Expired during the period (39,683) - (39,683) $ 153.60   Balance, June 30, 2019 515,984 1,405,505 1,921,489 $ 22.10 At June 30, 2019, the weighted average remaining contractual life of the outstanding warrants was 4.2 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: June 30, 2019 December 31, 2018  November 2015 Investors $ 10,765 $ 234,918  November 2015 Placement Agent - 435  March 2016 Investor 12,426 160,099  September 2016 Investors 43,752 333,834  June 2017 Investors 105,374 623,324  June 2017 Placement Agent 8,685 65,149  October 2017 Investors 169,925 801,551  October 2017 Placement Agent 15,805 88,276  Total: $ 366,732 $ 2,307,586  The assumptions used in calculating the fair values of the liability-classified warrants are as follows:     June 30, 2019 December 31, 2018  Trading market prices $ 5.16 $ 11.16  Estimated future volatility 102 % 105 %  Dividend - -  Estimated future risk-free rate 1.59 -1.76 % 2.35 -2.53 %  Equivalent volatility 84-87 % 99-104 %  Equivalent risk-free rate 1.86 -1.98 % 2.51 -2.55 %  Fundamental transaction likelihood, at end of warrant term 5 % 5 %  Changes in the fair value of the warrant liabilities, carried at fair value, reported as “unrealized gain on fair value of warrants” in the statement of operations:     For the Three Months Ended June 30, For the Six Months Ended June 30,  2019 2018 2019 2018  Expired Warrants $ - $ 26 $ - $ 64,307  November 2015 Investors 27,069 213,847 224,153 854,801  November 2015 Placement Agent 55 556 435 2,134  March 2016 Investors 32,874 112,581 147,673 440,035  September 2016 Investors 72,213 137,110 290,082 571,485  June 2017 Investors 129,559 278,040 517,950 1,101,211  June 2017 Placement Agent 14,553 31,031 56,464 128,340  October 2017 Investors 135,125 288,231 631,626 1,160,577  October 2017 Placement Agent 16,035 34,278 72,471 139,306  Total: $ 427,483 $ 1,095,700 $ 1,940,854 $ 4,462,196 

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2019
Income Taxes [Abstract]
Income Taxes	13. Income Taxes No provision for federal and state income taxes was required for the three and six months ended June 30, 2019 and 2018 due to the Company’s operating losses and increased deferred tax asset valuation allowance. At June 30, 2019 and December 31, 2018, the Company had unused net operating loss carry-forwards of approximately $152,421,000 and $ 147,086 ,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 June 30, 2019 and December 31, 2018, 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:     June 30, December 31,  2019 2018   Net Operating Loss Carryforwards $ 42,678,000 $ 41,184,000  Stock Compensation Expense 1,265,000 1,608,000  Book tax differences on assets and liabilities 508,000 195,000  Valuation Allowance (44,451,000) (42,987,000)   Net Deferred Tax Assets $ - $ - The Company files income tax returns in the U.S. federal and Maryland state jurisdictions. Tax years for fiscal 2015 through 2018 are open and potentially subject to examination by the federal and Maryland state taxing authorities.

Commitments And Contingencies

Commitments And Contingencies	6 Months Ended
	Jun. 30, 2019
Commitments And Contingencies [Abstract]
Commitments And Contingencies	14. 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 June 30, 2019, the total estimated cost to complete these agreements was approximately $3,870,000 . 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 June 30, 2019, 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 $18,506 and $34,468 for the three months ended June 30, 2019 and 2018, respectively, and $46,385 and $70,277 for the six months ended June 30, 2019 and 2018, respectively. d) On February 5, 2018, the Company and NEXT BT Co. Ltd (“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 June 30, 2019, the Company has not made any royalty payments to Next BT. 

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2019
Fair Value Measurements [Abstract]
Fair Value Measurements	15. 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; and 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. There have been no changes in the methodologies used at June 30, 2019 and December 31, 2018, and no transfers between Level 1, 2 and 3 during the six months ended June 30, 2019. de    Fair Value Measurements at June 30, 2019  Total Level 1 Level 2 Level 3  Assets:  Commercial Paper $ 5,945,560 $ - $ 5,945,560 $ -  Corporate Bonds 3,004,560 - 3,004,560 -  Total Assets: $ 8,950,120 $ - $ 8,950,120 $ -   Liabilities:  Warrant Liabilities $ 366,732 $ - $ - $ 366,732     Fair Value Measurements at December 31, 2018  Total Level 1 Level 2 Level 3  Assets:  Corporate Bonds $ 5,981,520 $ - $ 5,981,520 $ -   Liabilities:  Warrant Liabilities $ 2,307,586 $ - $ - $ 2,307,586   The reconciliation of changes to the fair value of the Company’s warrant liabilities for the six months ended June 30, 2019 is as follows:     Warrant Liabilities  Balance at January 1, 2019 $ 2,307,586  Unrealized gains, net (1,940,854)  Balance at June 30, 2019 $ 366,732

Operations And Organization (Po

Operations And Organization (Policies)	6 Months Ended
	Jun. 30, 2019
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 $159,494,522 at June 30 , 2019 and anticipates incurring losses through fiscal year 2019 and beyond. The Company has not yet generated commercial revenues and has funded its operations to date through the sale of shares of its common stock and warrants, exercises of stock warrants, interest income from cash, cash equivalents and marketable securities, and proceeds from reimbursed research and development costs. The Company believes that its cash, cash equivalents and marketable securities, will be sufficient to cover its cash flow requirements for its current activities for at least for the next 12 months from the date these financial statements were issued. Management believes it has the capability of managing the Company’s operations within existing cash available by focusing on select research and development activities, selecting projects in conjunction with potential financings and milestones, and efficiently managing its general and administrative affairs.
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 June 30 , 2019 and December 31, 2018 and of the results of operations, comprehensive loss and stockholders’ equity for the three and six months ended June 30 , 2019 and 2018 , and cash flows for the six months ended June 30, 2019 and 2018 have been included. Operating results for the three and six months ended June 30 , 2019 are not necessarily indicative of results that may be expected for any other interim period or the full fiscal year ending December 31, 2019. 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, 2018 (the “2018 Form 10-K”). Information included in the condensed balance sheet as of December 31, 2018 has been derived from the Company’s audited financial statements for the year ended December 31, 2018 included in the 2018 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.

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements Affecting The Company (Policies)	6 Months Ended
	Jun. 30, 2019
Recent Accounting Pronouncements Affecting The Company [Abstract]
Recent Accounting Pronouncements Affecting the Company	 Leases  In February 2016, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (“ASU 2016-02”). ASU 2016-02 requires the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous GAAP. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company adopted the standard on January 1, 2019. The Company elected the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allows carryforward of the historical lease classification. The Company is not electing the hindsight practical expedient. The Company made an accounting policy election to keep leases with an initial term of 12 months or less off the balance sheet. The Company will recognize those lease payments in the consolidated statements of operations on a straight-line basis over the lease term.  Adoption of this standard resulted in recognition of additional net right-of-use assets and lease liabilities, both of which were not quantitatively material to the Company’s financial statements, and there was no impact to the Company’s accumulated deficit. Adoption of this standard did not have a notable impact on the Company’s liquidity.  See Note 8 for additional discussion on the Company’s leases and the adoption of ASU 2016-02. 

Marketable Securities (Tables)

Marketable Securities (Tables)	6 Months Ended
	Jun. 30, 2019
Marketable Securities [Abstract]
Schedule Of Cost And Fair Value Of Marketable Securities	  June 30, 2019  Cost Gross Unrealized Gross Unrealized Fair  Basis Gains Losses Value  Commercial Paper $ 5,940,729 $ 4,831 $ - $ 5,945,560  Corporate Bonds 3,002,212 2,348 - 3,004,560  Total Marketable Securities $ 8,942,941 $ 7,179 $ - $ 8,950,120   December 31, 2018  Cost Gross Unrealized Gross Unrealized Fair  Basis Gains Losses Value  Corporate Bonds $ 5,999,356 $ - $ (17,836) $ 5,981,520 

Prepaid Expenses And Other Cu_2

Prepaid Expenses And Other Current Assets (Tables)	6 Months Ended
	Jun. 30, 2019
Prepaid Expenses And Other Current Assets [Abstract]
Schedule Of Prepaid Expenses And Other Current Assets	  June 30, December 31,  2019 2018   Deposits on contracts $ 370,942 $ 618,417  Prepaid expenses and other current assets 662,099 555,430   $ 1,033,041 $ 1,173,847 

Equipment, Net (Tables)

Equipment, Net (Tables)	6 Months Ended
	Jun. 30, 2019
Equipment, Net [Abstract]
Schedule Of Equipment, Net	  June 30, December 31,  2019 2018   Furniture and fixtures $ 67,650 $ 82,686  Office and computer equipment 178,872 159,489  Lab equipment - 447,653  Leasehold improvements 116,403 131,762   Total equipment 362,925 821,590  Less: Accumulated depreciation and amortization (268,240) (709,117)   Net carrying amount $ 94,685 $ 112,473 

Accounts Payable And Accrued _2

Accounts Payable And Accrued Expenses (Tables)	6 Months Ended
	Jun. 30, 2019
Accounts Payable And Accrued Expenses [Abstract]
Schedule Of Accounts Payable And Accrued Expenses	  June 30, December 31,  2019 2018   Trade payables $ 945,829 $ 547,519  Accrued expenses 89,000 140,637  Accrued research and development contract costs 623,266 1,782,131  Payroll liabilities 262,639 682,263   $ 1,920,734 $ 3,152,550 

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Summary Of Right Of Use Lease Assets And Lease Liabilities	  Right-of-Use Assets $ 263,658   Operating Lease Liabilities  Current $ 130,466  Long Term 136,196  Total Operating Lease Liabilities $ 266,662 
Scheduled Future Minimum Lease Payments	  Year Ending December 31:  2019 (excluding the six months ended June 30, 2019) $ 63,770  2020 154,961  2021 78,437  Minimum lease payments 297,168  Less: Imputed interest (30,506)  Present value of minimum lease payments 266,662  Less: current maturities of lease obligations (130,466)  Long-term lease obligations $ 136,196 

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2019
Stock-Based Compensation [Abstract]
Summary Of Stock Compensation Expense	  For the Three Months Ended June 30, For the Six Months Ended June 30,  2019 2018 2019 2018  Statement of operations line item:  General and administrative $ 119,719 $ 174,589 $ 236,398 $ 391,004  Research and development 7,934 92,562 52,255 172,724   Total $ 127,653 $ 267,151 $ 288,653 $ 563,728 
Schedule Of Assumptions Made In Calculating The Fair Value Of Options	   For the Six Months Ended June 30,  2019 2018  Black-Scholes assumptions  Expected dividend yield 0 % 0 %  Expected volatility 74-75 % 69-72 %  Risk-free interest rate 1.9 -2.6 % 2.3 -2.8 %  Expected term (in years) 5.5 -6 years 5.5 -6 years 
Summary Of Share-Based Transactions	   Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value  Outstanding, January 1, 2019 255,922 $ 41.88 7.8 years $ -  Granted 52,465 $ 6.41  Exercised - $ -  Expired (2,080) $ 97.78  Cancelled (67,961) $ 39.02   Outstanding, June 30, 2019 238,346 $ 34.36 7.8 years $ -  Exercisable, June 30, 2019 119,953 $ 55.44 6.3 years $ - 
Summary Of Unvested Shares	   2019  Number of Options Weighted Average Fair Value at Grant Date  Unvested at January 1, 2019 131,531 $ 13.19  Granted 52,465 $ 4.20  Vested (32,503) $ 16.16  Cancelled (33,100) $ 12.73   Unvested at June 30, 2019 118,393 $ 8.52 
Summary Of RSU Activity	  Number of RSUs Weighted Average Grant Date Fair Value  Outstanding, January 1, 2019 1,394 $ 22.08  Granted - $ -  Vested and Released (464) $ 22.08  Cancelled (659) $ 22.08   Outstanding, June 30, 2019 271 $ 22.08 

Warrants (Tables)

Warrants (Tables)	6 Months Ended
	Jun. 30, 2019
Warrants [Abstract]
Summary Of Warrants Outstanding	  Number of Warrants:  Warrant Issuance June 30, 2019 December 31, 2018 Exercise Price Expiration Date  Liability-classified Warrants  January 2014 Investors - 39,683 $ 153.60 Jan. 2019  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 Jun. 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 515,984 555,667   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 - $ 9.60 Jan. 2024  Total equity-classified warrants 1,405,505 509,619   Total outstanding warrants 1,921,489 1,065,286 
Summary Of Changes In Warrants Outstanding During The Period	  Number of Warrants  Liability-classified Equity- classified Total Weighted average exercise price  Balance, January 1, 2019 555,667 509,619 1,065,286 $ 37.52  Issued during the period - 895,886 895,886 $ 9.60  Exercised during the period - - - $ -  Expired during the period (39,683) - (39,683) $ 153.60   Balance, June 30, 2019 515,984 1,405,505 1,921,489 $ 22.10 
Schedule Of Fair Value Of Warrants Issued	  Fair Value as of:  Warrant Issuance: June 30, 2019 December 31, 2018  November 2015 Investors $ 10,765 $ 234,918  November 2015 Placement Agent - 435  March 2016 Investor 12,426 160,099  September 2016 Investors 43,752 333,834  June 2017 Investors 105,374 623,324  June 2017 Placement Agent 8,685 65,149  October 2017 Investors 169,925 801,551  October 2017 Placement Agent 15,805 88,276  Total: $ 366,732 $ 2,307,586 
Schedule Of Assumptions Used In Calculating Fair Value Of Warrants	   June 30, 2019 December 31, 2018  Trading market prices $ 5.16 $ 11.16  Estimated future volatility 102 % 105 %  Dividend - -  Estimated future risk-free rate 1.59 -1.76 % 2.35 -2.53 %  Equivalent volatility 84-87 % 99-104 %  Equivalent risk-free rate 1.86 -1.98 % 2.51 -2.55 %  Fundamental transaction likelihood, at end of warrant term 5 % 5 % 
Schedule Of Unrealized Gain/(Loss) On Fair Value Of Warrants	  For the Three Months Ended June 30, For the Six Months Ended June 30,  2019 2018 2019 2018  Expired Warrants $ - $ 26 $ - $ 64,307  November 2015 Investors 27,069 213,847 224,153 854,801  November 2015 Placement Agent 55 556 435 2,134  March 2016 Investors 32,874 112,581 147,673 440,035  September 2016 Investors 72,213 137,110 290,082 571,485  June 2017 Investors 129,559 278,040 517,950 1,101,211  June 2017 Placement Agent 14,553 31,031 56,464 128,340  October 2017 Investors 135,125 288,231 631,626 1,160,577  October 2017 Placement Agent 16,035 34,278 72,471 139,306  Total: $ 427,483 $ 1,095,700 $ 1,940,854 $ 4,462,196 

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Jun. 30, 2019
Income Taxes [Abstract]
Schedule Of Deferred Tax Assets And Valuation Allowance	   June 30, December 31,  2019 2018   Net Operating Loss Carryforwards $ 42,678,000 $ 41,184,000  Stock Compensation Expense 1,265,000 1,608,000  Book tax differences on assets and liabilities 508,000 195,000  Valuation Allowance (44,451,000) (42,987,000)   Net Deferred Tax Assets $ - $ - 

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2019
Fair Value Measurements [Abstract]
Schedule Of Assets And Liabilities Measured At Fair Value On A Recurring Basis	   Fair Value Measurements at June 30, 2019  Total Level 1 Level 2 Level 3  Assets:  Commercial Paper $ 5,945,560 $ - $ 5,945,560 $ -  Corporate Bonds 3,004,560 - 3,004,560 -  Total Assets: $ 8,950,120 $ - $ 8,950,120 $ -   Liabilities:  Warrant Liabilities $ 366,732 $ - $ - $ 366,732     Fair Value Measurements at December 31, 2018  Total Level 1 Level 2 Level 3  Assets:  Corporate Bonds $ 5,981,520 $ - $ 5,981,520 $ -   Liabilities:  Warrant Liabilities $ 2,307,586 $ - $ - $ 2,307,586 
Reconciliation Of Changes In The Fair Value Of Liabilities	  Warrant Liabilities  Balance at January 1, 2019 $ 2,307,586  Unrealized gains, net (1,940,854)  Balance at June 30, 2019 $ 366,732 

Operations And Organization (De

Operations And Organization (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Operations And Organization [Abstract]
Accumulated deficit	$ 159,494,522	$ 154,687,242

Marketable Securities (Details)

Marketable Securities (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	$ 8,942,941
Gross Unrealized Gains	7,179
Fair Value	8,950,120
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	5,940,729
Gross Unrealized Gains	4,831
Fair Value	5,945,560
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	3,002,212	$ 5,999,356
Gross Unrealized Gains	2,348
Gross Unrealized Losses		(17,836)
Fair Value	$ 3,004,560	$ 5,981,520

Prepaid Expenses And Other Cu_3

Prepaid Expenses And Other Current Assets (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Prepaid Expenses And Other Current Assets [Abstract]
Deposits on contracts	$ 370,942	$ 618,417
Prepaid expenses and other current assets	662,099	555,430
Total prepaid expenses and other current assets	$ 1,033,041	$ 1,173,847

Equipment, Net (Narrative) (Det

Equipment, Net (Narrative) (Details)	6 Months Ended
	Jun. 30, 2019USD ($)
Equipment, Net [Abstract]
Loss on sale of equipment	$ (9,594)

Equipment, Net (Schedule Of Equ

Equipment, Net (Schedule Of Equipment, Net) (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Total equipment	$ 362,925	$ 821,590
Less: Accumulated depreciation and amortization	(268,240)	(709,117)
Net carrying amount	94,685	112,473
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total equipment	67,650	82,686
Office And Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Total equipment	178,872	159,489
Lab Equipment [Member]
Property, Plant and Equipment [Line Items]
Total equipment		447,653
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total equipment	$ 116,403	$ 131,762

Accounts Payable And Accrued _3

Accounts Payable And Accrued Expenses (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Accounts Payable And Accrued Expenses [Abstract]
Trade payables	$ 945,829	$ 547,519
Accrued expenses	89,000	140,637
Accrued research and development contract costs	623,266	1,782,131
Payroll liabilities	262,639	682,263
Total accounts payable and accrued expenses	$ 1,920,734	$ 3,152,550

Collaboration Agreement (Detail

Collaboration Agreement (Details)	6 Months Ended
	Jun. 30, 2019USD ($)
Upfront payment	$ 3,000,000
Deferred revenue	1,500,000
Amount due	1,500,000
Fixed consideration	3,000,000
RX-3117 Development [Member]
Upfront payment	2,500,000
RX-3117 Clinical Material [Member]
Upfront payment	500,000
China [Member]
Milestone payment	126,000,000
Republic of Singapore, China, Hong Kong, Macau and Taiwan [Member]
Milestone payment	$ 100,000,000

Leases (Narrative) (Details)

Leases (Narrative) (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2019USD ($)ft²	Jun. 30, 2019USD ($)ft²
Lessee, Lease, Description [Line Items]
Lease expense | $	$ 53,788	$ 150,079
Operating lease costs | $	47,129	127,407
Variable lease costs | $	$ 6,659	$ 22,672
Discount rate	11.00%	11.00%
Weighted average lease term	2 years	2 years
Prior Office Space Rental [Member]
Lessee, Lease, Description [Line Items]
Area | ft²	7,193	7,193
Office Space Rental [Member]
Lessee, Lease, Description [Line Items]
Area | ft²	5,466	5,466
Laboratory Lease [Member]
Lessee, Lease, Description [Line Items]
Area | ft²	2,552	2,552

Leases (Summary Of Right Of Use

Leases (Summary Of Right Of Use Lease Assets And Lease Liabilities) (Details)	Jun. 30, 2019USD ($)
Leases [Abstract]
Right-of-Use Assets	$ 263,658
Current	130,466
Long Term	136,196
Total Operating Lease Liabilities	$ 266,662

Leases (Scheduled Future Minimu

Leases (Scheduled Future Minimum Lease Payments) (Details)	Jun. 30, 2019USD ($)
Leases [Abstract]
2019 (excluding the six months ended June 30, 2019)	$ 63,770
2020	154,961
2021	78,437
Minimum lease payments	297,168
Less: Imputed interest	(30,506)
Total Operating Lease Liabilities	266,662
Less: current maturities of lease obligations	(130,466)
Long-term lease obligations	$ 136,196

Net Loss Per Common Share (Deta

Net Loss Per Common Share (Details) - shares	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Stock Options, Restricted Stock Units And Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities	2,160,106	1,322,602

Common Stock (Details)

Common Stock (Details)	Apr. 12, 2019$ / sharesshares	Jan. 25, 2019USD ($)$ / sharesshares	Jun. 30, 2019$ / sharesshares	Dec. 31, 2018$ / sharesshares
Common Stock [Abstract]
Reverse stock split	0.083
Common Stock, Par Value | $ / shares	$ 0.0001		$ 0.0001	$ 0.0001
Common Stock, Shares Authorized	75,000,000		75,000,000	75,000,000
Preferred Stock, Shares Authorized	10,000,000		10,000,000	10,000,000
Shares issued		895,834
Warrants issued		895,886	895,886
Proceeds from issuance | $		$ 8,600,000
Share price | $ / shares		$ 9.60
Warrants exercise price | $ / shares		$ 9.60
Issuance cost incurred | $		$ 1,046,172
Restricted stock issued			464

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Jun. 10, 2013
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	238,346		238,346		255,922
Stock options granted			52,465
Stock option exercise price			$ 6.41
Intrinsic value of options exercised	$ 0	$ 0	$ 0	$ 0
Weighted average fair value at grant date, Vested			$ 4.20	$ 15.24
Unrecognized compensation cost	$ 908,838		$ 908,838
Weighted average vesting period, years			2 years 7 months 6 days
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of RSUs outstanding	271		271		1,394
Unrecognized compensation cost	$ 4,884		$ 4,884
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	61,505		61,505
The 2013 Plan [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options outstanding	219,526		219,526
The 2013 Plan [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of RSUs outstanding	271		271
The 2003 Plan [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options outstanding	18,820		18,820
Exercise Price Range $5.23 to $7.45 [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted			52,465
Stock option grants fair value			$ 220,540
Exercise Price Range $5.23 to $7.45 [Member] | Minimum [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option exercise price			$ 5.23
Exercise Price Range $5.23 to $7.45 [Member] | Maximum [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option exercise price			$ 7.45

Stock-Based Compensation (Summa

Stock-Based Compensation (Summary Of Stock Compensation Expense) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share Based Compensation	$ 127,653	$ 267,151	$ 288,653	$ 563,728
General and administrative [Member]
Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share Based Compensation	119,719	174,589	236,398	391,004
Research and development [Member]
Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share Based Compensation	$ 7,934	$ 92,562	$ 52,255	$ 172,724

Stock-Based Compensation (Sched

Stock-Based Compensation (Schedule Of Assumptions Made In Calculating The Fair Value Of Options) (Details) - Stock Option [Member]	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%	0.00%
Expected volatility, minimum	74.00%	69.00%
Expected volatility, maximum	75.00%	72.00%
Risk free interest rate, minimum	1.90%	2.30%
Risk free interest rate, maximum	2.60%	2.80%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	5 years 6 months	5 years 6 months
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 years	6 years

Stock-Based Compensation (Sum_2

Stock-Based Compensation (Summary Of Share-Based Transactions ) (Details) - Stock Option [Member] - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Number of Options, Oustanding	255,922
Number of Options, Granted	52,465
Number of Options, Exercised
Number of Options, Expired	(2,080)
Number of Options, Cancelled	(67,961)
Number of Options, Oustanding	238,346	255,922
Weighted Average Exercise Price, Outstanding	$ 41.88
Weighted Average Exercise Price, Granted	6.41
Weighted Average Exercise Price, Exercised
Weighted average exercise price, Expired	97.78
Weighted Average Exercise Price, Cancelled	39.02
Weighted Average Exercise Price, Outstanding	$ 34.36	$ 41.88
Weighted Average Remaining Contractual Term, Outstanding	7 years 7 months 6 days	7 years 9 months 18 days
Aggregate Intrinsic Value, Outstanding
Number of Options, Exercisable	119,953
Weighted Average Exercise Price, Exercisable	$ 55.44
Weighted Average Remaining Contractual Term, Exercisable	6 years 2 months 12 days
Aggregate Intrinsic Value, Exercisable

Stock-Based Compensation (Sum_3

Stock-Based Compensation (Summary Of Unvested Shares) (Details) - Stock Option [Member]	6 Months Ended
	Jun. 30, 2019$ / sharesshares
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of Options, Unvested | shares	131,531
Number of Options, Granted | shares	52,465
Number of Options, Vested | shares	(32,503)
Number of Options, Cancelled | shares	(33,100)
Number of Options, Unvested | shares	118,393
Weighted Average Fair Value at Grant Date, Unvested | $ / shares	$ 13.19
Weighted Average Fair Value at Grant Date, Granted | $ / shares	4.20
Weighted Average Fair Value at Grant Date, Vested | $ / shares	16.16
Weighted Average Fair Value at Grant Date, Cancelled | $ / shares	12.73
Weighted Average Fair Value at Grant Date, Unvested | $ / shares	$ 8.52

Stock-Based Compensation (Sum_4

Stock-Based Compensation (Summary Of RSU Activity) (Details) - Restricted Stock Units (RSUs) [Member]	6 Months Ended
	Jun. 30, 2019$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of RSUs, Outstanding | shares	1,394
Number of RSUs, Granted | shares
Number of RSUs, Vested and Released | shares	(464)
Number of RSUs, Cancelled | shares	(659)
Number of RSUs, Outstanding | shares	271
Weighted Average Grant Date Fair Value, Outstanding | $ / shares	$ 22.08
Weighted Average Grant Date Fair Value, Granted | $ / shares
Weighted Average Grant Date Fair Value, Vested and Released | $ / shares	22.08
Weighted Average Grant Date Fair Value, Cancelled | $ / shares	22.08
Weighted Average Grant Date Fair Value, Outstanding | $ / shares	$ 22.08

Warrants (Narrative) (Details)

Warrants (Narrative) (Details)	6 Months Ended
	Jun. 30, 2019
Warrants [Abstract]
Average remaining contractual life of warrants outstanding	4 years 2 months 12 days

Warrants (Summary Of Warrants O

Warrants (Summary Of Warrants Outstanding) (Details) - $ / shares	6 Months Ended
	Jun. 30, 2019	Jan. 25, 2019	Dec. 31, 2018
Class of Warrant or Right [Line Items]
Number of Warrants	1,921,489		1,065,286
Exercise Price		$ 9.60
Liability-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of Warrants	515,984		555,667
Equity-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of Warrants	1,405,505		509,619
January 2014 Investor Warrants [Member] | Liability-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of Warrants			39,683
Exercise Price	$ 153.60
Expiration Date	2019-01
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
Exercise Price	$ 9.60
Expiration Date	2024-01

Warrants (Summary Of Changes In

Warrants (Summary Of Changes In Warrants Outstanding During The Period) (Details) - $ / shares	Jan. 25, 2019	Jun. 30, 2019
Class of Warrant or Right [Line Items]
Number of warrants, Outstanding		1,065,286
Number of warrants, issued	895,886	895,886
Number of warrants, Exercised
Number of warrants, Expired		(39,683)
Number of warrants, Outstanding		1,921,489
Weigted average exercise price, Outstanding		$ 37.52
Weighted average exercise price, Issued		9.60
Weighted average exercise price, Exercised
Weighted average exercise price, Expired		153.60
Weigted average exercise price, Outstanding		$ 22.10
Liability-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of warrants, Outstanding		555,667
Number of warrants, Exercised
Number of warrants, Expired		(39,683)
Number of warrants, Outstanding		515,984
Equity-Classified Warrants [Member]
Class of Warrant or Right [Line Items]
Number of warrants, Outstanding		509,619
Number of warrants, issued		895,886
Number of warrants, Exercised
Number of warrants, Outstanding		1,405,505

Warrants (Schedule Of Fair Valu

Warrants (Schedule Of Fair Value Of Warrants Issued) (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Class of Warrant or Right [Line Items]
Fair value	$ 366,732	$ 2,307,586
November 2015 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	10,765	234,918
November 2015 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value		435
March 2016 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	12,426	160,099
September 2016 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	43,752	333,834
June 2017 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	105,374	623,324
June 2017 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	8,685	65,149
October 2017 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	169,925	801,551
October 2017 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Fair value	$ 15,805	$ 88,276

Warrants (Schedule Of Assumptio

Warrants (Schedule Of Assumptions Used In Calculating Fair Value Of Warrants) (Details) - $ / shares	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Class of Warrant or Right [Line Items]
Trading market prices	$ 5.16	$ 11.16
Estimated future volatility	102.00%	105.00%
Dividend
Estimated additional shares to be issued upon dilutive event	5.00%	5.00%
Minimum [Member]
Class of Warrant or Right [Line Items]
Estimated future risk-free rate	1.59%	2.35%
Equivalent volatility	84.00%	99.00%
Equivalent risk-free rate	1.86%	2.51%
Maximum [Member]
Class of Warrant or Right [Line Items]
Estimated future risk-free rate	1.76%	2.53%
Equivalent volatility	87.00%	104.00%
Equivalent risk-free rate	1.98%	2.55%

Warrants (Schedule Of Unrealize

Warrants (Schedule Of Unrealized Gain/(Loss) On Fair Value Of Warrants) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	$ 427,483	$ 1,095,700	$ 1,940,854	$ 4,462,196
Expired Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants		26		64,307
November 2015 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	27,069	213,847	224,153	854,801
November 2015 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	55	556	435	2,134
March 2016 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	32,874	112,581	147,673	440,035
September 2016 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	72,213	137,110	290,082	571,485
June 2017 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	129,559	278,040	517,950	1,101,211
June 2017 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	14,553	31,031	56,464	128,340
October 2017 Investor Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	135,125	288,231	631,626	1,160,577
October 2017 Placement Agent Warrants [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	$ 16,035	$ 34,278	$ 72,471	$ 139,306

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Provision for income taxes
Operating loss carry-forward	152,421,000		152,421,000		$ 147,086,000
Federal And State [Member]
Operating Loss Carryforwards [Line Items]
Provision for income taxes	$ 0	$ 0	$ 0	$ 0

Income Taxes (Schedule Of Defer

Income Taxes (Schedule Of Deferred Tax Assets And Valuation Allowance) (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Income Taxes [Abstract]
Net Operating Loss Carryforwards	$ 42,678,000	$ 41,184,000
Stock Compensation Expense	1,265,000	1,608,000
Book tax differences on assets and liabilities	508,000	195,000
Valuation Allowance	(44,451,000)	(42,987,000)
Net Deferred Tax Assets

Commitments And Contingencies (

Commitments And Contingencies (Details) - USD ($)	Jun. 22, 2009	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Feb. 05, 2018
Commitments And Contingencies [Line Items]
Estimated cost to complete contracts		$ 3,870,000		$ 3,870,000
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		$ 18,506	$ 34,468	$ 46,385	$ 70,277
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)	Jun. 30, 2019USD ($)
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 ($)	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:	$ 8,950,120
Warrant Liabilities	366,732	$ 2,307,586
Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:	3,004,560	5,981,520
Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:	5,945,560
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:
Warrant Liabilities
Level 1 [Member] | Corporate Bonds [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:	8,950,120
Warrant Liabilities
Level 2 [Member] | Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:	3,004,560	5,981,520
Level 2 [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:	5,945,560
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:
Warrant Liabilities	$ 366,732	2,307,586
Level 3 [Member] | Corporate Bonds [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]	6 Months Ended
	Jun. 30, 2019USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance	$ 2,307,586
Unrealized gains, net	(1,940,854)
Balance	$ 366,732