Opus Genetics (IRD) 10-Q 5 Aug 16 2016 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2016	Aug. 05, 2016
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2016
Entity Registrant Name	REXAHN PHARMACEUTICALS, INC.
Entity Central Index Key	1,228,627
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q2
Trading Symbol	rnn
Entity Common Stock, Shares Outstanding		213,308,785

Condensed Balance Sheet

Condensed Balance Sheet - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 7,877,995	$ 10,199,440
Marketable securities	11,519,899	13,240,086
Prepaid expenses and other current assets	996,083	1,221,818
Total Current Assets	20,393,977	24,661,344
Security Deposits	30,785	30,785
Equipment, Net	105,358	112,900
Total Assets	20,530,120	24,805,029
Current Liabilities:
Accounts payable and accrued expenses	1,794,647	2,661,298
Deferred Research and Development Arrangement	487,500	525,000
Other Liabilities	92,595	104,020
Warrant Liabilities	2,340,978	2,739,163
Total Liabilities	4,715,720	6,029,481
Commitments and Contingencies (note 14)
Stockholders' Equity:
Preferred stock, par value $0.0001, 100,000,000 authorized shares, none issued and outstanding
Common stock, par value $0.0001, 500,000,000 authorized shares, 213,233,785 and 197,413,785 issued and outstanding	21,323	19,741
Additional paid-in capital	127,422,480	124,490,712
Accumulated other comprehensive income (loss)	2,327	(18,041)
Accumulated deficit	(111,631,730)	(105,716,864)
Total Stockholders' Equity	15,814,400	18,775,548
Total Liabilities and Stockholders' Equity	$ 20,530,120	$ 24,805,029

Condensed Balance Sheet (Parent

Condensed Balance Sheet (Parenthetical) - $ / shares	Jun. 30, 2016	Dec. 31, 2015
Condensed Balance Sheet [Abstract]
Preferred Stock, Par or Stated Value Per Share	$ 0.0001	$ 0.0001
Preferred Stock, Shares Authorized	100,000,000	100,000,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Common Stock, Par or Stated Value Per Share	$ 0.0001	$ 0.0001
Common Stock, Shares Authorized	500,000,000	500,000,000
Common Stock, Shares, Issued	213,233,785	197,413,785
Common Stock, Shares, Outstanding	213,233,785	197,413,785

Condensed Statement Of Operatio

Condensed Statement Of Operations - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Condensed Statement Of Operations
Revenues
Expenses:
General and administrative	1,675,749	1,584,852	3,071,155	3,109,552
Research and development	2,237,033	3,235,088	5,705,607	6,128,096
Total Expenses	3,912,782	4,819,940	8,776,762	9,237,648
Loss from Operations	(3,912,782)	(4,819,940)	(8,776,762)	(9,237,648)
Other Income (Expense)
Interest income	28,868	27,020	57,738	57,602
Unrealized gain on fair value of warrants	2,118,090	1,558,760	2,974,045	1,674,175
Financing expense			(169,887)
Total Other Income (Expense)	2,146,958	1,585,780	2,861,896	1,731,777
Net Loss Before Provision for Income Taxes	(1,765,824)	(3,234,160)	(5,914,866)	(7,505,871)
Provision for income taxes
Net Loss	$ (1,765,824)	$ (3,234,160)	$ (5,914,866)	$ (7,505,871)
Net loss per share, basic and diluted	$ (0.01)	$ (0.02)	$ (0.03)	$ (0.04)
Weighted average number of shares outstanding, basic and diluted	213,184,334	179,849,433	207,885,571	179,475,741

Condensed Statement Of Comprehe

Condensed Statement Of Comprehensive Loss - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Condensed Statement Of Comprehensive Loss [Abstract]
Net Loss	$ (1,765,824)	$ (3,234,160)	$ (5,914,866)	$ (7,505,871)
Unrealized gain on available-for-sale securities	3,733	4,672	20,368	39,395
Comprehensive Loss	$ (1,762,091)	$ (3,229,488)	$ (5,894,498)	$ (7,466,476)

Condensed Statement Of Cash Flo

Condensed Statement Of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash Flows from Operating Activities:
Net Loss	$ (5,914,866)	$ (7,505,871)
Adjustments to reconcile net loss to net cash used in operating activities:
Compensatory stock	64,949	56,250
Depreciation and amortization	15,053	12,643
Amortization of premiums and discounts on marketable securities, net	22,315	13,900
Stock-based compensation	694,187	544,352
Amortization of deferred research and development arrangement	(37,500)	(37,500)
Unrealized gain on fair value of warrants	(2,974,045)	(1,674,175)
Financing expense	169,887
Amortization of deferred lease incentive	(6,222)	(6,221)
Deferred lease expenses	(5,203)	(3,290)
Changes in assets and liabilities:
Prepaid expenses and other assets	225,735	(551,351)
Accounts payable and accrued expenses	(866,651)	709,545
Net Cash Used in Operating Activities	(8,612,361)	(8,441,718)
Cash Flows from Investing Activities:
Purchase of equipment	(7,511)	(12,388)
Purchase of marketable securities	(1,721,760)	(740,825)
Redemption of marketable securities	3,440,000	7,625,000
Net Cash Provided by Investing Activities	1,710,729	6,871,787
Cash Flows from Financing Activities:
Issuance of common stock and units, net of issuance costs	4,580,187	1,005,715
Proceeds from exercise of stock options		708,617
Net Cash Provided by Financing Activities	4,580,187	1,714,332
Net (Decrease) Increase in Cash and Cash Equivalents	(2,321,445)	144,401
Cash and Cash Equivalents - beginning of period	10,199,440	9,826,245
Cash and Cash Equivalents - end of period	7,877,995	$ 9,970,646
Non-cash financing and investing activties:
Warrants issued	$ 2,575,860

Operations And Organization

Operations And Organization	6 Months Ended
	Jun. 30, 2016
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 discovery, development and commercialization of innovative treatments for cancer. The Company had an accumulated deficit of $ 111,631,730 at June 30, 2016 and anticipates incurring losses through fiscal year 2016 and beyond. The Company has not yet generated commercial revenues and has funded its operating losses to date through the sale of shares of its common stock and warrants to purchase shares of its common stock, convertible debt, financings, 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 the next 12 months. 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, 2016 and December 31, 2015 and of the results of operations and comprehensive loss for the three and six months ended June 30, 2016 and 2015, and the results of cash flows for the six months ended June 30, 2016 and 2015 have been included. Operating results for the three and six months ended June 30, 2016 are not necessarily indicative of results that may be expected for any other interim period or the full fiscal year ending December 31, 2016. 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, 2015 (the “2015 Form 10-K”). Information included in the condensed balance sheet as of December 31, 2015 has been derived from the Company’s audited financial statements for the year ended December 31, 2015 included in the 2015 Form 10-K.  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, 2016
Recent Accounting Pronouncements Affecting The Company [Abstract]
Recent Accounting Pronouncements Affecting The Company	2. Recent Accounting Pronouncements Affecting the Company Revenue from Contracts with Customers  In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers,” a comprehensive new revenue recognition standard that will supersede nearly all existing revenue recognition guidance under U.S. GAAP. The standard’s core principle is that a company should recognize revenue when it transfers goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods and services, and provides a revenue recognition framework in accordance with this principle. On August 12, 2015, the FASB issued ASU 2015-14, which defers the effective date of ASU 2014-09 by one year to December 15, 2017 for annual reporting periods beginning after that date and interim periods therein. Early adoption of the standard is permitted, but not before the original effective date of December 15, 2016. The Company is currently evaluating the impact that the adoption of this guidance will have on its financial statements and future operating results.  Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern  In August 2014, the FASB issued ASU 2014-15, “Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern,” which requires management to perform interim and annual assessments as to the entity’s ability to continue as a going concern and provides related disclosure guidance. ASU 2014-15 will be effective for reporting periods beginning after December 15, 2016, with early adoption permitted. The Company is currently evaluating the impact the adoption of this guidance will have on its financial statements.  Leases  In February 2016, the FASB issued ASU 2016-02, “Leases,” which requires an entity to recognize assets and liabilities arising from leases on the balance sheet and to provide additional disclosures about leasing arrangements. ASU 2016-02 will be effective for reporting periods beginning after December 15, 2018, with early adoption permitted. The Company is currently evaluating the impact the adoption of this guidance will have on its financial statements.  Compensation-Stock Compensation  In March 2016, the FASB issued ASU 2016-09, “Compensation-Stock Compensation: Improvements to Employee Share Based Payment Accounting,” which includes multiple provisions intended to simplify various aspects of accounting for share-based payments. The guidance is effective for reporting periods beginning after December 15, 2016, with early adoption permitted. The Company is currently evaluating the impact the adoption of this guidance will have on its financial statements.  

Marketable Securities

Marketable Securities	6 Months Ended
	Jun. 30, 2016
Marketable Securities [Abstract]
Marketable Securities	 3 . Marketable Securities  Marketable securities are considered “available-for-sale” in accordance with FASB Accounting Standard 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, 2016 and December 31, 2015:    June 30, 2016  Cost Gross Unrealized Gross Unrealized Fair  Basis Gains Losses Value  Certificates of Deposit $ 5,520,000 $ 2,219 $ (40) $ 5,522,179  Commercial Paper 2,992,580 954 (604) 2,992,930  Corporate Bonds 3,004,992 273 (475) 3,004,790  Total Marketable Securities $ 11,517,572 $ 3,446 $ (1,119) $ 11,519,899   December 31, 2015  Cost Gross Unrealized Gross Unrealized Fair  Basis Gains Losses Value  Certificates of Deposit $ 6,240,000 $ 571 $ (5,575) $ 6,234,996  Commercial Paper 2,981,307 - (3,737) 2,977,570  Corporate Bonds 4,036,820 - (9,300) 4,027,520  Total Marketable Securities $ 13,258,127 $ 571 $ (18,612) $ 13,240,086  The Company typically invests in highly-rated securities, with the primary objective of minimizing the potential risk of principal loss. As of June 30, 2016, the Company had f our certificates of deposit with a fair value of $ 959,960 and unrealized losses of $ 40 , one commercial paper with a fair value of $ 996,940 and an unrealized loss of $ 604 , and one corporate bond with a fair value of $ 1,003,060 and an unrealized loss of $ 425 , all of which have been unrealized losses for less than 12 months. The Company has one corporate bond with a fair value of $1,000, 230 and an unrealized loss of $ 50 which has been an unrealized loss for greater than 12 months. The Company does not intend to sell its marketable securities in an unrealized loss position. Based upon these securities’ fair value relative to the cost, high ratings, and volatility of fair value, the Company considers the declines in market value of its marketable securities to be temporary in nature and does not consider any of its investments other-than-temporarily impaired, and anticipates that it will recover the entire amortized cost basis.  As of June 30 2016, 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, 2016
Prepaid Expenses and Other Current Assets [Abstract]
Prepaid Expenses and Other Current Assets	4 . Prepaid Expenses and Other Current Assets     June 30, December 31,  2016 2015   Deposits on contracts $ 199,697 $ 501,170  Prepaid expenses and other current assets 796,386 720,648   $ 996,083 $ 1,221,818 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 o ther assets include prepaid general and administrative expense s, 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, 2016
Equipment, Net [Abstract]
Equipment, Net	5. Equipment, Net     June 30, December 31,  2016 2015   Furniture and fixtures $ 78,794 $ 78,794  Office and computer equipment 112,777 105,266  Lab equipment 431,650 431,650  Leasehold improvements 133,762 133,762   Total equipment 756,983 749,472  Less: Accumulated depreciation and amortization (651,625) (636,572)   Net carrying amount $ 105,358 $ 112,900

Accounts Payable And Accrued Ex

Accounts Payable And Accrued Expenses	6 Months Ended
	Jun. 30, 2016
Accounts Payable And Accrued Expenses [Abstract]
Accounts Payable And Accrued Expenses	6 . Accounts Payable and Accrued Expenses      June 30, December 31,  2016 2015   Trade payables $ 598,843 $ 774,543  Accrued expenses 64,139 92,752  Accrued research and development contract costs 967,930 1,515,151  Payroll liabilities 163,735 278,852   $ 1,794,647 $ 2,661,298 

Deferred Research And Developme

Deferred Research And Development Arrangements	6 Months Ended
	Jun. 30, 2016
Deferred Research And Development Arrangements [Abstract]
Deferred Research And Development Arrangements	7 . Deferred Research and Development Arrangements Rexgene Biotech Co., Ltd. In 2003, the Company entered into a collaborative research agreement with Rexgene Biotech Co., Ltd. (“Rexgene”), a shareholder. Rexgene is engaged in the development of pharmaceutical products in Asia and has agreed to assist the Company with the research, development and clinical trials necessary for registration of the Company’s drug candidate Archexin in Asia. This agreement provides Rexgene with exclusive rights to license, sublicense, make, have made, use, sell and import Archexin in Asia. In accordance with the agreement, Rexgene paid the Company a one-time fee of $ 1, 500,000 in 2003. The agreement terminates at the later of 20 years or the term of the patent. The amortization reduces research and development expenses for the periods presented. The Company is using 20 years as its basis for recognition and accordingly research and devel opment expenses were reduced by $18,750 and $37,500 for the three and six months ended June 30, 2016 and 2015, respectively. The remaining $ 487,500 and $ 525,000 to be amortized at June 30, 2016 and December 31, 2015, respectively, is reflected as a deferred resea rch and development arrangement on the balance sheet. The payment from Rexgene is being used in the cooperative funding of the costs of development of Archexin. Royalties of 3 % of net sales of licensed products will become payable by Rexgene to the Company on a quarterly basis once commercial sales of Archexin begin in Asia. The product is still under development and commercial sales in Asia are not expec ted to begin until at least 2017 . Under the terms of the agreement, Rexgene does not receive royalties on the Company’s net sales outside of Asia. 

Other Liabilities

Other Liabilities	6 Months Ended
	Jun. 30, 2016
Other Liabilities [Abstract]
Other Liabilities	8 . Other Liabilities  Deferred Lease Incentive  In accordance with the Company’s office lease agreement, as amended and further discussed in Note 14, the Company has been granted leasehold improvement allowances from the lessor to be used for the construction cost of improvements to the leased property, which included architectural and engineering fees, government agency plan check, permit and other fees, sales and use taxes, testing and inspection costs and telephone and data cabling and wiring in the premises. The Company accounted for the benefit of the leasehold improvement allowance as a reduction of rental expense over the term of the office lease. The following table sets forth the cumulative deferred lease incentive:     June 30, December 31,  2016 2015   Deferred lease incentive $ 154,660 $ 154,660  Less accumulated amortization (117,330) (111,108)   Balance $ 37,330 $ 43,552 Deferred Office Lease Expense The lease agreement , as amended, provided for an initial annual base rent with annual increases over the lease term . The Company recognizes rental expense on a straight-line basis over the term of the lease, which resulted in a deferred rent liability of $ 55,265 and $ 60,468 as of June 30, 2016 and December 31, 2015 , respectively.

Net Loss Per Common Share

Net Loss Per Common Share	6 Months Ended
	Jun. 30, 2016
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, 2016 and December 31, 2015, there were stock options and warrants to acquire, in the aggregate, 5 5,376,643 and 39,082,886 shares of the Company’s common stock, respectively, that are potentially dilutive. However, diluted loss per share for all periods presented is the same as basic loss per share because the inclusion of common share equivalents would be anti-dilutive.

Common Stock

Common Stock	6 Months Ended
	Jun. 30, 2016
Common Stock [Abstract]
Common Stock	10 . Common Stock The following t ransactions occurred since December 31, 2015: Public Offering On March 2, 2016 the Company closed on a registered direct public offering to issue and sell 15,625,000 shares of common stock and warrants to purchase up to 11,718,750 shares of common stock. The common stock and warrants were sold in units, consisting of common stock and a warrant to purchase 0.75 shares of common stock, at a price of $0. 32 per unit, and the warrants have an exercise price of $0. 42 per share . The total gross proceeds of the offering were $5,000,000 . The warrants issued are exercisable beginning six months after the closing date until the five-year anniversary of the initial exercise date and were recorded as liabilities at fair value. A summary of the allocation of the proceeds of the offering is shown below:     Gross Proceeds: $ 5,000,000   Allocated to warrant liabilities: 2,419,922  Allocated to common stock and additional paid-in capital 2,580,078   Total allocated gross proceeds: $ 5,000,000   The closing costs of $ 575,751 included 78 1,250 warrants valued at $15 5,938 and $ 419,813 for placement agent and other fees. Based upon the estimated fair value of the stock and warrants in the units, the Company allocated $1 69,887 to financing expense and $ 405,864 as stock issuance costs.  Compensatory Shares During the six months ended June 30, 2016, the Company issued 195,000 shares to vendors in exchange for investor relations services. The aggregate market value of the stock issued was $64,949 .  

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2016
Stock-Based Compensation [Abstract]
Stock-Based Compensation	11 . Stock-Based Compensation As of June 30, 2016, the Company had 1 6,384,739 options to purchase common stock outstanding. At the Company’s Annual Meeting of Stockholders held on June 10, 2013, the Company’s stockholders 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. A total of 17,000,000 shares of common stock have been reserved for issuance pursuant to the 2013 Plan. As of June 30, 2016 , there were 1 1,246,239 options outstanding under the 2013 Plan , and 5,746,261 sha res were available for issuance. On August 5, 2003, the Company established a stock option plan (the “2003 Plan”). Under the 2003 Plan, the Company granted stock options to key employees, directors and consultants of the Company. 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, 2016 , there were 5,018,500 outstanding options under the 2003 Plan. In March 2016, the Company granted to a third party an option to purchase up to 120,000 shares of the Company’s common stock. Of the Company’s outstanding options as of June 30, 2016, these were the only options that were not issued pursuant to the 2013 Plan or the 2003 Plan. At the Company’s Annual Meeting of the Stockholders held on June 9, 2016, the Company’s stockholders voted to approve an amendment to the 2013 Plan, including to provide for awards of restricted stock and restricted stock units. As of June 30, 2016, no awards of restricted stock or restricted stock units had been granted. For the majority of the option grants to employees, the vesting period is either ( i) 30% , 30% and 40% on the first , second and third anniversaries of the grant date, respectively, or ( ii) 25% each on the first four anniversaries of the grant date . With the exception of the options granted in March 2016, which have a three -year term, o ptions expire between five and ten years from the date of grant. For the majority of grants to non-employee consultants of the Company, the vesting period is between one and three years, s ubject to the fulfillment of certain conditions in the individual stock agreements, or 100% upon the occurrence of certain events specified in the individual stock agreements. Accounting for Awards Stock option 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 and six months ended June 30, 2016 and 2015 is as follows:      For the Three Months Ended June 30, For the Six Months Ended June 30,  2016 2015 2016 2015  Statement of operations line item:  General and administrative $ 224,786 $ 175,666 $ 440,113 $ 365,705  Research and development 126,390 96,300 254,074 178,647   Total $ 351,176 $ 271,966 $ 694,187 $ 544,352 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 4,487,090 stock options granted at exercise prices ranging from $0. 27 to $0. 37 with an aggregate fair value of $ 927,644 during the six months ended June 30, 2016. There were 3,726,316 stock options granted at exercise prices ranging from $0. 68 to $0. 89 with an aggregate fair value of $1, 835,853 during the six months ended June 30, 2015. 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:     Six Months Ended June 30,  2016 2015  Black-Scholes assumptions  Expected dividend yield 0 % 0 %  Expected volatility 32-75 % 77-80 %  Risk free interest rate 0.6 -1.4 % 1.3 -1.7 %  Expected term (in years) 2 -6 years 6 years T he following table summarizes share-based transactions:     Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value  Outstanding, January 1, 2016 12,590,982 $ 0.83 6.8 years $ 26,500  Granted 4,487,090 0.33  Exercised - -  Expired (610,000) 1.20  Cancelled (83,333) 0.51   Outstanding, June 30, 2016 16,384,739 $ 0.68 7.4 years $ -  Exercisable, June 30, 2016 8,120,929 $ 0.82 5.8 years $ -   There were no stock options exercised during the three and six months ended June 30 , 2016. The total intrinsic value of the options exercised was $1,844 and $99,895 for the three and six months ended June 30 , 2015 , respectively . The weighted average fair value of the options granted was $0.21 and $ 0.49 for the six months ended June 30 , 2016 and 2015 respectively. A summary of the Company’s unvested options as of June 30, 2016 and changes during the six months ended June 30, 2016 is presented below:     2016  Number of Options Weighted Average Fair Value at Grant Date  Unvested at January 1, 2016 5,888,432 $ 0.51  Granted 4,487,090 $ 0.21  Vested (2,066,504) $ 0.45  Cancelled (45,208) $ 0.35   Unvested at June 30, 2016 8,263,810 $ 0.36 As of June 30, 2016 there was $2, 444,014 of total unrecognized compensation cost related to unvested stock options, which is expected to be recognized over a weighted average vesting period of 2. 3 years .

Warrants

Warrants	6 Months Ended
	Jun. 30, 2016
Warrants [Abstract]
Warrants	12. Warrants As of June 30, 2016, warrants to purchase 38,991,904 shares were outstanding, having exercise prices ranging from $ 0.40 to $ 1.50 and expiration dates ranging from July 5, 2016 to September 2, 20 21 .     2016 2015  Number of warrants Weighted average exercise price Number of warrants Weighted average exercise price  Balance, January 1 26,491,904 $ 0.80 13,205,871 $ 1.07  Issued during the period 12,500,000 $ 0.42 - $ -  Exercised during the period - $ - - $ -  Expired during the period - $ - - $ -   Balance, June 30 38,991,904 $ 0.68 13,205,871 $ 1.07 At June 30, 2016 the weighted average remaining contractual life of the outstanding warrants was 3. 9 years.  The warrants issued to investors in the March 2011, December 2012, November 2015 and March 2016 offerings contain a provision for net cash settlement in the event that there is a fundamental transaction (contractually defined as a merger, sale of substantially all assets, tender offer or share exchange). If a fundamental transaction occurs in which the consideration issued consists principally of cash or stock in a non-public company, then the warrant holder has the option to receive cash, equal to the fair value of the remaining unexercised portion of the warrant. Due to this contingent redemption provision, the warrants require liability classification in accordance with ASC 480 and are recorded at fair value. The warrants issued to investors in the July 2013, October 2013 and January 2014 offerings contain a fundamental transaction provision, but the warrant holders only have an option as to the type of consideration received if the holders of common stock receive an option as to their consideration. In addition, the warrants issued in the March 2011, December 2012, July 2013, October 2013, January 2014, November 2015 and March 2016 contain a cashless exercise provision that is exercisable only in the event that a registration statement is not effective. That provision may not be operative if an effective registration statement is not available because an exemption under the U.S. securities laws may not be available to issue unregistered shares. As a result, net cash settlement may be required, and the warrants require liability classification.  ASC 820 provides requirements for disclosure of liabilities that are measured at fair value on a recurring basis in periods subsequent to the initial recognition. Fair values for warrants were determined using the Binomial Lattice (“Lattice”) valuation technique. The Lattice model provides for dynamic assumptions regarding volatility and risk-free interest rates within the total period to maturity. Accordingly, within the contractual term, the Company provided multiple date intervals over which multiple volatilities and risk free interest rates were used. These intervals allow the Lattice model to project outcomes along specific paths that consider volatilities and risk free rates that would be more likely in an early exercise scenario.  Significant assumptions are determined as follows: Trading market values —Published trading market values; Exercise price —Stated exercise price; Term —Remaining contractual term of the warrant; Volatility —Historical trading volatility for periods consistent with the remaining terms; and Risk-free rate —Yields on zero coupon government securities with remaining terms consistent with the remaining terms of the warrants.  Due to the fundamental transaction provision, which could provide for early redemption of the warrants, the model also considered the probability the Company would enter into a fundamental transaction during the remaining term of the warrant. Because the Company is not yet achieving positive cash flow, management believes the probability of a fundamental transaction occurring over the term of the warrant is unlikely and therefore estimates the probability of entering into a fundamental transaction to be 5 %. For valuation purposes, the Company also assumed that if such a transaction did occur, it was more likely to occur towards the end of the term of the warrants.  The significant unobservable inputs used in the fair value measurement of the warrants include management’s estimate of the probability that a fundamental transaction may occur in the future. Significant increases (decreases) in the probability of occurrence would result in a significantly higher (lower) fair value measurement. The following table summarizes the fair value of the warrants as of the respective balance sheet dates:     Fair Value as of:  Warrant Issuance: June 30, 2016 December 31, 2015  March 31, 2011 financing:  Warrants to institutional investors $ - $ 30  December 4, 2012 financing:  Warrants to institutional investors 2,540 9,818  Warrants to placement agent - 1,206  July 26, 2013 financing:  Warrants to institutional investors 27,520 121,420  Warrants to placement agent - 384  October 16, 2013 financing:  Warrants to institutional investors 39,742 169,349  Warrants to placement agent - 970  January 21, 2014 financing:  Warrants to institutional investors 13,762 131,476  November 12, 2015 financing:  Warrants to institutional investors 964,750 2,169,375  Warrants to placement agent 54,975 135,135  March 2, 2016 financing:  Warrants to institutional investors 1,167,656 -  Warrants to placement agent 70,033 -  Total: $ 2,340,978 $ 2,739,163 The following table summarizes the number of shares indexed to the warrants as of the respective balance sheet dates:     Number of Shares indexed as of:  Warrant Issuance June 30, 2016 December 31, 2015  March 31, 2011 financing:  Warrants to institutional investors 3,333,333 3,333,333  December 4, 2012 financing:  Warrants to institutional investors 174,300 174,300  Warrants to placement agent 40,000 40,000  July 26, 2013 financing:  Warrants to institutional investors 2,000,000 2,000,000  Warrants to placement agent 124,032 124,032  October 16, 2013 financing:  Warrants to institutional investors 2,317,309 2,317,309  Warrants to placement agent 407,692 407,692  January 21, 2014 financing:  Warrants to institutional investors 4,761,905 4,761,905  November 12, 2015 financing:  Warrants to institutional investors 12,500,000 12,500,000  Warrants to placement agent 833,333 833,333  March 2, 2016 financing:  Warrants to institutional investors 11,718,750 -  Warrants to placement agent 781,250 -  Total: 38,991,904 26,491,904 The assumptions used in calculating the fair values of the warrants are as follows:     June 30, 2016 December 31, 2015  Trading market prices $ 0.25 $ 0.36  Estimated future volatility 105 % 105 %  Dividend - -  Estimated future risk-free rate 0.20 -1.36 % 0.82 -2.38 %  Equivalent volatility 43-62 % 44-65 %  Equivalent risk-free rate 0.01 -0.63 % 0.22 -1.11 %  Changes in the fair value of the warrant liabilities, carried at fair value, as 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,  2016 2015 2016 2015  March 31, 2011 financing:  Warrants to institutional investors 33 202,963 30 305,040  December 4, 2012 financing:  Warrants to institutional investors 5,911 32,568 7,278 29,671  Warrants to placement agent 529 5,434 1,206 5,577  July 26, 2013 financing:  Warrants to institutional investors 63,246 289,146 93,900 264,360  Warrants to placement agent 64 15,209 384 19,554  October 16, 2013 financing:  Warrants to institutional investors 103,166 323,698 129,607 305,938  Warrants to placement agent 145 48,918 970 64,097  January 21, 2014 financing:  Warrants to institutional investors 92,428 640,824 117,714 679,938  November 12, 2015 financing:  Warrants to institutional investors 875,913 - 1,204,626 -  Warrants to placement agent 58,276 - 80,160 -  March 2, 2016 financing:  Warrants to institutional investors 860,121 - 1,252,266 -  Warrants to placement agent 58,258 - 85,904 -  Total: $ 2,118,090 $ 1,558,760 $ 2,974,045 $ 1,674,175 

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2016
Income Taxes [Abstract]
Income Taxes	13 . Income Taxes No provision for federal and state inc ome taxes was required for the three and six months ended June 30 , 2016 and 2015 due to the Company’s operating losses and increased deferred tax asset valuation allowance. At June 30, 2016 and December 31 , 2015, the Company had unused net operating loss carry-forwards of approximately $107,101,000 and $ 98,954,000 , respectively, which expire at various dates through 203 6 . 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, 2016 and December 31, 2015 , 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,  2016 2015   Net Operating Loss Carryforwards $ 41,769,000 $ 38,592,000  Stock Compensation Expense 1,905,000 1,891,000  Book tax differences on assets and liabilities 309,000 380,000  Valuation Allowance (43,983,000) (40,863,000)   Net Deferred Tax Assets $ - $ - The Company files income tax returns in the U.S. federal and Maryland state jurisdictions. Tax years for fis cal 2012 through 2015 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, 2016
Commitments And Contingencies [Abstract]
Commitments And Contingencies	14 . Commitments and Contingencies a) The Company has contracted with various vendors for resear ch and development services, the t erms which require payments over the term s of the agreement s , usually ranging from two to 36 months. The costs to be incurred are estimated and are subject to revision. As of June 30, 2016, the total estimated cost to complete t hese agreements was approximately $6,440,000 . 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 inte llectual property related to quinoxaline-p iperazine derivatives that were synthesized under a Joint Research Agreement. The initial license fee was $ 100,000 , all of which was paid as of December 31, 2009. 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 properties. As of June 30, 2016 , the milestone has not occurred. c ) Office Space Lease On June 7, 2013, the Company signed the first amendment to its commercial lease agreement for 5,466 square feet of office space in Rockville, Maryland. The amendment extends the lease term until June 30, 2019. Under the lease agreement, the Company pays its allocable portion of real estate taxes and common area operating charges. On July 26, 2014 the Company entered into the second amendment to the lease agreement. According to the terms of this amendment, the Company leased an additional 1,637 square feet of office space, beginning on September 1, 2014 and ending on August 31, 2015. The Company subsequently renewed the lease for this space for additional one -year terms, beginning on September 1, 2015 and 2016. Rent paid under the Company’s lease during the three months ended June 30 , 2016 and 2015 was $ 51,301 and $50,058 , respectively , and rent paid during the six months ended June 30, 2016 and 2015 was $102,603 and 100,117 , respectively. Prior Laboratory Lease On August 26, 2014, the Company signed a one -year renewal to use laboratory space commencing on July 1, 2014 and ending on June 30, 2015. The lease required monthly rental payments of $4,554 . Rent paid under the Company’s lease during the three and six months ended June 30 , 2015 was $ 13,662 and $27,324 , respectively. Current Laboratory Lease On April 20, 2015, the Company signed a five -year lease agreement for 2,552 square feet of laboratory space commencing on July 1, 2015 and ending on June 30, 2020. Under the lease agreement, the Company pays its allocable portion of real estate taxes and common area operating charges. Rent paid under this lease during the three and six months ended June 30, 2016 was $ 15,312 and $30,624 , respectively . Future rental payments over the next five years for all leases are as follows:    For the remaining six months ending December 31: 2016 134,264  For the year ending December 31: 2017 255,731  2018 233,923  2019 152,955  2020 34,468   Total $ 811,341   d ) 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 $31,5 87 and $ 34,799 for the three months ended June 30, 2016 and 2015, respectively, and $63,089 and $64,158 for the six months ended June 30, 2016 and 2015. e ) In July 2013, the Company entered into an exclusive license agreement with the University of Maryland, Baltimore for a novel drug delivery platform, Nano-Polymer Drug Conjugate Systems. RX-21101 is the Company’s first drug candidate utilizing this platform. The agreement requires the Company to make payments to the University of Maryland if RX-21101 or any products from the licensed delivery platform achieve development milestones. As of June 30, 2016, no development milestones have occurred. f ) In October 2013, the Company signed an exclusive license agreement with the Ohio State Innovation Foundation, for a novel oligonucleotide drug delivery platform, Lipid-Coated Albumin Nanoparticle. The agreement requires the Company to make payments to the Ohio State Innovation Foundation or any products from the licensed delivery platform achieve development milestones. As of June 30, 2016, no development milestones have occurred.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2016
Fair Value Measurements [Abstract]
Fair Value Measurements	1 5 . 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, 2016 and December 31, 2015. de    Fair Value Measurements at June 30, 2016  Total Level 1 Level 2 Level 3  Assets:  Certificates of Deposit $ 5,522,179 $ - $ 5,522,179 $ -  Commercial Paper 2,992,930 - 2,992,930 -  Corporate Bonds 3,004,790 - 3,004,790 -  Total Assets: $ 11,519,899 $ - $ 11,519,899 $ -   Liabilities:  Warrant Liabilities $ 2,340,978 - - $ 2,340,978     Fair Value Measurements at December 31, 2015  Total Level 1 Level 2 Level 3  Assets:  Certificates of Deposit $ 6,234,996 $ - $ 6,234,996 $ -  Commercial Paper 2,977,570 - 2,977,570 -  Corporate Bonds 4,027,520 - 4,027,520 -  Total Assets: $ 13,240,086 $ - $ 13,240,086 $ -   Liabilities:  Warrant Liabilities $ 2,739,163 - - $ 2,739,163  The fair value of the Company’s Level 2 marketable securities is determined by using quoted prices from independent pricing services that use market data for comparable securities in active or inactive markets. A variety of data inputs, including benchmark yields, interest rates, known historical trades and broker dealer quotes are used with pricing models to determine the quoted prices.  The fair value methodology for the warrant liabilities is disclosed in Note 1 2 .  The carrying amounts reported in the financial statements for cash and cash equivalents (Level 1), prepaid expenses, and other assets and accounts payable and accrued expenses approximate fair value because of the short term maturity of these financial instruments.  The following table sets forth a reconciliation of changes in the six months ended June 30, 2016 and 2015 in the fair value of the liabilities classified as L evel 3 in the fair value hierarchy:      Warrant Liabilities  Balance at January 1, 2016 $ 2,739,163  Additions 2,575,860  Unrealized gains, net (2,974,045)  Transfers out of level 3 -  Balance at June 30, 2016 $ 2,340,978     Warrant Liabilities  Balance at January 1, 2015 $ 3,768,351  Additions -  Unrealized gains, net (1,674,175)  Transfers out of level 3 -  Balance at June 30, 2015 $ 2,094,176 Additions consist of the fair value of warrant liabilities up on issuance. Transfers out of L evel 3 for warrant liabilities consist of warrant exercises, where the liability is converted to additional paid-in capital upon exercise. The Company’s policy is to recognize transfers in and transfers out as of the actual date of the event or change in circumstance that caused the transfer. 

Operations And Organization (Po

Operations And Organization (Policies)	6 Months Ended
	Jun. 30, 2016
Operations And Organization [Abstract]
Operations	Operations Rexahn Pharmaceuticals, Inc. (the “Company”), a Delaware corporation, is a biopharmaceutical company whose principal operations are the discovery, development and commercialization of innovative treatments for cancer. The Company had an accumulated deficit of $ 111,631,730 at June 30, 2016 and anticipates incurring losses through fiscal year 2016 and beyond. The Company has not yet generated commercial revenues and has funded its operating losses to date through the sale of shares of its common stock and warrants to purchase shares of its common stock, convertible debt, financings, 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 the next 12 months. 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, 2016 and December 31, 2015 and of the results of operations and comprehensive loss for the three and six months ended June 30, 2016 and 2015, and the results of cash flows for the six months ended June 30, 2016 and 2015 have been included. Operating results for the three and six months ended June 30, 2016 are not necessarily indicative of results that may be expected for any other interim period or the full fiscal year ending December 31, 2016. 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, 2015 (the “2015 Form 10-K”). Information included in the condensed balance sheet as of December 31, 2015 has been derived from the Company’s audited financial statements for the year ended December 31, 2015 included in the 2015 Form 10-K.
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 Pronounceme23

Recent Accounting Pronouncements Affecting The Company (Policies)	6 Months Ended
	Jun. 30, 2016
Recent Accounting Pronouncements Affecting The Company [Abstract]
Recent Accounting Pronouncements Affecting the Company	Revenue from Contracts with Customers  In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers,” a comprehensive new revenue recognition standard that will supersede nearly all existing revenue recognition guidance under U.S. GAAP. The standard’s core principle is that a company should recognize revenue when it transfers goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods and services, and provides a revenue recognition framework in accordance with this principle. On August 12, 2015, the FASB issued ASU 2015-14, which defers the effective date of ASU 2014-09 by one year to December 15, 2017 for annual reporting periods beginning after that date and interim periods therein. Early adoption of the standard is permitted, but not before the original effective date of December 15, 2016. The Company is currently evaluating the impact that the adoption of this guidance will have on its financial statements and future operating results.  Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern  In August 2014, the FASB issued ASU 2014-15, “Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern,” which requires management to perform interim and annual assessments as to the entity’s ability to continue as a going concern and provides related disclosure guidance. ASU 2014-15 will be effective for reporting periods beginning after December 15, 2016, with early adoption permitted. The Company is currently evaluating the impact the adoption of this guidance will have on its financial statements.  Leases  In February 2016, the FASB issued ASU 2016-02, “Leases,” which requires an entity to recognize assets and liabilities arising from leases on the balance sheet and to provide additional disclosures about leasing arrangements. ASU 2016-02 will be effective for reporting periods beginning after December 15, 2018, with early adoption permitted. The Company is currently evaluating the impact the adoption of this guidance will have on its financial statements.  Compensation-Stock Compensation  In March 2016, the FASB issued ASU 2016-09, “Compensation-Stock Compensation: Improvements to Employee Share Based Payment Accounting,” which includes multiple provisions intended to simplify various aspects of accounting for share-based payments. The guidance is effective for reporting periods beginning after December 15, 2016, with early adoption permitted. The Company is currently evaluating the impact the adoption of this guidance will have on its financial statements.

Marketable Securities (Tables)

Marketable Securities (Tables)	6 Months Ended
	Jun. 30, 2016
Marketable Securities [Abstract]
Schedule Of Cost And Fair Value Of Marketable Securities	  June 30, 2016  Cost Gross Unrealized Gross Unrealized Fair  Basis Gains Losses Value  Certificates of Deposit $ 5,520,000 $ 2,219 $ (40) $ 5,522,179  Commercial Paper 2,992,580 954 (604) 2,992,930  Corporate Bonds 3,004,992 273 (475) 3,004,790  Total Marketable Securities $ 11,517,572 $ 3,446 $ (1,119) $ 11,519,899   December 31, 2015  Cost Gross Unrealized Gross Unrealized Fair  Basis Gains Losses Value  Certificates of Deposit $ 6,240,000 $ 571 $ (5,575) $ 6,234,996  Commercial Paper 2,981,307 - (3,737) 2,977,570  Corporate Bonds 4,036,820 - (9,300) 4,027,520  Total Marketable Securities $ 13,258,127 $ 571 $ (18,612) $ 13,240,086 

Prepaid Expenses And Other Cu25

Prepaid Expenses And Other Current Assets (Tables)	6 Months Ended
	Jun. 30, 2016
Prepaid Expenses and Other Current Assets [Abstract]
Schedule Of Prepaid Expenses And Other Current Assets	   June 30, December 31,  2016 2015   Deposits on contracts $ 199,697 $ 501,170  Prepaid expenses and other current assets 796,386 720,648   $ 996,083 $ 1,221,818 

Equipment, Net (Tables)

Equipment, Net (Tables)	6 Months Ended
	Jun. 30, 2016
Equipment, Net [Abstract]
Schedule Of Equipment, Net	   June 30, December 31,  2016 2015   Furniture and fixtures $ 78,794 $ 78,794  Office and computer equipment 112,777 105,266  Lab equipment 431,650 431,650  Leasehold improvements 133,762 133,762   Total equipment 756,983 749,472  Less: Accumulated depreciation and amortization (651,625) (636,572)   Net carrying amount $ 105,358 $ 112,900 

Accounts Payable And Accrued 27

Accounts Payable And Accrued Expenses (Tables)	6 Months Ended
	Jun. 30, 2016
Accounts Payable And Accrued Expenses [Abstract]
Schedule Of Accounts Payable And Accrued Expenses	   June 30, December 31,  2016 2015   Trade payables $ 598,843 $ 774,543  Accrued expenses 64,139 92,752  Accrued research and development contract costs 967,930 1,515,151  Payroll liabilities 163,735 278,852   $ 1,794,647 $ 2,661,298 

Other Liabilities (Tables)

Other Liabilities (Tables)	6 Months Ended
	Jun. 30, 2016
Other Liabilities [Abstract]
Schedule Of Deferred Lease Incentive	   June 30, December 31,  2016 2015   Deferred lease incentive $ 154,660 $ 154,660  Less accumulated amortization (117,330) (111,108)   Balance $ 37,330 $ 43,552 

Common Stock (Tables)

Common Stock (Tables)	6 Months Ended
	Jun. 30, 2016
Common Stock [Abstract]
Summary Of Allocation Of Proceeds From Offering	   Gross Proceeds: $ 5,000,000   Allocated to warrant liabilities: 2,419,922  Allocated to common stock and additional paid-in capital 2,580,078   Total allocated gross proceeds: $ 5,000,000 

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2016
Stock-Based Compensation [Abstract]
Summary Of Stock Compensation Expense	    For the Three Months Ended June 30, For the Six Months Ended June 30,  2016 2015 2016 2015  Statement of operations line item:  General and administrative $ 224,786 $ 175,666 $ 440,113 $ 365,705  Research and development 126,390 96,300 254,074 178,647   Total $ 351,176 $ 271,966 $ 694,187 $ 544,352 
Schedule Of Assumptions Made In Calculating The Fair Value Of Options	   Six Months Ended June 30,  2016 2015  Black-Scholes assumptions  Expected dividend yield 0 % 0 %  Expected volatility 32-75 % 77-80 %  Risk free interest rate 0.6 -1.4 % 1.3 -1.7 %  Expected term (in years) 2 -6 years 6 years 
Summary Of Employee And Non-Employee Transactions	   Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value  Outstanding, January 1, 2016 12,590,982 $ 0.83 6.8 years $ 26,500  Granted 4,487,090 0.33  Exercised - -  Expired (610,000) 1.20  Cancelled (83,333) 0.51   Outstanding, June 30, 2016 16,384,739 $ 0.68 7.4 years $ -  Exercisable, June 30, 2016 8,120,929 $ 0.82 5.8 years $ - 
Summary Of Unvested Shares	   2016  Number of Options Weighted Average Fair Value at Grant Date  Unvested at January 1, 2016 5,888,432 $ 0.51  Granted 4,487,090 $ 0.21  Vested (2,066,504) $ 0.45  Cancelled (45,208) $ 0.35   Unvested at June 30, 2016 8,263,810 $ 0.36 

Warrants (Tables)

Warrants (Tables)	6 Months Ended
	Jun. 30, 2016
Warrants [Abstract]
Summary Of Changes In Warrants Outstanding During The Period	   2016 2015  Number of warrants Weighted average exercise price Number of warrants Weighted average exercise price  Balance, January 1 26,491,904 $ 0.80 13,205,871 $ 1.07  Issued during the period 12,500,000 $ 0.42 - $ -  Exercised during the period - $ - - $ -  Expired during the period - $ - - $ -   Balance, June 30 38,991,904 $ 0.68 13,205,871 $ 1.07 
Schedule Of Fair Value Of Warrants Issued	   Fair Value as of:  Warrant Issuance: June 30, 2016 December 31, 2015  March 31, 2011 financing:  Warrants to institutional investors $ - $ 30  December 4, 2012 financing:  Warrants to institutional investors 2,540 9,818  Warrants to placement agent - 1,206  July 26, 2013 financing:  Warrants to institutional investors 27,520 121,420  Warrants to placement agent - 384  October 16, 2013 financing:  Warrants to institutional investors 39,742 169,349  Warrants to placement agent - 970  January 21, 2014 financing:  Warrants to institutional investors 13,762 131,476  November 12, 2015 financing:  Warrants to institutional investors 964,750 2,169,375  Warrants to placement agent 54,975 135,135  March 2, 2016 financing:  Warrants to institutional investors 1,167,656 -  Warrants to placement agent 70,033 -  Total: $ 2,340,978 $ 2,739,163 
Summary Of Shares Indexed To The Warrants	   Number of Shares indexed as of:  Warrant Issuance June 30, 2016 December 31, 2015  March 31, 2011 financing:  Warrants to institutional investors 3,333,333 3,333,333  December 4, 2012 financing:  Warrants to institutional investors 174,300 174,300  Warrants to placement agent 40,000 40,000  July 26, 2013 financing:  Warrants to institutional investors 2,000,000 2,000,000  Warrants to placement agent 124,032 124,032  October 16, 2013 financing:  Warrants to institutional investors 2,317,309 2,317,309  Warrants to placement agent 407,692 407,692  January 21, 2014 financing:  Warrants to institutional investors 4,761,905 4,761,905  November 12, 2015 financing:  Warrants to institutional investors 12,500,000 12,500,000  Warrants to placement agent 833,333 833,333  March 2, 2016 financing:  Warrants to institutional investors 11,718,750 -  Warrants to placement agent 781,250 -  Total: 38,991,904 26,491,904 
Schedule Of Assumptions Used In Calculating Fair Value Of Warrants	   June 30, 2016 December 31, 2015  Trading market prices $ 0.25 $ 0.36  Estimated future volatility 105 % 105 %  Dividend - -  Estimated future risk-free rate 0.20 -1.36 % 0.82 -2.38 %  Equivalent volatility 43-62 % 44-65 %  Equivalent risk-free rate 0.01 -0.63 % 0.22 -1.11 % 
Schedule Of Unrealized Gain/(Loss) On Fair Value Of Warrants	  For the Three Months Ended June 30, For the Six Months Ended June 30,  2016 2015 2016 2015  March 31, 2011 financing:  Warrants to institutional investors 33 202,963 30 305,040  December 4, 2012 financing:  Warrants to institutional investors 5,911 32,568 7,278 29,671  Warrants to placement agent 529 5,434 1,206 5,577  July 26, 2013 financing:  Warrants to institutional investors 63,246 289,146 93,900 264,360  Warrants to placement agent 64 15,209 384 19,554  October 16, 2013 financing:  Warrants to institutional investors 103,166 323,698 129,607 305,938  Warrants to placement agent 145 48,918 970 64,097  January 21, 2014 financing:  Warrants to institutional investors 92,428 640,824 117,714 679,938  November 12, 2015 financing:  Warrants to institutional investors 875,913 - 1,204,626 -  Warrants to placement agent 58,276 - 80,160 -  March 2, 2016 financing:  Warrants to institutional investors 860,121 - 1,252,266 -  Warrants to placement agent 58,258 - 85,904 -  Total: $ 2,118,090 $ 1,558,760 $ 2,974,045 $ 1,674,175 

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Jun. 30, 2016
Income Taxes [Abstract]
Schedule Of Deferred Tax Assets And Valuation Allowance	   June 30, December 31,  2016 2015   Net Operating Loss Carryforwards $ 41,769,000 $ 38,592,000  Stock Compensation Expense 1,905,000 1,891,000  Book tax differences on assets and liabilities 309,000 380,000  Valuation Allowance (43,983,000) (40,863,000)   Net Deferred Tax Assets $ - $ - 

Commitments And Contingencies (

Commitments And Contingencies (Tables)	6 Months Ended
	Jun. 30, 2016
Commitments And Contingencies [Abstract]
Schedule Of Future Rental Payments	   For the remaining six months ending December 31: 2016 134,264  For the year ending December 31: 2017 255,731  2018 233,923  2019 152,955  2020 34,468   Total $ 811,341 

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2016
Fair Value Measurements [Abstract]
Schedule Of Assets And Liabilities Measured At Fair Value On A Recurring Basis	   Fair Value Measurements at June 30, 2016  Total Level 1 Level 2 Level 3  Assets:  Certificates of Deposit $ 5,522,179 $ - $ 5,522,179 $ -  Commercial Paper 2,992,930 - 2,992,930 -  Corporate Bonds 3,004,790 - 3,004,790 -  Total Assets: $ 11,519,899 $ - $ 11,519,899 $ -   Liabilities:  Warrant Liabilities $ 2,340,978 - - $ 2,340,978     Fair Value Measurements at December 31, 2015  Total Level 1 Level 2 Level 3  Assets:  Certificates of Deposit $ 6,234,996 $ - $ 6,234,996 $ -  Commercial Paper 2,977,570 - 2,977,570 -  Corporate Bonds 4,027,520 - 4,027,520 -  Total Assets: $ 13,240,086 $ - $ 13,240,086 $ -   Liabilities:  Warrant Liabilities $ 2,739,163 - - $ 2,739,163 
Reconciliation Of Changes In The Fair Value Of Liabilities	   Warrant Liabilities  Balance at January 1, 2016 $ 2,739,163  Additions 2,575,860  Unrealized gains, net (2,974,045)  Transfers out of level 3 -  Balance at June 30, 2016 $ 2,340,978     Warrant Liabilities  Balance at January 1, 2015 $ 3,768,351  Additions -  Unrealized gains, net (1,674,175)  Transfers out of level 3 -  Balance at June 30, 2015 $ 2,094,176 

Operations And Organization (De

Operations And Organization (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Operations And Organization [Abstract]
Accumulated deficit	$ 111,631,730	$ 105,716,864

Marketable Securities (Narrativ

Marketable Securities (Narrative) (Details)	Jun. 30, 2016USD ($)item	Dec. 31, 2015USD ($)
Schedule of Available-for-sale Securities [Line Items]
Fair value	$ 11,519,899	$ 13,240,086
Unrealized losses	$ 1,119	$ 18,612
4 Certificates Of Deposit With Unrealized Losses [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities in a loss position, less than one year | item	4
Fair value	$ 959,960
Unrealized losses	$ 40
1 Commercial Paper With Unrealized Losses [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities in a loss position, less than one year | item	1
Fair value	$ 996,940
Unrealized losses	$ 604
1 Corporate Bond Securities With Unrealized Losses Less Than 12 Months [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities in a loss position, less than one year | item	1
Fair value	$ 1,003,060
Unrealized losses	$ 425
1 Corporate Bond Securities With Unrealized Losses Greater Than 12 Months [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities in a loss position | item	1
Fair value	$ 1,000,230
Unrealized losses	$ 50

Marketable Securities (Schedule

Marketable Securities (Schedule Of Cost And Fair Value Of Marketable Securities) (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	$ 11,517,572	$ 13,258,127
Gross Unrealized Gains	3,446	571
Gross Unrealized Losses	(1,119)	(18,612)
Fair value	11,519,899	13,240,086
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	2,992,580	2,981,307
Gross Unrealized Gains	954
Gross Unrealized Losses	(604)	(3,737)
Fair value	2,992,930	2,977,570
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	3,004,992	4,036,820
Gross Unrealized Gains	273
Gross Unrealized Losses	(475)	(9,300)
Fair value	3,004,790	4,027,520
Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	5,520,000	6,240,000
Gross Unrealized Gains	2,219	571
Gross Unrealized Losses	(40)	(5,575)
Fair value	$ 5,522,179	$ 6,234,996

Prepaid Expenses And Other Cu38

Prepaid Expenses And Other Current Assets (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Prepaid Expenses and Other Current Assets [Abstract]
Deposits on contracts	$ 199,697	$ 501,170
Prepaid expenses and other current assets	796,386	720,648
Total prepaid expenses and other current assets	$ 996,083	$ 1,221,818

Equipment, Net (Details)

Equipment, Net (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Total equipment	$ 756,983	$ 749,472
Less: Accumulated depreciation and amortization	(651,625)	(636,572)
Net carrying amount	105,358	112,900
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total equipment	78,794	78,794
Office and Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Total equipment	112,777	105,266
Lab Equipment [Member]
Property, Plant and Equipment [Line Items]
Total equipment	431,650	431,650
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total equipment	$ 133,762	$ 133,762

Accounts Payable And Accrued 40

Accounts Payable And Accrued Expenses (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Accounts Payable And Accrued Expenses [Abstract]
Trade payables	$ 598,843	$ 774,543
Accrued expenses	64,139	92,752
Accrued research and development contract costs	967,930	1,515,151
Payroll liabilities	163,735	278,852
Total accounts payable and accrued expenses	$ 1,794,647	$ 2,661,298

Deferred Research And Develop41

Deferred Research And Development Arrangements (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2003	Dec. 31, 2015
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Deferred Research and Development Arrangement	$ 487,500		$ 487,500			$ 525,000
Rexgene [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development arrangement, one-time fee					$ 1,500,000
Reduction of research and development expenses	18,750	$ 18,750	$ 37,500	$ 37,500
Research and development period			20 years
Deferred Research and Development Arrangement	$ 487,500		$ 487,500			$ 525,000
Royalties paid, percentage of net sales			3.00%

Other Liabilities (Narrative) (

Other Liabilities (Narrative) (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Other Liabilities [Abstract]
Accrued Rent	$ 55,265	$ 60,468

Other Liabilities (Schedule Of

Other Liabilities (Schedule Of Deferred Lease Incentive) (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Other Liabilities [Abstract]
Deferred lease incentive	$ 154,660	$ 154,660
Less accumulated amortization	(117,330)	(111,108)
Balance	$ 37,330	$ 43,552

Net Loss Per Common Share (Deta

Net Loss Per Common Share (Details) - shares	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Net Loss Per Common Share [Abstract]
Potentially dilutive securities	55,376,643	39,082,886

Common Stock (Narrative) (Detai

Common Stock (Narrative) (Details) - USD ($)	Mar. 02, 2016	Jun. 30, 2016	Jun. 30, 2015
Common Stock [Abstract]
Shares issued	15,625,000
Warrants issued	11,718,750	12,500,000
Share Price	$ 0.32
Proceeds from issuance	$ 5,000,000
Cash paid in exchange for closing costs	419,813
Public offering closing costs	575,751
Proceeds allocated to financing expense	169,887
Issuance cost incurred	$ 405,864
Warrants issued per share of stock issued in unit offering	$ 0.75
Warrants issued included in closing costs	781,250
Fair value of placement agent warrants	$ 155,938
Stock Warrants, Exercise Price	$ 0.42
Stock issued for services		195,000
Aggregate market value stock issued for services		$ 64,949

Common Stock (Summary Of Alloca

Common Stock (Summary Of Allocation Of Proceeds From Offering) (Details)	Mar. 02, 2016USD ($)
Common Stock [Abstract]
Allocated to warrant liabilities	$ 2,419,922
Allocated to Common stock and additional paid-in capital	2,580,078
Gross Proceeds:	$ 5,000,000

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Mar. 31, 2016	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of Event Occurence to Vest				100.00%
Number of options, Oustanding		16,384,739		16,384,739		12,590,982
Share-based compensation expense		$ 351,176	$ 271,966	$ 694,187	$ 544,352
Income tax benefit from share-based compensation				$ 0
Valuation allowance on deferred tax assets				100.00%
Stock options granted				4,487,090
Stock option exercise price				$ 0.33
Intrinsic value of options exercised		0	$ 1,844	$ 0	$ 99,895
Weighted average fair value at grant date, Vested				$ 0.21	$ 0.49
Unrecognized compensation cost		$ 2,444,014		$ 2,444,014
Weighted average vesting period, years				2 years 3 months 18 days
March 2016 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration of options from grant date, years				3 years
The 2013 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options authorized for issuance		17,000,000		17,000,000
Number of options, Oustanding		11,246,239		11,246,239
Shares available for issuance		5,746,261		5,746,261
The 2003 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Oustanding		5,018,500		5,018,500
First Anniversary [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				30.00%
Second Anniversary [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				30.00%
Third Anniversary [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				40.00%
First Anniversary (B) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				25.00%
Second Anniversary (B) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				25.00%
Third Anniversary (B) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				25.00%
Fourth Anniversary (B) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				25.00%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration of options from grant date, years				5 years
Non-employee vesting period				1 year
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration of options from grant date, years				10 years
Non-employee vesting period				3 years
Exercise Price Range $0.27 to $0.37 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted				4,487,090
Stock option grants fair value				$ 927,644
Exercise Price Range $0.27 to $0.37 [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option exercise price				$ 0.27
Exercise Price Range $0.27 to $0.37 [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option exercise price				$ 0.37
Exercise Price Range $0.68 to $0.89 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted					3,726,316
Stock option grants fair value					$ 1,835,853
Exercise Price Range $0.68 to $0.89 [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option exercise price					$ 0.68
Exercise Price Range $0.68 to $0.89 [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option exercise price					$ 0.89
Third Party [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted	120,000

Stock-Based Compensation (Summa

Stock-Based Compensation (Summary Of Stock Compensation Expense) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share Based Compensation	$ 351,176	$ 271,966	$ 694,187	$ 544,352
General and administrative [Member]
Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share Based Compensation	224,786	175,666	440,113	365,705
Research and development [Member]
Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share Based Compensation	$ 126,390	$ 96,300	$ 254,074	$ 178,647

Stock-Based Compensation (Sched

Stock-Based Compensation (Schedule Of Assumptions Made In Calculating The Fair Value Of Options) (Details)	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Expected dividend yield	0.00%	0.00%
Expected volatility, minimum	32.00%	77.00%
Expected volatility, maximum	75.00%	80.00%
Risk free interest rate, minimum	0.60%	1.30%
Risk free interest rate, maximum	1.40%	1.70%
Expected term (in years)		6 years
Minimum [Member]
Expected term (in years)	2 years
Maximum [Member]
Expected term (in years)	6 years

Stock-Based Compensation (Sum50

Stock-Based Compensation (Summary Of Employee And Non-Employee Transactions) (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Stock-Based Compensation [Abstract]
Number of options, Oustanding	12,590,982
Number of options, Granted	4,487,090
Number of options, Expired	(610,000)
Number of options, Cancelled	(83,333)
Number of options, Oustanding	16,384,739	12,590,982
Weighted average exercise price, Outstanding	$ 0.83
Weighted average exercise price, Granted	0.33
Weighted average exercise price, Expired	1.20
Weighted average exercise price, Cancelled	0.51
Weighted average exercise price, Outstanding	$ 0.68	$ 0.83
Weighted average remaining contractual term, Outstanding	7 years 4 months 24 days	6 years 9 months 18 days
Aggregate intrinsic value, Outstanding		$ 26,500
Number of options, Exercisable	8,120,929
Weighted average exercise price, Exercisable	$ 0.82
Weighted average remaining contractual term, Exercisable	5 years 9 months 18 days
Aggregate intrinsic value, Exercisable

Stock-Based Compensation (Sum51

Stock-Based Compensation (Summary Of Unvested Shares) (Details) - $ / shares	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of options, Cancelled	(83,333)
Weighted average fair value at grant date, Vested	$ 0.21	$ 0.49
Nonvested Options [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of options, outstanding	5,888,432
Number of options, Granted	4,487,090
Number of options, Vested	(2,066,504)
Number of options, Cancelled	(45,208)
Number of options, outstanding	8,263,810
Weighted average fair value at grant date, Unvested	$ 0.51
Weighted average fair value at grant date, Granted	0.21
Weighted average fair value at grant date, Vested	0.45
Weighted average fair value at grant date, Cancelled	0.35
Weighted average fair value at grant date, Unvested	$ 0.36

Warrants (Narrative) (Details)

Warrants (Narrative) (Details) - $ / shares	6 Months Ended
	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014
Class of Warrant or Right [Line Items]
Number of warrants, Outstanding	38,991,904	26,491,904	13,205,871	13,205,871
Exercise price	$ 0.68	$ 0.80	$ 1.07	$ 1.07
Warrant expiration date, start	Jul. 5, 2016
Warrant expiration date, end	Sep. 2, 2021
Average remaining contractual life of warrants outstanding	3 years 10 months 24 days
Probability of entering into a fundamental transaction	5.00%
Maximum [Member]
Class of Warrant or Right [Line Items]
Exercise price	$ 1.50
Minimum [Member]
Class of Warrant or Right [Line Items]
Exercise price	$ 0.40

Warrants (Summary Of Changes In

Warrants (Summary Of Changes In Warrants Outstanding During The Period) (Details) - $ / shares	Mar. 02, 2016	Jun. 30, 2016	Jun. 30, 2015
Warrants [Abstract]
Number of warrants, Outstanding		26,491,904	13,205,871
Weigted average exercise price, Outstanding		$ 0.80	$ 1.07
Number of warrants, Issued	11,718,750	12,500,000
Weighted average exercise price, Issued		$ 0.42
Number of warrants, Exercised
Weighted average exercise price, Exercised
Number of warrants, Expired
Weighted average exercise price, Expired
Number of warrants, Outstanding		38,991,904	13,205,871
Weigted average exercise price, Outstanding		$ 0.68	$ 1.07

Warrants (Schedule Of Fair Valu

Warrants (Schedule Of Fair Value Of Warrants Issued) (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Class of Warrant or Right [Line Items]
Fair value	$ 2,340,978	$ 2,739,163
March 31, 2011 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Fair value		30
December 4, 2012 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Fair value	2,540	9,818
December 4, 2012 Warrants To Placement Agent [Member]
Class of Warrant or Right [Line Items]
Fair value		1,206
July 26, 2013 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Fair value	27,520	121,420
July 26, 2013 Warrants To Placement Agent [Member]
Class of Warrant or Right [Line Items]
Fair value		384
October 16, 2013 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Fair value	39,742	169,349
October 16, 2013 Warrants To Placement Agent [Member]
Class of Warrant or Right [Line Items]
Fair value		970
January 21, 2014 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Fair value	13,762	131,476
November 12, 2015 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Fair value	964,750	2,169,375
November 12, 2015 Warrants To Placement Agent [Member]
Class of Warrant or Right [Line Items]
Fair value	54,975	$ 135,135
March 2, 2016 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Fair value	1,167,656
March 2, 2016 Warrants To Placement Agent [Member]
Class of Warrant or Right [Line Items]
Fair value	$ 70,033

Warrants (Summary Of Shares Ind

Warrants (Summary Of Shares Indexed To The Warrants) (Details) - shares	Jun. 30, 2016	Dec. 31, 2015
Class of Warrant or Right [Line Items]
Number of shares indexed	38,991,904	26,491,904
March 31, 2011 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	3,333,333	3,333,333
December 4, 2012 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	174,300	174,300
December 4, 2012 Warrants To Placement Agent [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	40,000	40,000
July 26, 2013 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	2,000,000	2,000,000
July 26, 2013 Warrants To Placement Agent [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	124,032	124,032
October 16, 2013 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	2,317,309	2,317,309
October 16, 2013 Warrants To Placement Agent [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	407,692	407,692
January 21, 2014 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	4,761,905	4,761,905
November 12, 2015 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	12,500,000	12,500,000
November 12, 2015 Warrants To Placement Agent [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	833,333	833,333
March 2, 2016 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	11,718,750
March 2, 2016 Warrants To Placement Agent [Member]
Class of Warrant or Right [Line Items]
Number of shares indexed	781,250

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, 2016	Dec. 31, 2015
Warrants [Abstract]
Trading market prices	$ 0.25	$ 0.36
Estimated future volatility	105.00%	105.00%
Dividend
Estimated future risk-free rate, minimum	0.20%	0.82%
Estimated future risk-free rate, maximum	1.36%	2.38%
Equivalent volatility, minimum	43.00%	44.00%
Equivalent volatility, maximum	62.00%	65.00%
Equivalent risk-free rate, minimum	0.01%	0.22%
Equivalent risk-free rate, maximum	0.63%	1.11%

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, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	$ 2,118,090	$ 1,558,760	$ 2,974,045	$ 1,674,175
March 31, 2011 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	33	202,963	30	305,040
December 4, 2012 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	5,911	32,568	7,278	29,671
December 4, 2012 Warrants To Placement Agent [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	529	5,434	1,206	5,577
July 26, 2013 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	63,246	289,146	93,900	264,360
July 26, 2013 Warrants To Placement Agent [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	64	15,209	384	19,554
October 16, 2013 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	103,166	323,698	129,607	305,938
October 16, 2013 Warrants To Placement Agent [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	145	48,918	970	64,097
January 21, 2014 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	92,428	$ 640,824	117,714	$ 679,938
November 12, 2015 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	875,913		1,204,626
November 12, 2015 Warrants To Placement Agent [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	58,276		80,160
March 2, 2016 Warrants To Institutional Investors [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	860,121		1,252,266
March 2, 2016 Warrants To Placement Agent [Member]
Class of Warrant or Right [Line Items]
Unrealized gain on fair value of warrants	$ 58,258		$ 85,904

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Provision for income taxes
Operating loss carry-forward	107,101,000		$ 107,101,000		$ 98,954,000
Net operating loss carry-forwards expiration			Dec. 31, 2036
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, 2016	Dec. 31, 2015
Income Taxes [Abstract]
Net Operating Loss Carryforwards	$ 41,769,000	$ 38,592,000
Stock Compensation Expense	1,905,000	1,891,000
Book tax differences on assets and liabilities	309,000	380,000
Valuation Allowance	(43,983,000)	(40,863,000)
Net Deferred Tax Assets

Commitments And Contingencies60

Commitments And Contingencies (Narrative) (Details)	Apr. 20, 2015ft²	Jul. 26, 2014ft²	Jun. 07, 2013ft²	Jun. 22, 2009USD ($)	Jun. 30, 2016USD ($)	Jun. 30, 2015USD ($)	Jun. 30, 2016USD ($)	Jun. 30, 2015USD ($)	Dec. 31, 2009USD ($)
Commitments And Contingencies [Line Items]
Estimated cost to complete contracts					$ 6,440,000		$ 6,440,000
Renewed lease term							1 year
Size of lease space | ft²			5,466
Additional office space | ft²		1,637
License Costs									$ 100,000
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					31,587	$ 34,799	$ 63,089	$ 64,158
Maximum [Member]
Commitments And Contingencies [Line Items]
Contract term, months							36 months
Minimum [Member]
Commitments And Contingencies [Line Items]
Contract term, months							2 months
Prior Laboratory Lease [Member]
Commitments And Contingencies [Line Items]
Lease term							1 year
Required monthly rental payments							$ 4,554
Rent expense						13,662		27,324
Current Laboratory Lease [Member]
Commitments And Contingencies [Line Items]
Lease term							5 years
Size of lease space | ft²	2,552
Rent expense					15,312		$ 30,624
Office Space Rental [Member]
Commitments And Contingencies [Line Items]
Rent expense					$ 51,301	$ 50,058	$ 102,603	$ 100,117

Commitments and Contingencies61

Commitments and Contingencies (Schedule of Future Rental Payments) (Details)	Jun. 30, 2016USD ($)
Commitments And Contingencies [Abstract]
2,016	$ 134,264
2,017	255,731
2,018	233,923
2,019	152,955
2,020	34,468
Total	$ 811,341

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule Of Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:	$ 11,519,899	$ 13,240,086
Warrant Liabilities	2,340,978	2,739,163
Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:	3,004,790	4,027,520
Certificates of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:	5,522,179	6,234,996
Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:	2,992,930	2,977,570
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:	11,519,899	13,240,086
Level 2 [Member] | Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:	3,004,790	4,027,520
Level 2 [Member] | Certificates of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:	5,522,179	6,234,996
Level 2 [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets:	2,992,930	2,977,570
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant Liabilities	$ 2,340,978	$ 2,739,163

Fair Value Measurements (Reconc

Fair Value Measurements (Reconciliation Of Changes In The Fair Value Of Liabilities) (Details) - Warrant Liabilities [Member] - USD ($)	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance	$ 2,739,163	$ 3,768,351
Additions	2,575,860
Unrealized gains, net	(2,974,045)	(1,674,175)
Transfers out of level 3
Balance	$ 2,340,978	$ 2,094,176