Navidea Biopharmaceuticals (NAVB) 10-Q 12 Aug 21 2021 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2021	Aug. 06, 2021
Document Information [Line Items]
Entity Central Index Key	0000810509
Entity Registrant Name	NAVIDEA BIOPHARMACEUTICALS, INC.
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2021
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
Document Transition Report	false
Entity File Number	001-35076
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	31-1080091
Entity Address, Address Line One	4995 Bradenton Avenue, Suite 240
Entity Address, City or Town	Dublin
Entity Address, State or Province	OH
Entity Address, Postal Zip Code	43017-3552
City Area Code	614
Local Phone Number	793-7500
Title of 12(b) Security	Common Stock
Trading Symbol	NAVB
Security Exchange Name	NYSEAMER
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		30,163,245

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 7,114,103	$ 2,670,495
Stock subscriptions and other receivables	2,400,238	2,987,319
Inventory	178,830	169,798
Prepaid expenses and other	350,239	700,716
Total current assets	10,043,410	6,528,328
Property and equipment	848,085	845,379
Less accumulated depreciation and amortization	731,098	713,217
Property and equipment, net	116,987	132,162
Right-of-use lease assets	458,280	458,280
Less accumulated amortization	269,142	208,185
Right-of-use lease assets, net	189,138	250,095
License agreements, patents and trademarks	851,929	747,863
Less accumulated amortization	147,346	127,622
License agreements, patents and trademarks, net	704,583	620,241
Other assets	227,192	227,192
Total assets	11,281,310	7,758,018
Current liabilities:
Accounts payable	1,080,070	1,161,717
Accrued liabilities and other	2,630,747	2,512,994
Notes payable	0	745,443
Lease liabilities, current	313,852	294,951
Total current liabilities	4,024,669	4,715,105
Lease liabilities, net of current portion	120,471	296,006
Deferred revenue	700,000	700,000
Total liabilities	4,845,140	5,711,111
Commitments and contingencies (See Note 11)
Stockholders’ equity:
Common stock; $.001 par value; 300,000,000 shares authorized; 30,145,718 and 27,149,691 shares issued and outstanding as of June 30, 2021 and December 31, 2020, respectively	221,142	218,146
Common stock subscribed; $.001 par value, 0 and 995,000 shares subscribed as of June 30, 2021 and December 31, 2020, respectively	0	995
Common stock subscriptions receivable	0	(4,975,000)
Additional paid-in capital	370,181,268	375,428,014
Accumulated deficit	(364,697,612)	(359,056,683)
Navidea stockholders' equity	5,704,870	1,315,604
Noncontrolling interest	731,300	731,303
Total stockholders’ equity	6,436,170	2,046,907
Total liabilities and stockholders’ equity	11,281,310	7,758,018
Non-Series Preferred Stock [Member]
Stockholders’ equity:
Preferred stock	0	0
Series D Preferred Stock [Member]
Current assets:
Stock subscriptions and other receivables	2,200,000
Stockholders’ equity:
Preferred stock. subscriptions	22	132
Series D preferred stock subscriptions receivable	0	(10,300,000)
Series E Preferred Stock [Member]
Stockholders’ equity:
Preferred stock	$ 50	$ 0

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares	Jun. 30, 2021	Dec. 31, 2020
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock, shares issued (in shares)	30,145,718	27,149,691
Common stock, shares outstanding (in shares)	30,145,718	27,149,691
Common stock subscription, shares authorized (in shares)	0	995,000
Non-Series Preferred Stock [Member]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Series D Preferred Stock [Member]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock subscriptions, subscribed (in shares)	22,077	103,000
Series E Preferred Stock [Member]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	50,000	50,000
Preferred stock, shares outstanding (in shares)	50,000	0

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($)		3 Months Ended			6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020		Jun. 30, 2021		Jun. 30, 2020
Revenue:
Revenue from contract with customer		$ 13,000	$ 9,000		$ 36,000		$ 24,000
Grant and other revenue		247,983	262,181		349,234		403,232
Total revenue		261,046	271,101		384,783		427,373
Cost of revenue		0	357		0		966
Gross profit		261,046	270,744		384,783		426,407
Operating expenses:
Research and development		1,498,056	1,281,779		2,720,810		2,281,048
Selling, general and administrative		1,432,610	1,329,591		3,663,355		3,157,345
Total operating expenses		2,930,666	2,611,370		6,384,165		5,438,393
Loss from operations	[1]	(2,669,620)	(2,340,626)		(5,999,382)		(5,011,986)
Other (expense) income:
Interest income (expense), net		1,266	15,343		(1,609)		12,971
Gain on extinguishment of debt		0	0		366,000		0
Other, net		(5,686)	(336)		(5,941)		(212)
Total other (expense) income, net		(4,420)	15,007	[2]	358,450	[2]	12,759	[2]
Net loss		(2,674,040)	(2,325,619)		(5,640,932)		(4,999,227)
Loss (income) attributable to noncontrolling interest		1	1		3		(1)
Deemed dividend on Series C Preferred Stock beneficial conversion feature		0	(77,778)		0		(77,778)
Net loss attributable to common stockholders		$ (2,674,039)	$ (2,403,396)		$ (5,640,929)		$ (5,077,006)
Loss attributable to common stockholders per common share (basic and diluted) (in dollars per share)		$ (0.09)	$ (0.11)		$ (0.20)		$ (0.24)
Weighted average shares outstanding (in shares)		29,117,832	22,759,393		28,531,660		21,481,514
Royalty [Member]
Revenue:
Revenue from contract with customer		$ 0	$ 8,920		$ 0		$ 24,141
License [Member]
Revenue:
Revenue from contract with customer		$ 13,063	$ 0		$ 35,549		$ 0
[1]	Loss from operations does not reflect the allocation of certain selling, general and administrative expenses, excluding depreciation and amortization, to our individual reportable segments, other than those expenses directly incurred by Navidea Europe, Navidea UK and MT.
[2]	Amounts consist primarily of interest income and interest expense, which are not currently allocated to our individual reportable segments.

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($)	Preferred Stock [Member]	Preferred Stock Subscription [Member]	Preferred Stock Subscriptions Receivable [Member]	Additional Paid-in Capital [Member]Private Placement [Member]	Additional Paid-in Capital [Member]Registered Direct Offering [Member]	Additional Paid-in Capital [Member]	Common Stock [Member]Private Placement [Member]	Common Stock [Member]Registered Direct Offering [Member]	Common Stock [Member]	Common Stock Subscription [Member]Private Placement [Member]	Common Stock Subscription [Member]Registered Direct Offering [Member]	Common Stock Subscription [Member]	Common Stock Subscriptions Receivable [Member]Private Placement [Member]	Common Stock Subscriptions Receivable [Member]	Retained Earnings [Member]	Noncontrolling Interest [Member]	Private Placement [Member]	Registered Direct Offering [Member]	Total
Balance (in shares) at Dec. 31, 2019	0								19,234,960			902,162
Balance at Dec. 31, 2019	$ 0					$ 345,847,676			$ 210,232			$ 902		$ 0	$ (347,671,102)	$ 731,303			$ (880,989)
Issued stock (in shares)							902,162	1,000,001		(902,162)
Issued stock					$ 699,000		$ 902	$ 1,000		$ (902)								$ 700,000
Stock subscribed				$ 2,015,126	549,353					$ 2,374	$ 647		$ (912,500)				$ 1,105,000	550,000
Stock compensation expense						39,246													39,246
Net loss															(2,673,610)	2			(2,673,608)
Issued stock (in shares)							902,162	1,000,001		(902,162)
Issued stock					699,000		$ 902	$ 1,000		$ (902)								700,000
Series D Preferred Stock subscribed (See Note 12) (in shares)										(2,373,529)	(647,058)
Series D Preferred Stock subscribed (See Note 12)				$ (2,015,126)	$ (549,353)					$ (2,374)	$ (647)		912,500				(1,105,000)	$ (550,000)
Balance (in shares) at Mar. 31, 2020									21,194,248			3,020,587
Balance at Mar. 31, 2020						349,219,656			$ 212,191			$ 3,021		(912,500)	(350,344,712)	731,305			(1,091,039)
Issued stock in payment of services (in shares)	0								3,810
Issued stock in payment of services																			4,801
Issued stock in payment of employee bonuses (in shares)									53,315
Issued stock in payment of employee bonuses						64,458			$ 53										64,511
Stock subscribed (in shares)										2,373,529	647,058
Balance (in shares) at Dec. 31, 2019	0								19,234,960			902,162
Balance at Dec. 31, 2019	$ 0					345,847,676			$ 210,232			$ 902		0	(347,671,102)	731,303			$ (880,989)
Issued stock to 401(k) Plan (in shares)																			32,651
Issued stock to 401(k) Plan																			$ 40,000
Net loss																			(4,999,227)
Balance (in shares) at Jun. 30, 2020	0								24,547,961			461,729
Balance at Jun. 30, 2020	$ 0					350,178,082			$ 215,545			$ 462		0	(352,748,108)	731,304			(1,622,715)
Balance (in shares) at Dec. 31, 2019	0								19,234,960			902,162
Balance at Dec. 31, 2019	$ 0					345,847,676			$ 210,232			$ 902		0	(347,671,102)	731,303			(880,989)
Balance (in shares) at Dec. 31, 2020		132,250							27,149,691			995,000
Balance at Dec. 31, 2020		$ 132	$ (10,300,000)			375,428,014			$ 218,146			$ 995		(4,975,000)	(359,056,683)	731,303			2,046,907
Balance (in shares) at Mar. 31, 2020									21,194,248			3,020,587
Balance at Mar. 31, 2020						349,219,656			$ 212,191			$ 3,021		(912,500)	(350,344,712)	731,305			(1,091,039)
Issued restricted stock (in shares)									10,000
Issued restricted stock									$ 10										10
Issued stock to 401(k) Plan (in shares)									32,651
Issued stock to 401(k) Plan						39,801			$ 33										39,834
Issued stock (in shares)	70,000						1,911,800	647,058		(1,911,800)	(647,058)
Issued stock	$ 70					699,930	$ 1,912	$ 647		$ (1,912)	$ (647)		520,030				520,030		700,000
Issued stock upon conversion of Preferred Stock (in shares)	(70,000)								410,765
Issued stock upon conversion of Series D Preferred Stock	$ 70					341			$ (411)
Stock subscribed													392,470				392,470
Stock compensation expense						34,588													34,588
Net loss															(2,325,618)	(1)			(2,325,619)
Issued stock (in shares)	70,000						1,911,800	647,058		(1,911,800)	(647,058)
Issued stock	$ 70					699,930	$ 1,912	$ 647		$ (1,912)	$ (647)		520,030				520,030		700,000
Series D Preferred Stock subscribed (See Note 12)													$ (392,470)				$ (392,470)
Balance (in shares) at Jun. 30, 2020	0								24,547,961			461,729
Balance at Jun. 30, 2020	$ 0					350,178,082			$ 215,545			$ 462		0	(352,748,108)	731,304			(1,622,715)
Issued stock in payment of employee bonuses (in shares)									40,844
Issued stock in payment of employee bonuses						106,970			$ 41										107,011
Issued restricted stock (in shares)									10,000
Issued stock upon exercise of warrants (in shares)									300,595
Issued stock upon exercise of warrants						(300)			$ 300
Deemed dividend on Series C Preferred Stock						77,778									(77,778)
Issued stock upon conversion of Series C Preferred Stock	$ (70)					(341)			$ 411
Balance (in shares) at Dec. 31, 2020		132,250							27,149,691			995,000
Balance at Dec. 31, 2020		$ 132	$ (10,300,000)			375,428,014			$ 218,146			$ 995		$ (4,975,000)	(359,056,683)	731,303			$ 2,046,907
Issued stock to 401(k) Plan (in shares)																			30,018
Issued stock to 401(k) Plan																			$ 77,000
Net loss																			$ (5,640,932)
Issued stock upon stock option exercise (in shares)																			2,000
Balance (in shares) at Jun. 30, 2021	50,000	22,077							30,145,718
Balance at Jun. 30, 2021	$ 50	$ 22				$ 370,181,268			$ 221,142						$ (364,697,612)	$ 731,300			$ 6,436,170

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parentheticals)	3 Months Ended
	Jun. 30, 2021USD ($)
Stock issuance cost	$ 50,671

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	1 Months Ended		3 Months Ended				6 Months Ended		12 Months Ended
	Jan. 31, 2020	Dec. 31, 2019	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net loss			$ (2,674,040)	$ (2,966,892)	$ (2,325,619)	$ (2,673,608)	$ (5,640,932)	$ (4,999,227)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization							37,606	36,099
Non-cash lease expense							60,957	60,010
Stock compensation expense							263,478	73,834
Gain on extinguishment of debt			0		0		(366,000)	0
Value of stock issued to 401(k) plan for employer matching contributions							76,846	39,834
Value of stock issued in payment of employee bonuses							0	171,522
Value of stock issued in payment of services							0	4,801
Changes in operating assets and liabilities:
Receivables							(130,218)	756,622
Inventory							(9,032)	0
Prepaid expenses and other assets							350,477	866,070
Accounts payable							(81,647)	48,842
Accrued and other liabilities							71,825	(71,232)
Lease liabilities							(156,634)	(139,800)
Deferred revenue							45,928	166,805
Net cash used in operating activities							(5,477,346)	(2,985,820)
Cash flows from investing activities:
Payments for purchases of equipment			(2,707)		(1,947)		(2,707)	(8,406)
Patent and trademark costs							(104,067)	(115,271)
Net cash used in investing activities							(106,774)	(123,677)
Cash flows from financing activities:
Proceeds from issuance of preferred stock, including collection of stock subscriptions receivable							10,475,000	700,000
Proceeds from issuance of common stock	$ 812,000	$ 1,900,000					2,133	3,025,040		$ 1,100,000
Proceeds from note payable							0	366,000
Principal payments on notes payable							(379,443)	(261,701)
Net cash provided by financing activities							10,027,728	3,679,339
Net increase in cash and cash equivalents							4,443,608	569,842
Cash and cash equivalents, beginning of period	$ 1,047,159			$ 2,670,495		$ 1,047,159	2,670,495	1,047,159	$ 1,047,159
Cash and cash equivalents, end of period		$ 1,047,159	$ 7,114,103		$ 1,617,001		7,114,103	1,617,001	$ 2,670,495	$ 1,047,159
Preferred Stock Issuance Costs [Member]
Cash flows from financing activities:
Payment of stock issuance costs							(69,962)	0
Common Stock Issuance Costs [Member]
Cash flows from financing activities:
Payment of stock issuance costs							$ 0	$ (150,000)

Note 1 - Summary of Significant

Note 1 - Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Significant Accounting Policies [Text Block]	1. Summary of Significant Accounting Policies a. Basis of Presentation: June 30, 2021 three six June 30, 2021 2020 June 30, 2021 not December 31, 2020, 10 Our condensed consolidated financial statements include the accounts of Navidea and our wholly owned subsidiaries, Navidea Biopharmaceuticals Europe Limited (“Navidea Europe”) and Navidea Biopharmaceuticals Limited (“Navidea UK”), as well as those of our majority-owned subsidiary, Macrophage Therapeutics, Inc. (“MT”). All significant inter-company accounts were eliminated in consolidation. b. Financial Instruments and Fair Value: ( 1 Cash and cash equivalents, stock subscriptions and other receivables, and accounts payable: ( 2 Notes payable: June 30, 2021 December 31, 2020 June 30, 2021 December 31, 2020, 9. c. Revenue Recognition: We also earn revenues related to our licensing and distribution agreements. The consideration we are eligible to receive under our licensing and distribution agreements typically includes upfront payments, reimbursement for research and development costs, milestone payments, and royalties. Each licensing and distribution agreement is unique and requires separate assessment in accordance with current accounting standards. See Note 3. d. Leases: 2018. 12 not 10. e. Convertible Preferred Stock: 480, Distinguishing Liabilities from Equity 815, Derivatives and Hedging 470, Debt 268, Presentation in Financial Statements of Redeemable Preferred Stocks not not No. 2020 06, Accounting for Convertible Instruments and Contracts in an Entity s Own Equity January 1, 2021, not not 12. f. Recently Adopted Accounting Standards: December 2019, No. 2019 12, Income Taxes (Topic 740 2019 12 2019 12 740 2019 12 December 12, 2020, 2019 12 not In August 2020, No. 2020 06, Accounting for Convertible Instruments and Contracts in an Entity s Own Equity 2020 06 2020 06 2020 06 2020 06 December 15, 2021, December 15, 2023 2020 06 January 1, 2021 2020 06 not g. Recently Issued Accounting Standards: May 2021, No. 2021 04, Issuer s Accounting for Certain Modifications or Exchanges of Freestanding Equity-Classified Written Call Options 2021 04 ASU2 021 04 ASU2021 04 2021 04 December 15, 2021, not 2021 04

Note 2 - Liquidity

Note 2 - Liquidity	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Substantial Doubt about Going Concern [Text Block]	2. Liquidity As disclosed in the notes to the financial statements included in the Company’s Annual Report on Form 10 11. In addition, the Company is engaged in ongoing litigation with our former President and Chief Executive Officer, Dr. Michael Goldberg. See Note 11. The Company has also been engaged in ongoing litigation with Capital Royalty Partners II L.P. (“CRG”) and pursuing recovery of approximately $4.3 million and other damages. See Note 11. On August 30, 2020, 10 $5.0 second 2021, June 30, 2021. 12. On August 31, 2020, one nine 3 July 8, 2021 ( no June 30, 2021. 12 17. On March 2, 2021, 10 none 12. Navidea intends to use the net proceeds from these transactions to fund its research and development programs, including continued advancement of its two 2b 3 Tc99m The Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”) was enacted on March 27, 2020. 7 May 18, 2020, February 23, 2021, 9. We do not 19 19 NAV3 32 19 19 The Company has experienced recurring net losses and has used significant cash to fund its operations. The Company has considerable discretion over the extent of development project expenditures and has the ability to curtail the related cash flows as needed. The Company also has funds remaining under outstanding grant awards, and continues working to establish new sources of funding, including collaborations, potential equity investments, and additional grant funding that can augment the balance sheet. However, based on our current working capital and our projected cash burn, management believes that there is substantial doubt about the Company's ability to continue as a going concern for a period of one 10 No

Note 3 - Revenue From Contracts

Note 3 - Revenue From Contracts With Customers	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Revenue from Contract with Customer [Text Block]	3. Revenue from Contracts with Customers Navidea is focused on the development and commercialization of precision immunodiagnostic agents and immunotherapeutics. We manage our business based on two Tc99m Tc99m one Tc99 not May 11, 2020, The Company also has an agreement in place to provide Meilleur Technologies, Inc., (“Meilleur”), a wholly-owned subsidiary of Cerveau Technologies, Inc. (“Cerveau”), worldwide rights to conduct research using NAV4694, NAV4694 Currently, the Company recognizes revenue from up-front license fees and pre-market milestones after the cash has been received from its customers and the performance obligations have been met. Payments for sales-based royalties and milestones are generally received after the related revenue has been recognized and invoiced. Normal payment terms generally range from 15 to 90 days following milestone achievement or royalty invoice, in accordance with each contract. Up-front and milestone payments received related to our license and distribution agreements in India and China are deferred until Tc99m not Tc99m not no not eight ten The transaction price of a contract is the amount of consideration to which the Company expects to be entitled in exchange for transferring promised goods or services to a customer. Transaction prices do not third not When estimating a contract’s transaction price, the Company considers all the information (historical, current, and forecasted) that is reasonably available to it and identifies possible consideration amounts. Most of the Company’s contracts with customers include both fixed and variable components of the transaction price. Under those contracts, some or all of the consideration for satisfied performance obligations is contingent on events over which the Company has no Tc99m The milestone payments have a binary outcome (that is, the Company will either receive all or none not Royalties are estimated based on the expected value method because they are based on a variable amount of sales representing a range of possible outcomes. However, when taking into account the constraint on variable consideration, the estimate of future royalties included in the transaction price is generally $0. This conclusion is based on the fact that Tc99m not no no The sublicense of NAV4694 No. 606, Revenue from Contracts with Customers 606” Up-front fees, milestones and royalties are generally non-refundable. Therefore, the Company does not During the three June 30, 2021 2020, six June 30, 2021 2020, three six June 30, 2021 2020, not The following table disaggregates the Company’s revenue from contracts with customers for the three six June 30, 2021 2020. Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Royalty revenue: Tc99m tilmanocept - Europe $ — $ 8,920 $ — $ 24,141 License revenue: Tc99m tilmanocept - Europe $ 13,063 $ — $ 35,549 $ — The following economic factors affect the nature, amount, timing and uncertainty of the Company’s revenue and cash flows as indicated: Geographical Location of Customers: may may Tc99m Status of Regulatory Approval: Tc99m Tc99m Tc99m not may NAV4694 not Through June 30, 2021, not The following table summarizes the changes in contract liabilities, the current portion of which is included in accrued liabilities and other in the condensed consolidated balance sheets, during the three six June 30, 2021 2020. Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Total deferred revenue, beginning of period $ 700,000 $ 700,000 $ 700,000 $ 700,000 Revenue deferred related to sublicense — 160,000 — 160,000 Revenue recognized from satisfaction of performance obligations — — — — Total deferred revenue, end of period $ 700,000 $ 860,000 $ 700,000 $ 860,000 The Company had license revenue receivable of approximately $98,000 and $59,000 outstanding as of June 30, 2021 December 31, 2020. In addition to revenue from contracts from customers, we also generate revenue from National Institutes of Health (“NIH”) grants to support various product development initiatives. The revenue recognition standard applies to revenue from contracts with customers. A customer is defined as a party that has contracted with an entity to obtain goods or services that are an output of the entity’s ongoing major or central operations in exchange for consideration. The Company’s ongoing major or central operations consist of the development and commercialization of precision immunodiagnostic agents and immunotherapeutics. The NIH and its various institutes are responsible for biomedical and public health research and provide major biomedical research funding to non-NIH research facilities and entities such as Navidea. While the Company will directly benefit from any knowledge gained from the project, there is also a public health benefit provided, which justifies the use of public funds in the form of the grants. Based on the nature of the Company’s operations and the terms of the grant awards, Navidea does not not three June 30, 2021 2020, six June 30, 2021 2020, On May 11, 2020 ( March 5, 2015 ( Tc99m Pursuant to the Termination Agreement, the parties agreed that neither owed the other any payments due under the License Agreement as of the Termination Date and that, among other things, SpePharm no six ninety third 2021.

Note 4 - Stock-based Compensati

Note 4 - Stock-based Compensation	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Share-based Payment Arrangement [Text Block]	4. Stock-Based Compensation For the three June 30, 2021 2020, six June 30, 2021 2020, not three six June 30, 2021 2020. A summary of the status of our stock options as of June 30, 2021, six Six Months Ended June 30, 2021 Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Life (Years) Aggregate Intrinsic Value Outstanding, January 1, 2021 549,970 $ 8.81 8.0 $ 209,280 Granted 232,000 2.54 Exercised (2,000 ) 1.06 Cancelled/Forfeited (67,600 ) 4.01 Outstanding, June 30, 2021 712,370 $ 7.25 7.8 $ 143,695 Exercisable, June 30, 2021 186,638 $ 15.64 5.3 $ 52,874 The weighted average grant date fair value per stock option granted during the six June 30, 2021 six June 30, 2021 A summary of the status of our unvested restricted stock as of June 30, 2021, six Six Months Ended June 30, 2021 Number of Shares Weighted Average Grant-Date Fair Value Unvested, January 1, 2021 60,000 $ 2.90 Granted 15,000 2.17 Vested (15,000 ) 1.47 Unvested, June 30, 2021 60,000 $ 3.08 As of June 30, 2021,

Note 5 - Loss Per Share

Note 5 - Loss Per Share	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Earnings Per Share [Text Block]	5. Loss Per Share Basic loss per share is calculated by dividing net loss attributable to common stockholders by the weighted-average number of common shares. Diluted loss per share reflects additional common shares that would have been outstanding if dilutive potential common shares had been issued. Potential common shares that may Diluted loss per common share for the six June 30, 2021 2020 The Company’s unvested restricted stock awards contain nonforfeitable rights to dividends or dividend equivalents, whether paid or unpaid (referred to as “participating securities”). Therefore, the unvested restricted stock awards are required to be included in the number of shares outstanding for both basic and diluted earnings per share calculations. However, due to our loss from continuing operations, 60,000 and 10,000 shares of unvested restricted stock for the six June 30, 2021 2020,

Note 6 - Inventory

Note 6 - Inventory	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Inventory Disclosure [Text Block]	6. Inventory The components of inventory as of June 30, 2021 December 31, 2020 June 30, 2021 December 31, \2020 Materials $ 77,750 $ 77,750 Finished goods 101,080 92,048 Total inventory $ 178,830 $ 169,798 During the three six June 30, 2021,

Note 7 - Investment in Macropha

Note 7 - Investment in Macrophage Therapeutics, Inc.	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Investments in and Advances to Affiliates, Schedule of Investments [Text Block]	7. Investment in Macrophage Therapeutics, Inc. In August 2018, one February 2019, may December 18, 2020 no 11 7.

Note 8 - Accounts Payable, Accr

Note 8 - Accounts Payable, Accrued Liabilities and Other	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block]	8. Accounts Payable, Accrued Liabilities and Other Accounts payable as of June 30, 2021 December 31, 2020 June 30, 2021 December 31, 2020 second 2021, second June 30, 2021.

Note 9 - Notes Payable

Note 9 - Notes Payable	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Debt Disclosure [Text Block]	9. Notes Payable First Insurance Funding In November 2019, eight July 2020. Interest expense related to the FIF note payable totaled $2,000 and $5,000 during the three six June 30, 2020, IPFS Corporation In November 2020, seven June 2021. Interest expense related to the IPFS note payable totaled $1,000 and $4,000 during the three six June 30, 2021, June 30, 2021 December 31, 2020, Paycheck Protection Program The CARES Act was enacted on March 27, 2020. May 18, 2020, February 23, 2021, 2. Summary During the three June 30, 2021 2020, six June 30, 2021 2020,

Note 10 - Leases

Note 10 - Leases	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Leases of Lessee Disclosure [Text Block]	10. Leases We currently lease approximately 5,000 square feet of office space at 4995 June 2023. In addition, we currently lease approximately 25,000 square feet of office space at 5600 2021. October 2022 five not June 2017, October 2022. We also currently lease a vehicle at a monthly payment of approximately $300, expiring in September 2021, October 2024. Total operating lease expense was $44,000 and $50,000 for the three June 30, 2021 2020, six June 30, 2021 2020, The following table presents information about the amount, timing and uncertainty of cash flows arising from the Company’s operating leases as of June 30, 2021. Maturity of Lease Liabilities Operating Lease Payments 2021 (remaining) $ 159,131 2022 291,111 2023 19,699 2024 1,355 Total undiscounted operating lease payments 471,296 Less imputed interest 36,973 Present value of operating lease liabilities $ 434,323 Balance Sheet Classification Current lease liabilities $ 313,852 Noncurrent lease liabilities 120,471 Total operating lease liabilities $ 434,323 Other Information Weighted-average remaining lease term for operating leases (years) 1.4 Weighted-average discount rate for operating leases 11.0 % Cash paid for amounts included in the present value of operating lease liabilities was $185,000 and $181,000 during the six June 30, 2021 2020,

Note 11 - Commitments and Conti

Note 11 - Commitments and Contingencies	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	11. Commitments and Contingencies We are subject to legal proceedings and claims that arise in the ordinary course of business. In accordance with ASC Topic 450, Contingencies not CRG Litigation As disclosed in the notes to the financial statements included in the Company’s Annual Report on Form 10 December 2017, March 3, 2017. March 2017, not June 2016 $66.0 $4.1 $4.1 $7.0 On April 9, 2018, 414, 414” $4.1 $59.0 The Company had also been engaged in ongoing litigation with CRG in the Court of Common Pleas of Franklin County, Ohio (the “Ohio Court”) related to Navidea’s claims that the CRG Lenders fraudulently induced Navidea to enter into a settlement agreement and breached the terms of the same through certain actions taken by the CRG Lenders in connection with the Global Settlement Agreement, pursuant to which Navidea agreed to pay up to $66.0 $66.0 $4.1 June 2016 $66.0 $66.0 $7.1 414 May 7, 2019, June 28, 2019. November 27, 2019, $66.0 April 9, 2018, 414 no December 5, 2019, 10th March 27, 2020, September 23, 2020. March 16, 2021, 10th November 27, 2019 not not April 30, 2021, July 20, 2021 August 5, 2021, CRG filed another lawsuit in the Texas Court in April 2018. not $7.1 414 August 28, 2020. December 18, 2020, February 1, 2021. July 1, 2021. not 2. Platinum Litigation In November 2017, March 3, 2017, October 31, 2018, no On November 30, 2018, January 22, 2019, September 5, 2019. November 25, 2019, not April 28, 2020 19 not June 4, 2020. September 2, 2020, September 23, 2020 June 28, 2021. 2. Goldberg Agreement and Litigation In August 2018, one 1,175,000 November 2018, On February 11, 2019, February 19, 2019, March 1, 2019, February 20, 2019, may December 18, 2020 no New York Litigation Involving Dr. Goldberg On February 20, 2019, April 26, 2019, June 13, 2019, third On December 26, 2019, third not The District Court also rejected Dr. Goldberg’s claim for wrongful termination as Chief Executive Officer of MT. In addition, the District Court found that Dr. Goldberg lacked standing to seek injunctive relief to force the removal of Dr. Claudine Bruck and Michael Rice from MT’s Board of Directors, to invalidate all actions taken by the MT Board on or after November 29, 2018 ( In addition, the District Court found Navidea’s breach of fiduciary duty claim against Dr. Goldberg for conduct occurring more than three On January 31, 2020, April 1, 2020, On January 27, 2020, July 9, 2020, 1 2 3 4 On August 24, 2020, not third On May 27, 2021, 1 2 3 not 4 not third 5 6 not Fact discovery in the New York Action has been completed and the Court has ordered that expert discovery be completed no November 30, 2021. Delaware Litigation Involving Dr. Goldberg On February 20, 2019, June 12, 2019, not May 23, 2019 A trial on MT’s claims against Goldberg for breach of fiduciary duty and conversion was held on December 1 December 3, 2020. three not not Derivative Action Involving Dr. Goldberg On July 26, 2019, November 20, 2019, April 3, 2020, not 2 7. NYSE American Continued Listing Standards Navidea must maintain compliance with NYSE American continued listing standards, including those relating to stockholders’ equity. Specifically, Sections 1003 $6.0 five June 30, 2021, Even if an issuer does not 1003 not 1 $50,000,000; $50,000,000 two three 2 1,100,000 $15,000,000 400 June 30, 2021, June 30, 2021 $50.0 may not may

Note 12 - Equity

Note 12 - Equity	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Stockholders' Equity Note Disclosure [Text Block]	12. Equity In December 2019, 2019. January 2020. December 31, 2019. In February 2020, two 2020. On August 30, 2020, 10 $5.0 December 31, 2020. second 2021, June 30, 2021. 2. On August 31, 2020, one $15.0 June 30, 2021. June 30, 2021. June 30, 2021, 10 December 31, 2020. $2.925 December 31, 2020. 2 17. On March 2, 2021, Under the Series E Preferred Stock Purchase Agreement, Mr. Scott was granted a right of first no 33.33% 13 1934, not third not no no may December 31, 2021 In connection with the private placement, the Company entered into a registration rights agreement (the “Registration Rights Agreement”), pursuant to which, among other things, the Company prepared and filed with the Securities and Exchange Commission (the “SEC”) a registration statement on Form S- 1 20% 13 144 not 1933, not may not Except with respect to transactions which may no one may not one 2. Navidea intends to use the net proceeds from these transactions to fund its research and development programs, including continued advancement of its Phase 2b 3 Tc99m 2. During the six June 30, 2021 2020, 401 During the six June 30, 2020, 2019

Note 13 - Stock Warrants

Note 13 - Stock Warrants	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Stock Warrants Disclosure [Text Block]	13. Stock Warrants As of June 30, 2021,

Note 14 - Income Taxes

Note 14 - Income Taxes	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Income Tax Disclosure [Text Block]	14. Income Taxes Income taxes are accounted for under the asset and liability method in accordance with Accounting Standards Codification 740, Income Taxes Current accounting standards require a valuation allowance against DTAs if, based on the weight of available evidence, it is more likely than not may not June 30, 2021 December 31, 2020. In assessing the realizability of DTAs, management considers whether it is more likely than not not not not June 30, 2021. Current accounting standards include guidance on the accounting for uncertainty in income taxes recognized in the financial statements. Such standards also prescribe a recognition threshold and measurement model for the financial statement recognition of a tax position taken, or expected to be taken, and provides guidance on derecognition, classification, interest and penalties, accounting in interim periods, disclosure and transition. The Company believes that the ultimate deductibility of all tax positions is highly certain, although there is uncertainty about the timing of such deductibility. As a result, no liability for uncertain tax positions was recorded as of June 30, 2021 December 31, 2020 not twelve June 30, 2021, 2017 2020 As of June 30, 2021, 2021 2040.

Note 15 - Segments

Note 15 - Segments	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Segment Reporting Disclosure [Text Block]	15. Segments We report information about our operating segments using the “management approach” in accordance with current accounting standards. This information is based on the way management organizes and reports the segments within the enterprise for making operating decisions and assessing performance. Our reportable segments are identified based on differences in products, services and markets served. There were no inter-segment sales. We manage our business based on two Tc99m The information in the following tables is derived directly from each reportable segment’s financial reporting. Three Months Ended June 30, 2021 Diagnostics Therapeutics Corporate Total License revenue $ 13,063 $ — $ — $ 13,063 Grant and other revenue 247,983 — — 247,983 Total revenue 261,046 — — 261,046 Research and development expenses 1,358,123 139,933 — 1,498,056 Selling, general and administrative expenses, excluding depreciation and amortization (1) — 873 1,411,879 1,412,752 Depreciation and amortization (2) 6,041 — 13,817 19,858 Loss from operations (3) (1,103,118 ) (140,806 ) (1,425,696 ) (2,669,620 ) Other expense (4) — — (4,420 ) (4,420 ) Net loss (1,103,118 ) (140,806 ) (1,430,116 ) (2,674,040 ) Total assets, net of depreciation and amortization: United States $ 269,464 $ — $ 10,811,515 $ 11,080,979 International 199,741 — 590 200,331 Capital expenditures — — 2,707 2,707 Three Months Ended June 30, 2020 Diagnostics Therapeutics Corporate Total Royalty revenue $ 8,920 $ — $ — $ 8,920 Grant and other revenue 215,458 46,723 — 262,181 Total revenue 224,378 46,723 — 271,101 Cost of revenue 357 — — 357 Research and development expenses 1,193,151 88,628 — 1,281,779 Selling, general and administrative expenses, excluding depreciation and amortization (1) — 972 1,309,363 1,310,335 Depreciation and amortization (2) — — 19,256 19,256 Loss from operations (3) (969,130 ) (42,877 ) (1,328,619 ) (2,340,626 ) Other income (4) — — 15,007 15,007 Net loss (969,130 ) (42,877 ) (1,313,612 ) (2,325,619 ) Total assets, net of depreciation and amortization: United States $ 107,185 $ 36,483 $ 6,463,015 $ 6,606,683 Capital expenditures — — 1,947 1,947 Six Months Ended June 30, 2021 Diagnostics Therapeutics Corporate Total License revenue $ 35,549 $ — $ — $ 35,549 Grant and other revenue 349,234 — — 349,234 Total revenue 384,783 — — 384,783 Research and development expenses 2,452,513 268,297 — 2,720,810 Selling, general and administrative expenses, excluding depreciation and amortization (1) — 2,879 3,622,870 3,625,749 Depreciation and amortization (2) 12,081 — 25,525 37,606 Loss from operations (3) (2,079,811 ) (271,176 ) (3,648,395 ) (5,999,382 ) Other income (4) — — 358,450 358,450 Net loss (2,079,811 ) (271,176 ) (3,289,945 ) (5,640,932 ) Total assets, net of depreciation and amortization: United States $ 269,464 $ — $ 10,811,515 $ 11,080,979 International 199,741 — 590 200,331 Capital expenditures — — 2,707 2,707 Six Months Ended June 30, 2020 Diagnostics Therapeutics Corporate Total Royalty revenue $ 24,141 $ — $ — $ 24,141 Grant and other revenue 274,374 128,858 — 403,232 Total revenue 298,515 128,858 — 427,373 Cost of revenue 966 — — 966 Research and development expenses 2,150,777 130,271 — 2,281,048 Selling, general and administrative expenses, excluding depreciation and amortization (1) — (550 ) 3,121,796 3,121,246 Depreciation and amortization (2) — — 36,099 36,099 Loss from operations (3) (1,853,228 ) (863 ) (3,157,895 ) (5,011,986 ) Other income (4) — — 12,759 12,759 Net loss (1,853,228 ) (863 ) (3,145,136 ) (4,999,227 ) Total assets, net of depreciation and amortization: United States $ 107,185 $ 36,483 $ 6,463,015 $ 6,606,683 Capital expenditures — — 8,406 8,406 ( 1 not ( 2 three June 30, 2021 2020, six June 30, 2021 2020, ( 3 not ( 4 not

Note 16 - Supplemental Disclosu

Note 16 - Supplemental Disclosure for Statements of Cash Flows	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Cash Flow, Supplemental Disclosures [Text Block]	16. Supplemental Disclosure for Statements of Cash Flows During the six June 30, 2021 2020, six June 30, 2021, 10 December 31, 2020 December 31, 2020. February 2020, six June 30, 2021 2020, 401 six June 30, 2020, 2019 six June 30, 2020, six June 30, 2020,

Note 17 - Subsequent Events

Note 17 - Subsequent Events	6 Months Ended
	Jun. 30, 2021
Notes to Financial Statements
Subsequent Events [Text Block]	17. Subsequent Events The Company has evaluated events and transactions subsequent to June 30, 2021 10 On July 8, 2021, July 9, 2021 5 August 31, 2020 no The entire $2.2 million was received and the related 22,077 shares of Series D Preferred Stock were issued on July 8, 2021. June 30, 2021. 2 12.

Significant Accounting Policies

Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	a. Basis of Presentation: June 30, 2021 three six June 30, 2021 2020 June 30, 2021 not December 31, 2020, 10 Our condensed consolidated financial statements include the accounts of Navidea and our wholly owned subsidiaries, Navidea Biopharmaceuticals Europe Limited (“Navidea Europe”) and Navidea Biopharmaceuticals Limited (“Navidea UK”), as well as those of our majority-owned subsidiary, Macrophage Therapeutics, Inc. (“MT”). All significant inter-company accounts were eliminated in consolidation.
Fair Value of Financial Instruments, Policy [Policy Text Block]	b. Financial Instruments and Fair Value: ( 1 Cash and cash equivalents, stock subscriptions and other receivables, and accounts payable: ( 2 Notes payable: June 30, 2021 December 31, 2020 June 30, 2021 December 31, 2020, 9.
Revenue [Policy Text Block]	c. Revenue Recognition: We also earn revenues related to our licensing and distribution agreements. The consideration we are eligible to receive under our licensing and distribution agreements typically includes upfront payments, reimbursement for research and development costs, milestone payments, and royalties. Each licensing and distribution agreement is unique and requires separate assessment in accordance with current accounting standards. See Note 3.
Lessee, Leases [Policy Text Block]	d. Leases: 2018. 12 not 10.
Stockholders' Equity Note, Redeemable Preferred Stock, Issue, Policy [Policy Text Block]	e. Convertible Preferred Stock: 480, Distinguishing Liabilities from Equity 815, Derivatives and Hedging 470, Debt 268, Presentation in Financial Statements of Redeemable Preferred Stocks not not No. 2020 06, Accounting for Convertible Instruments and Contracts in an Entity s Own Equity January 1, 2021, not not 12.
New Accounting Pronouncements, Policy [Policy Text Block]	f. Recently Adopted Accounting Standards: December 2019, No. 2019 12, Income Taxes (Topic 740 2019 12 2019 12 740 2019 12 December 12, 2020, 2019 12 not In August 2020, No. 2020 06, Accounting for Convertible Instruments and Contracts in an Entity s Own Equity 2020 06 2020 06 2020 06 2020 06 December 15, 2021, December 15, 2023 2020 06 January 1, 2021 2020 06 not g. Recently Issued Accounting Standards: May 2021, No. 2021 04, Issuer s Accounting for Certain Modifications or Exchanges of Freestanding Equity-Classified Written Call Options 2021 04 ASU2 021 04 ASU2021 04 2021 04 December 15, 2021, not 2021 04

Note 3 - Revenue From Contrac_2

Note 3 - Revenue From Contracts With Customers (Tables)	6 Months Ended
	Jun. 30, 2021
Notes Tables
Disaggregation of Revenue [Table Text Block]	Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Royalty revenue: Tc99m tilmanocept - Europe $ — $ 8,920 $ — $ 24,141 License revenue: Tc99m tilmanocept - Europe $ 13,063 $ — $ 35,549 $ —
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]	Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 Total deferred revenue, beginning of period $ 700,000 $ 700,000 $ 700,000 $ 700,000 Revenue deferred related to sublicense — 160,000 — 160,000 Revenue recognized from satisfaction of performance obligations — — — — Total deferred revenue, end of period $ 700,000 $ 860,000 $ 700,000 $ 860,000

Note 4 - Stock-based Compensa_2

Note 4 - Stock-based Compensation (Tables)	6 Months Ended
	Jun. 30, 2021
Notes Tables
Share-based Payment Arrangement, Option, Activity [Table Text Block]	Six Months Ended June 30, 2021 Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Life (Years) Aggregate Intrinsic Value Outstanding, January 1, 2021 549,970 $ 8.81 8.0 $ 209,280 Granted 232,000 2.54 Exercised (2,000 ) 1.06 Cancelled/Forfeited (67,600 ) 4.01 Outstanding, June 30, 2021 712,370 $ 7.25 7.8 $ 143,695 Exercisable, June 30, 2021 186,638 $ 15.64 5.3 $ 52,874
Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]	Six Months Ended June 30, 2021 Number of Shares Weighted Average Grant-Date Fair Value Unvested, January 1, 2021 60,000 $ 2.90 Granted 15,000 2.17 Vested (15,000 ) 1.47 Unvested, June 30, 2021 60,000 $ 3.08

Note 6 - Inventory (Tables)

Note 6 - Inventory (Tables)	6 Months Ended
	Jun. 30, 2021
Notes Tables
Schedule of Inventory, Current [Table Text Block]	June 30, 2021 December 31, \2020 Materials $ 77,750 $ 77,750 Finished goods 101,080 92,048 Total inventory $ 178,830 $ 169,798

Note 10 - Leases (Tables)

Note 10 - Leases (Tables)	6 Months Ended
	Jun. 30, 2021
Notes Tables
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	Maturity of Lease Liabilities Operating Lease Payments 2021 (remaining) $ 159,131 2022 291,111 2023 19,699 2024 1,355 Total undiscounted operating lease payments 471,296 Less imputed interest 36,973 Present value of operating lease liabilities $ 434,323
Lessee, Operating Lease, Assets and Liabilities [Table Text Block]	Balance Sheet Classification Current lease liabilities $ 313,852 Noncurrent lease liabilities 120,471 Total operating lease liabilities $ 434,323
Lease, Cost [Table Text Block]	Other Information Weighted-average remaining lease term for operating leases (years) 1.4 Weighted-average discount rate for operating leases 11.0 %

Note 15 - Segments (Tables)

Note 15 - Segments (Tables)	6 Months Ended
	Jun. 30, 2021
Notes Tables
Schedule of Segment Reporting Information, by Segment [Table Text Block]	Three Months Ended June 30, 2021 Diagnostics Therapeutics Corporate Total License revenue $ 13,063 $ — $ — $ 13,063 Grant and other revenue 247,983 — — 247,983 Total revenue 261,046 — — 261,046 Research and development expenses 1,358,123 139,933 — 1,498,056 Selling, general and administrative expenses, excluding depreciation and amortization (1) — 873 1,411,879 1,412,752 Depreciation and amortization (2) 6,041 — 13,817 19,858 Loss from operations (3) (1,103,118 ) (140,806 ) (1,425,696 ) (2,669,620 ) Other expense (4) — — (4,420 ) (4,420 ) Net loss (1,103,118 ) (140,806 ) (1,430,116 ) (2,674,040 ) Total assets, net of depreciation and amortization: United States $ 269,464 $ — $ 10,811,515 $ 11,080,979 International 199,741 — 590 200,331 Capital expenditures — — 2,707 2,707 Three Months Ended June 30, 2020 Diagnostics Therapeutics Corporate Total Royalty revenue $ 8,920 $ — $ — $ 8,920 Grant and other revenue 215,458 46,723 — 262,181 Total revenue 224,378 46,723 — 271,101 Cost of revenue 357 — — 357 Research and development expenses 1,193,151 88,628 — 1,281,779 Selling, general and administrative expenses, excluding depreciation and amortization (1) — 972 1,309,363 1,310,335 Depreciation and amortization (2) — — 19,256 19,256 Loss from operations (3) (969,130 ) (42,877 ) (1,328,619 ) (2,340,626 ) Other income (4) — — 15,007 15,007 Net loss (969,130 ) (42,877 ) (1,313,612 ) (2,325,619 ) Total assets, net of depreciation and amortization: United States $ 107,185 $ 36,483 $ 6,463,015 $ 6,606,683 Capital expenditures — — 1,947 1,947 Six Months Ended June 30, 2021 Diagnostics Therapeutics Corporate Total License revenue $ 35,549 $ — $ — $ 35,549 Grant and other revenue 349,234 — — 349,234 Total revenue 384,783 — — 384,783 Research and development expenses 2,452,513 268,297 — 2,720,810 Selling, general and administrative expenses, excluding depreciation and amortization (1) — 2,879 3,622,870 3,625,749 Depreciation and amortization (2) 12,081 — 25,525 37,606 Loss from operations (3) (2,079,811 ) (271,176 ) (3,648,395 ) (5,999,382 ) Other income (4) — — 358,450 358,450 Net loss (2,079,811 ) (271,176 ) (3,289,945 ) (5,640,932 ) Total assets, net of depreciation and amortization: United States $ 269,464 $ — $ 10,811,515 $ 11,080,979 International 199,741 — 590 200,331 Capital expenditures — — 2,707 2,707 Six Months Ended June 30, 2020 Diagnostics Therapeutics Corporate Total Royalty revenue $ 24,141 $ — $ — $ 24,141 Grant and other revenue 274,374 128,858 — 403,232 Total revenue 298,515 128,858 — 427,373 Cost of revenue 966 — — 966 Research and development expenses 2,150,777 130,271 — 2,281,048 Selling, general and administrative expenses, excluding depreciation and amortization (1) — (550 ) 3,121,796 3,121,246 Depreciation and amortization (2) — — 36,099 36,099 Loss from operations (3) (1,853,228 ) (863 ) (3,157,895 ) (5,011,986 ) Other income (4) — — 12,759 12,759 Net loss (1,853,228 ) (863 ) (3,145,136 ) (4,999,227 ) Total assets, net of depreciation and amortization: United States $ 107,185 $ 36,483 $ 6,463,015 $ 6,606,683 Capital expenditures — — 8,406 8,406

Note 1 - Summary of Significa_2

Note 1 - Summary of Significant Accounting Policies (Details Textual) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Notes Payable, Fair Value Disclosure	$ 0	$ 745,000

Note 2 - Liquidity (Details Tex

Note 2 - Liquidity (Details Textual) - USD ($)	Aug. 12, 2021	Jul. 08, 2021	Mar. 02, 2021	Feb. 23, 2021	Aug. 31, 2020	May 18, 2020	Aug. 12, 2021	Jan. 31, 2020	Dec. 31, 2019	Nov. 30, 2017	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Dec. 31, 2019	Dec. 31, 2020	Aug. 30, 2020
Common Stock, Par or Stated Value Per Share (in dollars per share)											$ 0.001			$ 0.001		$ 0.001		$ 0.001
Proceeds from Issuance of Common Stock								$ 812,000	$ 1,900,000					$ 2,133	$ 3,025,040		$ 1,100,000
Stock Issued During Period, Shares, New Issues (in shares)									2,100,000
Stock Issued During Period, Value, New Issues											$ 1,800,000		$ 700,000
Stock Subscriptions and Other Receivables											2,400,238			2,400,238		$ 2,400,238		$ 2,987,319
Proceeds from Notes Payable, Total														0	366,000
Gain (Loss) on Extinguishment of Debt, Total											0		0	366,000	$ 0
Paycheck Protection Program CARES Act [Member]
Proceeds from Notes Payable, Total						$ 366,000
Gain (Loss) on Extinguishment of Debt, Total				$ 366,000
Series D Preferred Stock [Member]
Stock Issued During Period, Value, New Issues												$ 250,001
Stock Subscriptions and Other Receivables											$ 2,200,000			$ 2,200,000		$ 2,200,000
Series E Preferred Stock [Member]
Stock Issued During Period, Value, New Issues												$ 4,980,709
Subsequent Event [Member] | Series E Preferred Stock [Member]
Conversion of Stock, Shares Converted (in shares)	0
Keystone Capital Partners, LLC [Member] | Series D Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)					150,000											72,500
Stock Issued During Period, Value, New Issues					$ 15,000,000
Stock Purchase Agreement, Shares Remaining (in shares)											77,500			77,500		77,500
Keystone Capital Partners, LLC [Member] | Series D Preferred Stock [Member] | Maximum [Member]
Convertible Preferred Stock, Shares Issued upon Conversion (in shares)					5,147,000
Keystone Capital Partners, LLC [Member] | Subsequent Event [Member] | Series D Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)		22,077
Stock Issued During Period, Value, New Issues		$ 2,200,000
John K. Scott, Jr. [Member] | Series E Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)			50,000
Stock Issued During Period, Value, New Issues			$ 5,000,000
Preferred Stock, Convertible, Shares Issuable (in shares)			2,173,913
Private Placement [Member]
Stock Issued During Period, Value, New Issues													$ 520,030
Private Placement [Member] | Mastiff Group LLC [Member]
Sale of Stock, Commitment Amount											$ 4,975,000			$ 4,975,000		$ 4,975,000		$ 4,975,000	$ 25,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share)																			$ 0.001
Private Placement [Member] | Mastiff Group LLC [Member] | Subsequent Event [Member]
Proceeds from Issuance of Common Stock	$ 25,000						$ 25,000
Platinum-Montaur Life Sciences LLC Litigation [Member]
Loss Contingency, Damages Sought, Value										$ 1,900,000
CRG Loan Agreement, Ohio Case [Member]
Loss Contingency, Damages Sought, Value														$ 4,300,000

Note 3 - Revenue From Contrac_3

Note 3 - Revenue From Contracts With Customers (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Contract with Customer, Payment Term, Minimum (Day)			15 days
Contract with Customer, Payment Term, Maximum (Day)			90 days
Contract with Customer, Transaction Price of Royalties Using Expected Value Method	$ 0		$ 0
Revenue from Contract with Customer, Including Assessed Tax	13,000	$ 9,000	36,000	$ 24,000
Contract with Customer, Asset, Impairment Loss			0	0
Capitalized Contract Cost, Net, Total	0		0
Contract with Customer, Asset, after Allowance for Credit Loss, Total	98,000		98,000		$ 59,000
Grant [Member]
Revenue Not from Contract with Customer	$ 73,000	$ 262,000	$ 74,000	$ 403,000
INDIA
Contract with Customer, Term of Contract (Year)			8 years
CHINA
Contract with Customer, Term of Contract (Year)			10 years

Note 3 - Revenue From Contrac_4

Note 3 - Revenue From Contracts With Customers - Disaggregation of Revenue (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenue from contract with customer	$ 13,000	$ 9,000	$ 36,000	$ 24,000
Royalty [Member]
Revenue from contract with customer	0	8,920	0	24,141
Diagnostics Segment [Member] | Royalty [Member]
Revenue from contract with customer		8,920		24,141
Diagnostics Segment [Member] | Royalty [Member] | Europe [Member]
Revenue from contract with customer	0	8,920	0	24,141
Diagnostics Segment [Member] | Expanded Tc99m Tilmanocept License Agreement [Member] | Europe [Member]
Revenue from contract with customer	$ 13,063	$ 0	$ 35,549	$ 0

Note 3 - Revenue From Contrac_5

Note 3 - Revenue From Contracts With Customers - Changes in Contract Liabilities (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Total deferred revenue, beginning of period	$ 700,000	$ 700,000	$ 700,000	$ 700,000
Revenue deferred related to sublicense	0	160,000	0	160,000
Revenue recognized from satisfaction of performance obligations	0	0	0	0
Total deferred revenue, end of period	$ 700,000	$ 860,000	$ 700,000	$ 860,000

Note 4 - Stock-based Compensa_3

Note 4 - Stock-based Compensation (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Payment Arrangement, Expense	$ 142,000	$ 35,000	$ 263,000	$ 74,000
Share-based Payment Arrangement, Expense, Tax Benefit	0	$ 0	$ 0	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)			$ 1.86
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum			90.22%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate			0.67%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term (Year)			5 years 11 months 19 days
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	$ 415,000		$ 415,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)			1 year 7 months 6 days

Note 4 - Stock-based Compensa_4

Note 4 - Stock-based Compensation - Summary of Stock Option Activity (Details)	6 Months Ended	12 Months Ended
	Jun. 30, 2021USD ($)$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares
Outstanding at beginning of period (in shares) | shares	549,970
Outstanding at beginning of period, weighted average exercise price (in dollars per share) | $ / shares	$ 8.81
Outstanding, weighted average remaining contractual life (Year)	7 years 9 months 18 days	8 years
Outstanding, aggregate intrinsic value | $	$ 143,695	$ 209,280
Granted (in shares) | shares	232,000
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 2.54
Exercised (in shares) | shares	(2,000)
Exercised, weighted average exercise price (in dollars per share) | $ / shares	$ 1.06
Cancelled/Forfeited (in shares) | shares	(67,600)
Cancelled/Forfeited, weighted average exercise price (in dollars per share) | $ / shares	$ 4.01
Outstanding at end of period (in shares) | shares	712,370	549,970
Outstanding at end of period, weighted average exercise price (in dollars per share) | $ / shares	$ 7.25	$ 8.81
Exercisable at end of period (in shares) | shares	186,638
Exercisable at end of period, weighted average exercise price (in dollars per share) | $ / shares	$ 15.64
Exercisable, weighted average remaining contractual life (Year)	5 years 3 months 18 days
Exercisable, aggregate intrinsic value | $	$ 52,874

Note 4 - Stock-based Compensa_5

Note 4 - Stock-based Compensation - Summary of Unvested Restricted Stock (Details) - Restricted Stock [Member]	6 Months Ended
	Jun. 30, 2021$ / sharesshares
Unvested at beginning of period (in shares) | shares	60,000
Unvested at beginning of period, weighted average grant-date fair value (in dollars per share) | $ / shares	$ 2.90
Granted (in shares) | shares	15,000
Granted, weighted average grant-date fair value (in dollars per share) | $ / shares	$ 2.17
Vested (in shares) | shares	(15,000)
Vested, weighted average grant-date fair value (in dollars per share) | $ / shares	$ 1.47
Unvested at end of period (in shares) | shares	60,000
Unvested at end of period, weighted average grant-date fair value (in dollars per share) | $ / shares	$ 3.08

Note 5 - Loss Per Share (Detail

Note 5 - Loss Per Share (Details Textual) - shares	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Stock Options and Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)	1,684,694	1,423,344
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)	60,000	10,000

Note 6 - Inventory (Details Tex

Note 6 - Inventory (Details Textual) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021
Finished Goods [Member]
Inventory, Allocated to Research and Development Expense	$ 1,000	$ 5,000

Note 6 - Inventory - Net Invent

Note 6 - Inventory - Net Inventory (Details) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Materials	$ 77,750	$ 77,750
Finished goods	101,080	92,048
Total inventory	$ 178,830	$ 169,798

Note 8 - Accounts Payable, Ac_2

Note 8 - Accounts Payable, Accrued Liabilities and Other (Details Textual) - Director Fees [Member] - USD ($)	3 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Related Party Transaction, Percentage of Cash payments	50.00%
Related Party Transaction, Percentage of Stock Payments	50.00%
Accounts Payable [Member]
Due to Related Parties, Current, Total	$ 28,000	$ 66,000
Related Party Transaction, Percentage of Related Party Transaction	50.00%
Accrued Liabilities and Other [Member]
Due to Related Parties, Current, Total	$ 613,000	$ 755,000
Related Party Transaction, Percentage of Related Party Transaction	50.00%

Note 9 - Notes Payable (Details

Note 9 - Notes Payable (Details Textual) - USD ($)	Feb. 23, 2021	May 18, 2020	Nov. 30, 2020	Nov. 30, 2019	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Interest Expense, Debt, Total					$ 1,000	$ 2,000	$ 4,000	$ 5,000
Notes Payable, Current, Total					0		0		$ 745,443
Proceeds from Notes Payable, Total							0	366,000
Gain (Loss) on Extinguishment of Debt, Total					0	0	366,000	0
Notes Payable Issued for Prepayment of Insurance Premiums [Member] | FIF [Member]
Debt Instrument, Face Amount			$ 442,000	$ 349,000
Debt Instrument, Interest Rate, Stated Percentage			3.50%	5.00%
Debt Instrument, Term (Month)			7 months	8 months
Debt Instrument, Periodic Payment, Total			$ 64,000	$ 44,000
Interest Expense, Debt, Total					1,000	$ 2,000	4,000	$ 5,000
Notes Payable, Current, Total					$ 0		$ 0		$ 379,000
Paycheck Protection Program CARES Act [Member]
Proceeds from Notes Payable, Total		$ 366,000
Gain (Loss) on Extinguishment of Debt, Total	$ 366,000

Note 10 - Leases (Details Textu

Note 10 - Leases (Details Textual)	1 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2017USD ($)	Jun. 30, 2021USD ($)ft²	Jun. 30, 2020USD ($)	Jun. 30, 2021USD ($)ft²	Jun. 30, 2020USD ($)
Operating Lease, Expense		$ 44,000	$ 50,000	$ 90,000	$ 102,000
Operating Lease, Payments				$ 185,000	$ 181,000
Office Space at 4995 Bradenton Avenue, Dublin Ohio [Member]
Area of Real Estate Property (Square Foot) | ft²		5,000		5,000
Operating Lease, Monthly Base Rent				$ 3,000
Office Space at 5600 Blazer Parkway, Dublin, Ohio [Member]
Area of Real Estate Property (Square Foot) | ft²		25,000		25,000
Operating Lease, Monthly Base Rent	$ 39,000			$ 27,000
Lessee, Operating Lease, Renewal Term (Year)		5 years		5 years
Vehicle Lease [Member]
Operating Lease, Monthly Base Rent				$ 300
Office Equipment [Member]
Operating Lease, Monthly Base Rent				$ 100

Note 10 - Leases - Maturity of

Note 10 - Leases - Maturity of Lease Liabilities (Details)	Jun. 30, 2021USD ($)
2021 (remaining)	$ 159,131
2022	291,111
2023	19,699
2024	1,355
Total undiscounted operating lease payments	471,296
Less imputed interest	36,973
Present value of operating lease liabilities	$ 434,323

Note 10 - Leases - Balance Shee

Note 10 - Leases - Balance Sheet Classification (Details) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Current lease liabilities	$ 313,852	$ 294,951
Noncurrent lease liabilities	120,471	$ 296,006
Present value of operating lease liabilities	434,323
Other Current Liabilities [Member]
Current lease liabilities	313,852
Other Noncurrent Liabilities [Member]
Noncurrent lease liabilities	$ 120,471

Note 10 - Leases - Other Inform

Note 10 - Leases - Other Information (Details)	Jun. 30, 2021
Weighted-average remaining lease term for operating leases (years) (Year)	1 year 4 months 24 days
Weighted-average discount rate for operating leases	11.00%

Note 11 - Commitments and Con_2

Note 11 - Commitments and Contingencies (Details Textual) - USD ($)

Apr. 21, 2021

Mar. 16, 2021

Nov. 27, 2019

Apr. 09, 2018

Nov. 02, 2017

Mar. 03, 2017

Dec. 31, 2019

Nov. 30, 2018

Aug. 31, 2018

Nov. 30, 2017

Jun. 30, 2016

Jun. 30, 2021

Dec. 31, 2020

Stock Issued During Period, Shares, New Issues (in shares)

2,100,000

Stockholders' Equity Attributable to Parent, Ending Balance

$ 5,704,870

$ 1,315,604

Market Capitalization, Fair Value

$ 55,200,000

Common Stock [Member]

Stock Issued During Period, Shares, New Issues (in shares)

0

Former Chief Executive Officer and President [Member]

Common Stock Shares Provided by Agreement (in shares)

1,175,000

Common Stock Shares Provided by Agreement, Escrow Period (Month)

18 months

Former Chief Executive Officer and President [Member] | Common Stock [Member]

Stock Issued During Period, Shares, New Issues (in shares)

925,000

Stock Issued During Period, Shares, New Issues Placed in Escrow (in shares)

250,000

Former Chief Executive Officer and President [Member] | MT [Member] | Common Stock [Member] | Dr. Michael Goldberg [Member]

Ownership Percentage

5.00%

CRG [Member]

Draws on Letter of Credit

$ 7,100,000

CRG Loan Agreement, Texas Case [Member] | Judicial Ruling [Member]

Loss Contingency, Damages Awarded, Value, Additional Amount

$ 7,000,000

Loss Contingency, Damages Awarded, Value, Amount not Taken into Consideration

$ 4,100,000

Ohio Court of Common Pleas [Member]

Litigation Settlement, Amount Awarded from Other Party

$ 4,300,000

Litigation Settlement, Reversal of Amount Awarded from Other Party

$ 4,300,000

Platinum-Montaur Life Sciences LLC Litigation [Member]

Loss Contingency, Damages Sought, Value

$ 1,900,000

Platinum-Montaur Life Sciences LLC Litigation [Member] | Pending Litigation [Member]

Loss Contingency, Damages Sought, Value

$ 1,900,000

New York Litigation Involving Former CEO and President [Member] | Judicial Ruling [Member]

Litigation Settlement, Amount Can Be Awarded to Other Party for Indemnification for Attorneys’ Fees

$ 14,955

Litigation Settlement, Amount Can Be Advanced to Other Party for Attorneys’ Fees Subject to Repayment

$ 1,237.50

CRG [Member] | Term Loan Agreement [Member] | CRG Loan Agreement, Texas Case [Member] | Judicial Ruling [Member]

Repayments of Debt

59,000,000

CRG [Member] | Term Loan Agreement [Member] | Maximum [Member]

Debt Instrument, Agreed-upon Final Payoff Amount

$ 66,000,000

Note 12 - Equity (Details Textu

Note 12 - Equity (Details Textual) - USD ($)	Aug. 12, 2021	Jul. 08, 2021	Mar. 02, 2021	Aug. 31, 2020	Aug. 12, 2021	Feb. 29, 2020	Jan. 31, 2020	Dec. 31, 2019	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019	Aug. 30, 2020
Stock Issued During Period, Shares, New Issues (in shares)								2,100,000
Proceeds from Issuance of Common Stock							$ 812,000	$ 1,900,000					$ 2,133	$ 3,025,040			$ 1,100,000
Common Stock, Share Subscribed but Unissued, Subscriptions Receivable									$ 0				0		$ 0	$ 4,975,000
Proceeds from Issuance of Preferred Stock and Preference Stock													$ 10,475,000	$ 700,000
Stock Issued During Period, Value, New Issues									$ 1,800,000		$ 700,000
Stock Issued During Period, Shares, Employee Benefit Plan (in shares)													30,018	32,651
Stock Issued During Period, Value, Employee Benefit Plan										$ 76,846	$ 39,834		$ 77,000	$ 40,000
Issuance of Stock to Defined Contribution Plan for Employer Matching Contribution													$ 76,846	$ 39,834
Common Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)									0
Stock Issued During Period, Value, New Issues									$ 0
Stock Issued During Period, Shares, Employee Benefit Plan (in shares)										30,018	32,651
Stock Issued During Period, Value, Employee Benefit Plan										$ 30	$ 33
Stock Issued During Period, Shares, Issued for Employee Bonuses (in shares)											40,844	53,315
Conversion from Series D Preferred Stock To Common Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)													72,500
Stock Subscriptions Receivable									7,250,000				$ 7,250,000		$ 7,250,000
Series D Preferred Stock [Member]
Stock Issued During Period, Value, New Issues										250,001
Series E Preferred Stock [Member]
Stock Issued During Period, Value, New Issues										$ 4,980,709
Preferred Stock, Convertible, Conversion Price (in dollars per share)			$ 2.30
Preferred Stock, Redemption Price Per Share (in dollars per share)			$ 110
Subsequent Event [Member] | Conversion from Series D Preferred Stock To Common Stock [Member]
Conversion of Stock, Shares Converted (in shares)					72,500
Conversion of Stock, Shares Issued (in shares)					3,778,789
Subsequent Event [Member] | Series E Preferred Stock [Member]
Conversion of Stock, Shares Converted (in shares)	0
Keystone Capital Partners, LLC [Member] | Series D Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)				150,000											72,500
Stock Issued During Period, Value, Other				$ 15,000,000
Proceeds from Issuance of Preferred Stock and Preference Stock													2,925,000			2,925,000
Stock Issued During Period, Value, New Issues				$ 15,000,000
Keystone Capital Partners, LLC [Member] | Series D Preferred Stock [Member] | Maximum [Member]
Convertible Preferred Stock, Shares Issued upon Conversion (in shares)				5,147,000
Keystone Capital Partners, LLC [Member] | Subsequent Event [Member] | Series D Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)		22,077
Proceeds from Issuance of Preferred Stock and Preference Stock		$ 2,200,000
Stock Issued During Period, Value, New Issues		$ 2,200,000
John K. Scott, Jr. [Member] | Series E Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)			50,000
Stock Issued During Period, Value, New Issues			$ 5,000,000
Percentage of Securities Allowed to be Purchased in Third-Party Offering, Maximum			33.33%
Private Placement [Member]
Stock Issued During Period, Value, New Issues											$ 520,030
Private Placement [Member] | Common Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)											1,911,800	902,162
Stock Issued During Period, Value, New Issues											$ 1,912	$ 902
Private Placement [Member] | Mastiff Group LLC [Member]
Sale of Stock, Commitment Amount									$ 4,975,000				$ 4,975,000		$ 4,975,000	$ 4,975,000		$ 25,000,000
Private Placement [Member] | Mastiff Group LLC [Member] | Subsequent Event [Member]
Proceeds from Issuance of Common Stock	$ 25,000				$ 25,000
Investor [Member]
Stock Issued During Period, Shares, New Issues (in shares)						4,000,000										4,020,588
Proceeds from Issuance of Common Stock						$ 3,400,000										$ 3,400,000
Employees [Member] | Common Stock [Member]
Stock Issued During Period, Shares, Issued for Employee Bonuses (in shares)														94,159
Issuance of Stock to Defined Contribution Plan for Employer Matching Contribution														$ 172,000
Prepaid Expenses and Other Current Assets [Member]
Common Stock, Share Subscribed but Unissued, Subscriptions Receivable								$ 812,000									$ 812,000

Note 13 - Stock Warrants (Detai

Note 13 - Stock Warrants (Details Textual)	Jun. 30, 2021$ / sharesshares
Class of Warrant or Right, Outstanding (in shares) | shares	972,324
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 17.97
Minimum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0.20
Warrants and Rights Outstanding, Term (Month)	8 months
Maximum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 49.80
Warrants and Rights Outstanding, Term (Month)	14 years 1 month 6 days

Note 14 - Income Taxes (Details

Note 14 - Income Taxes (Details Textual) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Unrecognized Tax Benefits, Ending Balance	$ 0	$ 0
Domestic Tax Authority [Member]
Operating Loss Carryforwards, Total	$ 153,300
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Open Tax Year	2017 2018 2019 2020
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	$ 8,900
State and Local Jurisdiction [Member]
Open Tax Year	2017 2018 2019 2020
Operating Loss Carryforwards, Total	$ 20,100

Note 15 - Segments (Details Tex

Note 15 - Segments (Details Textual)		3 Months Ended		6 Months Ended
		Jun. 30, 2021USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2021USD ($)	Jun. 30, 2020USD ($)
Revenues, Total		$ 261,046	$ 271,101	$ 384,783	$ 427,373
Number of Primary Types of Products Sold		2		2
Depreciation, Depletion and Amortization, Nonproduction, Total	[1]	$ 19,858	$ 19,256	$ 37,606	$ 36,099
Intersegment Eliminations [Member]
Revenues, Total				$ 0
[1]	Depreciation and amortization are reflected in selling, general and administrative expenses ($19,858 and $19,256 for the three-month periods ended June 30, 2021 and 2020, and $37,606 and $36,099 for the six-month periods ended June 30, 2021 and 2020, respectively).

Note 15 - Segments - Segment In

Note 15 - Segments - Segment Information (Details) - USD ($)		3 Months Ended					6 Months Ended
		Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020		Mar. 31, 2020	Jun. 30, 2021		Jun. 30, 2020		Dec. 31, 2020
Revenue from contract with customer		$ 13,000		$ 9,000			$ 36,000		$ 24,000
Grant and other revenue		247,983		262,181			349,234		403,232
Revenues, Total		261,046		271,101			384,783		427,373
Research and development expenses		1,498,056		1,281,779			2,720,810		2,281,048
Selling, general and administrative expenses, excluding depreciation and amortization	[1]	1,412,752		1,310,335			3,625,749		3,121,246
Depreciation, Depletion and Amortization, Nonproduction, Total	[2]	19,858		19,256			37,606		36,099
Loss from operations	[3]	(2,669,620)		(2,340,626)			(5,999,382)		(5,011,986)
Other expense (4)	[4]	(4,420)
Net loss		(2,674,040)	$ (2,966,892)	(2,325,619)		$ (2,673,608)	(5,640,932)		(4,999,227)
Total assets, net of depreciation and amortization		11,281,310					11,281,310				$ 7,758,018
Capital expenditures		2,707		1,947			2,707		8,406
Cost of revenue		0		357			0		966
Other income (4)		(4,420)		15,007	[4]		358,450	[4]	12,759	[4]
UNITED STATES
Total assets, net of depreciation and amortization		11,080,979		6,606,683			11,080,979		6,606,683
Non-US [Member]
Total assets, net of depreciation and amortization		200,331					200,331
License [Member]
Revenue from contract with customer		13,063		0			35,549		0
Royalty [Member]
Revenue from contract with customer		0		8,920			0		24,141
Diagnostics Segment [Member]
Grant and other revenue		247,983		215,458			349,234		274,374
Revenues, Total		261,046		224,378			384,783		298,515
Research and development expenses		1,358,123		1,193,151			2,452,513		2,150,777
Selling, general and administrative expenses, excluding depreciation and amortization	[1]	0		0			0		0
Depreciation, Depletion and Amortization, Nonproduction, Total	[2]	6,041		0			12,081		0
Loss from operations	[3]	(1,103,118)		(969,130)			(2,079,811)		(1,853,228)
Other expense (4)	[4]	0
Net loss		(1,103,118)		(969,130)			(2,079,811)		(1,853,228)
Capital expenditures		0		0			0		0
Cost of revenue				357					966
Other income (4)	[4]			0			0		0
Diagnostics Segment [Member] | UNITED STATES
Total assets, net of depreciation and amortization		269,464		107,185			269,464		107,185
Diagnostics Segment [Member] | Non-US [Member]
Total assets, net of depreciation and amortization		199,741					199,741
Diagnostics Segment [Member] | License [Member]
Revenue from contract with customer		13,063					35,549
Diagnostics Segment [Member] | Royalty [Member]
Revenue from contract with customer				8,920					24,141
Therapeutics Segment [Member]
Grant and other revenue		0		46,723			0		128,858
Revenues, Total		0		46,723			0		128,858
Research and development expenses		139,933		88,628			268,297		130,271
Selling, general and administrative expenses, excluding depreciation and amortization	[1]	873		972			2,879		(550)
Depreciation, Depletion and Amortization, Nonproduction, Total	[2]	0		0			0		0
Loss from operations	[3]	(140,806)		(42,877)			(271,176)		(863)
Other expense (4)	[4]	0
Net loss		(140,806)		(42,877)			(271,176)		(863)
Capital expenditures		0		0			0		0
Cost of revenue				0					0
Other income (4)	[4]			0			0		0
Therapeutics Segment [Member] | UNITED STATES
Total assets, net of depreciation and amortization		0		36,483			0		36,483
Therapeutics Segment [Member] | Non-US [Member]
Total assets, net of depreciation and amortization		0					0
Therapeutics Segment [Member] | License [Member]
Revenue from contract with customer		0					0
Therapeutics Segment [Member] | Royalty [Member]
Revenue from contract with customer				0					0
Corporate Segment [Member]
Grant and other revenue		0		0			0		0
Revenues, Total		0		0			0		0
Research and development expenses		0		0			0		0
Selling, general and administrative expenses, excluding depreciation and amortization	[1]	1,411,879		1,309,363			3,622,870		3,121,796
Depreciation, Depletion and Amortization, Nonproduction, Total	[2]	13,817		19,256			25,525		36,099
Loss from operations	[3]	(1,425,696)		(1,328,619)			(3,648,395)		(3,157,895)
Other expense (4)	[4]	(4,420)
Net loss		(1,430,116)		(1,313,612)			(3,289,945)		(3,145,136)
Capital expenditures		2,707		1,947			2,707		8,406
Cost of revenue				0					0
Other income (4)	[4]			15,007			358,450		12,759
Corporate Segment [Member] | UNITED STATES
Total assets, net of depreciation and amortization		10,811,515		6,463,015			10,811,515		6,463,015
Corporate Segment [Member] | Non-US [Member]
Total assets, net of depreciation and amortization		590					590
Corporate Segment [Member] | License [Member]
Revenue from contract with customer		$ 0					$ 0
Corporate Segment [Member] | Royalty [Member]
Revenue from contract with customer				$ 0					$ 0
[1]	General and administrative expenses, excluding depreciation and amortization, represent costs that relate to the general administration of the Company and as such are not currently allocated to our individual reportable segments, other than those expenses directly incurred by Navidea Europe, Navidea UK and MT.
[2]	Depreciation and amortization are reflected in selling, general and administrative expenses ($19,858 and $19,256 for the three-month periods ended June 30, 2021 and 2020, and $37,606 and $36,099 for the six-month periods ended June 30, 2021 and 2020, respectively).
[3]	Loss from operations does not reflect the allocation of certain selling, general and administrative expenses, excluding depreciation and amortization, to our individual reportable segments, other than those expenses directly incurred by Navidea Europe, Navidea UK and MT.
[4]	Amounts consist primarily of interest income and interest expense, which are not currently allocated to our individual reportable segments.

Note 16 - Supplemental Disclo_2

Note 16 - Supplemental Disclosure for Statements of Cash Flows (Details Textual) - USD ($)	1 Months Ended	3 Months Ended			6 Months Ended		12 Months Ended
	Feb. 29, 2020	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Interest Paid, Excluding Capitalized Interest, Operating Activities					$ 4,000	$ 5,000
Proceeds from Issuance of Preferred Stock and Preference Stock					$ 10,475,000	$ 700,000
Stock Issued During Period, Shares, Employee Benefit Plan (in shares)					30,018	32,651
Stock Issued During Period, Value, Employee Benefit Plan		$ 76,846	$ 39,834		$ 77,000	$ 40,000
Issuance of Stock to Defined Contribution Plan for Employer Matching Contribution					76,846	$ 39,834
Conversion from Series C Preferred Stock To Common Stock [Member]
Conversion of Stock, Shares Converted (in shares)						70,000
Conversion of Stock, Shares Issued (in shares)						410,765
Series OO Warrants [Member]
Class of Warrant or Right, Exercised During Period (in shares)						411,000
Issued Stock Upon Exercise of Warrants, Shares (in shares)						300,595
Common Stock [Member]
Stock Issued During Period, Shares, Employee Benefit Plan (in shares)		30,018	32,651
Stock Issued During Period, Value, Employee Benefit Plan		$ 30	$ 33
Stock Issued During Period, Shares, Issued for Employee Bonuses (in shares)			40,844	53,315
Employees [Member] | Common Stock [Member]
Stock Issued During Period, Shares, Issued for Employee Bonuses (in shares)						94,159
Issuance of Stock to Defined Contribution Plan for Employer Matching Contribution						$ 172,000
Office Lease [Member]
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 100,432
Series D Preferred Stock [Member] | Keystone Capital Partners, LLC [Member]
Proceeds from Issuance of Preferred Stock and Preference Stock					$ 2,925,000		$ 2,925,000
Series C Preferred Stock [Member]
Preferred Stock, Deemed Dividend						$ 78,000
Conversion of Stock, Shares Converted (in shares)						70,000

Note 17 - Subsequent Events (De

Note 17 - Subsequent Events (Details Textual) - USD ($)	Jul. 08, 2021	Aug. 31, 2020	Dec. 31, 2019	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Dec. 31, 2020
Stock Issued During Period, Shares, New Issues (in shares)			2,100,000
Stock Issued During Period, Value, New Issues				$ 1,800,000		$ 700,000
Proceeds from Issuance of Preferred Stock and Preference Stock							$ 10,475,000	$ 700,000
Series D Preferred Stock [Member]
Stock Issued During Period, Value, New Issues					$ 250,001
Preferred Stock, Shares Subscribed but Unissued, Subscriptions Receivable				0			0		$ 0	$ 10,300,000
Series D Preferred Stock [Member] | Stock Subscriptions and Other Receivables [Member]
Preferred Stock, Shares Subscribed but Unissued, Subscriptions Receivable				$ 2,200,000			$ 2,200,000		$ 2,200,000
Keystone Capital Partners, LLC [Member] | Series D Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)		150,000							72,500
Stock Issued During Period, Value, New Issues		$ 15,000,000
Stock Purchase Agreement, Shares Remaining (in shares)				77,500			77,500		77,500
Proceeds from Issuance of Preferred Stock and Preference Stock							$ 2,925,000			$ 2,925,000
Subsequent Event [Member] | Keystone Capital Partners, LLC [Member] | Series D Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares)	22,077
Stock Issued During Period, Value, New Issues	$ 2,200,000
Proceeds from Issuance of Preferred Stock and Preference Stock	$ 2,200,000

Uncategorized Items - navb20210

Label	Element	Value
Issued stock upon stock option exercise	us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised	$ 2,120
Issued restricted stock	us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross	13
us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	5,008,882
Stock compensation expense	us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	121,298
Stock compensation expense	us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	142,180
Retained Earnings [Member]
Issued stock	us-gaap_StockIssuedDuringPeriodValueNewIssues	0
Net loss	us-gaap_ProfitLoss	(2,966,890)
Net loss	us-gaap_ProfitLoss	$ (2,764,039)
Common Stock [Member]
Issued stock upon conversion of Preferred Stock (in shares)	us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities	1,437,531
Issued stock upon stock option exercise	us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised	$ 2
Issued stock upon conversion of Series D Preferred Stock	us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities	1,437
Issued restricted stock	us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross	$ 13
Issued stock upon stock option exercise (in shares)	us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised	2,000
Issued restricted stock (in shares)	us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited	12,500
Preferred Stock [Member]
Issued stock	us-gaap_StockIssuedDuringPeriodValueNewIssues	$ 23
Issued stock upon conversion of Preferred Stock (in shares)	us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities	(23,000)
Issued stock (in shares)	us-gaap_StockIssuedDuringPeriodSharesNewIssues	23,000
Issued stock upon conversion of Series D Preferred Stock	us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities	$ (23)
Noncontrolling Interest [Member]
Issued stock	us-gaap_StockIssuedDuringPeriodValueNewIssues	0
Net loss	us-gaap_ProfitLoss	(2)
Net loss	us-gaap_ProfitLoss	(1)
Additional Paid-in Capital [Member]
Issued stock	us-gaap_StockIssuedDuringPeriodValueNewIssues	0
Stock subscribed	navb_StockSubscribedDuringPeriodValue	4,974,005
Issued stock upon stock option exercise	us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised	2,118
Issued stock upon conversion of Series D Preferred Stock	us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities	(1,414)
Stock compensation expense	us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	121,298
Stock compensation expense	us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	142,180
Issued stock to 401(k) Plan	us-gaap_StockIssuedDuringPeriodValueEmployeeBenefitPlan	76,816
Stock issuance cost	us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts	50,671
Common Stock Subscription [Member]
Issued stock	us-gaap_StockIssuedDuringPeriodValueNewIssues	0
Stock subscribed	navb_StockSubscribedDuringPeriodValue	$ 995
Issued stock (in shares)	us-gaap_StockIssuedDuringPeriodSharesNewIssues	0
Stock subscribed (in shares)	navb_StockSubscribedDuringPeriodShares	995,000
Preferred Stock Subscriptions Receivable [Member]
Issued stock	us-gaap_StockIssuedDuringPeriodValueNewIssues	$ 1,800,000
Common Stock Subscriptions Receivable [Member]
Issued stock	us-gaap_StockIssuedDuringPeriodValueNewIssues	0
Stock subscribed	navb_StockSubscribedDuringPeriodValue	(4,975,000)
Preferred Stock Subscription [Member]
Issued stock	us-gaap_StockIssuedDuringPeriodValueNewIssues	$ (23)
Issued stock (in shares)	us-gaap_StockIssuedDuringPeriodSharesNewIssues	(23,000)
Series E Preferred Stock [Member] | Preferred Stock [Member]
Issued stock	us-gaap_StockIssuedDuringPeriodValueNewIssues	$ 50
Issued stock (in shares)	us-gaap_StockIssuedDuringPeriodSharesNewIssues	50,000
Series E Preferred Stock [Member] | Additional Paid-in Capital [Member]
Issued stock	us-gaap_StockIssuedDuringPeriodValueNewIssues	$ 4,980,659
Series D Preferred Stock [Member]
Stock subscribed	navb_StockSubscribedDuringPeriodValue	500,000
Stock subscribed	navb_StockSubscribedDuringPeriodValue	$ (2,207,699)
Series D Preferred Stock [Member] | Common Stock [Member]
Issued stock upon conversion of Preferred Stock (in shares)	us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities	1,513,978
Issued stock upon conversion of Series D Preferred Stock	us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities	$ 1,514
Series D Preferred Stock [Member] | Preferred Stock [Member]
Issued stock	us-gaap_StockIssuedDuringPeriodValueNewIssues	$ 32
Issued stock upon conversion of Preferred Stock (in shares)	us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities	(31,750)
Issued stock (in shares)	us-gaap_StockIssuedDuringPeriodSharesNewIssues	31,750
Issued stock upon conversion of Series D Preferred Stock	us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities	$ (32)
Series D Preferred Stock [Member] | Additional Paid-in Capital [Member]
Stock subscribed	navb_StockSubscribedDuringPeriodValue	5,542,245
Issued stock upon conversion of Series D Preferred Stock	us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities	(1,482)
Series D Preferred Stock [Member] | Preferred Stock Subscriptions Receivable [Member]
Issued stock	us-gaap_StockIssuedDuringPeriodValueNewIssues	250,000
Stock subscribed	navb_StockSubscribedDuringPeriodValue	500,000
Stock subscribed	navb_StockSubscribedDuringPeriodValue	(7,750,000)
Series D Preferred Stock [Member] | Preferred Stock Subscription [Member]
Issued stock	us-gaap_StockIssuedDuringPeriodValueNewIssues	(31)
Stock subscribed	navb_StockSubscribedDuringPeriodValue	$ 56
Issued stock (in shares)	us-gaap_StockIssuedDuringPeriodSharesNewIssues	(31,750)
Stock subscribed (in shares)	navb_StockSubscribedDuringPeriodShares	55,423