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Document And Entity Information - USD ($) $ in Millions	12 Months Ended
Document And Entity Information - USD ($) $ in Millions	Dec. 31, 2019	Mar. 19, 2020	Jun. 28, 2019
Document Information [Line Items]
Entity Registrant Name	ArTara Therapeutics, Inc.
Entity Central Index Key	0001359931
Trading Symbol	tara
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Interactive Data Current	Yes
Entity Common Stock, Shares Outstanding (in shares)		5,843,203
Entity Public Float			$ 5.8
Entity Shell Company	false
Document Type	10-K
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false
Title of 12(b) Security	Common Stock, par value $0.001 per share

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 6,181	$ 19,371
Restricted cash	50
Available-for-sale investments		2,496
Prepaid expenses and other current assets	744	1,369
Total current assets	6,975	23,236
Property and equipment, net		263
Restricted cash		22
Total assets	6,975	23,521
Current liabilities:
Accounts payable	263	441
Accrued expenses	320	2,637
Total current liabilities	583	3,078
Total liabilities	583	3,078
Commitments and contingencies (Note 6)
Common stock, $0.001 par value, 100,000,000 shares authorized at December 31, 2019 and 2018; 557,631 and 481,091 shares issued and outstanding at December 31, 2019 and 2018, respectively
Additional paid-in capital	213,388	209,385
Accumulated deficit	(225,462)	(210,470)
Accumulated other comprehensive income	3	5
Total stockholders’ equity	6,392	20,443
Total liabilities and stockholders’ equity	6,975	23,521
Series A Convertible Preferred Stock [Member]
Current liabilities:
Preferred stock, $0.001 par value per share; 10,000,000 shares authorized at December 31, 2019 and 2018:Series A convertible preferred stock 22,000 shares authorized at December 31, 2019 and December 31, 2018; 18,954 and 22,000 issued and outstanding at December 31, 2019 and at December 31, 2018, respectively	$ 18,463	$ 21,523

Consolidated Balance Sheets (Parentheticals) - $ / shares	Dec. 31, 2019	Dec. 31, 2018	Aug. 02, 2017
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	557,631	481,091
Common stock, shares outstanding (in shares)	557,631	481,091
Series A Convertible Preferred Stock [Member]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	22,000	22,000
Preferred stock, shares issued (in shares)	18,954	22,000
Preferred stock, shares outstanding (in shares)	18,954	22,000

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Operating expenses:
Research and development	$ 6,438	$ 11,848
General and administrative	8,816	9,524
Total operating expenses	15,254	21,372
Loss from operations	(15,254)	(21,372)
Other income:
Investment income	262	436
Other income, net		207
Total other income	262	643
Net loss and net loss attributable to common stockholders	(14,992)	(20,729)
Foreign currency translation adjustment	(2)	(1)
Unrealized gain on available-for-sale investments		20
Comprehensive loss	$ (14,994)	$ (20,710)
Net loss per share attributable to common stockholders - basic and diluted (in dollars per share)	$ (30.15)	$ (45.80)
Weighted-average common shares outstanding used in net loss per share attributable to common stockholders - basic and diluted (in shares)	497,275	452,555

Statements of Stockholders' Equity - USD ($) $ in Thousands	Preferred Stock [Member] Series A Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balance (in shares) at Dec. 31, 2017	22,000	441,868
Balance at Dec. 31, 2017	$ 21,523		$ 202,972	$ (189,741)	$ (14)	$ 34,740
Issuance of common stock upon ESPP purchase (in shares)		1,859
Issuance of common stock upon ESPP purchase			132			132
Issuance of common stock, net of issuance costs (in shares)		37,364
Issuance of common stock, net of issuance costs			2,852			2,852
Stock-based compensation expense			3,429			3,429
Other comprehensive gain/(loss)					19	19
Net loss				(20,729)		(20,729)
Balance (in shares) at Dec. 31, 2018	22,000	481,091
Balance at Dec. 31, 2018	$ 21,523		209,385	(210,470)	5	20,443
Stock-based compensation expense			943			943
Other comprehensive gain/(loss)					(2)	(2)
Net loss				(14,992)		(14,992)
Conversion of Series A convertible preferred stock into Common Stock (in shares)	(3,046)
Conversion of Series A convertible preferred stock into Common Stock	$ (3,060)
Conversion of Series A convertible preferred stock into Common Stock (in shares)		76,540
Conversion of Series A convertible preferred stock into Common Stock			3,060
Balance (in shares) at Dec. 31, 2019	18,954	557,631
Balance at Dec. 31, 2019	$ 18,463		$ 213,388	$ (225,462)	$ 3	$ 6,392

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Operating activities
Net loss	$ (14,992)	$ (20,729)
Reconciliation of net loss to net cash used in operating activities:
Depreciation	279	115
Amortization of premium/discount on available-for-sale securities	(4)	(51)
Foreign currency remeasurement (loss)		(25)
Stock-based compensation	943	3,429
Changes in:
Prepaid expenses and other assets	608	141
Operating lease right-of-use asset	200
Interest receivable	17	49
Accounts payable and accrued expenses	(2,497)	(6,162)
Operating lease liability	(200)
Net cash used in operating activities	(15,646)	(23,233)
Investing activities
Purchases of available-for-sale investments		(15,443)
Proceeds from maturities of available-for-sale investments	2,500	31,990
Proceeds from sale of available-for-sale investments		1,999
Purchase of property and equipment	(16)	(119)
Net cash provided by (used in) investing activities	2,484	18,427
Financing activities
Proceeds from issuance of common stock, net of issuance costs		2,853
Proceeds from issuance of common stock under ESPP		132
Net cash provided by financing activities		2,985
Effect of exchange rate changes on cash		22
Decrease in cash, cash equivalents and restricted cash	(13,162)	(1,799)
Cash, cash equivalents and restricted cash, beginning of period	19,393	21,192
Cash, cash equivalents and restricted cash, end of period	$ 6,231	$ 19,393

Note 1 - Organization and Operations

12 Months Ended

Dec. 31, 2019

Notes to Financial Statements

Nature of Operations [Text Block]

Organization and Operations

The Company

ArTara Therapeutics, Inc (formerly Proteon Therapeutics, Inc., the “Company”) is a biopharmaceutical company that has historically focused on the development of novel,

first

-in-class pharmaceuticals to address the medical needs of patients with kidney and vascular disease. The Company was formed in

June 2001

and incorporated on

March 24, 2006.

March 28, 2019,

the Company announced that its

second

Phase

trial, PATENCY-

for vonapanitase did

not

meet its co-primary endpoints of fistula use for hemodialysis (

p=0.328

) and secondary patency (

p=0.932

). The PATENCY-

clinical trial was the

second

two

randomized, double-blind Phase

trials, comparing a

microgram dose of investigational vonapanitase to placebo in patients with chronic kidney disease, or CKD, undergoing creation of a radiocephalic fistula for hemodialysis. Following the release of top-line data from the PATENCY-

clinical trial of vonapanitase on

March 28, 2019,

the Company began to evaluate its strategic alternatives focusing on enhancing stockholder value. On

September 23, 2019,

the Company entered into a merger agreement with ArTara Subsidiary, Inc. (formerly ArTara Therapeutics, Inc. “Private ArTara”). As of

December 31, 2019,

the Company had discontinued substantially all its research and development activities, including a reduction in workforce. As of

December 31, 2019,

the Company had terminated all of its legacy Proteon Therapeutics, Inc. employees. The Company has recorded severance costs of

$2.9

million for the year ended

December 31, 2019.

The Company remains subject to a number of risks similar to other companies in the biotechnology industry, including compliance with government regulations, protection of proprietary technology, dependence on

third

parties and product liability.

Reverse Merger with Private ArTara

January 9, 2020,

the Company and Private ArTara completed the merger and reorganization (the “Merger”) in accordance with the terms of the Agreement and Plan of Merger and Reorganization, dated

September 23, 2019 (

the “Merger Agreement”), by and among the Company, Private ArTara and REM

Acquisition, Inc., a wholly owned subsidiary of the Company (the “Merger Sub”), whereby Merger Sub merged with and into Private ArTara, with Private ArTara surviving as a wholly owned subsidiary of the Company.

January 9, 2020,

in connection with, and prior to the completion of, the Merger, the Company effected a

-for-

reverse stock split of its common stock, (the “Reverse Stock Split”), Private ArTara changed its name from “ArTara Therapeutics, Inc.” to “ArTara Subsidiary, Inc.”, and the Company changed its name from “Proteon Therapeutics, Inc.” to “ArTara Therapeutics, Inc.” All share and per share amounts presented in these financial statements have been adjusted to reflect the Reverse Stock Split. In addition, immediately following the closing of the Private Placements (defined below), all of the outstanding shares of the Company’s Series A Preferred Stock were converted into shares of the Company’s common stock. Shares of the Company’s common stock commenced trading on The Nasdaq Capital Market under the new name and ticker symbol “TARA” as of market open on

January 10, 2020.

Under the terms of the Merger Agreement, the Company issued shares of its common stock (“Common Stock”) to Private ArTara’s stockholders, at an exchange ratio of

0.190756

shares of Common Stock, after taking into account the Reverse Stock Split, for each share of Private ArTara common stock outstanding immediately prior to the Merger. Proteon assumed all of the outstanding and unexercised stock options of Private ArTara, with such stock options now representing the right to purchase a number of shares of Common Stock equal to

0.190756

multiplied by the number of shares of Private ArTara common stock previously represented by such Private ArTara stock options. The Company also assumed all of the unvested Private ArTara restricted stock awards, which were exchanged for a number of shares of Common Stock equal to

0.190756

multiplied by the number of shares of Private ArTara common stock previously represented by such Private ArTara restricted stock awards and unvested to the same extent as such Private ArTara restricted stock awards and subject to the same restrictions as such Private ArTara restricted stock awards.

January 9, 2020,

the Company completed certain private placements pursuant to a subscription agreement entered into on

September 23, 2019.

September 23, 2019,

the Company and Private ArTara entered into a subscription agreement (as amended on

November 19, 2019,

the "Subscription Agreement") with certain institutional investors (the "Investors") pursuant to which, among other things, (i) the Company agreed to issue to certain Investors shares of Proteon Series

Convertible Non-Voting Preferred Stock and/or Proteon common stock immediately following the Merger in a private placement transaction for an aggregate purchase price of approximately

$40.5

million (the "Proteon Private Placement") and (ii) Private ArTara agreed to issue to an Investor (that is an existing investor in ArTara) shares of ArTara common stock (the "ArTara Private Placement Shares") immediately prior to the Merger in a private placement transaction for an aggregate purchase price of approximately

$2.0

million (together with the Proteon Private Placement, the "Private Placements"). Immediately after the Proteon Private Placement, the Company converted all outstanding shares of Proteon's Series A Convertible Preferred Stock into shares of Proteon common stock (the "Series A Preferred Automatic Conversion"). On

January 9, 2020,

the Company received approximately

$39.6

million, net of offering costs related to the Private Placements.

The Merger was structured as a reverse merger and Private ArTara was determined to be the accounting acquirer based on the terms of the Merger Agreement. The Merger will be accounted for as a business combination as of the effective date of the Merger.

The financial information included in the financial statements is that of the Company prior to the Merger because the Merger was consummated after the period covered by these financial statements.

Liquidity

As of

December 31, 2019,

the Company had cash and cash equivalents of

$6.2

million. The Company had an accumulated deficit of

$225.5

million as of

December 31, 2019.

In connection with the Merger, the Company consummated the Private Placements, raising gross proceeds of

$42.5

million. The Company expects there will be

further material near term cash expenditures to fund the Company’s vonapanitase clinical trials. From the date of the Merger, the activities of the Company will become those of Private ArTara.

The Company is in the business of developing biopharmaceuticals, has

current or near term revenues. The Company is incurring substantial clinical and other costs in its drug development efforts. The Company expects it will need to raise additional capital in order to fully realize management’s plans.

The Company believes that its current financial resources, as of the date of the issuance of these consolidated financial statements, are sufficient to fund its current

twelve

month operating budget, alleviating any substantial doubt raised by our historical operating results and satisfying our estimated liquidity needs for at least

twelve

months from the issuance of these consolidated financial statements.

The accompanying financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the ordinary course of business. The financial statements do

not

include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of the uncertainties described above.

At-The-Market Equity Offering Program

November 12, 2015,

the Company filed a shelf registration statement on Form S-

(the “Registration Statement”), and entered into a Sales Agreement with Cowen and Company, LLC (the “Sales Agreement”) to establish an at-the-market (“ATM”) equity offering program pursuant to which they are able, with the Company’s authorization, to offer and sell up to

$40

million of the Company’s Common Stock at prevailing market prices from time to time. The Registration Statement became effective on

January 12, 2016.

The Company paid Cowen a commission equal to

of the gross proceeds of the sales price of all shares sold through it as sales agent under the Sales Agreement. The offering costs were offset against proceeds from the sale of common stock under this agreement. The Company filed a prospectus supplement on

March 16, 2017

because the Company is currently subject to General Instruction

I.B.6

of Form S-

which limits the amounts that the Company

may

sell under the Registration Statement. The Company’s ATM program was terminated effective as of

February 7, 2019,

when its new shelf registration statement on Form S-

File

No.

333

228865,

was declared effective by the SEC. For the year ended

December 31, 2018,

the Company sold

1,494,579

shares of Common Stock under the Sales Agreement for aggregate gross proceeds of

$3.0

million. For the year ended

December 31, 2018,

total offering costs of

$46,000,

were offset against the proceeds from the sale of common stock. The

1,494,579

shares of Common Stock sold under the ATM program during the year ended

December 31, 2018

were all sold on

September 25, 2018

to New Leaf Venture Partners LLC.

Note 2 - Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2019

Notes to Financial Statements

Significant Accounting Policies [Text Block]

Summary of Significant Accounting Policies

Basis of Presentation, Principles of Consolidation and Use of Estimates

The accompanying consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. These consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”).

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. On an ongoing basis, the Company’s management evaluates its estimates, which include, but are

not

limited to, estimates related to stock-based compensation expense, clinical trial accruals and reported amounts of expenses during the reported period. The Company bases its estimates on historical experience and other market-specific or other relevant assumptions that it believes to be reasonable under the circumstances. Actual results

may

differ from those estimates or assumptions.

Segment Information

Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company and the Company's chief operating decision maker view the Company's operations and manage its business in

one

operating segment, which is the business of developing and commercializing vonapanitase for the treatment of renal and vascular disease. Currently, the Company operates in only

one

geographic segment.

Fair Value of Financial Instruments

The Company’s financial instruments consist of cash and cash equivalents, available-for-sale investments, forward foreign currency contracts (see Note

), accounts payable, and accrued liabilities. The Company is required to disclose information on all assets and liabilities reported at fair value that enables an assessment of the inputs used in determining the reported fair values. FASB ASC Topic

820,

Fair Value Measurement and Disclosures

, established a hierarchy of inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the observable inputs be used when available. Observable inputs are inputs that market participants would use in pricing the financial instrument based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the financial instrument and are developed based on the best information available under the circumstances. The fair value hierarchy applies only to the valuation inputs used in determining the reported or disclosed fair value of the financial instruments and is

not

a measure of the investment credit quality. Fair value measurements are classified and disclosed in

one

of the following

three

categories:

Level

1—Valuations

based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date.

Level

2—Valuations

based on quoted prices for similar assets or liabilities in markets that are

not

active or for which all significant inputs are observable, either directly or indirectly.

Level

3—Valuations

that require inputs that reflect the Company’s own assumptions that are both significant to the fair value measurement and unobservable.

To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level

A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement.

Financial instruments measured at fair value on a recurring basis include cash equivalents and available-for-sale investments (see Note

). There have been

changes to the valuation methods utilized by the Company during the years ended

December 31, 2019

and

2018.

The Company evaluates transfers between levels at the end of each reporting period. There were

transfers of financial instruments between levels during the years ended

December 31, 2019

and

2018.

Recent Accounting Pronouncements

May 2014,

the FASB issued ASU

2014

09,

Revenue from Contracts with Customers

(“ASU

2014

09”

), a new standard on revenue recognition providing a single, comprehensive revenue recognition model for all contracts with customers. The new revenue standard is based on the principle that revenue should be recognized to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The new standard was effective beginning

January 1, 2018,

with early adoption permitted. The Company adopted ASU

2014

during the quarter ended

March 31, 2018.

The adoption did

not

have a material impact on the consolidated financial statements.

February 2016,

the FASB issued ASU

2016

02,

Leases (Topic

842

): Amendments to FASB Codification (“ASU

2016

02”

), which increases transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. At the lease commencement date, the lessee must recognize a lease liability and right-of-use asset, which is initially measured at the present value of future lease payments. The Company adopted ASU

2016

January 1, 2019

using the optional transition method that allows for a cumulative-effect adjustment in the period of adoption and will

not

restate prior periods. It has have also elected to adopt the package of practical expedients permitted in Accounting Standards Codification Topic

842,

or ASC

842.

Accordingly, it is continuing to account for its existing operating lease as an operating lease under the new guidance, without reassessing whether the contract contains a lease under ASC

842

or whether classification of the operating leases would be different under ASC Topic

842,

and to treat lease and non-lease components as a single lease component. The Company has also elected the short-term lease accounting policy under which the Company would

not

recognize a lease liability or ROU asset for any lease that at the commencement date has a lease term of

twelve

months or less and does

not

include a purchase option that the Company is more than reasonably certain to exercise. Also, the Company elected the expedient allowing an entity to use hindsight to determine the lease term and impairment of ROU assets and the expedient to allow the Company to

not

have to separate lease and non-lease components. The Company’s sole lease at the adoption date was an operating lease for facilities and did

not

include any non-lease components.

As a result of the adoption of ASU

2016

02,

January 1, 2019,

the Company recognized (a) a lease liability of approximately

$0.2

million, which represents the present value of its remaining lease payments using an estimated incremental borrowing rate of

8%,

(b) a right-of-use asset of approximately

$0.2

million that was expensed as operating lease expense over the term of the lease which ended on

September 30, 2019.

Due to the adoption of the standard using the modified retrospective cumulative-effect adjustment method, there are

changes to previously reported results prior to

January 1, 2019.

Lease expense did

not

change materially as a result of the adoption of ASU

2016

02.

June 2018,

the FASB issued ASU

No.

2018

07,

Compensation - Stock Compensation (Topic

718

): Improvements to Nonemployee Share-Based Payment Accounting (“ASU

2018

07”

). ASU

2018

aims to simplify the accounting for share-based payments to nonemployees by aligning it to the accounting for share based payments to employees including determining the fair value of the award on the date of grant and recognizing the stock-based compensation expense as of the respective vesting date. The new standard also requires companies to elect to either measure the awards to nonemployees over an estimated expected term or contractual term as well as elect to estimate forfeitures or account for forfeitures as incurred. ASU

2018

is effective for fiscal years and interim periods within those fiscal years beginning after

December 15, 2018.

The guidance was effective for the Company on

January 1, 2019.

The Company adopted ASU

2018

during the quarter ended

March 31, 2019.

The adoption did

not

have an impact on the consolidated financial statements as all outstanding non-employee share-based awards had vested prior to

March 31, 2018.

Cash and Cash Equivalents

The Company considers all highly liquid investments with maturities of

days or less from the purchase date to be cash equivalents. Cash and cash equivalents are held in depository and money market accounts and are reported at fair value.

Short-Term Investments

The Company classifies its investments as available-for-sale and records such assets at estimated fair value in the consolidated balance sheets, with unrealized gains and losses, if any, reported as a component of other comprehensive income (loss) within the consolidated statements of operations and comprehensive loss and as a separate component of stockholders' equity (deficit). The Company invests its excess cash balances primarily in government debt securities and money market funds with strong credit ratings and maturities of less than

one

year. There have been

realized gains and losses for the years ended

December 31, 2019

and

2018.

At each balance sheet date, the Company assesses available-for-sale securities in an unrealized loss position to determine whether the unrealized loss is other-than-temporary. The Company considers factors including: the significance of the decline in value compared to the cost basis, underlying factors contributing to a decline in the prices of securities in a single asset class, the length of time the market value of the security has been less than its cost basis, the security's relative performance versus its peers, sector or asset class, expected market volatility and the market and economy in general. When the Company determines that a decline in the fair value below its cost basis is other-than-temporary, the Company recognizes an impairment loss in the year in which the other-than-temporary decline occurred. There have been

other-than-temporary declines in value of short-term investments for the years ended

December 31, 2019

and

2018,

as it is more likely than

not

the Company will hold the securities until maturity or a recovery of the cost basis.

Concentrations of Credit Risk and Off-Balance Sheet Risk

Financial instruments that potentially subject the Company to concentrations of credit risk are primarily cash, cash equivalents and short-term investments. The Company's cash and cash equivalents are held in accounts with financial institutions that management believes are creditworthy. The Company's investment policy includes guidelines on the quality of the institutions and financial instruments and defines allowable investments that the Company believes minimizes the exposure to concentration of credit risk. These amounts at times

may

exceed federally insured limits. The Company has

not

experienced any credit losses in such accounts and does

not

believe it is exposed to any significant credit risk on these funds. The Company has

financial instruments with off-balance sheet risk of loss.

Property and Equipment

Property and equipment is stated at cost, less accumulated depreciation. Maintenance and repairs that do

not

improve or extend the lives of the respective assets are expensed to operations as incurred. When capitalizing assets for research and development purposes the Company evaluates whether an alternative future use of the asset exists; if

not,

such assets are expensed as research and development. Upon disposal, the related cost and accumulated depreciation is removed from the accounts and any resulting gain or loss is included in the results of operations. Depreciation is recorded using the straight-line method over the estimated useful lives of the respective assets, which are as follows:

Asset	Estimated Useful Life (in years)
Computer equipment and software		3
Furniture, fixtures and other		5
Laboratory equipment		7

Research and Development Costs

Research and development costs are charged to expense as incurred in performing research and development activities. The costs include employee compensation costs, facilities and overhead, clinical study and related clinical manufacturing costs, regulatory and other related costs. Nonrefundable advanced payments for goods or services to be received in the future for use in research and development activities are deferred and capitalized. The capitalized amounts are expensed as the related goods are delivered or the services are performed.

Stock-Based Compensation Expense

The Company accounts for its stock-based compensation awards to employees and directors in accordance with FASB ASC Topic

718,

Compensation-Stock Compensation

(“ASC

718”

). ASC

718

requires all stock-based payments to employees, including grants of employee stock options and restricted stock, to be recognized in the consolidated statements of operations and comprehensive loss based on their grant date fair values. Compensation expense related to awards to employees is recognized on a straight-line basis based on the grant date fair value over the associated service period of the award, which is generally the vesting term. Share-based payments issued to non-employees are recorded at their fair values and are periodically revalued as the equity instruments vest and are recognized as expense over the related service period in accordance with the provisions of ASC

718

and are expensed using an accelerated attribution model.

The Company estimates the fair value of its stock options using the Black-Scholes option pricing model, which requires the input of subjective assumptions, including (a) the expected stock price volatility, (b) the expected term of the award, (c) the risk-free interest rate, (d) expected dividends and (e) the estimated fair value of its Common Stock on the measurement date. Due to the lack of company specific historical and implied volatility data of its Common Stock, the Company has based its estimate of expected volatility on the historical volatility of a group of similar companies that are publicly traded. When selecting these public companies on which it has based its expected stock price volatility, the Company selected companies with comparable characteristics to it, including enterprise value, risk profiles, position within the industry and with historical share price information sufficient to meet the expected term of the stock based awards. The Company computes historical volatility data using the daily closing prices for the selected companies' shares during the equivalent period of the calculated expected term of the stock-based awards. During

2018

the Company began to estimate volatility by using a blend of our stock price history, for the length of time we have market data for our stock and the historical volatility of similar public companies for the expected term of each grant. The Company accounts for forfeitures as they occur. Due to the lack of Company specific historical option activity, the Company has estimated the expected term of its employee stock options using the “simplified” method, whereby, the expected term equals the arithmetic average of the vesting term and the original contractual term of the option. The expected term for non-employee awards is the remaining contractual term of the option. The risk-free interest rates are based on the U.S. Treasury securities with a maturity date commensurate with the expected term of the associated award. The Company has never paid and does

not

expect to pay dividends in the foreseeable future. Refer to Note

“

Use of Estimates

,” for a discussion of the Company's estimated fair value of its Common Stock.

Income Taxes

Income taxes are recorded in accordance with FASB ASC Topic

740,

“Income Taxes” (“ASC

740”

), which provides for deferred taxes using an asset and liability approach. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial reporting and tax reporting basis of assets and liabilities and are measured using enacted tax rates and laws that are expected to be in effect when the differences are expected to reverse. Valuation allowances are provided if based upon the weight of available evidence, it is more likely than

not

that some or all of the deferred tax assets will

not

be realized. The Company has evaluated all available evidence and concluded that it is

not

more likely than

not

that the Company will realize the benefit of its deferred tax assets, therefore, a valuation allowance has been established for the full amount of the deferred tax assets.

The Company accounts for uncertain tax positions in accordance with the provisions of ASC

740.

When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit will more likely than

not

be realized. The determination as to whether the tax benefit will more likely than

not

be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. As of

December 31, 2019

and

2018,

the Company did

not

have any significant uncertain tax positions. The Company's practice is to recognize interest and/or penalties related to income tax matters in income tax expense. See Note

for further details.

Net Income (Loss) per Share Attributable to Common Stockholders

Basic net income (loss) per share is calculated by dividing net income (loss) attributable to common stockholders by the weighted-average number of common shares outstanding during the period. Diluted net income per share is calculated by dividing the net income attributable to common stockholders by the weighted-average number of common equivalent shares outstanding for the period, including any dilutive effect from outstanding stock options and warrants using the treasury stock method.

The Company follows the

two

-class method when computing net income (loss) per share in periods when issued shares that meet the definition of participating securities are outstanding. The

two

-class method determines net income (loss) per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The

two

-class method requires income available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to receive dividends as if all income for the period had been distributed. Accordingly, in periods in which the Company reports a net loss attributable to common stockholders when participating securities are outstanding, losses are

not

allocated to the participating securities. For purposes of calculating diluted net income per share attributable to common shareholders, preferred stock, stock options, warrants and convertible debt are considered common stock equivalents.

Comprehensive Loss

Comprehensive loss consists of net income or loss and changes in equity during a period from transactions and other events and circumstances generated from non-owner sources. The Company's net loss equals comprehensive loss, net of any changes in the unrealized gains and losses of the Company's short-term investments, held as available-for-sale, and foreign currency translation for all periods presented.

Subsequent Events

The Company evaluated subsequent events and transactions that occurred after the balance sheet date up to

March 19, 2020,

the date that the financial statements were available to be issued. Other than as described in Notes

and

13,

the Company did

not

identify any subsequent events that would have required adjustment or disclosure in the financial statements.

Note 3 - Fair Value Measurements

12 Months Ended

Dec. 31, 2019

Notes to Financial Statements

Fair Value Disclosures [Text Block]

Fair Value Measurements

Below is a summary of assets and liabilities measured at fair value (in thousands):

	As of December 31, 2019
	Quoted Prices		Significant		Significant
	in Active		Observable		Unobservable
	Markets		Inputs		Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets
Cash equivalents	$	5,841	$	-	$	-	$	5,841
Total	$	5,841	$	-	$	-	$	5,841

	As of December 31, 2018
	Quoted Prices		Significant		Significant
	in Active		Observable		Unobservable
	Markets		Inputs		Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets
Cash equivalents	$	18,353	$	-	$	-	$	18,353
Government securities		2,496		-		-		2,496
Total	$	20,849	$	-	$	-	$	20,849

As of

December 31, 2019,

and

2018,

the Company’s cash equivalents consist principally of money market funds and government debt securities with original maturities of

days or less. Government securities consist principally of government debt securities and money market funds which are classified as available-for-sale.

Available-for-sale securities at

December 31, 2019

and

2018

consist of the following (in thousands):

	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
December 31, 2019
Government securities
(Due within 1 year)	$	-	$	-	$	-	$	-
	$	-	$	-	$	-	$	-

December 31, 2018
Government securities
(Due within 1 year)	$	2,496	$	-	$	-	$	2,496
	$	2,496	$	-	$	-	$	2,496

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Note 4 - Property and Equipment, Net

12 Months Ended

Dec. 31, 2019

Notes to Financial Statements

Property, Plant and Equipment Disclosure [Text Block]

Property and Equipment, net

Property and equipment, net consists of the following (in thousands):

	As of December 31,
	2019		2018

Computer equipment and software	$	-	$	211
Furniture, fixtures, and other		-		365
Laboratory equipment		-		514
		-		1,090
Accumulated depreciation		-		(827	)
Property and equipment, net	$	-	$	263

Depreciation expense for the years ended

December 31, 2019

and

2018

was

$0.3

million and

$0.1

million, respectively.

During the

three

months ended

March 31, 2019,

the Company voluntarily discontinued substantially all research and development activities. As a result, as of

March 31, 2019

the Company performed an impairment assessment of the laboratory equipment used in development of vonapanitase by comparing the equipment’s carrying value to its estimated fair value, which was determined based on the recoverability of the assets remaining value as of

March 31, 2019.

As of

September 30, 2019,

the Company performed an additional impairment assessment due to the expiration of its lease agreement. The fair value of the remaining assets including office furniture, computer hardware and software licenses were determined be impaired as the Company determined there to be

future use for the assets. The Company recorded impairment charges of

$0.2

million and fully wrote off all property and equipment during the year ended

December 31, 2019.

Note 5 - Accrued Expenses

12 Months Ended

Dec. 31, 2019

Notes to Financial Statements

Accounts Payable and Accrued Liabilities Disclosure [Text Block]

Accrued Expenses

Accrued expenses consist of the following (in thousands):

	As of December 31,
	2019		2018

Payroll and employee-related costs	$	4	$	1,390
Contracted service costs		9		968
Professional fees and other		307		279
Total	$	320	$	2,637

Note 6 - Commitments and Contingencies

12 Months Ended

Dec. 31, 2019

Notes to Financial Statements

Commitments and Contingencies Disclosure [Text Block]

Commitments and Contingencies

Significant Contracts and Agreements

February 2002,

the Company entered into an agreement to license certain intellectual property with Johns Hopkins University. The agreement calls for payments to be made by the Company upon the commencement of product sales, in the form of a royalty of

2.5%

on net sales of the product. As of

December 31, 2019

the Company has

not

commenced product sales and therefore has recognized

royalties on product sales.

Operating Leases

The Company’s operating leases for facilities and office equipment all expired or were terminated during the year ended

December 31, 2019.

During the years ended

December 31, 2019

and

2018

the company recognized operating lease expense of

$0.2

million and

$0.3

million, respectively including property taxes and routine maintenance expense, which approximated its cash payments for the period.

Restricted cash related to certificate of deposit

November 2019

the Company took out a certificate of deposit in the amount of

$50,000

related to a letter of credit that the Company posted with World Customs Brokers so that they could import materials from Lonza an international vendor into the US and cover future import fees that might be due. At

December 31, 2019

and

2018

the Company had

$50,000

and

zero

which is included in current assets.

Restricted cash related to facilities leases

December 31, 2019

and

2018,

the Company had

zero

and

$22,000,

respectively, in an outstanding letter of credit to be used as collateral for leased premises which is in non-current assets. At

December 31, 2018

and

2017,

the Company pledged an aggregate of

$22,000

to the bank as collateral for the letter of credit, which is included in other non-current assets.

Litigation

From time to time, ArTara

may

be subject to various legal proceedings and claims that arise in the ordinary course of its business activities.

Between

November 15

and

December 23, 2019,

four

lawsuits were filed in federal court against Proteon, ArTara, Merger Sub and the individual members of the Proteon Board (captioned

Patrick Plumley v. Proteon Therapeutics, Inc., et al.

, Case

No.

1:19

-cv-

02143

-UNA (D. Del. filed

11/15/19

));

Jeffrey Teow v. Proteon Therapeutics, Inc., et al.

, Case

No.

1:19

-cv-

06745

(E.D.N.Y., filed

11/30/19

);

Neil Lanteigne v. Proteon Therapeutics, et al.

, Case

No.

1:19

-cv-

12436

(D. Mass., filed

12/03/19

);

Stephen Wagner v. Proteon Therapeutics, Inc., et al.

, Case

No.

1:19

-cv-

02343

(D. Del., filed

12/23/19

). The

Plumley

complaint is brought as a purported class action lawsuit. All

four

lawsuits alleged that the definitive proxy statement in the preliminary registration statement on Form S-

filed by Proteon on

November 7, 2019

with the SEC in connection with the proposed Merger (the “Proxy Statement”) omitted material information with respect to the transactions contemplated by the Merger Agreement, rendering it false and misleading in violation of Sections

(a) (and Rule

14a

promulgated thereunder) and

(a) of the Exchange Act. The plaintiffs in each of the

four

lawsuits sought, among other things, injunctive relief, rescission, declaratory relief and unspecified monetary damages. On

December 31, 2019,

Proteon filed an amendment to the Proxy Statement on Form

-K, which contained certain supplemental disclosures intended to moot the plaintiffs’ disclosure claims. On

January 9, 2019,

Proteon held a special meeting of its stockholders, at which the Company’s stockholders approved the Merger. On

January 27, 2020,

plaintiff in the

Lanteigne

action voluntarily dismissed his case. On

February 3, 2020,

plaintiff in the

Plumley

action voluntarily dismissed his case. On

February 7, 2020,

plaintiff in the

Teow

action voluntarily dismissed his case. On

February 10, 2020,

plaintiff in the

Wagner

action dismissed his case.

The Company believes that it is probable that it will incur a loss related to these matters. However, the Company is unable to reasonably estimate the loss, and as such the Company has

not

recorded a loss contingency.

Note 7 - Series A Preferred Financing

12 Months Ended

Dec. 31, 2019

Notes to Financial Statements

Preferred Stock [Text Block]

Series A Preferred Financing

August 2, 2017,

the Company issued and sold

22,000

shares of the Company’s Series A Convertible Preferred Stock, par value of

$0.001

per share (the “Series A Preferred”), for a purchase price of

$1,000

per share, or aggregate purchase price and gross proceeds of

$22.0

million, all upon the terms and conditions set forth in the Securities Purchase Agreement dated as of

June 22, 2017.

The Company incurred

$0.5

million of issuance costs in connection with the transaction. Each share of Series A Preferred is convertible into approximately

shares of the Company’s Common Stock at a conversion price of

$39.80

per share, in each case subject to adjustment for any stock splits, stock dividends and similar events, provided that any conversion of Series A Preferred by a holder into shares of Common Stock is prohibited if, as a result of such conversion, the holder, together with its affiliates and any other person or entity whose beneficial ownership of the Company’s Common Stock would be aggregated with such holder’s for purposes of Section

(d) of the Exchange Act would beneficially own more than

9.985%

of the total number of shares of Common Stock issued and outstanding after giving effect to such conversion. At

December 31, 2019

and

2018,

the Company had

22,000

shares of Series A Convertible Preferred Stock authorized.

The Company evaluated the Series A Preferred for liability or equity classification in accordance with the provisions of ASC

480,

Distinguishing Liabilities from Equity, and determined that equity treatment was appropriate because the Series A Preferred did

not

meet the definition of the liability instruments defined thereunder for convertible instruments. Specifically, the Series A Preferred are

not

mandatorily redeemable and do

not

embody an obligation to buy back the shares outside of the Company’s control in a manner that could require the transfer of assets. Additionally, the Company determined that the Series A Preferred would be recorded as permanent equity,

not

temporary equity, based on the guidance of ASC

480

given that there is

scenario where the holders of equally and more subordinated equity of the entity would

not

be entitled to also receive the same form of consideration upon the occurrence of the event that gives rise to the redemption. During the year ended

December 31, 2019,

3,046

shares of the Series A convertible preferred stock were converted into

76,540

shares of Common Stock. The Company had issued and outstanding

18,954

and

22,000

share of Series A Convertible Preferred Stock with a par value of

$0.001

December 31, 2019

and

2018,

respectively. On

January 9, 2020,

18,954

shares of Series A Convertible Preferred Stock were converted into

476,276

shares of Common Stock.

Dividends

Holders of the Series A Preferred Stock are entitled to receive dividends, if and when declared by the Board of Directors.

Liquidation Preference

Holders of the Series A Preferred Stock have preference in the event of a liquidation or dissolution of the Company equal to

$0.001

per share, plus any declared dividends.

Thereafter, the Holders of the shares of Series A Preferred Stock shall share ratably in any distributions and payments of any remaining assets of the Company, on an as converted basis, with the holders of Common Stock.

Voting Rights

Except for matters with specific voting rights as provided in the Series A Preferred Stock Purchase Agreement, the Holders of shares of Series A Preferred Stock have

voting rights.

Note 8 - Common Stock

12 Months Ended

Dec. 31, 2019

Notes to Financial Statements

Common Stock [Text Block]

Common Stock

General

December 31, 2019,

the Company has

100,000,000

shares of Common Stock authorized for issuance,

$0.001

par value per share, of which

557,631

shares were issued and outstanding.

Reserved for Future Issuance

The Company has the following shares of Common Stock reserved for future issuance:

	As of December 31,
	2019		2018

Conversion of Series A Preferred Stock		476,279		552,819
Stock-based compensation awards		185,729		129,099
Employee Stock Purchase Plan		2,953		2,953
Total		664,961		684,871

Note 9 - Stock-based Compensation

12 Months Ended

Dec. 31, 2019

Notes to Financial Statements

Share-based Payment Arrangement [Text Block]

Stock-based Compensation

August 21, 2014,

the Company’s Board of Directors superseded the

2006

Equity Incentive Plan (the

“2006

Plan”) with the

2014

Equity Incentive Plan (the

“2014

Plan”), and the

2014

Employee Stock Purchase Plan (the

“2014

ESPP”). On

October 3, 2014,

the stockholders approved these plans.

June 20, 2017,

the Company’s Board of Directors amended the

2014

Plan (the “Amended

2014

Plan”). On

July 31, 2017,

the stockholders approved this amendment.

The Plans provide for the grant of incentive and non-statutory stock options, stock appreciation rights, restricted stock and stock unit awards, performance units, stock grants and qualified performance-based awards. Under the

2006

Plan,

new stock compensation awards will be granted subsequent to the completion of the Company’s IPO. The Company initially reserved

17,600

shares of Common Stock for issuance under the

2014

Plan. The

2014

Plan provides that the number of shares reserved and available for issuance under the

2014

Plan will automatically increase each

January 1,

beginning

January 1, 2015

four

percent of the outstanding shares of Common Stock on the immediately preceding

December 31

or such lesser number of shares as determined by the Company’s Board of Directors prior to each such

January

1st.

The Amended

2014

Plan clarifies that the number of shares for purposes of calculating the evergreen feature includes the number of shares of Common Stock issuable upon conversion of any security that the Company

may

issue that is convertible into or exchangeable for Common Stock, including, but

not

limited to, preferred stock or warrants. Pursuant to the evergreen provision, the number of shares available for issuance under the Amended

2014

Plan will increase by

900,003

shares from

129,088

shares to

1,074,384

shares on

January 1, 2020.

Terms of the stock awards, including vesting requirements, are determined by the Board of Directors, subject to the provisions of the Plans. Options granted by the Company typically vest over

three

four

years. Certain awards provide for accelerated vesting if there is a change in control as defined in the Plans. Stock options outstanding under the

2006

Plan are exercisable from the date of grant for a period of

ten

years. Stock options granted under the Amended

2014

Plan are exercisable only upon vesting. For options granted to date, the exercise price equaled the fair value of the Common Stock as determined by the Board of Directors on the date of grant.

Stock-based compensation expense

Total stock-based compensation expense is recognized for stock options granted to employees and non-employees and has been reported in the Company’s consolidated statements of operations as follows (in thousands):

	Year Ended December 31,
	2019		2018

Research and development	$	233	$	1,142
General and administrative		710		2,287
Total	$	943	$	3,429

The Company estimates the fair value of each employee stock award on the grant date using the Black-Scholes option-pricing model based on the following assumptions regarding the fair value of the underlying Common Stock on each measurement date:

	Year Ended December 31,
	2019			2018
Weighted average expected volatility		89.6	%		93.5	%
Expected term (in years)		6.10			6.07
Risk free interest rate		2.60	%		2.55	%
Expected dividend yield		0	%		0	%

Stock Options

The following table summarizes stock option activity for employees and non-employees:

	Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (years)		Aggregate Intrinsic Value

Outstanding at December 31, 2018		114,931		$	204.76		7.4	$	404
Granted		29,562		$	106.32
Exercised		-		$	-
Forfeited		(80,431	)	$	124.40
Expired		(63,951	)	$	260.40
Outstanding at December 31, 2019		111		$	218.40		0.1	$	-
Exercisable at December 31, 2019		111		$	218.40		0.1	$	-
Vested or expected to vest at December 31, 2019 (1)		111		$	218.40		0.1	$	-

_____________

(

) Represents the number of vested options at

December 31, 2019

plus the number of unvested options expected to vest based on the unvested options outstanding at

December 31, 2019.

During the year ended

December 31, 2019,

the Company granted stock options to purchase an aggregate of

29,563

shares of its Common Stock with a weighted-average grant date fair value of

$80.00.

During the year ended

December 31, 2018,

the Company granted stock options to purchase an aggregate of

51,040

shares of its Common Stock with a weighted-average grant date fair value of

$104.32.

The total intrinsic value of options exercised in the years ended

December 31, 2019

and

2018

was

and

and respectively. As of

December 31, 2019,

and

2018

there was

$0.0

million and

$4.6

million, respectively of total unrecognized compensation cost related to employee non-vested stock options.

Employee Stock Purchase Plan

The

2014

Employee Stock Purchase Plan (“ESPP”) initially authorized the issuance of up to

3,513

shares of Common Stock. The number of shares increases each

January 1,

commencing on

January 1, 2015

and ending on (and including)

January 1, 2024,

by an amount equal to the lesser of

one

percent of the outstanding shares as of the end of the immediately preceding fiscal year,

281,000

shares or any lower amount determined by the Company’s Board of Directors prior to each such

January

1st.

As of

December 31, 2019,

as a result of an increase on

January 1, 2019

one

percent of the outstanding shares as of the end of the fiscal year ending

December 31, 2018,

the

2014

ESPP authorized the issuance of up to

4,811

shares of Common Stock. The

tenth

offering under the

2014

ESPP began on

July 1, 2019

and ended on

September 30, 2019.

During the years ended

December 31, 2019

and

2018,

shares and

1,859

shares, respectively, were issued under the

2014

ESPP. The Company incurred

$0.1

million in stock-based compensation expense related to the

2014

ESPP for the years ended

December 31, 2019,

2018,

and

2017.

January 1, 2020,

as a result of the increase of

one

percent of the outstanding shares as of the end of the fiscal year ending

December 31, 2019,

the

2014

ESPP increased the authorized shares available for issuance by

5,576

shares.

Note 10 - Income Taxes

12 Months Ended

Dec. 31, 2019

Notes to Financial Statements

Income Tax Disclosure [Text Block]

10.

Income Taxes

The components of loss from operations before income taxes are as follows (in thousands):

	Year Ended December 31,
	2019			2018
Domestic	$	(14,965	)	$	(17,855	)
Foreign		(27	)		(2,874	)
Total	$	(14,992	)	$	(20,729	)

For the years ended

December 31, 2019

and

2018,

the Company has

not

recorded a provision for federal or state income taxes as it has had net operating losses since inception.

A reconciliation of income taxes computed using the U.S. federal statutory rate to that reflected in operations is as follows (in thousands):

	Year Ended December 31,
	2019			2018
Income tax benefit computed at federal statutory tax rate	$	(3,148	)	$	(4,348	)
Permanent differences		1			6
Write-off of deferred tax asset		2,048			-
Stock compensation - permanent items		-			325
State income taxes, net of federal benefit		(930	)		(958	)
Tax credits		(465	)		(1,466	)
Change in valuation allowance		2,449			5,409
Foreign rate differential		5			602
Other		40			430
Total	$	-		$	-

The significant components of the Company's deferred tax assets are as follows (in thousands):

	Year Ended December 31,
	2019			2018
Deferred tax assets:
Net operating loss carryforwards	$	11,090		$	6,742
Federal and state tax credits		3,587			3,122
Accrued expenses		-			411
Patents		74			132
Stock-based compensation		-			1,782
Other		59			169
Total deferred tax assets		14,810			12,358
Valuation allowance		(14,810	)		(12,358	)
Net deferred assets	$	-		$	-

Management of the Company has evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets. Based on the Company's history of operating losses, management of the Company has concluded that it is more likely than

not

that the benefit of its deferred tax assets will

not

be realized. Accordingly, the Company has provided a full valuation allowance for deferred tax assets as of

December 31, 2019

and

2018.

Net operating loss and tax credit carryforwards are subject to review and possible adjustment by the Internal Revenue Service (the "IRS") and

may

become subject to an annual limitation in the event of certain cumulative changes in the ownership interest of significant shareholders over a

three

-year period in excess of

50%

as defined under Sections

382

and

383

in the Internal Revenue Code. This could substantially limit the amount of tax attributes that can be utilized annually to offset future taxable income or tax liabilities. The amount of the annual limitation is determined based on the Company's value immediately prior to the ownership change. Subsequent ownership changes

may

further affect the limitation in future years. The Company expects that there will be an ownership change in excess of

50%

in connection with the consummation of the Merger on

January 9, 2020.

This will substantially limit the amount of tax attributes that can be utilized annually to offset future taxable income or tax liabilities, the amount of which has

not

yet been determined.

As a result of current year activity, the valuation allowance increased by approximately

$2.4

million during the year ended

December 31, 2019.

This was due primarily to the generation of net operating losses. In the year ended

December 31, 2018,

the valuation allowance increased by approximately

$5.4

million. This was due primarily to the addition of Orphan Drug Tax credits and the generation of net operating losses.

Subject to the limitations described below, as of

December 31, 2019

and

2018

the Company has net operating loss carryforwards of approximately

$41.7

million and

$25.7

million, respectively, to offset future federal taxable income. The pre-

2018

federal net operating loss carryforwards expire at various dates through

2037.

Federal net operating loss carryforwards generated in

2018

and forward will have an unlimited carryforward period as part of the Tax Cuts and Jobs Act. The indefinite lived net operating loss carryforwards as of

December 31, 2019

are approximately

$30.6

million. As of

December 31, 2019

and

2018,

the Company has state net operating loss carryforwards of approximately

$37.2

million and

$21.5

million, respectively, to offset future state taxable income, which will expire at various dates through

2039.

As of

December 31, 2019

and

2018,

the Company has tax credit carryforwards of approximately

$3.6

million and

$3.1

million, respectively, to offset future federal and state income taxes, which will expire at various dates through

2039.

The Company had

unrecognized tax benefits or related interest and penalties accrued during the years ended

December 31, 2019

and

2018.

The Company will recognize interest and penalties related to uncertain tax positions in income tax expense.

The Company is subject to U.S. federal income tax and primarily Massachusetts state income tax. The statute of limitations for assessment by the IRS and state tax authorities is open for tax years ending

December 31, 2016

through

2019,

although carryforward attributes that were generated prior to tax year

2016

may

still be adjusted upon examination by the IRS or state tax authorities if they either have been or will be used in a future period. Currently,

federal or state income tax returns are under examination by the respective taxing authorities.

Note 11 - Net Loss Per Share Attributable to Common Stockholders

12 Months Ended

Dec. 31, 2019

Notes to Financial Statements

Earnings Per Share [Text Block]

11.

Net Loss per Share Attributable to Common Stockholders

As described in Note

Summary of Significant Accounting Policies, the Company computes basic and diluted loss per share using a methodology that gives effect to the impact of outstanding participating securities (the “two-class method”). As the years ended

December 31, 2019

and

2018

resulted in net losses, there is

income allocation required under the

two

-class method or dilution attributed to weighted-average shares outstanding in the calculation of diluted loss per share.

The following Common Stock equivalents, presented on an as converted basis, were excluded from the calculation of net loss per share for the periods presented, due to their anti-dilutive effect:

	Year Ended December 31,
	2019		2018
Outstanding stock options		111		114,931
Convertible preferred stock		476,279		552,819
		476,390		667,750

Note 12 - Restructuring Charges

12 Months Ended

Dec. 31, 2019

Notes to Financial Statements

Restructuring and Related Activities Disclosure [Text Block]

12.

Restructuring Charges

April 2019,

the Board of Directors approved a plan (

“2019

Restructuring Program”) to reduce operating expenses as the Company evaluates its strategic alternatives following the release of top-line data from the PATENCY-

clinical trial of vonapanitase on

March 28, 2019.

The restructuring initiatives are company-wide. The remainder of the charges were incurred by the end of the fiscal year ended

December 31, 2019 (

“Fiscal Year

2019”

) and were paid during the year ended

December 31, 2019.

Changes in the restructuring accrual during the year ended

December 31, 2019

are summarized below (in thousands):

	As of December 31, 2018		Charges/ (Benefits)		Payment/Other			As of December 31, 2019
2019 Restructuring Program
Employee Severance	$	-	$	2,854	$	(2,854	)	$	-
Total	$	-	$	2,854	$	(2,854	)	$	-

Note 13 - Subsequent Events

12 Months Ended

Dec. 31, 2019

Notes to Financial Statements

Subsequent Events [Text Block]

13.

Subsequent Events

Per the discussion in Note

“Organization and Basis of Presentation”, the Company and Private ArTara completed the Merger in accordance with the terms of the Merger Agreement whereby Merger Sub merged with and into Private ArTara, with Private ArTara surviving as a wholly owned subsidiary of the Company.

Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2019

Accounting Policies [Abstract]

Basis of Accounting, Policy [Policy Text Block]

Basis of Presentation, Principles of Consolidation and Use of Estimates

not

may

differ from those estimates or assumptions.

Fair Value Measurement, Policy [Policy Text Block]

Segment Information

one

operating segment, which is the business of developing and commercializing vonapanitase for the treatment of renal and vascular disease. Currently, the Company operates in only

one

geographic segment.

Derivatives, Policy [Policy Text Block]

Fair Value of Financial Instruments

The Company’s financial instruments consist of cash and cash equivalents, available-for-sale investments, forward foreign currency contracts (see Note

820,

Fair Value Measurement and Disclosures

not

a measure of the investment credit quality. Fair value measurements are classified and disclosed in

one

of the following

three

categories:

Level

1—Valuations

based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date.

Level

2—Valuations

based on quoted prices for similar assets or liabilities in markets that are

not

active or for which all significant inputs are observable, either directly or indirectly.

Level

3—Valuations

that require inputs that reflect the Company’s own assumptions that are both significant to the fair value measurement and unobservable.

A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement.

Financial instruments measured at fair value on a recurring basis include cash equivalents and available-for-sale investments (see Note

). There have been

changes to the valuation methods utilized by the Company during the years ended

December 31, 2019

and

2018.

The Company evaluates transfers between levels at the end of each reporting period. There were

transfers of financial instruments between levels during the years ended

December 31, 2019

and

2018.

New Accounting Pronouncements, Policy [Policy Text Block]

Recent Accounting Pronouncements

May 2014,

the FASB issued ASU

2014

09,

Revenue from Contracts with Customers

(“ASU

2014

09”

January 1, 2018,

with early adoption permitted. The Company adopted ASU

2014

during the quarter ended

March 31, 2018.

The adoption did

not

have a material impact on the consolidated financial statements.

February 2016,

the FASB issued ASU

2016

02,

Leases (Topic

842

): Amendments to FASB Codification (“ASU

2016

02”

2016

January 1, 2019

using the optional transition method that allows for a cumulative-effect adjustment in the period of adoption and will

not

restate prior periods. It has have also elected to adopt the package of practical expedients permitted in Accounting Standards Codification Topic

842,

or ASC

842.

Accordingly, it is continuing to account for its existing operating lease as an operating lease under the new guidance, without reassessing whether the contract contains a lease under ASC

842

or whether classification of the operating leases would be different under ASC Topic

842,

and to treat lease and non-lease components as a single lease component. The Company has also elected the short-term lease accounting policy under which the Company would

not

recognize a lease liability or ROU asset for any lease that at the commencement date has a lease term of

twelve

months or less and does

not

have to separate lease and non-lease components. The Company’s sole lease at the adoption date was an operating lease for facilities and did

not

include any non-lease components.

As a result of the adoption of ASU

2016

02,

January 1, 2019,

the Company recognized (a) a lease liability of approximately

$0.2

million, which represents the present value of its remaining lease payments using an estimated incremental borrowing rate of

8%,

(b) a right-of-use asset of approximately

$0.2

million that was expensed as operating lease expense over the term of the lease which ended on

September 30, 2019.

Due to the adoption of the standard using the modified retrospective cumulative-effect adjustment method, there are

changes to previously reported results prior to

January 1, 2019.

Lease expense did

not

change materially as a result of the adoption of ASU

2016

02.

June 2018,

the FASB issued ASU

No.

2018

07,

Compensation - Stock Compensation (Topic

718

): Improvements to Nonemployee Share-Based Payment Accounting (“ASU

2018

07”

). ASU

2018

is effective for fiscal years and interim periods within those fiscal years beginning after

December 15, 2018.

The guidance was effective for the Company on

January 1, 2019.

The Company adopted ASU

2018

during the quarter ended

March 31, 2019.

The adoption did

not

have an impact on the consolidated financial statements as all outstanding non-employee share-based awards had vested prior to

March 31, 2018.

Cash and Cash Equivalents, Policy [Policy Text Block]

Cash and Cash Equivalents

The Company considers all highly liquid investments with maturities of

days or less from the purchase date to be cash equivalents. Cash and cash equivalents are held in depository and money market accounts and are reported at fair value.

Investment, Policy [Policy Text Block]

Short-Term Investments

one

year. There have been

realized gains and losses for the years ended

December 31, 2019

and

2018.

other-than-temporary declines in value of short-term investments for the years ended

December 31, 2019

and

2018,

as it is more likely than

not

the Company will hold the securities until maturity or a recovery of the cost basis.

Concentration Risk, Credit Risk, Policy [Policy Text Block]

Concentrations of Credit Risk and Off-Balance Sheet Risk

may

exceed federally insured limits. The Company has

not

experienced any credit losses in such accounts and does

not

believe it is exposed to any significant credit risk on these funds. The Company has

financial instruments with off-balance sheet risk of loss.

Property, Plant and Equipment, Policy [Policy Text Block]

Property and Equipment

Property and equipment is stated at cost, less accumulated depreciation. Maintenance and repairs that do

not

not,

Asset	Estimated Useful Life (in years)
Computer equipment and software		3
Furniture, fixtures and other		5
Laboratory equipment		7

Research and Development Expense, Policy [Policy Text Block]

Research and Development Costs

Share-based Payment Arrangement [Policy Text Block]

Stock-Based Compensation Expense

The Company accounts for its stock-based compensation awards to employees and directors in accordance with FASB ASC Topic

718,

Compensation-Stock Compensation

(“ASC

718”

). ASC

718

and are expensed using an accelerated attribution model.

2018

not

expect to pay dividends in the foreseeable future. Refer to Note

“

Use of Estimates

,” for a discussion of the Company's estimated fair value of its Common Stock.

Income Tax, Policy [Policy Text Block]

Income Taxes

Income taxes are recorded in accordance with FASB ASC Topic

740,

“Income Taxes” (“ASC

740”

not

that some or all of the deferred tax assets will

not

be realized. The Company has evaluated all available evidence and concluded that it is

not

more likely than

not

that the Company will realize the benefit of its deferred tax assets, therefore, a valuation allowance has been established for the full amount of the deferred tax assets.

The Company accounts for uncertain tax positions in accordance with the provisions of ASC

740.

When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit will more likely than

not

be realized. The determination as to whether the tax benefit will more likely than

not

be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. As of

December 31, 2019

and

2018,

the Company did

not

have any significant uncertain tax positions. The Company's practice is to recognize interest and/or penalties related to income tax matters in income tax expense. See Note

for further details.

Earnings Per Share, Policy [Policy Text Block]

Net Income (Loss) per Share Attributable to Common Stockholders

The Company follows the

two

-class method when computing net income (loss) per share in periods when issued shares that meet the definition of participating securities are outstanding. The

two

not

Comprehensive Income, Policy [Policy Text Block]

Comprehensive Loss

Subsequent Events, Policy [Policy Text Block]

Subsequent Events

The Company evaluated subsequent events and transactions that occurred after the balance sheet date up to

March 19, 2020,

the date that the financial statements were available to be issued. Other than as described in Notes

and

13,

the Company did

not

identify any subsequent events that would have required adjustment or disclosure in the financial statements.

Note 2 - Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Property Plant and Equipment Useful Lives [Table Text Block]

Asset	Estimated Useful Life (in years)
Computer equipment and software		3
Furniture, fixtures and other		5
Laboratory equipment		7

Note 3 - Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Fair Value, Assets Measured on Recurring Basis [Table Text Block]

	As of December 31, 2019
	Quoted Prices		Significant		Significant
	in Active		Observable		Unobservable
	Markets		Inputs		Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets
Cash equivalents	$	5,841	$	-	$	-	$	5,841
Total	$	5,841	$	-	$	-	$	5,841

	As of December 31, 2018
	Quoted Prices		Significant		Significant
	in Active		Observable		Unobservable
	Markets		Inputs		Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets
Cash equivalents	$	18,353	$	-	$	-	$	18,353
Government securities		2,496		-		-		2,496
Total	$	20,849	$	-	$	-	$	20,849

Available-for-sale Securities [Table Text Block]

	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
December 31, 2019
Government securities
(Due within 1 year)	$	-	$	-	$	-	$	-
	$	-	$	-	$	-	$	-

December 31, 2018
Government securities
(Due within 1 year)	$	2,496	$	-	$	-	$	2,496
	$	2,496	$	-	$	-	$	2,496

Note 4 - Property and Equipment, Net (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Property, Plant and Equipment [Table Text Block]

	As of December 31,
	2019		2018

Computer equipment and software	$	-	$	211
Furniture, fixtures, and other		-		365
Laboratory equipment		-		514
		-		1,090
Accumulated depreciation		-		(827	)
Property and equipment, net	$	-	$	263

Note 5 - Accrued Expenses (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Schedule of Accrued Liabilities [Table Text Block]

	As of December 31,
	2019		2018

Payroll and employee-related costs	$	4	$	1,390
Contracted service costs		9		968
Professional fees and other		307		279
Total	$	320	$	2,637

Note 8 - Common Stock (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Common Stock Reserved for Future Issuance [Table Text Block]

	As of December 31,
	2019		2018

Conversion of Series A Preferred Stock		476,279		552,819
Stock-based compensation awards		185,729		129,099
Employee Stock Purchase Plan		2,953		2,953
Total		664,961		684,871

Note 9 - Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Year Ended December 31,
	2019		2018

Research and development	$	233	$	1,142
General and administrative		710		2,287
Total	$	943	$	3,429

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Year Ended December 31,
	2019			2018
Weighted average expected volatility		89.6	%		93.5	%
Expected term (in years)		6.10			6.07
Risk free interest rate		2.60	%		2.55	%
Expected dividend yield		0	%		0	%

Share-based Payment Arrangement, Option, Activity [Table Text Block]

	Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (years)		Aggregate Intrinsic Value

Outstanding at December 31, 2018		114,931		$	204.76		7.4	$	404
Granted		29,562		$	106.32
Exercised		-		$	-
Forfeited		(80,431	)	$	124.40
Expired		(63,951	)	$	260.40
Outstanding at December 31, 2019		111		$	218.40		0.1	$	-
Exercisable at December 31, 2019		111		$	218.40		0.1	$	-
Vested or expected to vest at December 31, 2019 (1)		111		$	218.40		0.1	$	-

Note 10 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]

	Year Ended December 31,
	2019			2018
Domestic	$	(14,965	)	$	(17,855	)
Foreign		(27	)		(2,874	)
Total	$	(14,992	)	$	(20,729	)

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	Year Ended December 31,
	2019			2018
Income tax benefit computed at federal statutory tax rate	$	(3,148	)	$	(4,348	)
Permanent differences		1			6
Write-off of deferred tax asset		2,048			-
Stock compensation - permanent items		-			325
State income taxes, net of federal benefit		(930	)		(958	)
Tax credits		(465	)		(1,466	)
Change in valuation allowance		2,449			5,409
Foreign rate differential		5			602
Other		40			430
Total	$	-		$	-

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	Year Ended December 31,
	2019			2018
Deferred tax assets:
Net operating loss carryforwards	$	11,090		$	6,742
Federal and state tax credits		3,587			3,122
Accrued expenses		-			411
Patents		74			132
Stock-based compensation		-			1,782
Other		59			169
Total deferred tax assets		14,810			12,358
Valuation allowance		(14,810	)		(12,358	)
Net deferred assets	$	-		$	-

Note 11 - Net Loss Per Share Attributable to Common Stockholders (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

	Year Ended December 31,
	2019		2018
Outstanding stock options		111		114,931
Convertible preferred stock		476,279		552,819
		476,390		667,750

Note 12 - Restructuring Charges (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Schedule of Restructuring Reserve by Type of Cost [Table Text Block]

	As of December 31, 2018		Charges/ (Benefits)		Payment/Other			As of December 31, 2019
2019 Restructuring Program
Employee Severance	$	-	$	2,854	$	(2,854	)	$	-
Total	$	-	$	2,854	$	(2,854	)	$	-

Note 1 - Organization and Operations (Details Textual)			12 Months Ended
Note 1 - Organization and Operations (Details Textual)	Jan. 09, 2020 USD ($)	Nov. 12, 2015 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) shares
Severance Costs			$ 2,900,000
Cash, Cash Equivalents, and Short-term Investments, Total			6,200,000
Retained Earnings (Accumulated Deficit), Ending Balance			$ (225,462,000)	$ (210,470,000)
Common Stock [Member]
Stock Issued During Period, Shares, New Issues \| shares				37,364
Sales Agreement [Member] \| Cowen and Company, LLC [Member] \| Common Stock [Member]
Sale of Stock, Maximum Value of Stock Offered		$ 40,000,000
Sale of Stock, Commission to Sales Agent, Percentage				3.00%
Sales Agreement [Member] \| New Leaf Venture Partners LLC [Member] \| Common Stock [Member]
Stock Issued During Period, Shares, New Issues \| shares				1,494,579
Proceeds from Issuance of Common Stock				$ 3,000,000
Payments of Stock Issuance Costs				$ 46,000
Reverse Merger with Private ArTara [Member] \| Subsequent Event [Member]
Business Combination, Consideration Transferred, Equity Interested Issued, Exchange Ratio	0.190756
Reverse Merger with Private ArTara [Member] \| Subsequent Event [Member] \| Proteon Private Placement [Member]
Proceeds from Issuance or Sale of Equity, Total	$ 40,500,000
Reverse Merger with Private ArTara [Member] \| Subsequent Event [Member] \| The ArTara Private Placement Shares [Member]
Proceeds from Issuance or Sale of Equity, Total	2,000,000
Reverse Merger with Private ArTara [Member] \| Subsequent Event [Member] \| The Private Placements [Member]
Proceeds from Issuance or Sale of Equity, Total	42,500,000
Sale of Stock, Consideration Received on Transaction	$ 39,600,000
Reverse Stock Split [Member] \| Reverse Merger with Private ArTara [Member] \| Subsequent Event [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio	40

Note 2 - Summary of Significant Accounting Policies (Details Textual) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jan. 01, 2019 USD ($)
Number of Operating Segments	1
Number of Reportable Segments	1
Debt Securities, Available-for-sale, Realized Gain (Loss), Total	$ 0	$ 0
Other-than-temporary Impairment Loss, Debt Securities, Available-for-sale, Total	0	0
Liability for Uncertainty in Income Taxes, Current	$ 0	$ 0
Accounting Standards Update 2016-02 [Member]
Operating Lease, Liability, Current			$ 200
Operating Lease, Weighted Average Discount Rate, Percent			8.00%
Operating Lease, Right-of-Use Asset			$ 200

Note 2 - Summary of Significant Accounting Policies - Property and Equipment Useful Lives (Details)	12 Months Ended
	Dec. 31, 2019
Computer Equipment and Software [Member]
Property and equipment, useful life (Year)	3 years
Furniture and Fixtures [Member]
Property and equipment, useful life (Year)	5 years
Laboratory Equipment [Member]
Property and equipment, useful life (Year)	7 years

Note 3 - Fair Value Measurements - Summary of Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Total	$ 5,841	$ 20,849
Cash Equivalents [Member]
Cash equivalents	5,841	18,353
US Government Agencies Debt Securities [Member]
Government securities		2,496
Fair Value, Inputs, Level 1 [Member]
Total	5,841	20,849
Fair Value, Inputs, Level 1 [Member] \| Cash Equivalents [Member]
Cash equivalents	5,841	18,353
Fair Value, Inputs, Level 1 [Member] \| US Government Agencies Debt Securities [Member]
Government securities		2,496
Fair Value, Inputs, Level 2 [Member]
Total
Fair Value, Inputs, Level 2 [Member] \| Cash Equivalents [Member]
Cash equivalents
Fair Value, Inputs, Level 2 [Member] \| US Government Agencies Debt Securities [Member]
Government securities
Fair Value, Inputs, Level 3 [Member]
Total
Fair Value, Inputs, Level 3 [Member] \| Cash Equivalents [Member]
Cash equivalents
Fair Value, Inputs, Level 3 [Member] \| US Government Agencies Debt Securities [Member]
Government securities

Note 3 - Fair Value Measurements - Available-for-sale Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Amortized Cost		$ 2,496
Unrealized Gains
Unrealized Losses
Fair Value		2,496
US Government Agencies Debt Securities [Member]
Amortized Cost		2,496
Unrealized Gains
Unrealized Losses
Fair Value		$ 2,496

Note 4 - Property and Equipment, Net (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Depreciation, Total	$ 279	$ 115
Laboratory Equipment [Member] \| Research and Development Expense [Member]
Impairment of Long-Lived Assets Held-for-use	$ 200

Note 4 - Property and Equipment, Net - Summary of Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property and equipment		$ 1,090
Accumulated depreciation		(827)
Property and equipment, net		263
Computer Equipment and Software [Member]
Property and equipment		211
Furniture and Fixtures [Member]
Property and equipment		365
Laboratory Equipment [Member]
Property and equipment		$ 514

Note 5 - Accrued Expenses - Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Payroll and employee-related costs	$ 4	$ 1,390
Contracted service costs	9	968
Professional fees and other	307	279
Total	$ 320	$ 2,637

Note 6 - Commitments and Contingencies (Details Textual)		1 Months Ended		9 Months Ended	12 Months Ended
	Feb. 10, 2020	Dec. 23, 2019	Feb. 28, 2002	Sep. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2019 USD ($)	Nov. 30, 2019 USD ($)	Dec. 31, 2017 USD ($)
Royalty Payment, Percentage of Net Sales			2.50%
Operating Lease, Expense				$ 200,000	$ 300,000
Certificates of Deposit, at Carrying Value					0	$ 50,000	$ 50,000
Letters of Credit Outstanding, Amount					22,000	$ 0
Loans Pledged as Collateral					$ 22,000			$ 22,000
Loss Contingency, New Claims Filed, Number		4
Subsequent Event [Member]
Loss Contingency, Claims Dismissed, Number	4

Note 7 - Series A Preferred Financing (Details Textual) - USD ($) $ / shares in Units, $ in Millions			12 Months Ended
	Jan. 09, 2020	Aug. 02, 2017	Dec. 31, 2019	Dec. 31, 2018
Preferred Stock, Par or Stated Value Per Share			$ 0.001	$ 0.001
Preferred Stock, Shares Authorized			10,000,000	10,000,000
Conversion of Series A Preferred Stock to Common Stock [Member] \| Subsequent Event [Member]
Conversion of Stock, Shares Issued	476,276
Conversion of Stock, Shares Converted	18,954
Series A Convertible Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues		22,000
Preferred Stock, Par or Stated Value Per Share		$ 0.001	$ 0.001	$ 0.001
Shares Issued, Price Per Share		$ 1,000
Proceeds from Issuance of Convertible Preferred Stock		$ 22.0
Payments of Stock Issuance Costs		$ 0.5
Convertible Preferred Stock, Shares Issued upon Conversion		25
Convertible Preferred Stock, Conversion Price of Shares Issued upon Conversion		$ 39.80
Convertible Preferred Stock, Maximum Ownership Percentage Allowed after Conversion of Stock		9.985%
Preferred Stock, Shares Authorized			22,000	22,000
Conversion of Stock, Shares Issued			76,540
Preferred Stock, Shares Issued, Total			18,954	22,000
Preferred Stock, Liquidation Preference Per Share			$ 0.001
Preferred Stock, Shares Outstanding, Ending Balance			18,954	22,000

Note 8 - Common Stock (Details Textual) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
Common Stock, Shares Authorized	100,000,000	100,000,000
Common Stock, Par or Stated Value Per Share	$ 0.001	$ 0.001
Common Stock, Shares, Issued, Total	557,631	481,091
Common Stock, Shares, Outstanding, Ending Balance	557,631	481,091

Note 8 - Common Stock - Common Stock Reserved for Future Issuance (Details) - shares	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2014
Reserved for future issuance (in shares)	664,961	684,871
The 2014 Employee Stock Purchase Plan [Member]
Reserved for future issuance (in shares)	2,953	2,953	3,513
Performance Shares [Member]
Reserved for future issuance (in shares)	185,729	129,099
Conversion of Series A Preferred Stock to Common Stock [Member]
Reserved for future issuance (in shares)	476,279	552,819

Note 9 - Stock-based Compensation (Details Textual) - USD ($) $ / shares in Units, $ in Thousands			12 Months Ended
	Jan. 09, 2020	Jan. 01, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 08, 2020	Jan. 01, 2020	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term			36 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross			29,563	51,040
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value			$ 80	$ 104.32
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value			$ 0	$ 0
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount			$ 0	$ 4,600
Common Stock, Capital Shares Reserved for Future Issuance			664,961	684,871
Share-based Payment Arrangement, Expense			$ 943	$ 3,429
The 2014 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized			17,600
Share-based Compensation Arrangement by Share-based Payment Award, Number of Annual Additional Shares, Percentage			4.00%
The 2014 Plan [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			3 years
The 2014 Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			4 years
The Second Amended 2014 Plan [Member] \| Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	1,074,384					129,088
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized	900,003
The 2006 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term			10 years
The 2014 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized		4,811
Share-based Compensation Arrangement by Share-based Payment Award, Number of Annual Additional Shares, Percentage		1.00%	1.00%
Common Stock, Capital Shares Reserved for Future Issuance			2,953	2,953				3,513
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Additional Shares Authorizable		281,000
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period			0	1,859
Share-based Payment Arrangement, Expense			$ 100	$ 100	$ 100
The 2014 Employee Stock Purchase Plan [Member] \| Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized							5,576
Share-based Compensation Arrangement by Share-based Payment Award, Number of Annual Additional Shares, Percentage							1.00%

Note 9 - Stock-based Compensation - Stock-based Compensation Expense Recognized for Stock Options Granted (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Allocated share based compensation expense	$ 943	$ 3,429
Research and Development Expense [Member]
Allocated share based compensation expense	233	1,142
General and Administrative Expense [Member]
Allocated share based compensation expense	$ 710	$ 2,287

Note 9 - Stock-based Compensation - Black-scholes Valuation Assumptions (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Weighted average expected volatility	89.60%	93.50%
Expected term (in years) (Year)	6 years 36 days	6 years 25 days
Risk free interest rate	2.60%	2.55%
Expected dividend yield	0.00%	0.00%

Note 9 - Stock-based Compensation - Stock Option Activity for Employees and Non-employees (Details) - USD ($)
$ / shares in Units, $ in Thousands

12 Months Ended

Dec. 31, 2019

Dec. 31, 2018

Options Outstanding, Beginning Balance (in shares)

114,931

Options Outstanding, Weighted Average Exercise Price, Beginning Balance (in dollars per share)

$ 204.76

Options Outstanding, Weighted-average Remaining Contractual Term (Year)

36 days

7 years 146 days

Options Outstanding, Aggregate Intrinsic Value

$ 404

Options Granted (in shares)

29,563

51,040

Options Granted, Weighted Average Exercise Price (in dollars per share)

$ 106.32

Options Exercised (in shares)

Options Exercised, Weighted Average Exercise Price (in dollars per share)

Options Forfeited (in shares)

(80,431)

Options Forfeited, Weighted Average Exercise Price (in dollars per share)

$ 124.40

Options Expired (in shares)

(63,951)

Options Expired, Weighted Average Exercise Price (in dollars per share)

$ 260.40

Options Outstanding, Ending Balance (in shares)

111

114,931

Options Outstanding, Weighted Average Exercise Price, Ending Balance (in dollars per share)

$ 218.40

$ 204.76

Options Exercisable (in shares)

111

Options Exercisable, Weighted Average Exercise Price (in dollars per share)

$ 218.40

Options Exercisable, Weighted-average Remaining Contractual Term (Year)

36 days

Options Exercisable, Aggregate Intrinsic Value

Options Vested or Expected to Vest (in shares)

^[1]

111

Options Vested or Expected to Vest, Weighted Average Exercise Price (in dollars per share)

^[1]

$ 218.40

Options Vested or Expected to Vest, Weighted-average Remaining Contractual Term (Year)

^[1]

36 days

Options Vested or Expected to Vest, Aggregate Intrinsic Value

^[1]

[1]	Represents the number of vested options at December 31, 2019 plus the number of unvested options expected to vest based on the unvested options outstanding at December 31, 2019.

Note 10 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards, Net, Indefinite Lived	$ 30,600
Tax Credit Carryforward, Amount	3,600	$ 3,100
Unrecognized Tax Benefits, Ending Balance	0	0
Domestic Tax Authority [Member]
Operating Loss Carryforwards, Total	41,700	25,700
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Total	37,200	21,500
Current Year Deferred Tax Assets Activity [Member]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 2,400	$ 5,400

Note 10 - Income Taxes - Domestic and Foreign Loss Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Domestic	$ (14,965)	$ (17,855)
Foreign	(27)	(2,874)
Total	$ (14,992)	$ (20,729)

Note 10 - Income Taxes - Reconciliation of Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income tax benefit computed at federal statutory tax rate	$ (3,148)	$ (4,348)
Permanent differences	1	6
Write-off of deferred tax asset	2,048
Stock compensation - permanent items		325
State income taxes, net of federal benefit	(930)	(958)
Tax credits	(465)	(1,466)
Change in valuation allowance	2,449	5,409
Foreign rate differential	5	602
Other	40	430
Total

Note 10 - Income Taxes - Summary of Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Net operating loss carryforwards	$ 11,090	$ 6,742
Federal and state tax credits	3,587	3,122
Accrued expenses		411
Patents	74	132
Stock-based compensation		1,782
Other	59	169
Total deferred tax assets	14,810	12,358
Valuation allowance	(14,810)	(12,358)
Net deferred assets

Note 11 - Net Loss Per Share Attributable to Common Stockholders - Common Stock Equivalents Excluded From Calculation of Net Loss Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Antidilutive Securities (in shares)	476,390	667,750
Convertible Preferred Stock [Member]
Antidilutive Securities (in shares)	476,279	552,819
Share-based Payment Arrangement, Option [Member]
Antidilutive Securities (in shares)	111	114,931

Note 12 - Restructuring Charges - Changes in the Restructuring Accrual (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Beginning balance
Charges/(Benefits)	2,854
Payment/Other	(2,854)
Ending balance
Employee Severance [Member]
Beginning balance
Charges/(Benefits)	2,854
Payment/Other	(2,854)
Ending balance