Protara Therapeutics (TARA) 10-Q 7 Aug 18 2018 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2018	Jul. 31, 2018
Document Information [Line Items]
Entity Registrant Name	PROTEON THERAPEUTICS INC
Entity Central Index Key	1,359,931
Trading Symbol	prto
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Common Stock, Shares Outstanding (in shares)		17,726,713
Document Type	10-Q
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 12,485	$ 21,170
Available-for-sale investments	13,969	20,971
Prepaid expenses and other current assets	1,057	1,339
Total current assets	27,511	43,480
Property and equipment, net	219	259
Restricted cash	22	22
Other non-current assets	100	218
Total assets	27,852	43,979
Current liabilities:
Accounts payable	431	291
Accrued expenses	1,800	8,949
Total current liabilities	2,231	9,240
Total liabilities	2,231	9,240
Commitments and contingencies (Note 4)
Stockholders’ equity:
Preferred Stock	0	0
Common stock, $0.001 par value, 100,000,000 shares authorized at June 30, 2018 and December 31, 2017; 17,726,713 and 17,674,729 shares issued and outstanding at June 30, 2018 and December 31, 2017, respectively.	18	18
Additional paid-in capital	204,780	202,953
Accumulated deficit	(200,701)	(189,741)
Accumulated other comprehensive income (loss)	1	(14)
Total stockholders’ equity	25,621	34,739
Total liabilities and stockholders’ equity	27,852	43,979
Series A Convertible Preferred Stock [Member]
Stockholders’ equity:
Preferred Stock	$ 21,523	$ 21,523

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares	Jun. 30, 2018	Dec. 31, 2017
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	9,978,000	9,978,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
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)	17,726,713	17,674,729
Common stock, shares outstanding (in shares)	17,726,713	17,674,729
Series A Convertible Preferred Stock [Member]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	22,000	22,000
Preferred stock, shares issued (in shares)	22,000	22,000
Preferred stock, shares outstanding (in shares)	22,000	22,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Operating expenses:
Research and development	$ 2,760	$ 3,891	$ 6,831	$ 8,137
General and administrative	2,240	2,095	4,534	4,329
Total operating expenses	5,000	5,986	11,365	12,466
Loss from operations	(5,000)	(5,986)	(11,365)	(12,466)
Other income:
Investment income	106	46	198	78
Other income, net	15	332	207	282
Total other income	121	378	405	360
Net loss	(4,879)	(5,608)	(10,960)	(12,106)
Foreign currency translation adjustment	(3)	0	(1)
Unrealized gain (loss) on available-for-sale investments	8	(7)	16	(7)
Comprehensive loss	(4,874)	(5,615)	(10,945)	(12,113)
Net loss attributable to common stockholders	$ (4,879)	$ (5,608)	$ (10,960)	$ (12,106)
Net loss per share attributable to common stockholders - basic and diluted (in dollars per share)	$ (0.28)	$ (0.33)	$ (0.62)	$ (0.72)
Weighted-average common shares outstanding used in net loss per share attributable to common stockholders - basic and diluted (in shares)	17,674,729	17,207,672	17,674,729	16,923,515
Included in operating expenses, above, are the following amounts for non-cash stock-based compensation expense:
Allocated share-based compensation	$ 922	$ 867	$ 1,743	$ 1,712
Research and Development Expense [Member]
Included in operating expenses, above, are the following amounts for non-cash stock-based compensation expense:
Allocated share-based compensation	312	308	579	606
General and Administrative Expense [Member]
Included in operating expenses, above, are the following amounts for non-cash stock-based compensation expense:
Allocated share-based compensation	$ 610	$ 559	$ 1,164	$ 1,106

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating activities
Net loss	$ (10,960)	$ (12,106)
Reconciliation of net loss to net cash used in operating activities:
Depreciation	61	77
Amortization of premium/discount on available-for-sale securities	(14)	1
Foreign currency remeasurement (loss)/gain	(25)	279
Stock-based compensation	1,743	1,712
Changes in:
Prepaid expenses and other assets	396	263
Interest receivable	4	(12)
Accounts payable and accrued expenses	(7,009)	(942)
Net cash used in operating activities	(15,804)	(10,728)
Investing activities
Purchases of available-for-sale investments	(10,957)	(13,360)
Proceeds from maturities of available-for-sale investments	15,990	4,920
Proceeds from sale of available-for-sale investments	1,999
Purchase of property and equipment	(21)	(14)
Net cash provided by (used in) investing activities	7,011	(8,454)
Financing activities
Proceeds from issuance of common stock, net of issuance costs		1,287
Proceeds from issuance of common stock under ESPP	84	58
Exercise of stock options		109
Net cash provided by financing activities	84	1,454
Effect of exchange rate changes on cash	24	(279)
Decrease in cash, cash equivalents and restricted cash	(8,685)	(18,007)
Cash, cash equivalents and restricted cash, beginning of period	21,192	36,406
Cash, cash equivalents and restricted cash, end of period	$ 12,507	$ 18,399

Note 1 - Organization and Opera

Note 1 - Organization and Operations	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Nature of Operations [Text Block]	1. Organization and Operations The Company Proteon Therapeutics, Inc. (the “Company”) is a late-stage biopharmaceutical company focused on the development of novel, first June 2001 March 24, 2006. The Company devotes substantially all of its efforts to product research and development, initial market development and raising capital. The Company has not third As of June 30, 2018, $26.5 fourth 2019. $200.7 June 30, 2018. On November 12, 2015, 3 $40 January 12, 2016. 3% March 14, 2018 I.B.6 3, may December 31, 2017, 896,811 $1.4 $0.1 not six June 30, 2018. On June 22, 2017, 22,000 $0.001 $1,000 $22.0 August 2, 2017 ( 5 Pursuant to the Series A Financing, on August 2, 2017, August 3, 2017, 3 August 21, 2017.

Note 2 - Summary of Significant

Note 2 - Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Significant Accounting Policies [Text Block]	2. Summary of Significant Accounting Policies Basis of Presentation, Principles of Consolidation and Use of Estimates The unaudited interim condensed consolidated financial statements of the Company included herein have been prepared, pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been condensed or omitted from this report, as is permitted by such rules and regulations. Accordingly, these condensed consolidated financial statements should be read in conjunction with the financial statements as of and for the year ended December 31, 2017 10 March 14, 2018. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited financial statements. In the opinion of the Company’s management, the accompanying unaudited interim condensed consolidated financial statements contain all adjustments which are necessary to fairly present the Company’s financial position as of June 30, 2018, three six June 30, 2018 2017 six June 30, 2018 2017. three six June 30, 2018 not December 31, 2018, The unaudited interim condensed 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 condensed 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 may Fair Value of Financial Instruments The Company’s financial instruments consist of cash and cash equivalents, available-for-sale investments, 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 not one three Level 1—Valuations Level 2—Valuations not Level 3—Valuations 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 3. Financial instruments measured at fair value on a recurring basis include cash equivalents and available-for-sale investments. There have been no three six June 30, 2018 2017. no three six June 30, 2018 2017. 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 two two not Recent Accounting Pronouncements In May 2014, 2014 09, Revenue from Contracts with Customers 2014 09” January 1, 2018, 2017 09 March 31, 2018. not In February 2016, 2016 02, Leases (Topic 842 2016 02” 2016 02 December 15, 2018, 2016 02 In August 2016, 2016 15, Statement of Cash Flows (Topic 230 2016 15” eight December 15, 2017, first 2018 2016 15 March 31, 2018. not In May 2017, No. 2017 09, Compensation - Stock Compensation (Topic 718 2017 09” 2017 09, not 2017 09 December 15, 2017. 2017 09 March 31, 2018. not In November 2016, 2016 18, Statement of Cash Flows, Restricted Cash December 15, 2017, first 2018. 2016 18 March 31, 2018. $22,000 $14,000 $22,000 $14,000, six June 30, 2018 2017.

Note 3 - Fair Value Measurement

Note 3 - Fair Value Measurements	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Fair Value Disclosures [Text Block]	3. Fair Value Measurements Below is a summary of assets and liabilities measured at fair value (in thousands): As of June 30, 2018 Quoted Prices Significant Significant Total Assets Cash equivalents $ 10,425 $ - $ - $ 10,425 Government securities 13,969 - - 13,969 Total $ 24,394 $ - $ - $ 24,394 As of December 31, 2017 Quoted Prices Significant Significant Total Assets Cash equivalents $ 11,662 $ - $ - $ 11,662 Government securities 20,971 - - 20,971 Total $ 32,633 $ - $ - $ 32,633 As of June 30, 2018 December 31, 2017, 90 Available-for-sale securities at June 30, 2018 December 31, 2017 Amortized Cost Unrealized Gains Unrealized Losses Fair Value June 30, 2018 Government securities (Due within 1 year) $ 13,973 $ - $ (4 ) $ 13,969 $ 13,973 $ - $ (4 ) $ 13,969 December 31, 2017 Government securities (Due within 1 year) $ 20,991 $ - $ (20 ) $ 20,971 $ 20,991 $ - $ (20 ) $ 20,971

Note 4 - Commitments and Contin

Note 4 - Commitments and Contingencies	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	4. Commitments and Contingencies Future minimum payments required under operating leases as of June 30, 2018 Year Ending December 31: Amount 2018 138 2019 207 Total minimum lease payments $ 345 In addition to the base rent, the Company is also responsible for its share of operating expenses and real estate taxes, in accordance with the terms of the lease agreement. As of June 30, 2018, $22,000 Restricted cash related to facilities leases As of June 30, 2018 December 31, 2017, $22,000 June 30, 2018 December 31, 2017, $22,000

Note 5 - Series A Preferred Fin

Note 5 - Series A Preferred Financing	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Preferred Stock [Text Block]	5. Series A Preferred Financing On August 2, 2017, 22,000 $0.001 $1,000 $22.0 June 22, 2017. $0.5 1,005 $0.9949 13 1934, 9.985% Upon issuance, each share of Series A Preferred included an embedded beneficial conversion feature as the market price of the Company’s Common Stock on the date of issuance of the Series A Preferred was $1.30 $6.7 not The Company evaluated the Series A Preferred for liability or equity classification in accordance with the provisions of ASC 480, not not not not 480 no not

Note 6 - Stock-based Compensati

Note 6 - Stock-based Compensation	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]	6. Stock-based Compensation Stock Options The following table summarizes stock option activity for employees: Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (years) Aggregate Intrinsic Value Outstanding at December 31, 2017 2,681,072 $ 7.18 6.8 $ 121 Granted 1,891,600 $ 2.65 Exercised - $ - Forfeited (83,433 ) $ 5.82 Expired (42,013 ) $ 13.30 Outstanding at June 30, 2018 4,447,226 $ 5.22 7.9 $ 614 Exercisable at June 30, 2018 1,844,871 $ 7.44 6.1 $ 286 Vested or expected to vest at June 30, 2018 (1) 4,447,226 $ 5.22 7.9 $ 614 _____________________ ( 1 June 30, 2018 June 30, 2018. Employee Stock Purchase Plan The 2014 140,500 January 1, January 1, 2015 January 1, 2024, one 281,000 January 1st. no January 1, 2018. June 30, 2018, 2014 304,991 seventh 2014 January 1, 2018 June 30, 2018. 51,984 three six June 30, 2018 2014 $24,000 $48,000 2014 three six June 30, 2018, $52,000 $0.1 2014 three six June 30, 2017, Common Stock The Company has the following shares of Common Stock reserved for future issuance: June 30, December 31, 2018 2017 Conversion of Series A Preferred Stock 22,112,775 22,112,775 Stock-based compensation awards 5,163,957 3,572,457 Employee Stock Purchase Plan 140,479 192,463 Total 27,417,211 25,877,695

Note 7 - Income Taxes

Note 7 - Income Taxes	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Income Tax Disclosure [Text Block]	7. Income Taxes Deferred taxes are recognized for temporary differences between the basis of assets and liabilities for financial statement and income tax purposes. The Company has evaluated the positive and negative evidence bearing upon the Company’s ability to realize the benefit of its deferred tax assets. Based on the Company’s history of operating losses, the Company has concluded that it is more likely than not not no six June 30, 2018 2017.

Note 8 - Net Loss Per Share Att

Note 8 - Net Loss Per Share Attributable to Common Stockholders	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Earnings Per Share [Text Block]	8. Net Loss per Share Attributable to Common Stockholders As described in Note 2, three six June 30, 2018 2017 no two 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: Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Outstanding stock options 4,447,226 2,783,570 4,447,226 2,783,570 Convertible preferred stock 22,112,775 - 22,112,775 - 26,560,001 2,783,570 26,560,001 2,783,570

Note 9 - Subsequent Events

Note 9 - Subsequent Events	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Subsequent Events [Text Block]	9. Subsequent Events The Company has evaluated all activity that occurred subsequent to quarter end but prior to issuance of the unaudited condensed consolidated financial statements for events or transactions that could require disclosure or that could impact the carrying value of assets or liabilities as of the balance sheet date.

Significant Accounting Policies

Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2018
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation, Principles of Consolidation and Use of Estimates The unaudited interim condensed consolidated financial statements of the Company included herein have been prepared, pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been condensed or omitted from this report, as is permitted by such rules and regulations. Accordingly, these condensed consolidated financial statements should be read in conjunction with the financial statements as of and for the year ended December 31, 2017 10 March 14, 2018. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited financial statements. In the opinion of the Company’s management, the accompanying unaudited interim condensed consolidated financial statements contain all adjustments which are necessary to fairly present the Company’s financial position as of June 30, 2018, three six June 30, 2018 2017 six June 30, 2018 2017. three six June 30, 2018 not December 31, 2018, The unaudited interim condensed 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 condensed 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 may
Fair Value Measurement, Policy [Policy Text Block]	Fair Value of Financial Instruments The Company’s financial instruments consist of cash and cash equivalents, available-for-sale investments, 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 not one three Level 1—Valuations Level 2—Valuations not Level 3—Valuations 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 3. Financial instruments measured at fair value on a recurring basis include cash equivalents and available-for-sale investments. There have been no three six June 30, 2018 2017. no three six June 30, 2018 2017.
Earnings Per Share, Policy [Policy Text Block]	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 two two not
New Accounting Pronouncements, Policy [Policy Text Block]	Recent Accounting Pronouncements In May 2014, 2014 09, Revenue from Contracts with Customers 2014 09” January 1, 2018, 2017 09 March 31, 2018. not In February 2016, 2016 02, Leases (Topic 842 2016 02” 2016 02 December 15, 2018, 2016 02 In August 2016, 2016 15, Statement of Cash Flows (Topic 230 2016 15” eight December 15, 2017, first 2018 2016 15 March 31, 2018. not In May 2017, No. 2017 09, Compensation - Stock Compensation (Topic 718 2017 09” 2017 09, not 2017 09 December 15, 2017. 2017 09 March 31, 2018. not In November 2016, 2016 18, Statement of Cash Flows, Restricted Cash December 15, 2017, first 2018. 2016 18 March 31, 2018. $22,000 $14,000 $22,000 $14,000, six June 30, 2018 2017.

Note 3 - Fair Value Measureme16

Note 3 - Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2018
Notes Tables
Fair Value, Assets Measured on Recurring Basis [Table Text Block]	As of June 30, 2018 Quoted Prices Significant Significant Total Assets Cash equivalents $ 10,425 $ - $ - $ 10,425 Government securities 13,969 - - 13,969 Total $ 24,394 $ - $ - $ 24,394 As of December 31, 2017 Quoted Prices Significant Significant Total Assets Cash equivalents $ 11,662 $ - $ - $ 11,662 Government securities 20,971 - - 20,971 Total $ 32,633 $ - $ - $ 32,633
Available-for-sale Securities [Table Text Block]	Amortized Cost Unrealized Gains Unrealized Losses Fair Value June 30, 2018 Government securities (Due within 1 year) $ 13,973 $ - $ (4 ) $ 13,969 $ 13,973 $ - $ (4 ) $ 13,969 December 31, 2017 Government securities (Due within 1 year) $ 20,991 $ - $ (20 ) $ 20,971 $ 20,991 $ - $ (20 ) $ 20,971

Note 4 - Commitments and Cont17

Note 4 - Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2018
Notes Tables
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	Year Ending December 31: Amount 2018 138 2019 207 Total minimum lease payments $ 345

Note 6 - Stock-based Compensa18

Note 6 - Stock-based Compensation (Tables)	6 Months Ended
	Jun. 30, 2018
Notes Tables
Share-based Compensation, Stock Options, Activity [Table Text Block]	Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (years) Aggregate Intrinsic Value Outstanding at December 31, 2017 2,681,072 $ 7.18 6.8 $ 121 Granted 1,891,600 $ 2.65 Exercised - $ - Forfeited (83,433 ) $ 5.82 Expired (42,013 ) $ 13.30 Outstanding at June 30, 2018 4,447,226 $ 5.22 7.9 $ 614 Exercisable at June 30, 2018 1,844,871 $ 7.44 6.1 $ 286 Vested or expected to vest at June 30, 2018 (1) 4,447,226 $ 5.22 7.9 $ 614
Common Stock Reserved for Future Issuance [Table Text Block]	June 30, December 31, 2018 2017 Conversion of Series A Preferred Stock 22,112,775 22,112,775 Stock-based compensation awards 5,163,957 3,572,457 Employee Stock Purchase Plan 140,479 192,463 Total 27,417,211 25,877,695

Note 8 - Net Loss Per Share A19

Note 8 - Net Loss Per Share Attributable to Common Stockholders (Tables)	6 Months Ended
	Jun. 30, 2018
Notes Tables
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Outstanding stock options 4,447,226 2,783,570 4,447,226 2,783,570 Convertible preferred stock 22,112,775 - 22,112,775 - 26,560,001 2,783,570 26,560,001 2,783,570

Note 1 - Organization and Ope20

Note 1 - Organization and Operations (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	Aug. 02, 2017	Nov. 12, 2015	Jun. 30, 2018	Dec. 31, 2017
Cash, Cash Equivalents, and Short-term Investments, Total			$ 26,500
Retained Earnings (Accumulated Deficit), Ending Balance			$ (200,701)	$ (189,741)
Preferred Stock, Par or Stated Value Per Share			$ 0.001	$ 0.001
Series A Convertible Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues	22,000
Payments of Stock Issuance Costs	$ 500
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	$ 22,000
Sales Agreement [Member] | Cowen and Company, LLC [Member] | Common Stock [Member]
Sale of Stock, Maximum Value of Stock Offered		$ 40,000
Sale of Stock, Commission to Sales Agent, Percentage			3.00%
Stock Issued During Period, Shares, New Issues			0	896,811
Proceeds from Issuance of Common Stock				$ 1,400
Payments of Stock Issuance Costs				$ 100

Note 2 - Summary of Significa21

Note 2 - Summary of Significant Accounting Policies (Details Textual) - USD ($)	Jun. 30, 2018	Jun. 30, 2017
Restricted Cash and Cash Equivalents, Total	$ 22,000	$ 14,000

Note 3 - Fair Value Measureme22

Note 3 - Fair Value Measurements - Summary of Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Total	$ 24,394	$ 32,633
Cash Equivalents [Member]
Cash equivalents	10,425	11,662
US Government Agencies Debt Securities [Member]
Government securities	13,969	20,971
Fair Value, Inputs, Level 1 [Member]
Total	24,394	32,633
Fair Value, Inputs, Level 1 [Member] | Cash Equivalents [Member]
Cash equivalents	10,425	11,662
Fair Value, Inputs, Level 1 [Member] | US Government Agencies Debt Securities [Member]
Government securities	13,969	20,971
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 Measureme23

Note 3 - Fair Value Measurements - Available-for-sale Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Amortized Cost	$ 13,973	$ 20,991
Unrealized Gains
Unrealized Losses	(4)	(20)
Fair Value	13,969	20,971
US Government Agencies Debt Securities [Member]
Amortized Cost	13,973	20,991
Unrealized Gains
Unrealized Losses	(4)	(20)
Fair Value	$ 13,969	$ 20,971

Note 4 - Commitments and Cont24

Note 4 - Commitments and Contingencies (Details Textual) - USD ($)	Jun. 30, 2018	Dec. 31, 2017
Security Deposit	$ 22,000
Letters of Credit Outstanding, Amount	22,000	$ 22,000
Loans Pledged as Collateral	$ 22,000	$ 22,000

Note 4 - Commitments and Cont25

Note 4 - Commitments and Contingencies - Future Minimum Payments for Operating Leases (Details) $ in Thousands	Jun. 30, 2018USD ($)
2,018	$ 138
2,019	207
Total minimum lease payments	$ 345

Note 5 - Series A Preferred F26

Note 5 - Series A Preferred Financing (Details Textual) - USD ($) $ / shares in Units, $ in Millions	Aug. 02, 2017	Jun. 30, 2018	Dec. 31, 2017
Preferred Stock, Par or Stated Value Per Share		$ 0.001	$ 0.001
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
Payments of Stock Issuance Costs	$ 0.5
Convertible Preferred Stock, Shares Issued upon Conversion	1,005
Convertible Preferred Stock, Conversion Price of Shares Issued upon Conversion	$ 0.9949
Convertible Preferred Stock, Maximum Ownership Percentage Allowed after Conversion of Stock	9.985%
Preferred Stock, Redemption Price Per Share	$ 1.30
Accretion of Redeemable Convertible Preferred Stock to Redemption Value	$ 6.7

Note 6 - Stock-based Compensa27

Note 6 - Stock-based Compensation (Details Textual) - USD ($)	Jan. 01, 2018	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2014
Common Stock, Capital Shares Reserved for Future Issuance		27,417,211		27,417,211		25,877,695
Allocated Share-based Compensation Expense, Total		$ 922,000	$ 867,000	$ 1,743,000	$ 1,712,000
The 2014 Employee Stock Purchase Plan [Member]
Common Stock, Capital Shares Reserved for Future Issuance		140,479		140,479		192,463	140,500
Share-based Compensation Arrangement by Share-based Payment Award, Number of Annual Additional Shares, Percentage		1.00%		1.00%
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, Number of Additional Shares Authorized	0
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized		304,991		304,991
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period		51,984		51,984
Allocated Share-based Compensation Expense, Total		$ 24,000	$ 52,000	$ 48,000	$ 100,000

Note 6 - Stock-based Compensa28

Note 6 - Stock-based Compensation - Stock Option Activity for Employees and Non-employees (Details) - USD ($) $ / shares in Units, $ in Thousands		6 Months Ended	12 Months Ended
		Jun. 30, 2018	Dec. 31, 2017
Options Outstanding, Beginning Balance (in shares)		2,681,072
Options Outstanding, Weighted Average Exercise Price, Beginning Balance (in dollars per share)		$ 7.18
Options Outstanding, Weighted-average Remaining Contractual Term (Year)		7 years 328 days	6 years 292 days
Options Outstanding, Aggregate Intrinsic Value		$ 614	$ 121
Options Granted (in shares)		1,891,600
Options Granted, Weighted Average Exercise Price (in dollars per share)		$ 2.65
Options Exercised (in shares)
Options Exercised, Weighted Average Exercise Price (in dollars per share)
Options Forfeited (in shares)		(83,433)
Options Forfeited, Weighted Average Exercise Price (in dollars per share)		$ 5.82
Options Expired (in shares)		(42,013)
Options Expired, Weighted Average Exercise Price (in dollars per share)		$ 13.30
Options Outstanding, Ending Balance (in shares)		4,447,226	2,681,072
Options Outstanding, Weighted Average Exercise Price, Ending Balance (in dollars per share)		$ 5.22	$ 7.18
Options Exercisable (in shares)		1,844,871
Options Exercisable, Weighted Average Exercise Price (in dollars per share)		$ 7.44
Options Exercisable, Weighted-average Remaining Contractual Term (Year)		6 years 36 days
Options Exercisable, Aggregate Intrinsic Value		$ 286
Options Vested or Expected to Vest (in shares)	[1]	4,447,226
Options Vested or Expected to Vest, Weighted Average Exercise Price (in dollars per share)	[1]	$ 5.22
Options Vested or Expected to Vest, Weighted-average Remaining Contractual Term (Year)	[1]	7 years 328 days
Options Vested or Expected to Vest, Aggregate Intrinsic Value	[1]	$ 614
[1]	Represents the number of vested options at June 30, 2018 plus the number of unvested options expected to vest based on the unvested options outstanding at June 30, 2018.

Note 6 - Stock-based Compensa29

Note 6 - Stock-based Compensation - Common Stock Reserved for Future Issuance (Details) - shares	Jun. 30, 2018	Dec. 31, 2017	Dec. 31, 2014
Reserved for future issuance (in shares)	27,417,211	25,877,695
The 2014 Employee Stock Purchase Plan [Member]
Reserved for future issuance (in shares)	140,479	192,463	140,500
Performance Shares [Member]
Reserved for future issuance (in shares)	5,163,957	3,572,457
Conversion of Series A Preferred Stock to Common Stock [Member]
Reserved for future issuance (in shares)	22,112,775	22,112,775

Note 7 - Income Taxes (Details

Note 7 - Income Taxes (Details Textual) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Income Tax Expense (Benefit), Total	$ 0	$ 0

Note 8 - Net Loss Per Share A31

Note 8 - Net Loss Per Share Attributable to Common Stockholders - Common Stock Equivalents Excluded From Calculation of Net Loss Per Share (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Antidilutive Securities (in shares)	26,560,001	2,783,570	26,560,001	2,783,570
Convertible Preferred Stock [Member]
Antidilutive Securities (in shares)	22,112,775		22,112,775
Employee Stock Option [Member]
Antidilutive Securities (in shares)	4,447,226	2,783,570	4,447,226	2,783,570