View Filing Data

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-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. Since inception, the Company has devoted substantially all of its efforts to product research and development, initial market development and raising capital. The Company has not generated any product revenue related to its primary business purpose to date and is subject to a number of risks similar to those of other development stage companies, including dependence on key individuals, competition from other companies, the need for development of commercially viable products and the need to obtain adequate additional financing to fund the development of its product candidates. The Company is also subject to a number of risks similar to other companies in the biotechnology industry, including regulatory approval of products, uncertainty of market acceptance of products, competition from substitute products and larger companies, the need to obtain additional financing, compliance with government regulations, protection of proprietary technology, dependence on third parties, product liability and dependence on key individuals.

As of March 31, 2016, the Company had cash, cash equivalents and available-for-sale investments of $59.4 million. The Company believes that its existing cash, cash equivalents and available-for-sale investments will be sufficient to fund operations and capital expenditures into the fourth quarter of 2017. The Company had an accumulated deficit of $137.8 million as of March 31, 2016.

On November 12, 2015, the Company filed a shelf registration statement on Form S-3 (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. As of March 31, 2016, the Company had not commenced sales under this program.

Note 2 - Summary of Significant Accounting Policies

3 Months Ended

Mar. 31, 2016

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, 2015 and notes thereto, included in the Company’s Annual Report on Form 10-K, as filed with the SEC on March 14, 2016.

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 March 31, 2016, the results of its operations for the three months ended March 31, 2016 and 2015 and its cash flows for the three months ended March 31, 2016 and 2015. Such adjustments are of a normal and recurring nature. The results for the three months ended March 31, 2016 are not necessarily indicative of the results for the year ending December 31, 2016, or for any future period.

The unaudited interim condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, Proteon Therapeutics Limited and Proteon Securities Corp. 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 limited to, estimates related to convertible notes, stock-based compensation expense, clinical trial accruals and reported amounts of revenues and 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.

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 4), 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 3. 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, short-term investments and forward foreign currency contracts (see Note 4). There have been no changes to the valuation methods utilized by the Company during the three months ended March 31, 2016 and 2015. The Company evaluates transfers between levels at the end of each reporting period. There were no transfers of financial instruments between levels during the three months ended March 31, 2016 and 2015.

Derivative Financial Instruments

The Company enters into forward foreign currency contracts to mitigate its exposure to fluctuations in the exchange rates between the Swiss Franc and the U.S. dollar (see Note 4). The Company records these derivative financial instruments on the consolidated balance sheets at fair value. Although these derivative contracts are intended to economically hedge foreign exchange risk, the Company has not elected to apply hedge accounting. As such, changes in the fair value of these instruments are recorded directly in earnings as a component of other income (expense), as they occur. The Company executes its derivative instruments with financial institutions that the Company judges to be credit-worthy, defined as institutions that hold an investment-grade credit rating.

Recent Accounting Pronouncements

In 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 is effective beginning January 1, 2018, with no early adoption permitted. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. The amendments may be applied retrospectively to each prior period presented or retrospectively with the cumulative effect recognized as of the date of initial application. The Company is currently evaluating the impact of the new guidance on its condensed consolidated financial statements, if any.

In August 2014, the FASB issued ASU 2014-15,

“Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern”

(“ASU 2014-15”). ASU 2014-15 is authoritative guidance on determining when and how reporting entities must disclose going-concern uncertainties in their financial statements, including requiring management to perform interim and annual assessments of an entity’s ability to continue as a going concern within one year of the date of issuance of the entity’s financial statements and providing certain disclosures if there is substantial doubt about the entity’s ability to continue as a going concern. This guidance will be effective for the Company’s fiscal year 2016 and for interim periods beginning in the first quarter of fiscal 2017. The Company is still evaluating the impact of this guidance on its financial statement disclosures.

The adoption of this accounting standard may affect the Company’s financial statement disclosures in future periods.

In November 2015, the FASB issued ASU No. 2015-17,

Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes

(“ASU 2015-17”), which simplifies the presentation of deferred income taxes. ASU 2015-17 requires that deferred tax assets and liabilities be classified as noncurrent in a classified statement of financial position. ASU 2015-17 is effective for financial statements issued for fiscal years beginning after December 15, 2016 (and interim periods within those fiscal years) with early adoption permitted. ASU 2015-17 may be either applied prospectively to all deferred tax assets and liabilities or retrospectively to all periods presented. The Company elected to early adopt ASU 2015-17 prospectively in the fourth quarter of 2015. As a result, the Company presented all deferred tax assets and liabilities as noncurrent on the consolidated balance sheet as of December 31, 2015. There was no impact on the Company’s results of operations as a result of the adoption of ASU 2015-17.

There have been no other material changes to the significant accounting policies previously disclosed in the Company’s Annual Report on Form 10-K, as filed with the SEC on March 14, 2016.

Note 3 - Fair Value Measurements

3 Months Ended

Mar. 31, 2016

Fair Value Disclosures [Text Block]

Fair Value Measurements

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

	As of March 31, 2016
	Quoted Prices		Significant		Significant
	in Active		Observable		Unobservable
	Markets		Inputs		Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets
Cash equivalents	$	22,873	$	-	$	-	$	22,873
Government securities		35,326		-		-		35,326
Total	$	58,199	$	-	$	-	$	58,199

Liabilities
Foreign currency forward contracts	$	-	$	319	$	-	$	319
Total	$	-	$	319	$	-	$	319

	As of December 31, 2015
	Quoted Prices		Significant		Significant
	in Active		Observable		Unobservable
	Markets		Inputs		Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets
Cash equivalents	$	39,233	$	-	$	-	$	39,233
Government securities		25,232		-		-		25,232
Total	$	64,465	$	-	$	-	$	64,465

Liabilities
Foreign currency forward contracts	$	-	$	537	$	-	$	537
Total	$	-	$	537	$	-	$	537

As of March 31, 2016 and December 31, 2015, the Company’s cash equivalents consist principally of money market funds and government debt securities with original maturities of 90 days or less. Government securities consist principally of government debt securities and money market funds which are classified as available-for-sale. Corporate bonds consist of bonds issued by highly-rated corporate entities which are classified as available-for-sale. Forward foreign currency contracts consist of contracts with credit-worthy financial institutions to buy Swiss Francs with U.S. dollars in the future at agreed upon exchange rates.

Forward foreign currency contracts are stated at fair value and consist of Level 2 financial instruments in the fair value hierarchy. The Company determines the fair value of its forward foreign currency contracts based on pricing from a service provider. The service provider values the instruments based on market prices from a variety of industry-standard independent data providers. Such market prices are based on inputs other than quoted prices included within Level 1 that are observable for the asset, either directly or indirectly (Level 2 inputs). Cash equivalents and government securities are stated at fair value and consist of Level 1 financial instruments in the fair value hierarchy

The Company determined the fair value of its debt security holdings and corporate bonds based on pricing from a service provider. The service provider values the securities based on market prices from a variety of industry-standard independent data providers. These market prices are quoted prices in active markets for identical assets (Level 1 inputs). Corporate bonds are stated at fair value and consist of Level 2 financial instruments in the fair value hierarchy. The Company determines the fair value of its corporate bonds holdings based on pricing from a service provider. The service provider values the securities based on market prices from a variety of industry-standard independent data providers. Such market prices are based on inputs other than quoted prices included within Level 1 that are observable for the asset, either directly or indirectly (Level 2 inputs).

Available-for-sale securities at March 31, 2016 and December 31, 2015 consist of the following (in thousands):

	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
March 31, 2016
Government securities
(Due within 1 year)	$	35,314	$	13	$	(1	)	$	35,326
	$	35,314	$	13	$	(1	)	$	35,326

December 31, 2015
Government securities
(Due within 1 year)	$	25,243	$	1	$	(12	)	$	25,232
	$	25,243	$	1	$	(12	)	$	25,232

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.

Note 4 - Derivative Financial Instruments

3 Months Ended

Mar. 31, 2016

Derivative Instruments and Hedging Activities Disclosure [Text Block]

4.	Derivative Financial Instruments

The Company enters into forward foreign currency contracts to mitigate its exposure to fluctuations in the U.S dollar value of forecasted transactions denominated in Swiss Franc. During the three months ended March 31, 2016, the Company had forward foreign currency contract activity for which it did not elect hedge accounting for the forward foreign currency contracts outstanding as of March 31, 2016, but may elect to apply hedge accounting in the future. As a result, during the three months ended March 31, 2016, the Company experienced unrealized gains within other expense in the consolidated statements of operations from the mark-to-market of outstanding forward foreign currency contracts. The Company expects potential volatility within other income (expense) in future periods for contracts for which the Company does not apply hedge accounting.

As of March 31, 2016, the Company had the following outstanding forward foreign currency contracts that were not designated for hedge accounting and that were used to reduce the exposure to fluctuations in the U.S dollar value of forecasted transactions denominated in Swiss Franc (dollars in thousands):

Notional Amount

Effective Date

Maturity Date

Number of Instruments

$5,281

June 12, 2015

Various dates through December 15, 2016

No forward foreign currency contracts were held by the Company prior to May 2015. The table below presents the fair value of the Company’s derivative financial instruments as well as their classification on the balance sheet as of March 31, 2016 (in thousands):

		Balance Sheet line item				Gross amounts of recognized liabilities				Gross amount offset in consolidated balance sheet				Net Amount
Forward foreign currency contracts			Other current liabilities			$	319			$	-			$	319

The entire disclosure for derivative instruments and hedging activities including, but not limited to, risk management strategies, non-hedging derivative instruments, assets, liabilities, revenue and expenses, and methodologies and assumptions used in determining the amounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6441202&loc=d3e80720-113993

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64837297&loc=d3e41620-113959

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624163-113959

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5579240-113959

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4D
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624177-113959

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80784-113994

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=64837297&loc=d3e41641-113959

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5579245-113959

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624258-113959

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80748-113994

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4K
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5708775-113959

Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4J
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5708773-113959

Reference 14: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5618551-113959

Reference 15: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5580258-113959

Reference 16: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4E
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624181-113959

Reference 17: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

Reference 18: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=64837297&loc=d3e41638-113959

Reference 19: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(n))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Note 5 - Commitments and Contingencies

3 Months Ended

Mar. 31, 2016

Commitments and Contingencies Disclosure [Text Block]

Commitments and Contingencies

In July 2015, the Company entered into a manufacturing services agreement with Lonza Ltd for the processing, development and manufacture of the active pharmaceutical ingredient (“API”) in its lead product candidate, vonapanitase. Under the agreement, the Company will execute purchase orders authorizing Lonza to manufacture API batches and will pay for the services and batches in accordance with terms and assumptions in the agreement and to be set forth in a project plan. As of March 31, 2016, the Company has executed one purchase order for $1.9 million (originally denominated in Swiss Francs) for the manufacturing of one batch to commence in July 2016. Management expects to pay $0.3 million to Lonza in the second quarter of 2016 for Lonza’s acquisition of raw materials in connection with this purchase order. In addition, management has executed a purchase order for 7.6 million Swiss Francs, approximately $7.9 million at current exchange rates, for the manufacturing of four batches to commence in June 2017.

Future minimum payments required under operating leases as of March 31, 2016 are summarized as follows (in thousands):

Year Ending December 31:	Amount

2016	$	126
2017		168
2018		84
Total minimum lease payments	$	378

Rental expense for the three months ended March 31, 2016 and 2015 was $45,000 and $47,000, respectively. 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 March 31, 2016, the Company has provided a security deposit in the amount of $14,000 to the lessor.

At March 31, 2016 and December 31, 2015, the Company had $14,000 in an outstanding letter of credit to be used as collateral for leased premises. At March 31, 2016 and December 31, 2015, the Company pledged an aggregate of $14,000 to the bank as collateral for the letter of credit, which is included in long-term assets and both short-term deposits and long-term assets, respectively.

Note 6 - Stock-based Compensation

3 Months Ended

Mar. 31, 2016

Disclosure of Compensation Related Costs, Share-based Payments [Text Block]

Stock-based Compensation

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, 2015		2,200,369		$	8.52		7.8	$	15,705
Granted		10,000		$	6.68
Exercised		(6,394	)	$	1.92
Outstanding at March 31, 2016		2,203,975		$	8.53		7.6	$	4,445
Exercisable at March 31, 2016		939,661		$	4.35		5.6	$	3,657
Vested or expected to vest at March 31, 2016 (1)		2,021,309		$	8.22		7.4	$	4,355

______________________

(1) Represents the number of vested options at March 31, 2016 plus the number of unvested options expected to vest based on the unvested options outstanding at March 31, 2016.

The Company has the following shares reserved for future issuance:

	March 31,		December 31,
	2016		2015

Stock-based compensation awards		3,073,567		2,419,901
Employee Stock Purchase Plan		297,359		297,359
Total		3,370,926		2,717,260

The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.

Note 7 - Income Taxes

3 Months Ended

Mar. 31, 2016

Income Tax Disclosure [Text Block]

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 that the benefit of its deferred tax assets will not be realized. Due to the uncertainty surrounding the realization of the favorable tax attributes in future tax returns, the Company has provided a full valuation allowance against its deferred tax assets. There were no significant income tax provisions or benefits for the three months ended March 31, 2016 and 2015.

Note 8 - Net Loss Per Share Attributable to Common Stockholders

3 Months Ended

Mar. 31, 2016

Earnings Per Share [Text Block]

Net Loss per Share Attributable to Common Stockholders

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 three months ended March 31, 2016 and 2015 resulted in net losses, there is no 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:

	Three Months Ended March 31,
	2016		2015
Outstanding stock options		2,203,975		1,635,219
Outstanding ESPP shares		8,841		2,859
		2,212,816		1,638,078

Note 9 - Subsequent Events

3 Months Ended

Mar. 31, 2016

Subsequent Events [Text Block]

Subsequent Events

The Company has evaluated all activity that occurred subsequent to quarter end but prior to issuance of the 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.

On April 20, 2016, the Company formed a wholly-owned holding company in Delaware, Proteon International Holdings, Inc. (“Proteon International”). On May 4, 2016, Proteon International formed a wholly-owned holding company in Bermuda, (Proteon Bermuda Limited) (“Proteon Bermuda”).

Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2016

Accounting Policies [Abstract]

Basis of Accounting, Policy [Policy Text Block]

Basis of Presentation, Principles of Consolidation and Use of Estimates

Fair Value Measurement, Policy [Policy Text Block]

Fair Value of Financial Instruments

Fair Value Measurement and Disclosures

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.

Derivatives, Policy [Policy Text Block]

Derivative Financial Instruments

New Accounting Pronouncements, Policy [Policy Text Block]

Recent Accounting Pronouncements

In May 2014, the FASB issued ASU 2014-09,

“Revenue from Contracts with Customers”

In August 2014, the FASB issued ASU 2014-15,

“Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern”

The adoption of this accounting standard may affect the Company’s financial statement disclosures in future periods.

In November 2015, the FASB issued ASU No. 2015-17,

Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes

There have been no other material changes to the significant accounting policies previously disclosed in the Company’s Annual Report on Form 10-K, as filed with the SEC on March 14, 2016.

Note 3 - Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2016

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

	As of March 31, 2016
	Quoted Prices		Significant		Significant
	in Active		Observable		Unobservable
	Markets		Inputs		Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets
Cash equivalents	$	22,873	$	-	$	-	$	22,873
Government securities		35,326		-		-		35,326
Total	$	58,199	$	-	$	-	$	58,199

Liabilities
Foreign currency forward contracts	$	-	$	319	$	-	$	319
Total	$	-	$	319	$	-	$	319

	As of December 31, 2015
	Quoted Prices		Significant		Significant
	in Active		Observable		Unobservable
	Markets		Inputs		Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets
Cash equivalents	$	39,233	$	-	$	-	$	39,233
Government securities		25,232		-		-		25,232
Total	$	64,465	$	-	$	-	$	64,465

Liabilities
Foreign currency forward contracts	$	-	$	537	$	-	$	537
Total	$	-	$	537	$	-	$	537

Available-for-sale Securities [Table Text Block]

	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
March 31, 2016
Government securities
(Due within 1 year)	$	35,314	$	13	$	(1	)	$	35,326
	$	35,314	$	13	$	(1	)	$	35,326

December 31, 2015
Government securities
(Due within 1 year)	$	25,243	$	1	$	(12	)	$	25,232
	$	25,243	$	1	$	(12	)	$	25,232

Tabular disclosure of available-for-sale securities which includes, but is not limited to, changes in the cost basis and fair value, fair value and gross unrealized gain (loss), fair values by type of security, contractual maturity and classification, amortized cost basis, contracts to acquire securities to be accounted for as available-for-sale, debt maturities, transfers to trading, change in net unrealized holding gain (loss) net of tax, continuous unrealized loss position fair value, aggregate losses qualitative disclosures, other than temporary impairment (OTTI) losses or other disclosures related to available for sale securities.

Note 4 - Derivative Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2016

Schedule of Derivative Instruments [Table Text Block]

Notional Amount

Effective Date

Maturity Date

Number of Instruments

$5,281

June 12, 2015

Various dates through December 15, 2016

Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]

		Balance Sheet line item				Gross amounts of recognized liabilities				Gross amount offset in consolidated balance sheet				Net Amount
Forward foreign currency contracts			Other current liabilities			$	319			$	-			$	319

Tabular disclosure of pertinent information about a derivative or group of derivatives on a disaggregated basis, such as for individual instruments, or small groups of similar instruments. May include a combination of the type of instrument, risks being hedged, notional amount, hedge designation, related hedged item, inception date, maturity date, or other relevant item.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=64837297&loc=d3e41641-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624163-113959

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64837297&loc=d3e41678-113959

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=64837297&loc=d3e41638-113959

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5580258-113959

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5579245-113959

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5579240-113959

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64837297&loc=d3e41620-113959

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(n)(2))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Note 5 - Commitments and Contingencies (Tables)

3 Months Ended

Mar. 31, 2016

Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]

Year Ending December 31:	Amount

2016	$	126
2017		168
2018		84
Total minimum lease payments	$	378

Note 6 - Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2016

Schedule of 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, 2015		2,200,369		$	8.52		7.8	$	15,705
Granted		10,000		$	6.68
Exercised		(6,394	)	$	1.92
Outstanding at March 31, 2016		2,203,975		$	8.53		7.6	$	4,445
Exercisable at March 31, 2016		939,661		$	4.35		5.6	$	3,657
Vested or expected to vest at March 31, 2016 (1)		2,021,309		$	8.22		7.4	$	4,355

Common Stock Reserved for Future Issuance [Table Text Block]

<div style="display: inline; font-family: times new roman; font-size: 10pt"><table cellpadding="0" cellspacing="0" style="border-collapse: collapse;; width: 700px;"> <tr style="vertical-align: bottom"> <td style="font-size: 10pt"> </td> <td style="font-size: 10pt; font-weight: bold"> </td> <td colspan="3" style="font-size: 10pt; font-weight: bold; text-align: center">March 31,</td> <td style="font-size: 10pt; font-weight: bold"> </td> <td colspan="3" style="font-size: 10pt; font-weight: bold; text-align: center">December 31,</td> </tr> <tr style="vertical-align: bottom"> <td style="font-size: 10pt"> </td> <td style="font-size: 10pt; font-weight: bold; padding-bottom: 1pt"> </td> <td colspan="3" style="font-size: 10pt; font-weight: bold; text-align: center; border-bottom: Black 1pt solid">2016</td> <td style="font-size: 10pt; font-weight: bold; padding-bottom: 1pt"> </td> <td colspan="3" style="font-size: 10pt; font-weight: bold; text-align: center; border-bottom: Black 1pt solid">2015</td> </tr> <tr style="vertical-align: bottom"> <td style="font-size: 10pt"> </td> <td style="font-size: 10pt; font-weight: bold; padding-bottom: 1pt"> </td> <td colspan="3" style="font-size: 10pt; font-weight: bold; text-align: center; padding-bottom: 1pt"> </td> <td style="font-size: 10pt; font-weight: bold; padding-bottom: 1pt"> </td> <td colspan="3" style="font-size: 10pt; font-weight: bold; text-align: center; padding-bottom: 1pt"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(204,238,255)"> <td style="width: 74%; font-size: 10pt; text-align: left">Stock-based compensation awards</td> <td style="width: 1%; font-size: 10pt"> </td> <td style="width: 1%; font-size: 10pt; text-align: left"> </td> <td style="width: 10%; font-size: 10pt; text-align: right">3,073,567</td> <td style="width: 1%; font-size: 10pt; text-align: left"> </td> <td style="width: 1%; font-size: 10pt"> </td> <td style="width: 1%; font-size: 10pt; text-align: left"> </td> <td style="width: 10%; font-size: 10pt; text-align: right">2,419,901</td> <td style="width: 1%; font-size: 10pt; text-align: left"> </td> </tr> <tr style="vertical-align: bottom; background-color: White"> <td style="font-size: 10pt; text-align: left; padding-bottom: 1pt">Employee Stock Purchase Plan</td> <td style="font-size: 10pt; padding-bottom: 1pt"> </td> <td style="border-bottom: Black 1pt solid; font-size: 10pt; text-align: left"> </td> <td style="border-bottom: Black 1pt solid; font-size: 10pt; text-align: right">297,359</td> <td style="border-bottom: Black 1pt solid; font-size: 10pt; text-align: left"> </td> <td style="font-size: 10pt; padding-bottom: 1pt"> </td> <td style="border-bottom: Black 1pt solid; font-size: 10pt; text-align: left"> </td> <td style="border-bottom: Black 1pt solid; font-size: 10pt; text-align: right">297,359</td> <td style="border-bottom: Black 1pt solid; font-size: 10pt; text-align: left"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(204,238,255)"> <td style="font-size: 10pt; padding-bottom: 2.25pt">Total</td> <td style="font-size: 10pt; padding-bottom: 2.25pt"> </td> <td style="border-bottom: Black 2.25pt double; font-size: 10pt; text-align: left"> </td> <td style="border-bottom: Black 2.25pt double; font-size: 10pt; text-align: right">3,370,926</td> <td style="border-bottom: Black 2.25pt double; font-size: 10pt; text-align: left"> </td> <td style="font-size: 10pt; padding-bottom: 2.25pt"> </td> <td style="border-bottom: Black 2.25pt double; font-size: 10pt; text-align: left"> </td> <td style="border-bottom: Black 2.25pt double; font-size: 10pt; text-align: right">2,717,260</td> <td style="border-bottom: Black 2.25pt double; font-size: 10pt; text-align: left"> </td> </tr> </table></div>

Note 8 - Net Loss Per Share Attributable to Common Stockholders (Tables)

3 Months Ended

Mar. 31, 2016

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

	Three Months Ended March 31,
	2016		2015
Outstanding stock options		2,203,975		1,635,219
Outstanding ESPP shares		8,841		2,859
		2,212,816		1,638,078

Note 1 - Organization and Operations (Details Textual) - USD ($)	Mar. 31, 2016	Dec. 31, 2015
Cash, Cash Equivalents, and Short-term Investments	$ 59,400,000
Retained Earnings (Accumulated Deficit)	$ (137,803,000)	$ (131,251,000)

Cash includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the customer may deposit additional funds at any time and effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid Investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Short-term investments, exclusive of cash equivalents, generally consist of marketable securities intended to be sold within one year (or the normal operating cycle if longer) and may include trading securities, available-for-sale securities, or held-to-maturity securities (if maturing within one year), as applicable.