Entellus Medical (ENTL) 10-K 25 Feb 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Feb. 11, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Trading Symbol	ENTL
Entity Registrant Name	ENTELLUS MEDICAL INC
Entity Central Index Key	1,374,128
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		18,793,754
Entity Public Float			$ 178

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2015	Dec. 31, 2014
CURRENT ASSETS
Cash and cash equivalents	$ 28,548,000	$ 3,484,000
Short-term investments	38,210,000	0
Accrued interest income	247,000
Accounts receivable, net	10,440,000	8,746,000
Inventories	3,889,000	2,439,000
Prepaid expenses and other current assets	1,691,000	883,000
Total current assets	83,025,000	15,552,000
PROPERTY AND EQUIPMENT, NET	4,126,000	1,730,000
OTHER ASSETS
Debt issuance costs, net	176,000	237,000
Other non-current assets	34,000	1,717,000
Total assets	87,361,000	19,236,000
CURRENT LIABILITIES
Accounts payable	2,208,000	2,414,000
Convertible preferred stock warrant liability		291,000
Accrued expenses	6,995,000	5,084,000
Total current liabilities	9,203,000	7,789,000
LONG-TERM LIABILITIES
Long-term debt, less current portion	20,000,000	20,000,000
Other non-current liabilities	562,000	247,000
Total liabilities	$ 29,765,000	$ 28,036,000
COMMITMENTS AND CONTINGENCIES (See Note M)
CONVERTIBLE PREFERRED STOCK, issuable in series, $0.001 par value; Authorized shares: none at December 31, 2015 and 44,567 at December 31, 2014 Issued and outstanding shares: none at December 31, 2015 and 44,317 at December 31, 2014		$ 91,553,556
STOCKHOLDERS' EQUITY (DEFICIT) (see Note I)
Preferred stock, $0.001 par value per share: Authorized shares: 10,000 at December 31, 2015 and none at December 31, 2014 Issued and outstanding shares: none
Common stock, $0.001 par value per share: Authorized shares: 200,000 at December 31, 2015 and 62,276 at December 31, 2014 Issued and outstanding shares: 18,767 and 1,887 at December 31, 2015 and December 31, 2014, respectively	$ 19,000	$ 2,000
Additional paid-in capital	179,673,000	3,402,000
Accumulated other comprehensive loss	(38,000)
Accumulated deficit	(122,058,000)	(103,758,000)
Total stockholders' equity (deficit)	57,596,000	(100,354,000)
Total liabilities and stockholders' equity (deficit)	$ 87,361,000	$ 19,236,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Statement Of Financial Position [Abstract]
Convertible preferred stock, par value	$ 0.001	$ 0.001
Convertible preferred stock, shares authorized	0	44,567,071
Convertible preferred stock, shares issued	0	44,317,071
Convertible preferred stock, shares outstanding	0	44,317,071
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	0
Preferred stock, shares Issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	200,000,000	62,276,000
Common stock, shares issued	18,794,000	1,887,000
Common stock, shares outstanding	18,794,000	1,887,000

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2013
Income Statement [Abstract]
Revenue	$ 61,570	$ 32,545
Cost of goods sold	14,058	7,808
Gross profit	47,512	24,737
Operating expenses
Selling and marketing	44,947	27,631
Research and development	5,387	5,143
General and administrative	13,034	4,311
Total operating expenses	63,368	37,085
Loss from operations	(15,856)	(12,348)
Other income (expense)
Interest income	171	6
Interest expense	(2,604)	(1,082)
Other non-operating (expense) income	(11)	28
Total other expense, net	(2,444)	(1,048)
Net loss	(18,300)	(13,396)
Other comprehensive loss
Unrealized loss on short term investments, net of tax	(16)	(1)
Foreign currency translation loss, net of tax	(22)
Comprehensive loss	$ (18,338)	$ (13,397)
Net loss per share, basic and diluted	$ (1.06)	$ (11.82)
Weighted average common shares used to compute net loss per share, basic and diluted	17,217	1,133

Consolidated Statements of Conv

Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income(Loss) [Member]
Balance at Dec. 31, 2012	$ (81,902)	$ 91,554	$ 1	$ 1,529	$ (83,433)	$ 1
Balance, shares at Dec. 31, 2012		44,317,000	866,000
Stock options exercised	$ 717		$ 1	716
Stock options exercised, shares	583,000		583,000
Stock-based compensation expense	$ 354			354
Comprehensive loss	(13,397)				(13,396)	(1)
Balance at Dec. 31, 2013	(94,228)	$ 91,554	$ 2	2,599	(96,829)
Balance, shares at Dec. 31, 2013		44,317,000	1,449,000
Stock options exercised	$ 576			576
Stock options exercised, shares	466,000		466,000
Repurchase of common stock	$ (21)			(21)
Repurchase of common stock, shares			(28,000)
Stock-based compensation expense	248			248
Comprehensive loss	(6,929)				(6,929)
Balance at Dec. 31, 2014	$ (100,354)	$ 91,554	$ 2	3,402	(103,758)
Balance, shares at Dec. 31, 2014		44,317,000	1,887,000
Conversion of convertible preferred stock to common stock, shares	11,404,311
Stock options exercised	$ 323		$ 209	$ 323
Stock options exercised, shares	209,000
Repurchase of common stock, shares	(1,000)			(1,000)
Stock-based compensation expense	$ 2,811			$ 2,811
Comprehensive loss	(18,338)				(18,300)	(38)
Balance at Dec. 31, 2015	57,596		$ 19	179,673	$ (122,058)	$ (38)
Balance, shares at Dec. 31, 2015			18,794,000
Issuance of common stock upon IPO, net of issuance costs	80,953		$ 5	80,948
Issuance of common stock upon IPO, net of issuance costs, shares			5,294,000
Conversion of convertible preferred stock to common stock	91,554	$ (91,554)	$ 12	91,542
Conversion of convertible preferred stock to common stock, shares		(44,317,000)	11,404,000
Conversion of convertible preferred stock to common stock warrants	$ 648			$ 648

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net loss	$ (18,300)	$ (6,929)	$ (13,396)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,005	618	460
Amortization of debt issuance costs	61	59	82
Amortization of premium on investments	425		9
Accretion of final payment fee on long-term debt	307	227
Deferred rent	6	(13)	8
Accretion of debt discount			125
Gain on disposal of equipment		(1)	(1)
Stock-based compensation	2,811	248	354
Changes in fair value of convertible preferred stock warrants	357	80	80
Changes in operating assets and liabilities:
Accrued interest income	(247)		46
Accounts receivables, net	(1,715)	(2,923)	(2,283)
Inventories	(1,450)	(570)	(297)
Prepaid expenses and other current assets	(808)	(67)	(340)
Other non-current assets	1,683	(1,698)
Accounts payable	(206)	1,212	(54)
Accrued expenses	1,913	980	1,996
Net cash used in operating activities	(14,158)	(8,777)	(13,211)
Cash flows from investing activities:
Purchase of property and equipment	(3,402)	(999)	(587)
Proceeds from sale of property and equipment		1	1
Purchase of investments	(122,677)
Proceeds from maturities of short-term investments	84,026		6,624
Net cash (used in) provided by investing activities	(42,053)	(998)	6,038
Cash flows from financing activities:
Proceeds from long-term debt		5,000	7,500
Debt issuance costs		(5)	(16)
Proceeds from stock options exercised	323	576	717
Proceeds from initial public offering, net of issuance costs	80,953
Repurchase of common stock	(1)	(21)
Net cash provided by financing activities	81,275	5,550	8,201
Net increase (decrease) in cash and cash equivalents	25,064	(4,225)	1,028
Cash and cash equivalents - beginning of period	3,484	7,709	6,681
Cash and cash equivalents - end of period	28,548	3,484	7,709
Supplemental cash flow information:
Debt issuance costs		5
Cash paid for interest	$ 1,864	$ 1,349	$ 626

Nature of Business

Nature of Business	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Nature of Business	NOTE A – NATURE OF BUSINESS Entellus Medical, Inc. (the “Company”) was incorporated in Minnesota in April 2006 and was reincorporated in Delaware in August 2006. The Company is focused on the design, development and commercialization of products for the minimally invasive treatment of patients suffering from chronic sinusitis. The Company’s XprESS family of products is used by ear, nose and throat (“ENT”) physicians to treat patients with chronic sinusitis by opening narrowed or obstructed sinus drainage pathways using balloon sinus dilation performed in the physician office or the operating room. The Company currently sells product through its sales force in the United States and United Kingdom and to a limited number of additional countries through international distributors.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE B – SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Initial Public Offering In February 2015, the Company completed its initial public offering (“IPO”) by issuing 5,294 shares of common stock at an offering price of $17.00 per share, for net proceeds to the Company of approximately $80,953, after deducting underwriting discounts and commissions and offering expenses payable by the Company. In connection with the IPO, the Company’s outstanding shares of convertible preferred stock were automatically converted into an aggregate of 11,404 shares of common stock and warrants exercisable for convertible preferred stock were automatically converted into warrants to purchase up to an aggregate of 38 shares of common stock, resulting in the reclassification of the related redeemable convertible preferred stock warrant liability of $648 to additional paid-in-capital. 1-for-4 Reverse Stock Split In connection with the IPO, the Company’s board of directors and stockholders approved a reverse stock split of the Company’s common stock on a 1-for-4 basis. The reverse stock split became effective on January 12, 2015. The par value of the common stock was not adjusted as a result of the reverse stock split. Adjustments corresponding to the reverse stock split were made to the ratio at which the convertible preferred stock converted into common stock immediately prior to the closing of the IPO. Accordingly, all share and per share amounts for all periods presented in these consolidated financial statements and notes thereto have been adjusted retroactively, where applicable, to reflect the reverse stock split and adjustment of the preferred stock’s conversion ratios. Basis of Preparation The consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) and pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”). JOBS Act Accounting Election As an emerging growth company under the Jumpstart Our Business Startups Act of 2012 (“JOBS Act”), the Company is eligible to take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies. The Company has elected to take advantage of the extended transition period for adopting new or revised accounting standards that have different effective dates for public and private companies until such time as those standards apply to private companies. Principles of Consolidation The consolidated financial statements include the accounts of Entellus Medical, Inc., and its wholly owned subsidiary. All significant intercompany transactions and accounts have been eliminated. Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates. Foreign Currency Translation Sales and expenses denominated in foreign currencies are translated at average exchange rates in effect throughout the year. Assets and liabilities of foreign operations are translated at period-end exchange rates with the impacts of foreign currency translation recognized to foreign currency translation adjustment, a component of accumulated other comprehensive loss. Foreign currency transaction gains and losses are included in other income (expense) in the consolidated statements of operations and comprehensive loss. Cash and Equivalents The Company considers all highly liquid investments purchased with an initial maturity of 90 days or less to be cash equivalents. At December 31, 2015 and 2014, cash equivalents consisted of money market funds recorded at fair value and federal and corporate debt securities recorded at amortized costs. Investments in marketable securities of $16,747 were classified as cash equivalents as of December 31, 2015 and none as of 2014. The Company maintains cash in bank accounts which, at times, may exceed Federal Deposit Insurance Corporation (“FDIC”) limits. The Company has not experienced any losses from maintaining balances in excess of FDIC limits. Short-term Investments Short-term investments represent holdings of marketable securities in accordance with the Company’s investment policy and cash management strategy. Short-term investments are classified as available-for-sale and mature within 12 months from the balance sheet date. Investments with maturity dates greater than one year from the balance sheet date are classified as long-term investments. At the time that the maturity dates of these investments become one year or less, the securities are reclassified to short-term investments. The Company’s investments are recorded at fair value, with any unrealized gains and losses reported as a component of stockholders’ equity (deficit) until realized or until a determination is made that an other-than-temporary decline in market value has occurred. The cost of investments sold is determined based on the specific identification method and any realized gains or losses on the sale of investments are reflected as a component of interest income or expense. These investments are deemed Level 2 assets under the fair value hierarchy as their fair value is determined under a market approach using valuation models that utilize observable inputs, including maturity date, issue date, settlements date, and current interest rates. Fair Value of Financial Instruments As of December 31, 2015 and 2014, the carrying amounts of cash and cash equivalents, accounts receivable, accounts payable and accrued expenses approximated their estimated fair value because of the short-term nature of the financial instruments. The Company determines the fair value of its assets and liabilities based on the exchange price that would be received for an asset or paid to transfer a liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value maximize the use of observable inputs and minimize the use of unobservable inputs. A fair value hierarchy with three levels of inputs, of which the first two are considered observable and the last unobservable, is used to measure fair value. The fair value hierarchy gives the highest priority to quoted prices in active markets for identical assets or liabilities (Level 1). The next highest priority is based on quoted prices for similar assets or liabilities in active markets or quoted prices for identical or similar assets or liabilities in non-active markets or other observable inputs (Level 2). The lowest priority is given to unobservable inputs (Level 3). Concentration of Credit Risk Financial instruments, which potentially subject the Company to concentrations of credit risk, consist principally of cash equivalents and accounts receivable. The Company generally does not require collateral and losses on accounts receivable have historically been within management’s expectations. The Company’s investment policy limits investments, when held, to certain types of debt securities issued by the U.S. government, its agencies, and institutions with investment-grade credit ratings, as well as corporate debt or commercial paper issued by the highest quality financial and non-financial companies, and places restrictions on maturities and concentration by type and issuer. The Company is exposed to credit risk in the event of a default by the financial institutions holding its cash and equivalents and issuers of debt securities to the extent recorded on the consolidated balance sheets. Accounts Receivable Credit is granted to customers in the normal course of business, generally without collateral or any other security to support amounts due. Accounts are considered past due generally after 30 days. The Company maintains an allowance for doubtful accounts for estimated losses in the collection of accounts receivable. The Company makes estimates regarding the future ability of its customers to make required payments based on historical credit experience, delinquency and expected future trends. The Company will write off accounts receivable when it determines that the accounts receivable are uncollectible, typically upon customer bankruptcy or the customer’s non-response to continued collection efforts. The allowance for doubtful accounts was $135 and $150 as of December 31, 2015 and 2014, respectively. The Company also maintains an allowance for sales returns based on historical experience and evaluation of current sales and returns trends. The allowance for sales returns was $250 and $140 as of December 31, 2015 and 2014, respectively. Inventories Inventories are stated at the lower of cost to purchase or manufacture the inventory or the net realizable value of such inventory. Cost is determined using the standard cost method which approximates the first-in, first-out basis. Market value is determined as the lower of replacement cost or net realizable value. The Company regularly reviews inventory quantities in consideration of actual loss experiences, projected future demand, and remaining shelf life to record a provision for excess and obsolete inventory when appropriate. Property and Equipment Property and equipment are recorded at cost. Depreciation of furniture, office, computer and laboratory equipment is calculated on a straight-line basis over the asset’s estimated useful life, which ranges from three to ten years. Tooling and molds are depreciated on a straight-line basis over three to five years. Leasehold improvements are amortized on a straight-line basis over the shorter of the remaining life of the lease or the useful life of the asset. Repair and maintenance expenditures are charged to earnings as incurred. Major repairs and maintenance expenditures that extend useful lives of property and equipment are capitalized. Deferred Offering Costs Deferred offering costs, primarily consisting of legal, accounting and other direct fees and costs relating to the initial public offering, are capitalized. The deferred offering costs were offset against the IPO proceeds upon the closing of the offering in February 2015. As of December 31, 2014, there was $1,698 in deferred offering costs capitalized in other non-current assets on the consolidated balance sheet. There were no deferred offering costs capitalized as of December 31, 2015. Impairment of Long-Lived Assets The Company reviews its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceed the fair value of the assets. Assets to be disposed of are reported at the lower of the carrying amount or fair value less costs to sell. The Company has not recorded impairment charges on long-lived assets for the periods presented in these consolidated financial statements. Deferred Rent The Company accounts for rent expense related to operating leases by determining total minimum rent payments on the leases over their respective periods and recognizing the rent expense on a straight-line basis. The difference between the actual amount paid and the amount recorded as rent expense in each period presented is recorded as an adjustment to other non-current liabilities in the consolidated balance sheet. Debt Issuance and Debt Discount Debt issuance costs are stated at cost, net of accumulated amortization and included within other assets. Debt discount is recorded as a reduction of long-term debt. Amortization of debt issuance costs and the debt discount is calculated using the effective interest method over the term of the debt and is recorded in interest expense in the accompanying consolidated statements of operations and comprehensive loss. Revenue Recognition The Company recognizes revenue when persuasive evidence of a sales arrangement exists, delivery of goods has occurred through the transfer of title and risks and rewards of ownership, the selling price is fixed or determinable and collectability is reasonably assured. Revenue is reported net of the allowance for sales returns. Taxes assessed by a governmental authority that are directly imposed on revenue-producing transactions between a seller and a customer are not recorded as revenue. The Company entered into a distribution agreement with CogENT Therapeutics in September 2013 and began exclusive distribution of XeroGel in October 2013 in the United States. For products shipped from the CogENT warehouse to customers, CogENT is responsible for all manufacturing, order fulfillment, quality and regulatory requirements of the product. For these direct shipment orders, the Company does not take title to CogENT products prior to products being ordered by customers or in the event CogENT products are returned by customers. The Company records transactions under this arrangement on a net basis based on the difference between the amounts billed to customers less the amounts paid to CogENT for the XeroGel product. The Company’s net revenue for the year ended December 31, 2015, 2014 and 2013 were approximately $1,162, $839 and $65, respectively. For products for which the Company takes title, ships the product and handles returns, the Company records transactions under these arrangements on a gross basis. The amounts of revenue recorded on a gross basis for the year ended December 31, 2015, 2014 and 2013 were approximately $156, $143 and $0, respectively. Shipping and Handling Shipping and handling costs charged to customers are included as a component of revenue and related costs are included in costs of goods sold. Cost of Goods Sold Cost of goods sold consists primarily of manufacturing overhead costs, material costs and direct labor. A significant portion of the Company’s cost of goods sold currently consists of manufacturing overhead costs. These overhead costs include the cost of quality assurance, material procurement, inventory control, facilities, equipment, operations supervision and management, depreciation expense for production equipment, amortization of leasehold improvements, shipping costs and royalty expense payable in connection with sales of certain products. For those products we sell as a distributor, our cost of goods sold consists primarily of transfer price. Research and Development Costs Research and development expenses consist primarily of engineering, product development, clinical and regulatory affairs, consulting services, materials, depreciation and other costs associated with products and technologies in development. These expenses include employee and non-employee compensation, including stock-based compensation, supplies, materials, consulting, related travel expenses and facility costs. Clinical expenses include clinical trial design, clinical site reimbursement, data management and travel expenses, and the cost of manufacturing products for clinical trials. Expenditures for research and development activities are charged to operations as incurred. Advertising Expense Expenditures for advertising are charged to operations as incurred. Advertising expenses were $1,103, $645 and $587 during the years ended December 31, 2015, 2014 and 2013, respectively. Common Stock Valuation and Stock-based Compensation Prior to the IPO, the Company maintained its 2006 Stock Incentive Plan (the “2006 Plan”) to provide long-term incentives for employees, consultants and members of the board of directors. The 2006 Plan allowed for the issuance of non-statutory and incentive stock options to employees and non-statutory stock options to consultants and non-employee directors. In connection with the IPO, the 2006 Plan terminated, and the Company adopted a new equity incentive plan, the 2015 Incentive Award Plan (the “2015 Plan”). The Company is required to determine the fair value of equity incentive awards and recognize compensation expense for all equity incentive awards made to employees and directors, including employee stock options. The Company also determines the fair value of non-statutory stock options issued to consultants based on the fair value of the consultant’s commitment at the date of grant. Such expense is recognized over the requisite service period. In addition, stock-based compensation expense recognized in the consolidated statements of operations and comprehensive loss is based on awards expected to vest and therefore the amount of expense has been reduced for estimated forfeitures. The Company uses the straight-line method for expense attribution, except for awards issued with performance-based conditions which require an accelerated attribution method over the requisite performance and service periods. Under the applicable accounting guidance for equity incentive awards issued to non-employees, the date at which the fair value of such awards is measured is equal to the earlier of: 1) the date at which a commitment for performance by the counterparty to earn the equity instrument is reached; or 2) the date at which the counterparty’s performance is complete. The Company recognizes stock-based compensation expense for the fair value of the vested portion of the non-employee awards in the consolidated statements of operations and comprehensive loss. The valuation model used for calculating the fair value of awards for stock-based compensation expense is the Black-Scholes option-pricing model (the “Black-Scholes model”). The Black-Scholes model requires the Company to make assumptions and judgments about the variables used in the calculation, including the expected term (weighted average period of time that the options granted are expected to be outstanding), the volatility of common stock and an assumed risk-free interest rate. The Company uses the “simplified method” to determine the expected term of the stock option. Volatility is based on an average of the historical volatilities of the common stock of publicly-traded companies with characteristics similar to those of the Company. The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant for periods corresponding with the expected term of the option. The expected dividend assumption is based on the Company’s history of not paying dividends and its expectation that it will not declare dividends for the foreseeable future. Potential forfeitures of awards are estimated based on the Company’s historical forfeiture experience. The estimate of forfeitures will be adjusted over the service period to the extent that actual forfeitures differ, or are expected to differ, from prior estimates. Convertible Preferred Stock Warrant Liability For a warrant classified as a derivative liability, the fair value of that warrant is recorded on the consolidated balance sheet when granted and adjusted to fair value at each financial reporting date. The changes in the fair value of the warrants are recorded in the statement of operations and comprehensive loss as a component of interest income or expense as appropriate. The Company issued warrants to purchase shares of convertible preferred stock in connection with the Company’s entry into its original credit facility in October 2012. The warrants were recorded at fair value using the Black Scholes model. The fair value of these warrants was remeasured at each financial reporting period with any changes in fair value being recognized as a component of other income (expense) in the consolidated statements of operations and comprehensive loss. In connection with the IPO, in January 2015, the Company performed the final remeasurement of the warrant liability. There were costs of $357 during the year ended December 31, 2015 recorded as interest expense from the final remeasurement. Upon the closing of the IPO, warrants to purchase shares of convertible preferred stock automatically converted into warrants to purchase shares of common stock. The Company reclassified the warrant liability to additional paid-in capital, as the warrants met the definition of an equity instrument. Income Taxes Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax base and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The Company applies a recognition threshold for income tax positions taken or expected to be taken on a tax return. The impact of an uncertain tax position taken or expected to be taken on an income tax return are recognized in the consolidated financial statements at the largest amount that is more-likely-than not to be sustained upon audit by the relevant taxing authority. An uncertain tax position is not recognized in the consolidated financial statements unless it is more-likely-than not of being sustained. The Company has no reserve for unrecognized tax benefits at December 31, 2015 and 2014, and accordingly, there is no interest or penalties recorded on the consolidated balance sheet for such reserves. The Company is currently open to audit under the statute of limitations by the Internal Revenue Service and the appropriate state income taxing authorities for 2006 through 2015. Net Loss per Share Basic net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock outstanding during the period. Diluted net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock and dilutive potential shares of common stock outstanding during the period. Because the Company has reported a net loss for all periods presented, diluted net loss per share is the same as basic net loss per share for those periods as all potentially dilutive shares consisting of convertible preferred stock, stock options and warrants were antidilutive in those periods. The Company allocates no loss to participating securities because they have no contractual obligation to share in the losses of the Company. The shares of the Company’s convertible preferred stock participate in any dividends declared by the Company and are therefore considered to be participating securities. Comprehensive Loss Comprehensive loss consists of net loss, changes in unrealized gains and losses on available-for-sale marketable securities and changes in unrealized translation gains and losses. Accumulated other comprehensive income is presented in the accompanying consolidated balance sheets, when applicable. Segment, Geographical and Customer Concentration The Company operates in one segment. No single customer accounted for more than 10% of its revenue during the years ended December 31, 2015, 2014 and 2013. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers. This standard will eliminate the transaction and industry specific revenue recognition guidance under current U.S. GAAP and replace it with a principles based approach for determining revenue recognition. The new guidance is effective for annual and interim periods beginning after December 15, 2017. The Company is in the process of evaluating the impact of the adoption of this standard. In February 2015, the FASB issued ASU 2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis. The new consolidation standard amended the process that a reporting entity must perform to determine whether it should consolidate certain types of legal entities. ASU 2015-02 is effective for the annual period beginning after December 15, 2015, and for annual and interim periods thereafter. Early application is permitted. The Company does not expect the adoption of ASU 2015-02 to have a material impact on its financial position or results of operations. In April 2015, the FASB issued ASU 2015-03, Simplifying the Presentation of Debt Issuance, which changes the presentation of debt issuance costs in financial statements. Under ASU 2015-03, an entity presents such costs in the balance sheet as a direct deduction from the related debt liability rather than as an asset. Amortization of the costs is reported as interest expense. ASU 2015-03 is effective for fiscal years and interim periods within those fiscal years, beginning after December 15, 2015 . Early adoption is permitted for financial statements that have not been previously issued. A company should apply the new guidance on a retrospective basis, wherein the balance sheet of each individual period presented should be adjusted to reflect the period-specific effects of applying the new guidance. Upon transition, a company is required to comply with the applicable disclosures for a change in an accounting principle. The guidance only affects the presentation of debt issuance costs in the balance sheet and has no impact on results of operations. In July 2015, the FASB issued ASU 2015-11, Simplifying the Measurement of Inventory, which requires inventory not measured using either the last in, first out or the retail inventory method to be measured at the lower of cost and net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable cost of completion, disposal, and transportation. The new standard will be effective January 1, 2017 and will be applied prospectively. Early adoption is permitted. The Company early adopted ASU 2011-15 effective December 31, 2015 prospectively. Adoption had no impact on the Company’s results of operations. In November 2015, the FASB issued ASU 2015-17, Balance Sheet Classification of Deferred Taxes, which amends the guidance requiring companies to separate deferred income tax liabilities and assets into current and non-current amounts in a classified statement of financial position. ASU 2015-17 simplifies the presentation of deferred income taxes, such that deferred tax liabilities and assets be classified as non-current in a classified statement of financial position. The new standard will be effective beginning in the first quarter of 2018. Early adoption is permitted. The Company early adopted ASU 2015-17 effective December 31, 2015. The adoption of ASU 2015-17 did not have an impact on the Company’s consolidated balance sheet due to the full valuation allowance against the net deferred tax assets as of December 31, 2015 and 2014. In January 2016, the FASB issued ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities, which addresses certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. ASU 2016-01 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017, and early adoption is not permitted. The Company does not expect that adoption of ASU 2016-01 will have a significant impact on its consolidated financial statements.

Composition of Certain Financia

Composition of Certain Financial Statement Items	12 Months Ended
	Dec. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Composition of Certain Financial Statement Items	NOTE C – COMPOSITION OF CERTAIN FINANCIAL STATEMENT ITEMS Inventories December 31, December 31, 2015 2014 Finished goods $ 1,487 $ 859 Work in process 388 318 Raw materials 2,014 1,262 Total $ 3,889 $ 2,439 Property and Equipment December 31, December 31, 2015 2014 Furniture and office equipment $ 533 $ 401 Computer hardware and software 2,187 837 Laboratory equipment 2,915 1,427 Tooling and molds 1,243 1,237 Leasehold improvements 583 494 $ 7,461 $ 4,396 Less accumulated depreciation and amortization (3,766 ) (2,768 ) Property and equipment in progress 431 102 Total $ 4,126 $ 1,730 Depreciation and amortization expense was $1,005, $618 and $460 during the years ended December 31, 2015, 2014 and 2013, respectively. Other Non-Current Assets December 31, December 31, 2015 2014 Security deposit on operating lease $ 34 $ 19 Deferred offering costs — 1,698 Total $ 34 $ 1,717 Accrued Expenses December 31, December 31, 2015 2014 Compensation and commissions payable $ 3,898 $ 3,001 Royalty payable 1,800 1,537 Other accrued expenses 1,297 546 Total $ 6,995 $ 5,084 Interest Expense December 31, December 31, December 31, 2015 2014 2013 Interest expense $ 2,247 $ 1,750 $ 1,000 Increase in fair value of convertible preferred stock warrants 357 154 82 Total $ 2,604 $ 1,904 $ 1,082

Liquidity and Business Risks

Liquidity and Business Risks	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Liquidity and Business Risks	NOTE D – LIQUIDITY AND BUSINESS RISKS As of December 31, 2015 and 2014, the Company had cash and equivalents of $28,548 and $3,484 and an accumulated deficit of $122,058 and $103,758, respectively. In February 2015, the Company completed its IPO by issuing 5,294 shares of common stock at an offering price of $17.00 per share, for net proceeds to the Company of approximately $80,953 after deducting underwriting discounts and commissions and offering expenses payable by the Company. Prior to the IPO, the Company financed its operations with a combination of revenue, private placements of convertible preferred securities and amounts borrowed under its credit facility.

Short-Term Investments

Short-Term Investments	12 Months Ended
	Dec. 31, 2015
Investments Debt And Equity Securities [Abstract]
Short-Term Investments	NOTE E – SHORT-TERM INVESTMENTS The Company determines the appropriate classification of its investments at the time of purchase and revaluates such determinations at each balance sheet date. Marketable securities are classified as held-to-maturity when the Company has the positive intent and ability to hold the securities to maturity. Marketable securities for which the Company does not have the intent or ability to hold to maturity are classified as available-for-sale. Marketable securities classified as available-for-sale are carried at fair market value, with the unrealized gains and losses included in the determination of comprehensive income and reported in stockholders’ equity. The following is a summary of the available-for-sale investments by type of instrument, which are included in short-term investments in the consolidated balance sheet as of December 31, 2015. As of December 31, 2014, there were no short or long-term investments. Unrealized Unrealized Gain in Losses in Accumulated Accumulated Other Other Amortized Comprehensive Comprehensive Estimated December 31, 2015 Cost Income Income Fair Value Short-Term Commercial paper $ 9,482 $ 10 $ — $ 9,492 Corporate bonds 19,605 — (19 ) 19,586 Government bonds 1,999 — — 1,999 Foreign assets 7,140 — (7 ) 7,133 Total available-for-sale securities $ 38,226 $ 10 $ (26 ) $ 38,210 Based on an evaluation of securities that have been in a loss position, the Company did not recognize any other-than-temporary impairment charges during year ended December 31, 2015. The Company considered various factors which included a credit and liquidity assessment of the underlying securities and the Company’s intent and ability to hold the underlying securities until the estimated date of recovery of its amortized cost. As of December 31, 2015, available-for-sale maturities as noted in the table above mature in one year or less.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	NOTE F – FAIR VALUE MEASUREMENTS As of December 31, 2015 and 2014, the carrying amounts of cash and cash equivalents, receivables, accounts payable and accrued expenses approximated their estimated fair values because of the short term nature of these financial instruments. Fair value is defined as the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three categories: · Level 1: Quoted market prices in active markets for identical assets or liabilities. · Level 2: Includes other than level 1 inputs that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs for which all significant inputs are observable or can be corroborated by observable market data for substantially the full term of the asset or liabilities. · Level 3: Unobservable inputs that are supported by little or no market activities, which would require the Company to develop its own assumptions. Short-term Investments The following is a summary of available-for-sale investments by type of instrument measured at fair value on a recurring basis at December 31, 2015. As of December 31, 2014, there were no available-for-sale investments. December 31, 2015 Level 1 Level 2 Level 3 Total Commercial paper $ — $ 9,492 $ — $ 9,492 Corporate bonds — 19,586 — 19,586 Government bonds — 1,999 — 1,999 Foreign assets — 7,133 — 7,133 Total $ — $ 38,210 $ — $ 38,210 There were no transfers in or out of Level 1, Level 2 or Level 3 fair value measurement during the year ended December 31, 2015. The Company has not experienced any significant realized gains or losses on its investments in the periods presented in the consolidated statements of operations and comprehensive loss. Convertible Preferred Stock Warranty Liability The following table sets forth a summary of the changes in the estimated fair value of the Company’s convertible preferred stock warrant liability, which represents financial instruments that were categorized as Level 3, according to the three-level fair value hierarchy. Year Ended December 31, 2015 2014 Beginning of the period $ 291 $ 211 Issued — — Exercised — — Expired — — Reclassified to equity (1) (648 ) — Change in fair value 357 80 End of the period $ — $ 291 (1) In connection with the closing of the IPO in February 2015, warrants to purchase shares of convertible preferred stock were converted to warrants to purchase shares of common stock, resulting in the reclassification of the related convertible preferred stock warrant liability to additional paid-in-capital. The fair market value of the convertible preferred stock prior to the IPO was determined using the option pricing method and the probability weighted expected return method. The fair value of the convertible preferred stock warrant liability was determined using the Black-Scholes option pricing model with the following assumptions: Year Ended December 31, 2015 2014 Expected life in years N/A 7.8 Risk-free interest rate N/A 2.0 % Expected dividend yield N/A 0.0 % Expected volatility N/A 50 %

Debt

Debt	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Debt	NOTE G – DEBT In October 2012, the Company entered into a credit facility with Oxford Finance LLC (the “lender”) under which it could borrow up to a total of $17,000 in two tranches at a fixed rate floor of 8.35%. The first tranche of $7,500 was borrowed in October 2012. In December 2013, the Company amended and restated the loan and security agreement and in October 2014, the Company further amended the loan and security agreement (as currently in effect, the “credit facility”). Under the credit facility, the Company can borrow up to a total of $25,000 in three tranches at a fixed rate of 9.40%. The first tranche of $15,000, including the refinance of $7,500 previously outstanding, was borrowed in December 2013. In connection with the funding of the first tranche, the Company paid a prorated final payment fee on the original credit facility of $143. The second tranche of up to $5,000 (the “2014 tranche”) was available through December 31, 2014, of which $5,000 was borrowed during the three months ended December 31, 2014. The third tranche of up to $5,000 was available at any time through December 31, 2015, subject to certain six-month revenue milestones. The Company achieved the specified revenue milestones for the third tranche but elected not to borrow additional funds. The credit facility matures and all amounts borrowed thereunder are due on December 1, 2018. As a result of achieving certain funding and revenue milestones provided for in the credit facility in December 2015, the Company was permitted to extend the interest-only period to February 2017. After February 2017, the Company will make 24 monthly payment of principle and interest. In addition to the principal and interest payments, under the credit facility the Company is required to pay a final payment fee of 7.15% on all amounts outstanding, which is being accrued over the credit facility term and shall be due at the earlier of maturity or prepayment. If the Company repays the amounts borrowed under the credit facility prior to maturity, the Company will also be required to pay a prepayment fee equal to 0.75%, with respect to the principal amount that is prepaid. The credit facility includes affirmative and restrictive covenants and events of default, including the following events of default: payment defaults, breaches of covenants, judgment defaults, cross defaults to certain other contracts, certain events with respect to governmental approvals if such events could cause a material adverse change, a material impairment in the perfection or priority of the lender’s security interest or in the value of the collateral, a material adverse change in the business, operations or condition of the Company or any of its subsidiaries and a material impairment of the prospect of repayment of the credit facility. Upon the occurrence of an event of default, a default increase in the interest rate of an additional 5.00% could be applied to the outstanding loan balance and the lender could declare all outstanding obligations immediately due and payable and take such other actions as set forth in the credit facility. The Company’s obligations under the credit facility are secured by a first priority security interest in substantially all of its assets, other than its intellectual property. There are no financial covenants contained in the credit facility and the Company is in compliance with the affirmative and restrictive covenants as of December 31, 2015. As of December 31, 2015, the Company has borrowed and had outstanding $20,000 of debt under the credit facility. In association with the original credit facility and in conjunction with the close of the first tranche in October 2012, the Company issued the lender warrants to purchase 151 shares of Series E Preferred Stock at an exercise price of $1.9594 per share. In connection with the IPO in February 2015, the warrants became exercisable for up to 38 shares of the Company’s common stock with an exercise price of $7.84 per share. Each warrant may be exercised on a cashless basis in whole or in part. Using the Black-Scholes valuation model, management estimated the fair value of these warrants to be approximately $132 at issuance of the warrant. The following assumptions were used to estimate the fair value: expected volatility of 45.00%, risk-free interest rate of 1.64%, and expected term of 10 years. These warrants were considered to be costs incurred as part of the credit facility and were recorded as a debt discount which was offset against the loan, and were to be amortized over the life of the original credit facility based on the effective interest method to interest expense. In connection with the amended credit facility, the Company amortized the remaining debt discount to interest expense. No stock warrants were issued in conjunction with the amended credit facility. Assuming a 24-month amortization period, the Company’s principal payments are due under the amended credit facility as follows for the years ending December 31, 2015: 2016 $ — 2017 9,118 2018 10,882 $ 20,000 At December 31, 2015 and 2014, the carrying value of debt approximated fair market value. The fair value of the Company’s debt is considered a Level 3 measurement.

Convertible Preferred Stock

Convertible Preferred Stock	12 Months Ended
	Dec. 31, 2015
Temporary Equity Disclosure [Abstract]
Convertible Preferred Stock	NOTE H – CONVERTIBLE PREFERRED STOCK During 2012, 2011, 2009, 2008, 2007 and 2006, the Company issued 5,104, 12,759, 15,311, 3,717, 4,986 and 2,440 shares of Series E, E, D, C, B and A Preferred Stock, respectively. The Series A, B, C, D and E Preferred Stock are collectively referred to as the Convertible Preferred Stock. As of December 31, 2015 and 2014, respectively, the Convertible Preferred Stock consisted of the following (presented in actual amounts): December 31, 2015 December 31, 2014 Number of Number of Number of Number of shares Number of shares shares Shares issued and Carrying Shares issued and converted Carrying authorized outstanding value authorized outstanding common Stock value Series A — — — 2,440,000 2,440,000 610,000 $ 2,963,745 Series B — — — 4,986,188 4,986,188 1,246,547 8,988,134 Series C — — — 3,717,329 3,717,329 1,254,375 14,937,389 Series D — — — 15,310,943 15,310,943 3,827,736 29,822,047 Series E — — — 18,112,611 17,862,611 4,465,653 34,842,241 Total — — — 44,567,071 44,317,071 11,404,311 $ 91,553,556 The Series C Preferred Stock included an antidilution adjustment that resulted in the applicable conversion rate of the Series C Preferred Stock increasing from 0.2500 to 0.3374 as a result of the sale of the Series D Preferred Stock. The resulting incremental common stock to the Series C Preferred Stockholders did not result in any intrinsic value due, because the estimated fair market value of common stock when the Series C Preferred Stock was issued was greater than the estimated fair market value of common stock when the conversion rate increased to 1.3498. If there had been intrinsic value, the Company would have recorded a deemed dividend, resulting in a reduction of retained earnings and increase to Series C Preferred Stock, equal to the fair value of the incremental shares of common stock. The Company recorded its Convertible Preferred Stock at fair value on the dates of issuance, net of issuance costs. A redemption event would have occurred only upon the liquidation or winding up of the Company, a greater than 50% change in control, or sale of substantially all of the assets of the Company. As the redemption event was outside the control of the Company, all shares of Convertible Preferred Stock have been presented outside of permanent equity. Further, the Company also elected not to adjust the carrying values of the Convertible Preferred Stock to the redemption value of such shares, since it was uncertain whether or when a redemption event would occur. In connection with the IPO, all of the Company’s outstanding shares of convertible preferred stock were automatically converted into an aggregate of 11,404 shares of common stock and warrants exercisable for convertible preferred stock were automatically converted into warrants to purchase up to an aggregate of 38 shares of common stock, resulting in the reclassification of the related redeemable convertible preferred stock warrant liability of $648 to additional paid-in-capital. The terms of the Company’s Convertible Preferred Stock were as follows: (a) Conversion and Redemption Rights The Convertible Preferred Stock was convertible into common stock at the option of the holder immediately upon issuance. The conversion price per share was equal to a rate determined by dividing the initial purchase price by the then applicable conversion price. The initial purchase price was equal to $1.25, $1.81, $4.035, $1.9594 and $1.9594 for Series A, Series B, Series C, Series D and Series E Preferred Stock, respectively. The applicable conversion price was equal to $5.00, $7.24, $11.9576, $7.8376 and $7.8376 for Series A, Series B, Series C, Series D and Series E, respectively. The Convertible Preferred Stock would automatically convert into common stock upon a qualified public offering or by consent of the holders of at least a majority in interest of the then-outstanding Convertible Preferred Stock voting together, as a single class on an as-if-converted-to-common stock basis. The Convertible Preferred Stock was not redeemable. (b) Dividends The holders of Series A, B, C, D and E Convertible Preferred Stock were entitled to receive dividends (as determined on a per annum basis and on an as-converted basis), from any assets legally available, prior and in preference to any declaration or payment of any dividend to the common stockholders. Such dividends were payable when and if declared by the Board of Directors and are not cumulative. No dividends were declared through December 31, 2015. (c) Liquidation Preferences As of December 31, 2015, there are no liquidation preferences. In the event of any liquidation, dissolution, change in control or winding-up of the Company, the holders of Series E Preferred Stock would have been entitled to be paid out of the assets of the Company available for distribution to its stockholders on a pro rata basis, prior and in preference to the holders of Series A, B, C and D Preferred Stock and common stock, for the sum of $1.9594 per share of Series E held, plus unpaid dividends thereon, if declared and unpaid. After the payment in full of the aggregate Series E Liquidation Preference, the holders of the Series D Preferred Stock would have been entitled to distribution on a pro rata basis, prior and in preference to the holders of Series A, B and C Preferred Stock and common stock, for the sum of $1.9594 per share of Series D held, plus unpaid dividends thereon, if declared and unpaid. Any remaining assets of the Company would then have been distributed on a pari passu basis among the holders of Series A, B and C on a pro rata basis, prior and in preference to the holders of common stock, for the sum of $1.25 per share of Series A held, $1.81 per share of Series B held and $4.035 per share of Series C held, plus unpaid dividends thereon, if declared and unpaid. Any remaining assets of the Company would then have been distributed equally, on a per share basis, among the holders of the Series D Preferred Stock, Series E Preferred Stock and common stockholders on an as-if converted basis. The maximum aggregate proceeds that the holders of Series D Preferred Stock and Series E Preferred Stock may receive upon liquidation is equal to $3.223 per share of Series D and Series E held. A liquidation of the Company includes a liquidation, dissolution, or winding up of the Company and, unless waived by the holders of a majority in interest of the Convertible Preferred Stock, the sale, transfer, exclusive licensing or other disposition of all or substantially all of the Company’s assets including intellectual property, or the merger or consolidation of the Company with another entity gaining greater than 50% ownership of the Company. (d) Voting Agreement For so long as at least 20% of the shares of Convertible Preferred Stock originally issued remained outstanding, the holders of Convertible Preferred Stock, voting separately as a class, were entitled to elect three members of the Board, the holders of common stock, voting separately as a class, were entitled to elect one member of the Board, and the holders of Preferred Stock and common stock, voting together, as a single class on an as-if-converted-to-common-stock basis, were entitled to elect one member of the Board. For so long as at least any shares of Convertible Preferred Stock originally issued remained outstanding, the Company could not, without the affirmative vote of at least a majority in interest of the then outstanding Convertible Preferred Stock, (i) increase or decrease the number of authorized shares of Convertible Preferred Stock, (ii) create any new class or series of capital stock senior to the Convertible Preferred Stock, (iii) redeem any shares of Convertible Preferred Stock or common stock, (iv) declare, authorize or pay a dividend or distribution, (v) dispose of all or substantially all of the assets of the corporation, (vi) change the authorized number of directors, (vii) increase shares reserved for issuance under any stock-based compensation plan, (viii) fundamentally change the principal business of the corporation, (ix) acquire or invest in another corporation or entity, (x) alter or change the voting power, rights, preferences, privileges or restrictions of Convertible Preferred Stock, (xi) amend, repeal or waive any provision of the Company’s certificate of incorporation or bylaws in a manner adverse to the holders of Convertible Preferred Stock, (xii) create any debt security or incur any debt or lease obligation, other than equipment leases, bank lines of credit and venture debt transactions or (xiii) create or hold capital stock in any subsidiary that was not a wholly-owned subsidiary.

Stockholders' Deficit

Stockholders' Deficit	12 Months Ended
	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stockholders' Deficit	NOTE I – STOCKHOLDERS’ DEFICIT Common Stock In May 2014, the Company amended its Certificate of Incorporation to increase the authorized number of shares of common stock available for issuance from 57,000 to 57,565 shares of $0.001 par value common stock. In December 2014, the Company further amended its Certificate of Incorporation to increase the authorized number of common stock shares available for issuance to 62,276 shares. In connection with the IPO, the Company amended and restated its certificate of incorporation. The amended and restated certificate of incorporation authorizes 200,000 shares of common stock. The common stockholders are generally entitled to one vote for each share held on all matters submitted to a vote of the stockholders and do not have any cumulative voting rights. The Company’s common stockholders are entitled to receive proportionally any dividends declared by the Company’s Board of Directors, subject to any preferential dividend rights of outstanding preferred stock. In the event of the Company’s liquidation or dissolution, the common stockholders are entitled to share ratably in all assets remaining after payment of all debts and other liabilities, subject to any preferential rights of any outstanding preferred stock. The common stockholders have no preemptive, subscription, redemption or conversion rights. 2006 Equity Incentive Plan Under the 2006 Plan approved by the Company’s Board of Directors in August 2006, 3,541 shares of common stock have been reserved for the issuance of incentive stock options (“ISOs”), non-statutory stock options (“NSOs”), stock bonuses and rights to acquire restricted stock to employees, officers, directors and consultants of the Company as of December 31, 2014. ISOs and NSOs have been granted with exercise prices at no less than 100% of the fair value of the common stock on the date of grant. Options granted to a 10% stockholder shall be at no less than 110% of the fair value and ISO stock option grants to such 10% stockholders expire five years from the date of grant. ISOs granted under the 2006 Plan generally vest ratably over a four-year vesting term and expire 10 years from the grant date, unless subject to provisions regarding 10% stockholders. NSOs vest per the specific agreement and expire 10 years from the date of grant. New shares are issued upon exercise of options under the 2006 Plan. At December 31, 2014, there were 23 shares available for issuance under the 2006 Plan. In connection with the IPO, the 2006 Plan terminated, and the Company adopted a new equity incentive plan, the 2015 Plan. 2015 Incentive Award Plan In December 2014, the Company’s Board of Directors adopted, and in January 2015 the Company’s stockholders approved, the 2015 Plan. The 2015 Plan became effective on the effective date of the IPO, at which time the Company ceased making awards under the 2006 Plan. Under the 2015 Plan, the Company may grant stock options, stock appreciation rights, restricted stock, restricted stock units and certain other awards to individuals who are employees, officers, directors or consultants of the Company. A total of 1,346 shares of common stock were initially reserved for issuance under the 2015 Plan. In addition, the number of shares available for issuance under the 2015 Plan will be annually increased by an amount equal to the lesser of (A) 875 shares, (B) 4% of the outstanding shares of the Company’s common stock as of the last day of our immediately preceding fiscal year or, an amount determined by the Company’s Board of Directors. A summary of the Company’s stock option activity and related information is as follows: Weighted average Aggregate Weighted remaining intrinsic average contractual value Options exercise price term ($000) Balance at December 31, 2012 1,505 $ 1.37 Granted 437 1.33 Exercised (583 ) 1.23 Cancelled (112 ) 4.08 Forfeited (31 ) 0.84 Balance at December 31, 2013 1,216 $ 1.18 Granted 1,396 10.55 Exercised (466 ) 1.24 Cancelled — — Forfeited (48 ) 2.43 Balance at December 31, 2014 2,098 $ 7.38 Granted 745 21.53 Exercised (209 ) 1.55 Cancelled — — Forfeited (51 ) 14.43 Balance at December 31, 2015 2,583 $ 11.79 8.5 years $ 16,377 Exercisable 822 $ 6.26 7.1 years $ 9,077 During the years ended December 31, 2015, 2014 and 2013, the aggregate pre-tax intrinsic value of options exercised was $3,162, $4,197 and $173 respectively. The aggregate pre-tax intrinsic value was calculated as the difference between the exercise prices of the underlying options and the estimated fair value of the common stock on the date of exercise or December 31, 2015, 2014 and 2013, as applicable. The total cash received upon the exercise of options was $323, $576 and $717 during the years ended December 31, 2015, 2014 and 2013, respectively. Early Exercise of Stock Options Stock options granted under the 2006 Plan provide option holders the right to elect to exercise unvested options in exchange for restricted common stock. As of December 31, 2013, 41 shares remained unvested and subject to a repurchase right held by the Company at the original issuance price in the event the optionees’ service was voluntarily or involuntarily terminated. On October 31, 2014, a director resigned from the Board of Directors of the Company and the Company repurchased the remaining 28 unvested shares at a total purchase price of $21 in November 2014. Reserved Shares The Company is required to reserve and keep available out of its authorized but unissued shares of common stock a number of shares sufficient to effect the conversion of all outstanding shares of convertible preferred stock (and preferred stock warrants), plus options granted and available for grant under the incentive stock plan. The number of such shares of common stock reserved for the conversion, exercise and issuance of the following options and shares outstanding as of December 31, 2015 and 2014, were as follows: December 31, 2015 2014 Convertible preferred stock: Series A outstanding — 610 Series B outstanding — 1,246 Series C outstanding — 929 Series C anti-dilution shares — 325 Series D outstanding — 3,828 Series E outstanding — 4,466 Warrants issued in connection with the credit facility 38 38 2006 Stock Incentive Plan, options outstanding 1,861 2,098 2015 Stock Incentive Plan, options outstanding 723 — Options available for future grant — 23 2,622 13,563 Employee Stock Purchase Plan (ESPP) In December 2014, the Company’s board of directors adopted, and in January 2015 the Company’s stockholders approved, the 2015 Employee Stock Purchase Plan (“2015 ESPP”). The 2015 ESPP became effective on the effective date of the IPO. A total of 200 shares were initially reserved for issuance under the 2015 ESPP. In addition, the number of shares available for issuance under the ESPP will be annually increased on the first day of each fiscal year during the term of the ESPP, beginning with the 2016 fiscal year, by an amount equal to the lesser of (A) 1% of the shares of the Company’s common stock outstanding on the date of the adoption of the plan or (B) a lesser amount determined by the Company’s Board of Directors. The first offering date was January 1, 2016. As of December 31, 2015, the Company did not recognize any stock-based compensation expense related to the ESPP.

Stock Based Compensation Expens

Stock Based Compensation Expense	12 Months Ended
	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Based Compensation Expense	NOTE J – STOCK-BASED COMPENSATION EXPENSE Stock-based compensation expense was reflected in the statement of operations and comprehensive loss for the years ended December 31, 2015, 2014 and 2013, as follows: Years ended December 31, 2015 2014 2013 Cost of goods sold $ 65 $ 11 $ 15 Selling and marketing 750 111 78 Research and development 260 46 68 General and administrative 1,736 80 193 Total $ 2,811 $ 248 $ 354 The amount of unearned stock-based compensation currently estimated to be expensed through the year 2019 related to unvested employee stock-based payment awards as of December 31, 2015, is approximately $12,710. The weighted average period over which the unearned stock-based compensation is expected to be recognized as of December 31, 2015, is approximately 3.1 years. If there are any modifications or cancellations of the underlying unvested securities, the Company may be required to accelerate, increase or cancel any remaining unearned stock-based compensation expense. Future stock-based compensation expense and unearned stock-based compensation will increase to the extent that the Company grants additional share-based payments. The Company estimates the fair value of stock-based compensation on the date of grant using the Black-Scholes option-pricing model. The Black-Scholes model determines the fair value of stock-based payment awards based on the fair market value of the Company’s common stock on the date of grant and is affected by assumptions regarding a number of highly complex and subjective variables. These variables include, but are not limited to, the fair market value of the Company’s common stock, volatility over the expected term of the awards and actual and projected employee stock option exercise behaviors. The Company has opted to use the “simplified method” for estimating the expected term of options, whereby the expected term equals the arithmetic average of the vesting term and the original contractual term of the option. Due to the Company’s limited operating history and a lack of company-specific historical and implied volatility data, the Company has based its estimate of expected volatility on the historical volatility of a group of similar companies that are publicly traded. The historical volatility data was computed using the daily closing prices for the selected companies’ shares during the equivalent period of the calculated expected term of the share-based payments. The Company will continue to analyze the historical stock price volatility and expected term assumptions as more historical data for the Company’s common stock becomes available. The risk-free rate assumption is based on the U.S. Treasury instruments with maturities similar to the expected term of the Company’s stock options. The expected dividend assumption is based on the Company’s history of not paying dividends and its expectation that it will not declare dividends for the foreseeable future. As stock-based compensation expense recognized in the consolidated financial statements is based on awards ultimately expected to vest, it has been reduced for estimated forfeitures. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from estimates. Forfeitures are estimated based on estimated future employee turnover and historical experience. The fair value of the options granted to employees or directors during the years ended December 31, 2015, 2014 and 2013, was estimated as of the grant date using the Black-Scholes model assuming the weighted average assumptions listed in the following table: Years ended December 31, 2015 2014 2013 Expected life in years 6.0 5.8 5.7 Risk-free interest rate 1.8 % 1.7 % 1.1 % Expected dividend yield 0 % 0 % 0 % Expected volatility 56 % 54 % 68 % Weighted average fair value $ 11.41 $ 5.32 $ 3.04 Performance-Based Options Options issued during the year ended December 31, 2014, included grants to certain employees totaling 23 shares that contained vesting conditions contingent on the achievement of certain milestones. Assuming continued service by the employee, the option would vest immediately upon achievement of the performance criteria. At December 31, 2014, certain milestones were achieved and therefore five shares vested immediately. The Company recorded stock-based compensation expense totaling $11 related to these options. The remaining 18 shares were cancelled. There was no performance-based option activity for the year ended December 31, 2015.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	NOTE K – INCOME TAXES During the years ended December 31, 2015 and 2014, the Company did not record a provision or benefit for current or deferred income taxes in the statement of operations and comprehensive loss due to its cumulative net losses. In assessing the realization of deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Based on the level of historical taxable income and projections of future taxable income over the periods in which the deferred tax assets are deductible, management believes that it is more likely than not that the Company will not realize the benefits of these deductible differences. Accordingly, the Company has recorded a full valuation allowance against its net deferred tax assets as of December 31, 2015 and 2014. The Company’s valuation allowance increased by $5,654 in 2015 due to the increase in total deferred tax assets. The components of loss before taxes for the years ended December 31, 2015 and 2014, consist of the following: Years ended December 31, 2015 2014 Domestic $ (17,860 ) $ (6,929 ) Foreign (440 ) - Total loss before income taxes $ (18,300 ) $ (6,929 ) Income tax expense differs from the amount computed by applying the statutory federal income tax rate as follows: December 31, 2015 2014 Tax at statutory federal rate 34.0 % 34.0 % State tax, net of federal benefit 1.8 1.1 Meals and entertainment (2.0 ) (4.2 ) Stock-based compensation (1.9 ) (0.8 ) Other (0.3 ) 0.8 Valuation allowance (31.6 ) (30.9 ) Total 0 % 0 % The tax effects of temporary differences that give rise to significant portions of the net deferred tax asset (liability) were as follows at December 31: December 31, 2015 2014 Deferred tax asset: Accounts receivable $ 136 $ 103 Inventories 71 32 Accrued expenses 158 218 Depreciation and amortization 97 192 Research and development credits generated 1,091 837 Net operating loss carryforward 40,185 35,231 Organizational costs 4 5 Stock-based compensation expense (non-qualified options) 780 211 Other 28 20 Total deferred tax assets 42,550 36,849 Deferred tax liabilities: Prepaid expense (251 ) (207 ) Total deferred tax liabilities (251 ) (207 ) Total deferred tax assets, net 42,299 36,642 Less valuation allowance (42,299 ) (36,642 ) Total deferred tax assets $ — $ — As of December 31, 2015 and 2014, the Company had federal tax net operating loss carryforwards of approximately $116,103 and $98,700, respectively, which will be available to offset earnings during the carryforward period. If not used, these carryforwards begin to expire in 2027. In addition, changes in ownership could put limitations on the availability of the net operating loss carryforwards. At December 31, 2015, there were $1,246 of unrecognized deferred tax assets that arose from tax deductions for equity compensation in excess of compensation recognized for financial reporting during years when net operating losses were created. Additional paid-in-capital will be increased if such deferred tax assets are realized and reduce current tax payable .

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Earnings Per Share	NOTE L – EARNINGS PER SHARE Basic net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock outstanding during the period. Diluted net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock and dilutive potential shares of common stock outstanding during the period. Because the Company has reported a net loss for all periods presented, diluted net loss per share is the same as basic net loss per share for those periods as all potentially dilutive shares consisting of convertible preferred stock, stock options and warrants were antidilutive in those periods. The following table sets forth the computation of the Company’s net loss per share: Years ended December 31, 2015 2014 2013 Net loss $ (18,300 ) $ (6,929 ) $ (13,396 ) Weighted average common stock outstanding 17,217 1,499 1,133 Net loss per share, basic and diluted $ (1.06 ) $ (4.62 ) $ (11.82 ) The following potentially dilutive securities outstanding have been excluded from the computations of diluted weighted average shares outstanding because such securities have an antidilutive impact due to losses reported: Years ended December 31, 2015 2014 2013 Convertible preferred stock outstanding — 11,404 11,404 Convertible preferred stock warrants — 38 38 Common stock warrants 38 — — Common stock options 2,584 2,098 1,216 Total 2,622 13,540 12,658

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	NOTE M – COMMITMENTS AND CONTINGENCIES License Agreement with Acclarent, Inc. In February 2011, the Company entered into a license agreement with Acclarent, Inc. (“Acclarent”) in connection with the settlement of a then-ongoing litigation in which Acclarent alleged that the Company’s FinESS and XprESS products infringed certain claims of five of their patents, which allegations the Company denied. In October 2012, the Company agreed with Acclarent to amend certain terms of the license agreement (as amended, the “Acclarent License”). Pursuant to the Acclarent License, Acclarent granted the Company a worldwide, non-exclusive, royalty-bearing license under certain patents held by Acclarent to manufacture, use and commercialize the Company’s currently marketed XprESS, PathAssist and FinESS products and certain future versions of those products (collectively, the “Covered Products”) in the field of the expansion of paranasal sinuses and sinus pathways. Under the Acclarent License, the Company made an initial up-front, lump-sum payment to Acclarent as a retroactive royalty payment. The Company is also required to pay Acclarent an ongoing royalty in the low double-digit percentages, on a country-by-country basis, on net sales of Covered Products. Royalty expense is included in the costs of goods sold and is recognized in the period when revenue is recognized on Covered Products. The Acclarent License will expire upon the expiration or abandonment of the last to expire of the patents licensed to us under the agreement. Acclarent has the right to terminate the agreement upon 60 days’ notice in the event of the Company’s uncured material breach. Amounts due for royalties payable are recorded within accrued expenses on the consolidated balance sheets. Operating Leases As of December 31, 2015, the Company has two leased facilities under operating lease agreements. The Company entered into a 41-month lease in February 2012, effective April 1, 2012, for its manufacturing facility and corporate headquarters. The Company entered into a 50-month lease on June 30, 2014, effective July 1, 2014, for additional distribution space in a second facility. On February 26, 2015, the Company exercised its right to extend the lease term of its manufacturing facility and corporate headquarters for an additional three years through August 2018. On June 30, 2015, the Company entered into amendments to each lease agreement, among other things, to expand the space occupied by the Company at the property at which the Company’s corporate headquarters are located, and to extend the term of each lease agreement through June 2021, with an option to extend each lease for an additional term through June 2024. Rental payments on operating leases are charged to expense on a straight-line basis over the period of the lease. The lease agreement requires the Company to pay executory costs such as real estate taxes, insurance and repairs, and includes renewal and escalation clauses. Approximate minimum future obligations which include monthly contractual lease payments under operating leases with initial terms in excess of one year are as follows: 2016 $ 351 2017 366 2018 373 2019 381 2020 389 2021 and thereafter 197 Total $ 2,057 Total lease expense was approximately $343, $305 and $234 for the years ended December 31, 2015, 2014 and 2013, respectively.

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2015
Compensation And Retirement Disclosure [Abstract]
Employee Benefit Plan	NOTE N – EMPLOYEE BENEFIT PLAN The Company’s employees are eligible to participate in a defined contribution benefit plan. Employees may contribute a percentage of their wages, subject to limits established by the Internal Revenue Code. The Company may elect to make discretionary contributions to the plan. Company matching contributions to the defined contribution benefit plan are at the discretion of the Board of Directors. There were no discretionary contributions during the years ended December 31, 2015, 2014 and 2013.

Segments

Segments	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Segments	NOTE O – SEGMENTS Operating segments are defined as components of an enterprise for which separate discrete financial information is available and evaluated regularly by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company globally manages the business within one reporting segment. Segment information is consistent with how management reviews the business, makes investing and resource allocation decisions and assesses operating performance. Products are sold principally in the United States. The following table represents total revenue by geographic area, based on the location of the customer: Years ended December 31, 2015 2014 2013 United States $ 60,911 $ 48,820 $ 32,545 International 659 — — Total $ 61,570 $ 48,820 $ 32,545 All of the Company’s long-lived assets are located in the United States.

Quarterly Results of Operations

Quarterly Results of Operations	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results of Operations	NOTE P – QUARTERLY RESULTS OF OPERATIONS (UNAUDITED) The following is a summary of the Company’s unaudited quarterly results of operations for the years December 31, 2015 and 2014: Three Months Ended March 31, June 30, September 30, December 31, 2015 2015 2015 2015 Revenue $ 13,502 $ 15,191 $ 14,804 $ 18,073 Cost of goods sold 2,949 3,348 3,431 4,330 Gross profit 10,553 11,843 11,373 13,743 Operating expenses Selling and marketing 9,887 9,815 12,308 12,937 Research and development 1,300 1,308 1,392 1,387 General and administrative 2,816 3,074 3,230 3,914 Total operating expense 14,003 14,197 16,930 18,238 Loss from operations (3,450 ) (2,354 ) (5,557 ) (4,495 ) Other income (expense) Interest income 21 50 47 53 Interest expense (919 ) (562 ) (561 ) (562 ) Other non-operating expense — (2 ) — (9 ) Total other expense, net (898 ) (514 ) (514 ) (518 ) Net loss $ (4,348 ) $ (2,868 ) $ (6,071 ) $ (5,013 ) Net loss per share, basic and diluted $ (0.35 ) $ (0.15 ) $ (0.32 ) $ (0.27 ) Weighted average common shares used to compute net loss per share, basic and diluted 12,542 18,718 18,738 18,784 Three Months Ended March 31, June 30, September 30, December 31, 2014 2014 2014 2014 Revenue $ 10,175 $ 12,498 $ 11,691 $ 14,456 Cost of goods sold 2,298 2,716 2,501 3,239 Gross profit 7,877 9,782 9,190 11,217 Operating expenses Selling and marketing 7,722 8,163 8,391 8,487 Research and development 1,116 1,047 972 1,172 General and administrative 1,158 1,222 1,387 2,330 Total operating expense 9,996 10,432 10,750 11,989 Loss from operations (2,119 ) (650 ) (1,560 ) (772 ) Other income (expense) Interest income 4 — — 71 Interest expense (421 ) (523 ) (473 ) (487 ) Other non-operating income 1 — — — Total other expense, net (416 ) (523 ) (473 ) (416 ) Net loss $ (2,535 ) $ (1,173 ) $ (2,033 ) $ (1,188 ) Net loss per share, basic and diluted $ (1.80 ) $ (0.81 ) $ (1.36 ) $ (0.73 ) Weighted average common shares used to compute net loss per share, basic and diluted 1,412 1,455 1,500 1,628

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2015
Valuation And Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts	SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS (in thousands) Beginning Ending Balance Additions Deductions Balance Allowance for doubtful accounts receivable Year ended December 31, 2015 $ 150 $ 46 $ 61 $ 135 Year ended December 31, 2014 135 49 34 150 Year ended December 31, 2013 125 69 59 135 Reserve for sales returns and allowances Year ended December 31, 2015 $ 140 $ 230 $ 119 $ 251 Year ended December 31, 2014 100 120 80 140 Year ended December 31, 2013 62 135 97 100

Summary of Significant Accoun24

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Initial Public Offering	Initial Public Offering In February 2015, the Company completed its initial public offering (“IPO”) by issuing 5,294 shares of common stock at an offering price of $17.00 per share, for net proceeds to the Company of approximately $80,953, after deducting underwriting discounts and commissions and offering expenses payable by the Company. In connection with the IPO, the Company’s outstanding shares of convertible preferred stock were automatically converted into an aggregate of 11,404 shares of common stock and warrants exercisable for convertible preferred stock were automatically converted into warrants to purchase up to an aggregate of 38 shares of common stock, resulting in the reclassification of the related redeemable convertible preferred stock warrant liability of $648 to additional paid-in-capital.
1-for-4 Reverse Stock Split	1-for-4 Reverse Stock Split In connection with the IPO, the Company’s board of directors and stockholders approved a reverse stock split of the Company’s common stock on a 1-for-4 basis. The reverse stock split became effective on January 12, 2015. The par value of the common stock was not adjusted as a result of the reverse stock split. Adjustments corresponding to the reverse stock split were made to the ratio at which the convertible preferred stock converted into common stock immediately prior to the closing of the IPO. Accordingly, all share and per share amounts for all periods presented in these consolidated financial statements and notes thereto have been adjusted retroactively, where applicable, to reflect the reverse stock split and adjustment of the preferred stock’s conversion ratios.
Basis of Preparation	Basis of Preparation The consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) and pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”). JOBS Act Accounting Election As an emerging growth company under the Jumpstart Our Business Startups Act of 2012 (“JOBS Act”), the Company is eligible to take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies. The Company has elected to take advantage of the extended transition period for adopting new or revised accounting standards that have different effective dates for public and private companies until such time as those standards apply to private companies.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of Entellus Medical, Inc., and its wholly owned subsidiary. All significant intercompany transactions and accounts have been eliminated.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.
Foreign Currency Translation	Foreign Currency Translation Sales and expenses denominated in foreign currencies are translated at average exchange rates in effect throughout the year. Assets and liabilities of foreign operations are translated at period-end exchange rates with the impacts of foreign currency translation recognized to foreign currency translation adjustment, a component of accumulated other comprehensive loss. Foreign currency transaction gains and losses are included in other income (expense) in the consolidated statements of operations and comprehensive loss.
Cash and Equivalents	Cash and Equivalents The Company considers all highly liquid investments purchased with an initial maturity of 90 days or less to be cash equivalents. At December 31, 2015 and 2014, cash equivalents consisted of money market funds recorded at fair value and federal and corporate debt securities recorded at amortized costs. Investments in marketable securities of $16,747 were classified as cash equivalents as of December 31, 2015 and none as of 2014. The Company maintains cash in bank accounts which, at times, may exceed Federal Deposit Insurance Corporation (“FDIC”) limits. The Company has not experienced any losses from maintaining balances in excess of FDIC limits.
Short-term Investments	Short-term Investments Short-term investments represent holdings of marketable securities in accordance with the Company’s investment policy and cash management strategy. Short-term investments are classified as available-for-sale and mature within 12 months from the balance sheet date. Investments with maturity dates greater than one year from the balance sheet date are classified as long-term investments. At the time that the maturity dates of these investments become one year or less, the securities are reclassified to short-term investments. The Company’s investments are recorded at fair value, with any unrealized gains and losses reported as a component of stockholders’ equity (deficit) until realized or until a determination is made that an other-than-temporary decline in market value has occurred. The cost of investments sold is determined based on the specific identification method and any realized gains or losses on the sale of investments are reflected as a component of interest income or expense. These investments are deemed Level 2 assets under the fair value hierarchy as their fair value is determined under a market approach using valuation models that utilize observable inputs, including maturity date, issue date, settlements date, and current interest rates.
Fair Value of Financial Instruments	Fair Value of Financial Instruments As of December 31, 2015 and 2014, the carrying amounts of cash and cash equivalents, accounts receivable, accounts payable and accrued expenses approximated their estimated fair value because of the short-term nature of the financial instruments. The Company determines the fair value of its assets and liabilities based on the exchange price that would be received for an asset or paid to transfer a liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value maximize the use of observable inputs and minimize the use of unobservable inputs. A fair value hierarchy with three levels of inputs, of which the first two are considered observable and the last unobservable, is used to measure fair value. The fair value hierarchy gives the highest priority to quoted prices in active markets for identical assets or liabilities (Level 1). The next highest priority is based on quoted prices for similar assets or liabilities in active markets or quoted prices for identical or similar assets or liabilities in non-active markets or other observable inputs (Level 2). The lowest priority is given to unobservable inputs (Level 3).
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments, which potentially subject the Company to concentrations of credit risk, consist principally of cash equivalents and accounts receivable. The Company generally does not require collateral and losses on accounts receivable have historically been within management’s expectations. The Company’s investment policy limits investments, when held, to certain types of debt securities issued by the U.S. government, its agencies, and institutions with investment-grade credit ratings, as well as corporate debt or commercial paper issued by the highest quality financial and non-financial companies, and places restrictions on maturities and concentration by type and issuer. The Company is exposed to credit risk in the event of a default by the financial institutions holding its cash and equivalents and issuers of debt securities to the extent recorded on the consolidated balance sheets.
Accounts Receivable	Accounts Receivable Credit is granted to customers in the normal course of business, generally without collateral or any other security to support amounts due. Accounts are considered past due generally after 30 days. The Company maintains an allowance for doubtful accounts for estimated losses in the collection of accounts receivable. The Company makes estimates regarding the future ability of its customers to make required payments based on historical credit experience, delinquency and expected future trends. The Company will write off accounts receivable when it determines that the accounts receivable are uncollectible, typically upon customer bankruptcy or the customer’s non-response to continued collection efforts. The allowance for doubtful accounts was $135 and $150 as of December 31, 2015 and 2014, respectively. The Company also maintains an allowance for sales returns based on historical experience and evaluation of current sales and returns trends. The allowance for sales returns was $250 and $140 as of December 31, 2015 and 2014, respectively.
Inventories	Inventories Inventories are stated at the lower of cost to purchase or manufacture the inventory or the net realizable value of such inventory. Cost is determined using the standard cost method which approximates the first-in, first-out basis. Market value is determined as the lower of replacement cost or net realizable value. The Company regularly reviews inventory quantities in consideration of actual loss experiences, projected future demand, and remaining shelf life to record a provision for excess and obsolete inventory when appropriate.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost. Depreciation of furniture, office, computer and laboratory equipment is calculated on a straight-line basis over the asset’s estimated useful life, which ranges from three to ten years. Tooling and molds are depreciated on a straight-line basis over three to five years. Leasehold improvements are amortized on a straight-line basis over the shorter of the remaining life of the lease or the useful life of the asset. Repair and maintenance expenditures are charged to earnings as incurred. Major repairs and maintenance expenditures that extend useful lives of property and equipment are capitalized.
Deferred Offering Costs	Deferred Offering Costs Deferred offering costs, primarily consisting of legal, accounting and other direct fees and costs relating to the initial public offering, are capitalized. The deferred offering costs were offset against the IPO proceeds upon the closing of the offering in February 2015. As of December 31, 2014, there was $1,698 in deferred offering costs capitalized in other non-current assets on the consolidated balance sheet. There were no deferred offering costs capitalized as of December 31, 2015.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company reviews its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceed the fair value of the assets. Assets to be disposed of are reported at the lower of the carrying amount or fair value less costs to sell. The Company has not recorded impairment charges on long-lived assets for the periods presented in these consolidated financial statements.
Deferred Rent	Deferred Rent The Company accounts for rent expense related to operating leases by determining total minimum rent payments on the leases over their respective periods and recognizing the rent expense on a straight-line basis. The difference between the actual amount paid and the amount recorded as rent expense in each period presented is recorded as an adjustment to other non-current liabilities in the consolidated balance sheet.
Debt Issuance and Debt Discount	Debt Issuance and Debt Discount Debt issuance costs are stated at cost, net of accumulated amortization and included within other assets. Debt discount is recorded as a reduction of long-term debt. Amortization of debt issuance costs and the debt discount is calculated using the effective interest method over the term of the debt and is recorded in interest expense in the accompanying consolidated statements of operations and comprehensive loss.
Revenue Recognition	Revenue Recognition The Company recognizes revenue when persuasive evidence of a sales arrangement exists, delivery of goods has occurred through the transfer of title and risks and rewards of ownership, the selling price is fixed or determinable and collectability is reasonably assured. Revenue is reported net of the allowance for sales returns. Taxes assessed by a governmental authority that are directly imposed on revenue-producing transactions between a seller and a customer are not recorded as revenue. The Company entered into a distribution agreement with CogENT Therapeutics in September 2013 and began exclusive distribution of XeroGel in October 2013 in the United States. For products shipped from the CogENT warehouse to customers, CogENT is responsible for all manufacturing, order fulfillment, quality and regulatory requirements of the product. For these direct shipment orders, the Company does not take title to CogENT products prior to products being ordered by customers or in the event CogENT products are returned by customers. The Company records transactions under this arrangement on a net basis based on the difference between the amounts billed to customers less the amounts paid to CogENT for the XeroGel product. The Company’s net revenue for the year ended December 31, 2015, 2014 and 2013 were approximately $1,162, $839 and $65, respectively. For products for which the Company takes title, ships the product and handles returns, the Company records transactions under these arrangements on a gross basis. The amounts of revenue recorded on a gross basis for the year ended December 31, 2015, 2014 and 2013 were approximately $156, $143 and $0, respectively.
Shipping and Handling	Shipping and Handling Shipping and handling costs charged to customers are included as a component of revenue and related costs are included in costs of goods sold.
Cost of Goods Sold	Cost of Goods Sold Cost of goods sold consists primarily of manufacturing overhead costs, material costs and direct labor. A significant portion of the Company’s cost of goods sold currently consists of manufacturing overhead costs. These overhead costs include the cost of quality assurance, material procurement, inventory control, facilities, equipment, operations supervision and management, depreciation expense for production equipment, amortization of leasehold improvements, shipping costs and royalty expense payable in connection with sales of certain products. For those products we sell as a distributor, our cost of goods sold consists primarily of transfer price.
Research and Development Costs	Research and Development Costs Research and development expenses consist primarily of engineering, product development, clinical and regulatory affairs, consulting services, materials, depreciation and other costs associated with products and technologies in development. These expenses include employee and non-employee compensation, including stock-based compensation, supplies, materials, consulting, related travel expenses and facility costs. Clinical expenses include clinical trial design, clinical site reimbursement, data management and travel expenses, and the cost of manufacturing products for clinical trials. Expenditures for research and development activities are charged to operations as incurred.
Advertising Expense	Advertising Expense Expenditures for advertising are charged to operations as incurred. Advertising expenses were $1,103, $645 and $587 during the years ended December 31, 2015, 2014 and 2013, respectively.
Common Stock Valuation and Stock-based Compensation	Common Stock Valuation and Stock-based Compensation Prior to the IPO, the Company maintained its 2006 Stock Incentive Plan (the “2006 Plan”) to provide long-term incentives for employees, consultants and members of the board of directors. The 2006 Plan allowed for the issuance of non-statutory and incentive stock options to employees and non-statutory stock options to consultants and non-employee directors. In connection with the IPO, the 2006 Plan terminated, and the Company adopted a new equity incentive plan, the 2015 Incentive Award Plan (the “2015 Plan”). The Company is required to determine the fair value of equity incentive awards and recognize compensation expense for all equity incentive awards made to employees and directors, including employee stock options. The Company also determines the fair value of non-statutory stock options issued to consultants based on the fair value of the consultant’s commitment at the date of grant. Such expense is recognized over the requisite service period. In addition, stock-based compensation expense recognized in the consolidated statements of operations and comprehensive loss is based on awards expected to vest and therefore the amount of expense has been reduced for estimated forfeitures. The Company uses the straight-line method for expense attribution, except for awards issued with performance-based conditions which require an accelerated attribution method over the requisite performance and service periods. Under the applicable accounting guidance for equity incentive awards issued to non-employees, the date at which the fair value of such awards is measured is equal to the earlier of: 1) the date at which a commitment for performance by the counterparty to earn the equity instrument is reached; or 2) the date at which the counterparty’s performance is complete. The Company recognizes stock-based compensation expense for the fair value of the vested portion of the non-employee awards in the consolidated statements of operations and comprehensive loss. The valuation model used for calculating the fair value of awards for stock-based compensation expense is the Black-Scholes option-pricing model (the “Black-Scholes model”). The Black-Scholes model requires the Company to make assumptions and judgments about the variables used in the calculation, including the expected term (weighted average period of time that the options granted are expected to be outstanding), the volatility of common stock and an assumed risk-free interest rate. The Company uses the “simplified method” to determine the expected term of the stock option. Volatility is based on an average of the historical volatilities of the common stock of publicly-traded companies with characteristics similar to those of the Company. The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant for periods corresponding with the expected term of the option. The expected dividend assumption is based on the Company’s history of not paying dividends and its expectation that it will not declare dividends for the foreseeable future. Potential forfeitures of awards are estimated based on the Company’s historical forfeiture experience. The estimate of forfeitures will be adjusted over the service period to the extent that actual forfeitures differ, or are expected to differ, from prior estimates.
Convertible Preferred Stock Warrant Liability	Convertible Preferred Stock Warrant Liability For a warrant classified as a derivative liability, the fair value of that warrant is recorded on the consolidated balance sheet when granted and adjusted to fair value at each financial reporting date. The changes in the fair value of the warrants are recorded in the statement of operations and comprehensive loss as a component of interest income or expense as appropriate. The Company issued warrants to purchase shares of convertible preferred stock in connection with the Company’s entry into its original credit facility in October 2012. The warrants were recorded at fair value using the Black Scholes model. The fair value of these warrants was remeasured at each financial reporting period with any changes in fair value being recognized as a component of other income (expense) in the consolidated statements of operations and comprehensive loss. In connection with the IPO, in January 2015, the Company performed the final remeasurement of the warrant liability. There were costs of $357 during the year ended December 31, 2015 recorded as interest expense from the final remeasurement. Upon the closing of the IPO, warrants to purchase shares of convertible preferred stock automatically converted into warrants to purchase shares of common stock. The Company reclassified the warrant liability to additional paid-in capital, as the warrants met the definition of an equity instrument.
Income Taxes	Income Taxes Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax base and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The Company applies a recognition threshold for income tax positions taken or expected to be taken on a tax return. The impact of an uncertain tax position taken or expected to be taken on an income tax return are recognized in the consolidated financial statements at the largest amount that is more-likely-than not to be sustained upon audit by the relevant taxing authority. An uncertain tax position is not recognized in the consolidated financial statements unless it is more-likely-than not of being sustained. The Company has no reserve for unrecognized tax benefits at December 31, 2015 and 2014, and accordingly, there is no interest or penalties recorded on the consolidated balance sheet for such reserves. The Company is currently open to audit under the statute of limitations by the Internal Revenue Service and the appropriate state income taxing authorities for 2006 through 2015.
Net Loss Per Share	Net Loss per Share Basic net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock outstanding during the period. Diluted net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock and dilutive potential shares of common stock outstanding during the period. Because the Company has reported a net loss for all periods presented, diluted net loss per share is the same as basic net loss per share for those periods as all potentially dilutive shares consisting of convertible preferred stock, stock options and warrants were antidilutive in those periods. The Company allocates no loss to participating securities because they have no contractual obligation to share in the losses of the Company. The shares of the Company’s convertible preferred stock participate in any dividends declared by the Company and are therefore considered to be participating securities.
Comprehensive Loss	Comprehensive Loss Comprehensive loss consists of net loss, changes in unrealized gains and losses on available-for-sale marketable securities and changes in unrealized translation gains and losses. Accumulated other comprehensive income is presented in the accompanying consolidated balance sheets, when applicable.
Segment Geographical and Customer Concentration	Segment, Geographical and Customer Concentration The Company operates in one segment. No single customer accounted for more than 10% of its revenue during the years ended December 31, 2015, 2014 and 2013.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers. This standard will eliminate the transaction and industry specific revenue recognition guidance under current U.S. GAAP and replace it with a principles based approach for determining revenue recognition. The new guidance is effective for annual and interim periods beginning after December 15, 2017. The Company is in the process of evaluating the impact of the adoption of this standard. In February 2015, the FASB issued ASU 2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis. The new consolidation standard amended the process that a reporting entity must perform to determine whether it should consolidate certain types of legal entities. ASU 2015-02 is effective for the annual period beginning after December 15, 2015, and for annual and interim periods thereafter. Early application is permitted. The Company does not expect the adoption of ASU 2015-02 to have a material impact on its financial position or results of operations. In April 2015, the FASB issued ASU 2015-03, Simplifying the Presentation of Debt Issuance, which changes the presentation of debt issuance costs in financial statements. Under ASU 2015-03, an entity presents such costs in the balance sheet as a direct deduction from the related debt liability rather than as an asset. Amortization of the costs is reported as interest expense. ASU 2015-03 is effective for fiscal years and interim periods within those fiscal years, beginning after December 15, 2015 . Early adoption is permitted for financial statements that have not been previously issued. A company should apply the new guidance on a retrospective basis, wherein the balance sheet of each individual period presented should be adjusted to reflect the period-specific effects of applying the new guidance. Upon transition, a company is required to comply with the applicable disclosures for a change in an accounting principle. The guidance only affects the presentation of debt issuance costs in the balance sheet and has no impact on results of operations. In July 2015, the FASB issued ASU 2015-11, Simplifying the Measurement of Inventory, which requires inventory not measured using either the last in, first out or the retail inventory method to be measured at the lower of cost and net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable cost of completion, disposal, and transportation. The new standard will be effective January 1, 2017 and will be applied prospectively. Early adoption is permitted. The Company early adopted ASU 2011-15 effective December 31, 2015 prospectively. Adoption had no impact on the Company’s results of operations. In November 2015, the FASB issued ASU 2015-17, Balance Sheet Classification of Deferred Taxes, which amends the guidance requiring companies to separate deferred income tax liabilities and assets into current and non-current amounts in a classified statement of financial position. ASU 2015-17 simplifies the presentation of deferred income taxes, such that deferred tax liabilities and assets be classified as non-current in a classified statement of financial position. The new standard will be effective beginning in the first quarter of 2018. Early adoption is permitted. The Company early adopted ASU 2015-17 effective December 31, 2015. The adoption of ASU 2015-17 did not have an impact on the Company’s consolidated balance sheet due to the full valuation allowance against the net deferred tax assets as of December 31, 2015 and 2014. In January 2016, the FASB issued ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities, which addresses certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. ASU 2016-01 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017, and early adoption is not permitted. The Company does not expect that adoption of ASU 2016-01 will have a significant impact on its consolidated financial statements.
Reclassification

Composition of Certain Financ25

Composition of Certain Financial Statement Items (Tables)	12 Months Ended
	Dec. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Schedule of Inventories	Inventories December 31, December 31, 2015 2014 Finished goods $ 1,487 $ 859 Work in process 388 318 Raw materials 2,014 1,262 Total $ 3,889 $ 2,439
Schedule of Property and Equipment	Property and Equipment December 31, December 31, 2015 2014 Furniture and office equipment $ 533 $ 401 Computer hardware and software 2,187 837 Laboratory equipment 2,915 1,427 Tooling and molds 1,243 1,237 Leasehold improvements 583 494 $ 7,461 $ 4,396 Less accumulated depreciation and amortization (3,766 ) (2,768 ) Property and equipment in progress 431 102 Total $ 4,126 $ 1,730
Schedule of Other Non-Current Assets	Other Non-Current Assets December 31, December 31, 2015 2014 Security deposit on operating lease $ 34 $ 19 Deferred offering costs — 1,698 Total $ 34 $ 1,717
Schedule of Accrued Expenses	Accrued Expenses December 31, December 31, 2015 2014 Compensation and commissions payable $ 3,898 $ 3,001 Royalty payable 1,800 1,537 Other accrued expenses 1,297 546 Total $ 6,995 $ 5,084
Schedule of Interest Expense	Interest Expense December 31, December 31, December 31, 2015 2014 2013 Interest expense $ 2,247 $ 1,750 $ 1,000 Increase in fair value of convertible preferred stock warrants 357 154 82 Total $ 2,604 $ 1,904 $ 1,082

Short-Term Investments (Tables)

Short-Term Investments (Tables)	12 Months Ended
	Dec. 31, 2015
Investments Debt And Equity Securities [Abstract]
Summary of Investments by Type of Instrument	The following is a summary of the available-for-sale investments by type of instrument, which are included in short-term investments in the consolidated balance sheet as of December 31, 2015. As of December 31, 2014, there were no short or long-term investments. Unrealized Unrealized Gain in Losses in Accumulated Accumulated Other Other Amortized Comprehensive Comprehensive Estimated December 31, 2015 Cost Income Income Fair Value Short-Term Commercial paper $ 9,482 $ 10 $ — $ 9,492 Corporate bonds 19,605 — (19 ) 19,586 Government bonds 1,999 — — 1,999 Foreign assets 7,140 — (7 ) 7,133 Total available-for-sale securities $ 38,226 $ 10 $ (26 ) $ 38,210

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Summary of Available for Sale Investments at Fair Value on Recurring Basis	The following is a summary of available-for-sale investments by type of instrument measured at fair value on a recurring basis at December 31, 2015. As of December 31, 2014, there were no available-for-sale investments. December 31, 2015 Level 1 Level 2 Level 3 Total Commercial paper $ — $ 9,492 $ — $ 9,492 Corporate bonds — 19,586 — 19,586 Government bonds — 1,999 — 1,999 Foreign assets — 7,133 — 7,133 Total $ — $ 38,210 $ — $ 38,210
Summary of Changes in Estimated Fair Value of Company's Convertible Preferred Stock Warrants	The following table sets forth a summary of the changes in the estimated fair value of the Company’s convertible preferred stock warrant liability, which represents financial instruments that were categorized as Level 3, according to the three-level fair value hierarchy. Year Ended December 31, 2015 2014 Beginning of the period $ 291 $ 211 Issued — — Exercised — — Expired — — Reclassified to equity (1) (648 ) — Change in fair value 357 80 End of the period $ — $ 291 (1) In connection with the closing of the IPO in February 2015, warrants to purchase shares of convertible preferred stock were converted to warrants to purchase shares of common stock, resulting in the reclassification of the related convertible preferred stock warrant liability to additional paid-in-capital.
Summary of Fair Value of Convertible Preferred Stock Warrant Liability	The fair market value of the convertible preferred stock prior to the IPO was determined using the option pricing method and the probability weighted expected return method. The fair value of the convertible preferred stock warrant liability was determined using the Black-Scholes option pricing model with the following assumptions: Year Ended December 31, 2015 2014 Expected life in years N/A 7.8 Risk-free interest rate N/A 2.0 % Expected dividend yield N/A 0.0 % Expected volatility N/A 50 %

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Schedule of Principal Payments due under Amended Credit Facility	Assuming a 24-month amortization period, the Company’s principal payments are due under the amended credit facility as follows for the years ending December 31, 2015: 2016 $ — 2017 9,118 2018 10,882 $ 20,000

Convertible Preferred Stock (Ta

Convertible Preferred Stock (Tables)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Summary of Convertible Preferred Stock	As of December 31, 2015 and 2014, respectively, the Convertible Preferred Stock consisted of the following (presented in actual amounts): December 31, 2015 December 31, 2014 Number of Number of Number of Number of shares Number of shares shares Shares issued and Carrying Shares issued and converted Carrying authorized outstanding value authorized outstanding common Stock value Series A — — — 2,440,000 2,440,000 610,000 $ 2,963,745 Series B — — — 4,986,188 4,986,188 1,246,547 8,988,134 Series C — — — 3,717,329 3,717,329 1,254,375 14,937,389 Series D — — — 15,310,943 15,310,943 3,827,736 29,822,047 Series E — — — 18,112,611 17,862,611 4,465,653 34,842,241 Total — — — 44,567,071 44,317,071 11,404,311 $ 91,553,556

Stockholders' Deficit (Tables)

Stockholders' Deficit (Tables)	12 Months Ended
	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity and Related Information	A summary of the Company’s stock option activity and related information is as follows: Weighted average Aggregate Weighted remaining intrinsic average contractual value Options exercise price term ($000) Balance at December 31, 2012 1,505 $ 1.37 Granted 437 1.33 Exercised (583 ) 1.23 Cancelled (112 ) 4.08 Forfeited (31 ) 0.84 Balance at December 31, 2013 1,216 $ 1.18 Granted 1,396 10.55 Exercised (466 ) 1.24 Cancelled — — Forfeited (48 ) 2.43 Balance at December 31, 2014 2,098 $ 7.38 Granted 745 21.53 Exercised (209 ) 1.55 Cancelled — — Forfeited (51 ) 14.43 Balance at December 31, 2015 2,583 $ 11.79 8.5 years $ 16,377 Exercisable 822 $ 6.26 7.1 years $ 9,077
Summary of Common Stock Reserved for Conversion, Exercise and Issuance of Options and Shares Outstanding	The number of such shares of common stock reserved for the conversion, exercise and issuance of the following options and shares outstanding as of December 31, 2015 and 2014, were as follows: December 31, 2015 2014 Convertible preferred stock: Series A outstanding — 610 Series B outstanding — 1,246 Series C outstanding — 929 Series C anti-dilution shares — 325 Series D outstanding — 3,828 Series E outstanding — 4,466 Warrants issued in connection with the credit facility 38 38 2006 Stock Incentive Plan, options outstanding 1,861 2,098 2015 Stock Incentive Plan, options outstanding 723 — Options available for future grant — 23 2,622 13,563

Stock Based Compensation Expe31

Stock Based Compensation Expense (Tables)	12 Months Ended
	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock-based Compensation Expense in Condensed Statement of Operations and Comprehensive Loss	Stock-based compensation expense was reflected in the statement of operations and comprehensive loss for the years ended December 31, 2015, 2014 and 2013, as follows: Years ended December 31, 2015 2014 2013 Cost of goods sold $ 65 $ 11 $ 15 Selling and marketing 750 111 78 Research and development 260 46 68 General and administrative 1,736 80 193 Total $ 2,811 $ 248 $ 354
Summary of Weighted Average Assumptions Used in Black-Scholes Model in Estimating Fair Value of Option Granted	The fair value of the options granted to employees or directors during the years ended December 31, 2015, 2014 and 2013, was estimated as of the grant date using the Black-Scholes model assuming the weighted average assumptions listed in the following table: Years ended December 31, 2015 2014 2013 Expected life in years 6.0 5.8 5.7 Risk-free interest rate 1.8 % 1.7 % 1.1 % Expected dividend yield 0 % 0 % 0 % Expected volatility 56 % 54 % 68 % Weighted average fair value $ 11.41 $ 5.32 $ 3.04

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Components of Loss Before Taxes	The components of loss before taxes for the years ended December 31, 2015 and 2014, consist of the following: Years ended December 31, 2015 2014 Domestic $ (17,860 ) $ (6,929 ) Foreign (440 ) - Total loss before income taxes $ (18,300 ) $ (6,929 )
Schedule of Effective Income Tax Rate Reconciliation	Income tax expense differs from the amount computed by applying the statutory federal income tax rate as follows: December 31, 2015 2014 Tax at statutory federal rate 34.0 % 34.0 % State tax, net of federal benefit 1.8 1.1 Meals and entertainment (2.0 ) (4.2 ) Stock-based compensation (1.9 ) (0.8 ) Other (0.3 ) 0.8 Valuation allowance (31.6 ) (30.9 ) Total 0 % 0 %
Schedule of Deferred Tax Assets and Liabilities	The tax effects of temporary differences that give rise to significant portions of the net deferred tax asset (liability) were as follows at December 31: December 31, 2015 2014 Deferred tax asset: Accounts receivable $ 136 $ 103 Inventories 71 32 Accrued expenses 158 218 Depreciation and amortization 97 192 Research and development credits generated 1,091 837 Net operating loss carryforward 40,185 35,231 Organizational costs 4 5 Stock-based compensation expense (non-qualified options) 780 211 Other 28 20 Total deferred tax assets 42,550 36,849 Deferred tax liabilities: Prepaid expense (251 ) (207 ) Total deferred tax liabilities (251 ) (207 ) Total deferred tax assets, net 42,299 36,642 Less valuation allowance (42,299 ) (36,642 ) Total deferred tax assets $ — $ —

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Schedule of Net Loss Per Share	The following table sets forth the computation of the Company’s net loss per share: Years ended December 31, 2015 2014 2013 Net loss $ (18,300 ) $ (6,929 ) $ (13,396 ) Weighted average common stock outstanding 17,217 1,499 1,133 Net loss per share, basic and diluted $ (1.06 ) $ (4.62 ) $ (11.82 )
Schedule of Antidilutive Securities Outstanding Excluded from Computation of Earnings Per Share	The following potentially dilutive securities outstanding have been excluded from the computations of diluted weighted average shares outstanding because such securities have an antidilutive impact due to losses reported: Years ended December 31, 2015 2014 2013 Convertible preferred stock outstanding — 11,404 11,404 Convertible preferred stock warrants — 38 38 Common stock warrants 38 — — Common stock options 2,584 2,098 1,216 Total 2,622 13,540 12,658

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments And Contingencies Disclosure [Abstract]
Summary of Annual Future Minimum Lease Payments	Approximate minimum future obligations which include monthly contractual lease payments under operating leases with initial terms in excess of one year are as follows: 2016 $ 351 2017 366 2018 373 2019 381 2020 389 2021 and thereafter 197 Total $ 2,057

Segments (Tables)

Segments (Tables)	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Revenue by Geographical Area, Based on the Location of Customer	The following table represents total revenue by geographic area, based on the location of the customer: Years ended December 31, 2015 2014 2013 United States $ 60,911 $ 48,820 $ 32,545 International 659 — — Total $ 61,570 $ 48,820 $ 32,545

Quarterly Results of Operatio36

Quarterly Results of Operations (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results of Operations	The following is a summary of the Company’s unaudited quarterly results of operations for the years December 31, 2015 and 2014: Three Months Ended March 31, June 30, September 30, December 31, 2015 2015 2015 2015 Revenue $ 13,502 $ 15,191 $ 14,804 $ 18,073 Cost of goods sold 2,949 3,348 3,431 4,330 Gross profit 10,553 11,843 11,373 13,743 Operating expenses Selling and marketing 9,887 9,815 12,308 12,937 Research and development 1,300 1,308 1,392 1,387 General and administrative 2,816 3,074 3,230 3,914 Total operating expense 14,003 14,197 16,930 18,238 Loss from operations (3,450 ) (2,354 ) (5,557 ) (4,495 ) Other income (expense) Interest income 21 50 47 53 Interest expense (919 ) (562 ) (561 ) (562 ) Other non-operating expense — (2 ) — (9 ) Total other expense, net (898 ) (514 ) (514 ) (518 ) Net loss $ (4,348 ) $ (2,868 ) $ (6,071 ) $ (5,013 ) Net loss per share, basic and diluted $ (0.35 ) $ (0.15 ) $ (0.32 ) $ (0.27 ) Weighted average common shares used to compute net loss per share, basic and diluted 12,542 18,718 18,738 18,784 Three Months Ended March 31, June 30, September 30, December 31, 2014 2014 2014 2014 Revenue $ 10,175 $ 12,498 $ 11,691 $ 14,456 Cost of goods sold 2,298 2,716 2,501 3,239 Gross profit 7,877 9,782 9,190 11,217 Operating expenses Selling and marketing 7,722 8,163 8,391 8,487 Research and development 1,116 1,047 972 1,172 General and administrative 1,158 1,222 1,387 2,330 Total operating expense 9,996 10,432 10,750 11,989 Loss from operations (2,119 ) (650 ) (1,560 ) (772 ) Other income (expense) Interest income 4 — — 71 Interest expense (421 ) (523 ) (473 ) (487 ) Other non-operating income 1 — — — Total other expense, net (416 ) (523 ) (473 ) (416 ) Net loss $ (2,535 ) $ (1,173 ) $ (2,033 ) $ (1,188 ) Net loss per share, basic and diluted $ (1.80 ) $ (0.81 ) $ (1.36 ) $ (0.73 ) Weighted average common shares used to compute net loss per share, basic and diluted 1,412 1,455 1,500 1,628

Summary of Significant Accoun37

Summary of Significant Accounting Policies - Additional Information (Detail)	1 Months Ended	12 Months Ended
	Feb. 28, 2015USD ($)$ / sharesshares	Dec. 31, 2015USD ($)SegmentCustomershares	Dec. 31, 2014USD ($)Customershares	Dec. 31, 2013USD ($)Customer
Accounting Policies [Line Items]
Number of common stock converted from preferred stock | shares			11,404,311
Period for considering accounts receivable as past due		30 days
Allowance for doubtful accounts receivable		$ 135,000	$ 150,000
Allowance for sales returns		250,000	140,000
Deferred offering costs		0	1,698,000
Net revenue		1,162,000	839,000	$ 65,000
Gross revenue		156,000	143,000	0
Advertising expense		1,103,000	645,000	587,000
Changes in fair value of convertible preferred stock warrants		$ 357,000	$ 80,000	$ 80,000
Number of reportable segments | Segment		1
Number of customers accounted for more than 10% of revenue | Customer		0	0	0
Loss allocated to participating securities		$ 0
Debt issuance costs		176,000	$ 237,000
Interest Expense [Member]
Accounting Policies [Line Items]
Changes in fair value of convertible preferred stock warrants		357,000
Cash Equivalents [Member]
Accounting Policies [Line Items]
Investment in marketable securities		$ 16,747,000	$ 0
Initial Public Offering [Member]
Accounting Policies [Line Items]
Common stock, shares issued | shares	5,294,000
Common stock offering price per share | $ / shares	$ 17
Proceeds from issuance of common stock, net of issuance costs	$ 80,953,000
Number of common stock converted from preferred stock | shares	11,404,000	11,404,000
Shares purchasable upon conversion of preferred stock | shares	38,000	38,000
Preferred stock warrant liability reclassified	$ 648,000	$ 648,000

Composition of Certain Financ38

Composition of Certain Financial Statement Items - Schedule of Inventories (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Finished goods	$ 1,487	$ 859
Work in process	388	318
Raw materials	2,014	1,262
Total	$ 3,889	$ 2,439

Composition of Certain Financ39

Composition of Certain Financial Statement Items - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property plant and equipment, Gross	$ 7,461	$ 4,396
Less accumulated depreciation and amortization	(3,766)	(2,768)
Property and equipment in progress	431	102
Total	4,126	1,730
Furniture and Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, Gross	533	401
Computer Hardware and Software [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, Gross	2,187	837
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, Gross	2,915	1,427
Tooling and Molds [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, Gross	1,243	1,237
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, Gross	$ 583	$ 494

Composition of Certain Financ40

Composition of Certain Financial Statement Items - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property Plant And Equipment [Abstract]
Depreciation and amortization	$ 1,005	$ 618	$ 460

Composition of Certain Financ41

Composition of Certain Financial Statement Items - Schedule of Other Non-Current Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets Noncurrent [Abstract]
Security deposit on operating lease	$ 34	$ 19
Deferred offering costs	0	1,698
Other non-current assets, Total	$ 34	$ 1,717

Composition of Certain Financ42

Composition of Certain Financial Statement Items - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Payables And Accruals [Abstract]
Compensation and commissions payable	$ 3,898	$ 3,001
Royalty payable	1,800	1,537
Other accrued expenses	1,297	546
Accrued expenses, Total	$ 6,995	$ 5,084

Composition of Certain Financ43

Composition of Certain Financial Statement Items - Schedule of Interest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule Of Interest Expenses [Line Items]
Interest expense									$ 2,247	$ 1,750	$ 1,000
Increase in fair value of convertible preferred stock warrants									357	80	80
Interest expense, Total	$ 562	$ 561	$ 562	$ 919	$ 487	$ 473	$ 523	$ 421	2,604	1,904	1,082
Convertible Preferred Stock [Member]
Schedule Of Interest Expenses [Line Items]
Increase in fair value of convertible preferred stock warrants									$ 357	$ 154	$ 82

Liquidity and Business Risks -

Liquidity and Business Risks - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	1 Months Ended
	Feb. 28, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Subsidiary, Sale of Stock [Line Items]
Cash and equivalents		$ 28,548	$ 3,484	$ 7,709	$ 6,681
Accumulated deficit		$ 122,058	$ 103,758
Initial Public Offering [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock, shares issued	5,294
Common stock offering price per share	$ 17
Proceeds from issuance of common stock, net of issuance costs	$ 80,953

Short-term Investments - Additi

Short-term Investments - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Investments Debt And Equity Securities [Abstract]
Short-term investments	$ 38,210,000	$ 0
Long-term investments		$ 0
Other-than-temporary impairment charges	$ 0

Short-term Investments - Summar

Short-term Investments - Summary of Investments by Type of Instrument (Detail) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 38,226,000
Unrealized Gain in Accumulated Other Comprehensive Income	10,000
Unrealized Losses in Accumulated Other Comprehensive Income	(26,000)
Estimated Fair Value	38,210,000	$ 0
Short-term Investments [Member] | Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	9,482,000
Unrealized Gain in Accumulated Other Comprehensive Income	10,000
Estimated Fair Value	9,492,000
Short-term Investments [Member] | Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	19,605,000
Unrealized Losses in Accumulated Other Comprehensive Income	(19,000)
Estimated Fair Value	19,586,000
Short-term Investments [Member] | Government Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,999,000
Estimated Fair Value	1,999,000
Short-term Investments [Member] | Foreign Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	7,140,000
Unrealized Losses in Accumulated Other Comprehensive Income	(7,000)
Estimated Fair Value	$ 7,133,000

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Available-for-sale investments	$ 38,210,000	$ 0
Transfer of assets between level 1, level 2 or level 3	$ 0

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Available for Sale Investments at Fair Value on Recurring Basis (Detail) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments	$ 38,210,000	$ 0
Fair Value, Measurements, Recurring [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments	38,210,000
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments	38,210,000
Fair Value, Measurements, Recurring [Member] | Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments	9,492,000
Fair Value, Measurements, Recurring [Member] | Commercial Paper [Member] | Level 2 [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments	9,492,000
Fair Value, Measurements, Recurring [Member] | Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments	19,586,000
Fair Value, Measurements, Recurring [Member] | Corporate Bonds [Member] | Level 2 [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments	19,586,000
Fair Value, Measurements, Recurring [Member] | Government Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments	1,999,000
Fair Value, Measurements, Recurring [Member] | Government Bonds [Member] | Level 2 [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments	1,999,000
Fair Value, Measurements, Recurring [Member] | Foreign Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments	7,133,000
Fair Value, Measurements, Recurring [Member] | Foreign Assets [Member] | Level 2 [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments	$ 7,133,000

Fair Value Measurements - Sum49

Fair Value Measurements - Summary of Changes in Estimated Fair Value of Company's Convertible Preferred Stock Warrants (Detail) - Convertible Preferred Stock Warrants [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Class of Warrant or Right [Line Items]
Beginning of the period	$ 291	$ 211
Reclassified to equity	(648)
Change in fair value	$ 357	80
End of the period		$ 291

Fair Value Measurements - Sum50

Fair Value Measurements - Summary of Fair Value of Convertible Preferred Stock Warrant Liability (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Abstract]
Expected life in years	0 years	7 years 9 months 18 days
Risk-free interest rate		2.00%
Expected dividend yield		0.00%
Expected volatility		50.00%

Debt - Additional Information (

Debt - Additional Information (Detail)	1 Months Ended		12 Months Ended
	Dec. 31, 2013USD ($)Tranches	Oct. 31, 2012USD ($)Tranches$ / sharesshares	Dec. 31, 2015USD ($)shares	Dec. 31, 2014USD ($)	Feb. 28, 2015$ / sharesshares	Oct. 31, 2014USD ($)
Debt Instrument [Line Items]
Line of credit facility, amount outstanding			$ 20,000,000
Expected volatility				50.00%
Risk-free interest rate				2.00%
Expected life in years			0 years	7 years 9 months 18 days
Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 17,000,000				$ 25,000,000
Line of credit facility, amount outstanding			$ 20,000,000
Fixed interest floor rate		8.35%				9.40%
Number of tranches | Tranches	3	2
Maturity date of debt instrument			Dec. 1, 2018
Credit facility interest payment period			24 months
Credit facility final payment fee			7.15%
Default increase in additional interest rate	5.00%
Exercise price of warrants | $ / shares					$ 7.84
Estimated fair value of warrants			$ 132,000
Expected volatility			45.00%
Risk-free interest rate			1.64%
Expected life in years			10 years
Stock warrants issued in conjunction with amended facility | shares			0
Credit Facility [Member] | Series E Preferred Stock [Member]
Debt Instrument [Line Items]
Issuance of warrants to purchase stock | shares		151,000
Exercise price of warrants | $ / shares		$ 1.9594
Credit Facility [Member] | Maximum
Debt Instrument [Line Items]
Warrant exercisable in connection with IPO | shares					38,000
First Tranche [Member] | Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, amount outstanding	$ 15,000,000	$ 7,500,000
Payment fee	143,000
First Tranche [Member] | Credit Facility [Member] | Scenario, Previously Reported [Member]
Debt Instrument [Line Items]
Line of credit facility, amount outstanding	$ 7,500,000
Second Tranche [Member] | Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, amount outstanding				$ 5,000,000
Second Tranche [Member] | Credit Facility [Member] | Maximum
Debt Instrument [Line Items]
Line of credit facility, amount outstanding				$ 5,000,000
Third Tranche [Member] | Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity			$ 5,000,000
Prior to First Anniversary | Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility prepayment fee			0.75%

Debt - Schedule of Principal Pa

Debt - Schedule of Principal Payments due under Amended Credit Facility (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Long Term Debt By Maturity [Abstract]
2,017	$ 9,118
2,018	10,882
Total principal payments	$ 20,000

Convertible Preferred Stock - A

Convertible Preferred Stock - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Feb. 28, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2007	Dec. 31, 2006
Temporary Equity [Line Items]
Convertible preferred stock redemption description		A redemption event would have occurred only upon the liquidation or winding up of the Company, a greater than 50% change in control, or sale of substantially all of the assets of the Company.
Minimum percentage of change in control or sale of assets to trigger a redemption event		50.00%
Number of common stock converted from preferred stock			11,404,311
Preferred stock, dividends declared		$ 0
Convertible preferred stock liquidation description		A liquidation of the Company includes a liquidation, dissolution, or winding up of the Company and, unless waived by the holders of a majority in interest of the Convertible Preferred Stock, the sale, transfer, exclusive licensing or other disposition of all or substantially all of the Company’s assets including intellectual property, or the merger or consolidation of the Company with another entity gaining greater than 50% ownership of the Company
Percentage of ownership held by another entity		50.00%
Percentage of convertible preferred stock outstanding		20.00%
Initial Public Offering [Member]
Temporary Equity [Line Items]
Common stock, shares issued	5,294,000
Number of common stock converted from preferred stock	11,404,000	11,404,000
Shares purchasable upon conversion of preferred stock	38,000	38,000
Preferred stock warrant liability reclassified	$ 648,000	$ 648,000
Series A Preferred Stock [Member]
Temporary Equity [Line Items]
Common stock, shares issued									2,440,000
Number of common stock converted from preferred stock			610,000
Initial Purchase Price		$ 1.25
Applicable conversion price		5
Liquidation price per share		1.25
Series B Preferred Stock [Member]
Temporary Equity [Line Items]
Common stock, shares issued								4,986,000
Number of common stock converted from preferred stock			1,246,547
Initial Purchase Price		1.81
Applicable conversion price		7.24
Liquidation price per share		1.81
Series C Preferred Stock [Member]
Temporary Equity [Line Items]
Common stock, shares issued							3,717,000
Number of common stock converted from preferred stock			1,254,375
Initial Purchase Price		4.035
Applicable conversion price		11.9576
Liquidation price per share		4.035
Series C Preferred Stock [Member] | Minimum [Member]
Temporary Equity [Line Items]
Conversion rate of preferred stock							0.25%
Series C Preferred Stock [Member] | Maximum
Temporary Equity [Line Items]
Conversion rate of preferred stock							0.3374%
Conversion rate of common stock increased							1.3498%
Series D Preferred Stock [Member]
Temporary Equity [Line Items]
Common stock, shares issued						15,311,000
Number of common stock converted from preferred stock			3,827,736
Initial Purchase Price		1.9594
Applicable conversion price		7.8376
Liquidation price per share		1.9594
Series D Preferred Stock [Member] | Maximum
Temporary Equity [Line Items]
Liquidation price per share		3.223
Series E Preferred Stock [Member]
Temporary Equity [Line Items]
Common stock, shares issued				5,104,000	12,759,000
Number of common stock converted from preferred stock			4,465,653
Initial Purchase Price		1.9594
Applicable conversion price		$ 7.8376
Liquidation preferences		$ 0
Liquidation price per share		$ 1.9594
Series E Preferred Stock [Member] | Maximum
Temporary Equity [Line Items]
Liquidation price per share		$ 3.223

Convertible Preferred Stock - S

Convertible Preferred Stock - Summary of Convertible Preferred Stock (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2015
Temporary Equity [Line Items]
Number of shares authorized	44,567,071	0
Number of shares issued	44,317,071	0
Number of shares outstanding	44,317,071	0
Number of shares converted to common Stock	11,404,311
Carrying Value	$ 91,553,556
Series A [Member]
Temporary Equity [Line Items]
Number of shares authorized	2,440,000
Number of shares issued	2,440,000
Number of shares outstanding	2,440,000
Number of shares converted to common Stock	610,000
Carrying Value	$ 2,963,745
Series B [Member]
Temporary Equity [Line Items]
Number of shares authorized	4,986,188
Number of shares issued	4,986,188
Number of shares outstanding	4,986,188
Number of shares converted to common Stock	1,246,547
Carrying Value	$ 8,988,134
Series C [Member]
Temporary Equity [Line Items]
Number of shares authorized	3,717,329
Number of shares issued	3,717,329
Number of shares outstanding	3,717,329
Number of shares converted to common Stock	1,254,375
Carrying Value	$ 14,937,389
Series D [Member]
Temporary Equity [Line Items]
Number of shares authorized	15,310,943
Number of shares issued	15,310,943
Number of shares outstanding	15,310,943
Number of shares converted to common Stock	3,827,736
Carrying Value	$ 29,822,047
Series E [Member]
Temporary Equity [Line Items]
Number of shares authorized	18,112,611
Number of shares issued	17,862,611
Number of shares outstanding	17,862,611
Number of shares converted to common Stock	4,465,653
Carrying Value	$ 34,842,241

Stockholders' Deficit - Additio

Stockholders' Deficit - Additional Information (Detail) - USD ($)	Nov. 30, 2014	Jan. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	May. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares authorized			200,000,000	62,276,000	57,000,000	57,565,000
Common stock, par value			$ 0.001	$ 0.001
Aggregate pre-tax intrinsic value of options exercised			$ 3,162,000	$ 4,197,000	$ 173,000
Total cash received upon the exercise of options			$ 323,000	576,000	$ 717,000
Unvested and subject to a repurchase, shares					41,000
Repurchase of common stock, shares	28,000		1,000
Repurchase of common stock	$ 21,000			21,000
Stock-based compensation			$ 2,811,000	$ 248,000	$ 354,000
2015 ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance			200,000
Increase in share reserve as percentage of shares of Common Stock outstanding on plan adoption date			1.00%
First offering date			Jan. 1, 2016
Stock-based compensation			$ 0
2006 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance				3,541,000
Price of option granted percentage				100.00%
Option available for future grant				23,000
2006 Equity Incentive Plan [Member] | Incentive Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiry period for option granted				10 years
Vesting term				4 years
2006 Equity Incentive Plan [Member] | Incentive Stock Options [Member] | 10% Stockholder [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price of option granted percentage				110.00%
Expiry period for option granted				5 years
2006 Equity Incentive Plan [Member] | Non-Statutory Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiry period for option granted				10 years
2015 Incentive Award Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance		1,346,000
Annual increase in shares available for grant		875,000
Annual percentage increase in shares available for grant		4.00%

Stockholders' Deficit - Summary

Stockholders' Deficit - Summary of Stock Option Activity and Related Information (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding, Beginning balance	2,098	1,216	1,505
Options Granted	745	1,396	437
Options Exercised	(209)	(466)	(583)
Option Cancelled			(112)
Options Forfeited	(51)	(48)	(31)
Options outstanding, Ending balance	2,583	2,098	1,216
Options Exercisable, Ending balance	822
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted Average Exercise Price, Beginning balance	$ 7.38	$ 1.18	$ 1.37
Weighted Average Exercise Price, Granted	21.53	10.55	1.33
Weighted Average Exercise Price, Exercised	1.55	1.24	1.23
Weighted Average Exercise Price, Cancelled			4.08
Weighted Average Exercise Price, Forfeited	14.43	2.43	0.84
Weighted Average Exercise Price, Ending balance	11.79	$ 7.38	$ 1.18
Weighted Average Exercise Price, Exercisable	$ 6.26
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted Average Remaining Contractual Term, Ending balance	8 years 6 months
Weighted Average Remaining Contractual Term, Exercisable, Ending balance	7 years 1 month 6 days
Aggregate Intrinsic Value, Ending balance	$ 16,377
Aggregate Intrinsic Value Exercisable	$ 9,077

Stockholders' Deficit - Summa57

Stockholders' Deficit - Summary of Common Stock Reserved for Conversion, Exercise and Issuance of Options and Shares Outstanding (Detail) - shares	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Class Of Stock [Line Items]
Options available for future grant	2,583,000	2,098,000	1,216,000	1,505,000
Options available for future grant	2,622,000	13,563,000
Credit Facility [Member]
Class Of Stock [Line Items]
Options available for future grant	38,000	38,000
2006 Equity Incentive Plan [Member]
Class Of Stock [Line Items]
Options available for future grant	1,861,000	2,098,000
2015 Stock Incentive Plan [Member]
Class Of Stock [Line Items]
Options available for future grant	723,000
Series A Outstanding [Member]
Class Of Stock [Line Items]
Options available for future grant		610,000
Series B Outstanding [Member]
Class Of Stock [Line Items]
Options available for future grant		1,246,000
Series C Outstanding [Member]
Class Of Stock [Line Items]
Options available for future grant		929,000
Series C Anti-Dilution Shares [Member]
Class Of Stock [Line Items]
Options available for future grant		325,000
Series D Outstanding [Member]
Class Of Stock [Line Items]
Options available for future grant		3,828,000
Series E Outstanding [Member]
Class Of Stock [Line Items]
Options available for future grant		4,466,000
Convertible Preferred Stock [Member]
Class Of Stock [Line Items]
Options available for future grant		23,000

Stock Based Compensation Expe58

Stock Based Compensation Expense - Summary of Stock-Based Compensation Expense in Condensed Statement of Operations and Comprehensive Loss (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 2,811	$ 248	$ 354
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	2,811	248	354
Employee Stock Option [Member] | Cost of Goods Sold [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	65	11	15
Employee Stock Option [Member] | Selling and Marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	750	111	78
Employee Stock Option [Member] | Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	260	46	68
Employee Stock Option [Member] | General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 1,736	$ 80	$ 193

Stock Based Compensation Expe59

Stock Based Compensation Expense - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested employee stock-based payment award	$ 12,710
Options Granted	745,000	1,396,000	437,000
Stock-based compensation expense	$ 2,811	$ 248	$ 354
Number of employees stock options, cancelled	51,000	48,000	31,000
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period for unearned stock-based compensation cost	3 years 1 month 6 days
Stock-based compensation expense	$ 2,811	$ 248	$ 354
Performance-Based Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted		23,000
Number of employees stock options, vested		5,000
Stock-based compensation expense		$ 11
Number of employees stock options, cancelled		18,000

Stock Based Compensation Expe60

Stock Based Compensation Expense - Summary of Weighted Average Assumptions Used in Black-Scholes Model in Estimating Fair Value of Option Granted (Detail) - Employee Stock Option [Member] - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life in years	6 years	5 years 9 months 18 days	5 years 8 months 12 days
Risk-free interest rate	1.80%	1.70%	1.10%
Expected dividend yield	0.00%	0.00%	0.00%
Expected volatility	56.00%	54.00%	68.00%
Weighted average fair value	$ 11.41	$ 5.32	$ 3.04

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Income Taxes [Line Items]
Current income tax expense (benefit)	$ 0	$ 0
Deferred income tax expense (benefit)	0	0
Increase in valuation allowance, deferred tax assets	5,654,000
Unrecognized Deferred Tax Assets	1,246,000
Federal [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 116,103,000	$ 98,700,000
Net operating loss carryforwards expiration year	2,027

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Loss Before Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Domestic	$ (17,860)	$ (6,929)
Foreign	(440)
Total loss before income taxes	$ (18,300)	$ (6,929)

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Federal Statutory to Effective Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Effective Income Tax Rate Continuing Operations Tax Rate Reconciliation [Abstract]
Tax at statutory federal rate	34.00%	34.00%
State tax, net of federal benefit	1.80%	1.10%
Meals and entertainment	(2.00%)	(4.20%)
Stock-based compensation	(1.90%)	(0.80%)
Other	(0.30%)	0.80%
Valuation allowance	(31.60%)	(30.90%)
Total	0.00%	0.00%

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax asset:
Accounts receivable	$ 136	$ 103
Inventories	71	32
Accrued expenses	158	218
Depreciation and amortization	97	192
Research and development credits generated	1,091	837
Net operating loss carryforward	40,185	35,231
Organizational costs	4	5
Stock-based compensation expense (non-qualified options)	780	211
Other	28	20
Total deferred tax assets	42,550	36,849
Deferred tax liabilities:
Prepaid expense	(251)	(207)
Total deferred tax liabilities	(251)	(207)
Total deferred tax assets, net	42,299	36,642
Less valuation allowance	$ (42,299)	$ (36,642)

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Net Loss Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
Net loss	$ (5,013)	$ (6,071)	$ (2,868)	$ (4,348)	$ (1,188)	$ (2,033)	$ (1,173)	$ (2,535)	$ (18,300)	$ (6,929)	$ (13,396)
Weighted average common stock outstanding	18,784	18,738	18,718	12,542	1,628	1,500	1,455	1,412	17,217	1,499	1,133
Net loss per share, basic and diluted	$ (0.27)	$ (0.32)	$ (0.15)	$ (0.35)	$ (0.73)	$ (1.36)	$ (0.81)	$ (1.80)	$ (1.06)	$ (4.62)	$ (11.82)

Earnings Per Share - Schedule66

Earnings Per Share - Schedule of Antidilutive Securities Outstanding Excluded from Computation of Earnings Per Share (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive potential common shares excluded from computation of diluted earning per share	2,622	13,540	12,658
Convertible Preferred Stock Outstanding [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive potential common shares excluded from computation of diluted earning per share		11,404	11,404
Convertible Preferred Stock Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive potential common shares excluded from computation of diluted earning per share		38	38
Common Stock Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive potential common shares excluded from computation of diluted earning per share	38
Common Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive potential common shares excluded from computation of diluted earning per share	2,584	2,098	1,216

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Thousands	Feb. 26, 2015	Jun. 30, 2014	Feb. 29, 2012	Dec. 31, 2015USD ($)Facilities	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Commitments And Contingencies Disclosure [Abstract]
Loss Contingency, Settlement Agreement, Terms				In February 2011, the Company entered into a license agreement with Acclarent, Inc. (“Acclarent”) in connection with the settlement of a then-ongoing litigation in which Acclarent alleged that the Company’s FinESS and XprESS products infringed certain claims of five of their patents, which allegations the Company denied.
Notice period for termination of agreement				Acclarent has the right to terminate the agreement upon 60 days’ notice in the event of the Company’s uncured material breach.
Number of leased facilities under operating lease agreement | Facilities				2
Operating leased facility, period		50 months	41 months
Operating leased facility, effective date		Jul. 1, 2014	Apr. 1, 2012
Operating leased facility, additional period	3 years
Operating leased facility, amendment description				On June 30, 2015, the Company entered into amendments to each lease agreement, among other things, to expand the space occupied by the Company at the property at which the Company’s corporate headquarters are located, and to extend the term of each lease agreement through June 2021, with an option to extend each lease for an additional term through June 2024.
Total lease expense | $				$ 343	$ 305	$ 234

Commitment and Contingencies -

Commitment and Contingencies - Summary of Annual Future Minimum Lease Payments (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Commitments And Contingencies Disclosure [Abstract]
2,016	$ 351
2,017	366
2,018	373
2,019	381
2,020	389
2021 and thereafter	197
Total minimum payment required	$ 2,057

Employee Benefit Plan - Additio

Employee Benefit Plan - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Compensation And Retirement Disclosure [Abstract]
Defined contribution benefit plan, employer contribution	$ 0	$ 0	$ 0

Segments - Additional Informati

Segments - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015Segment
Segment Reporting [Abstract]
Number of reportable segments	1

Segments - Schedule of Total Re

Segments - Schedule of Total Revenue by Geographic Area (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Total revenue	$ 18,073	$ 14,804	$ 15,191	$ 13,502	$ 14,456	$ 11,691	$ 12,498	$ 10,175	$ 61,570	$ 48,820	$ 32,545
United States
Segment Reporting Information [Line Items]
Total revenue									60,911	$ 48,820	$ 32,545
International
Segment Reporting Information [Line Items]
Total revenue									$ 659

Quarterly Results of Operatio72

Quarterly Results of Operations (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 18,073	$ 14,804	$ 15,191	$ 13,502	$ 14,456	$ 11,691	$ 12,498	$ 10,175	$ 61,570	$ 48,820	$ 32,545
Cost of goods sold	4,330	3,431	3,348	2,949	3,239	2,501	2,716	2,298	14,058	10,754	7,808
Gross profit	13,743	11,373	11,843	10,553	11,217	9,190	9,782	7,877	47,512	38,066	24,737
Operating expenses
Selling and marketing	12,937	12,308	9,815	9,887	8,487	8,391	8,163	7,722	44,947	32,763	27,631
Research and development	1,387	1,392	1,308	1,300	1,172	972	1,047	1,116	5,387	4,307	5,143
General and administrative	3,914	3,230	3,074	2,816	2,330	1,387	1,222	1,158	13,034	6,097	4,311
Total operating expenses	18,238	16,930	14,197	14,003	11,989	10,750	10,432	9,996	63,368	43,167	37,085
Loss from operations	(4,495)	(5,557)	(2,354)	(3,450)	(772)	(1,560)	(650)	(2,119)	(15,856)	(5,101)	(12,348)
Other income (expense)
Interest income	53	47	50	21	71			4	171	75	6
Interest expense	(562)	(561)	(562)	(919)	(487)	(473)	(523)	(421)	(2,604)	(1,904)	(1,082)
Other non-operating (expense) income	(9)		(2)					1	(11)	1	28
Total other expense, net	(518)	(514)	(514)	(898)	(416)	(473)	(523)	(416)	(2,444)	(1,828)	(1,048)
Net loss	$ (5,013)	$ (6,071)	$ (2,868)	$ (4,348)	$ (1,188)	$ (2,033)	$ (1,173)	$ (2,535)	$ (18,300)	$ (6,929)	$ (13,396)
Net loss per share, basic and diluted	$ (0.27)	$ (0.32)	$ (0.15)	$ (0.35)	$ (0.73)	$ (1.36)	$ (0.81)	$ (1.80)	$ (1.06)	$ (4.62)	$ (11.82)
Weighted average common shares used to compute net loss per share, basic and diluted	18,784	18,738	18,718	12,542	1,628	1,500	1,455	1,412	17,217	1,499	1,133

Schedule II - Valuation and Q73

Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for Doubtful Accounts Receivable [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Beginning Balance	$ 150	$ 135	$ 125
Additions	46	49	69
Deductions	61	34	59
Ending Balance	135	150	135
Reserve for Sales Returns and Allowances [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Beginning Balance	140	100	62
Additions	230	120	135
Deductions	119	80	97
Ending Balance	$ 251	$ 140	$ 100