Invuity (IVTY) 10-K 16 Mar 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2016	Mar. 10, 2017	Jun. 30, 2016
Document And Entity Information
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Entity Registrant Name	Invuity, Inc.
Entity Central Index Key	1,393,020
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Public Float			$ 103,909,545
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		16,969,285

Balance Sheets

Balance Sheets - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 28,300,000	$ 46,296,000
Short-term investments	10,737,000	0
Restricted cash - current	181,000
Accounts receivable, net	5,782,000	3,619,000
Inventory	5,052,000	5,182,000
Prepaid expenses and other current assets	1,088,000	923,000
Total current assets	51,140,000	56,020,000
Restricted Cash	909,000	1,090,000
Property and equipment, net	8,286,000	9,195,000
Total assets	60,335,000	66,305,000
Current liabilities:
Accounts payable	2,192,000	2,458,000
Accrued and other current liabilities	6,351,000	4,214,000
Short-term debt - related party	1,362,000
Total current liabilities	9,905,000	6,672,000
Deferred rent	2,721,000	2,810,000
Long-term debt - related party	13,261,000	14,480,000
Total liabilities	25,887,000	23,962,000
Commitments and contingencies (Note 7)
Stockholders' equity :
Preferred stock, $0.001 par value - 10,000,000 shares authorized at December 31, 2016 and December 31, 2015, respectively; no shares issued and outstanding at December 31, 2016 and December 31, 2015
Common stock, $0.001 par value - 100,000,000 shares authorized at December 31, 2016 and December 31, 2015 respectively; 16,950,940 and 13,392,358 shares issued and outstanding at December 31, 2016 and December 31, 2015, respectively	17,000	13,000
Additional paid-in capital	180,647,000	147,937,000
Accumulated deficit	(146,216,000)	(105,607,000)
Total stockholders' equity	34,448,000	42,343,000
Total liabilities and stockholders' equity	$ 60,335,000	$ 66,305,000

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
Balance Sheets
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	16,950,940	13,392,358
Common stock, shares outstanding	16,950,940	13,392,358

Statements of Operations and Co

Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statements of Operations and Comprehensive Loss
Revenue	$ 32,461	$ 21,031	$ 13,103
Cost of goods sold	8,824	7,733	4,630
Gross profit	23,637	13,298	8,473
Operating expenses:
Research and development	9,908	7,869	5,181
Selling, general and administrative	52,409	40,636	23,044
Total operating expenses	62,317	48,505	28,225
Loss from operations	(38,680)	(35,207)	(19,752)
Interest expense	(2,018)	(1,881)	(1,402)
Interest and other income (expense), net	89	(482)	492
Net loss and comprehensive loss	$ (40,609)	$ (37,570)	$ (20,662)
Net loss per common share, basic and diluted	$ (2.73)	$ (4.94)	$ (31.63)
Weighted-average shares used to compute net loss per common share, basic and diluted	14,868,501	7,606,172	653,195

Statements of Convertible Prefe

Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($)	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Convertible Preferred Stock [Member]	Total
Beginning balance at Dec. 31, 2013	$ 1,000	$ 1,468,000	$ (47,375,000)		$ (45,906,000)
Beginning balance at Dec. 31, 2013				$ 52,949,000
Beginning balance, shares at Dec. 31, 2013	656,184
Beginning balance, shares at Dec. 31, 2013				4,458,589
Issuance of convertible preferred stock, net of issuance costs				$ 20,806,000
Issuance of convertible preferred stock, net of issuance costs, shares				1,597,814
Exercise of common stock options		78,000			78,000
Exercise of common stock options, shares	55,065
Stock-based compensation expense		$ 663,000			663,000
Net loss			$ (20,662,000)		(20,662,000)
Ending balance at Dec. 31, 2014	$ 711,249				(65,827,000)
Ending balance at Dec. 31, 2014				$ 73,755,000
Ending balance, shares at Dec. 31, 2014	1,000	2,209,000	(68,037,000)
Ending balance, shares at Dec. 31, 2014				6,056,403
Issuance of convertible preferred stock, net of issuance costs				$ 22,769,000
Issuance of convertible preferred stock, net of issuance costs, shares				1,596,212
Conversion of Convertible Preferred Stock upon IPO	$ 8,000	$ 96,516,000		$ (96,524,000)	96,524,000
Conversion of Convertible Preferred Stock upon IPO, shares	7,979,332			(7,652,615)
Conversion of preferred stock warrants to common stock warrants		608,000			608,000
Proceeds from issuance of common stock, net	$ 4,000	47,215,000			47,219,000
Proceeds from issuance of common stock, net, shares	4,600,000
Exercise of common stock options		$ 139,000			$ 139,000
Exercise of common stock options, shares	102,250				274,582
Repurchase of early exercised options	(473)	(1,000)			(1,000)
Vesting of early exercise options		$ 2,000			$ 2,000
Stock-based compensation expense		1,249,000			1,249,000
Net loss			$ (37,570,000)		(37,570,000)
Ending balance at Dec. 31, 2015	$ 13,000	147,937,000	(105,607,000)		$ 42,343,000
Ending balance, shares at Dec. 31, 2015	13,392,358				13,392,358
Proceeds from issuance of common stock, net	$ 3,000	29,675,000			$ 29,678,000
Proceeds from issuance of common stock, net, shares	3,220,000
Exercise of common stock options	$ 1,000	732,000			733,000
Exercise of common stock options, shares	338,582
Stock-based compensation expense		2,303,000			2,303,000
Net loss			(40,609,000)		(40,609,000)
Ending balance at Dec. 31, 2016	$ 17,000	$ 180,647,000	$ (146,216,000)		$ 34,448,000
Ending balance, shares at Dec. 31, 2016	16,950,940				16,950,940

Statements of Convertible Pref6

Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Common Stock [Member]
Net of stock issuance costs	$ 590	$ 7,988
Series E Convertible Preferred Stock [Member]
Convertible preferred stock, par value			$ 13.3052
Net of stock issuance costs			$ 454
Series F Convertible Preferred Stock [Member]
Convertible preferred stock, par value			$ 14.3449
Net of stock issuance costs			$ 128

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net loss	$ (40,609)	$ (37,570)	$ (20,662)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,995	1,710	344
Stock-based compensation	2,303	1,249	663
Changes in fair value of convertible preferred stock warrant liability		472	(522)
Provision for doubtful accounts	136	216	87
Noncash interest expense	143	143	90
Accretion of premium on marketable securities	9		243
Changes in operating assets and liabilities:
Accounts receivable	(2,300)	(1,033)	(1,384)
Inventory	130	(911)	(786)
Prepaid expenses and other assets	(165)	1,568	(1,923)
Other non-current assets			(55)
Accounts payable	(284)	1,349	143
Accrued and other current liabilities	2,107	1,537	1,034
Deferred rent	(89)	105	2,910
Net cash used in operating activities	(36,624)	(31,165)	(19,818)
Cash flows from investing activities:
Purchases of property and equipment	(1,037)	(3,748)	(6,791)
Purchases of marketable securities	10,746		17,510
Sales of marketable securities			17,270
Maturities of marketable securities			850
Change in restricted cash		35	(1,090)
Net cash used in investing activities	(11,783)	(3,713)	(7,271)
Cash flows from financing activities:
Proceeds from issuance of common stock upon initial public offering, net of issuance costs		47,219
Proceeds from financing offering, net of offering costs	29,678
Proceeds from issuance of long-term debt -related party, net of issuance costs		5,000	9,800
Proceeds from issuance of common stock upon exercise of stock options	733	139	78
Repayments of long-term debt			(2,500)
Payments to repurchase early exercised common stock		(1)
Proceeds from issuance of convertible preferred stock, net of issuance costs		22,769	20,806
Net cash provided by financing activities	30,411	75,126	28,184
Net increase (decrease) in cash and cash equivalents	(17,996)	40,248	1,095
Cash and cash equivalents, beginning of period	46,296	6,048	4,953
Cash and cash equivalents, end of period	28,300	46,296	6,048
Supplemental disclosures of cash flow information:
Interest paid			275
Interest paid to related party	1,875	1,740	1,052
Non-cash investing and financing activities:
Purchases of property and equipment in accounts payable and accrued liabilities at period end	$ 48	78	1,462
Offering issuance costs in accounts payable at period end			$ 30
Reclassification of convertible preferred stock warrant liability to additional paid-in capital upon conversion of preferred stock warrants into common stock warrants		608
Conversion of convertible preferred stock into common stock and additional paid in capital		$ 96,524

Organization and Description of

Organization and Description of Business	12 Months Ended
	Dec. 31, 2016
Organization and Description of Business
Organization and Description of Business	INVUITY, INC. Notes to Financial Statements 1. Invuity, Inc. (the “Company”), was incorporated in the state of California on November 29, 2004 and reincorporated in Delaware in May 2015. The Company is a commercial-stage medical technology company which utilizes its proprietary Intelligent Photonics technology to develop single-use and reusable illuminated surgical devices, which provide surgeons with illumination and direct visualization of surgical cavities during open and minimal access procedures. The Company’s facilities are located in San Francisco, California. Reverse Stock Split In May 2015, the Company’s board of directors and its stockholders approved an amendment to the Company’s amended and restated articles of incorporation to effect a reverse split of shares of the Company’s common stock on a 1-for-18.5 basis (the “Reverse Stock Split”). All authorized, issued and outstanding shares of common stock, convertible preferred stock, warrants for common stock and preferred stock, options to purchase common stock and the related per share amounts contained in the financial statements have been retroactively adjusted to reflect this Reverse Stock Split for all periods presented. The Reverse Stock Split was effected on May 27, 2015. Initial Public Offering In June 2015, the Company completed an initial public offering (the “IPO”) of its common stock. In connection with its IPO, the Company sold 4,600,000 shares of common stock at $12.00 per share for aggregate net proceeds of $47.2 million after underwriting discounts and commissions and offering costs incurred by the Company. These amounts include the exercise in full by the underwriters of their option to purchase up to 600,000 additional shares of common stock at the same price to cover over-allotments. Upon the closing of the IPO, all shares of convertible preferred stock then outstanding converted into 7,979,332 shares of common stock. Upon the effectiveness of the Amended and Restated Certificate of Incorporation of the Company on June 18, 2015, the number of shares of capital stock the Company is authorized to issue was increased to 110,000,000 shares, of which 100,000,000 shares are common stock and 10,000,000 shares are preferred stock. Both the common stock and preferred stock have a par value of $0.001 per share. There are no shares of preferred stock outstanding at December 31, 2016. Liquidity The Company has incurred net losses from operations since inception and has an accumulated deficit of $146.2 million as of December 31, 2016. The Company expects to incur additional losses and negative cash flows in the next twelve months as it seeks to continue to grow its business and transition to operating as a public company. Management believes that its cash and cash equivalents and short term investments at December 31, 2016 and additional funding, available under the credit and security agreement with MidCap Financial Trust (“MidCap”) will provide sufficient funds to enable the Company to meet its operating plan through at least the next twelve months. The agreement, as disclosed in Note 13, was signed on March 10, 2017 and provides for up to $30 million in term loans, which are repayable in monthly installments, commencing April 1, 2019. The first term loan of $20 million was drawn down on March 10, 2017 and is subject to a financial covenant, based on revenue levels, to be met over the term of the agreement. The second term loan can only be drawn down assuming the Company meets a certain revenue target in a 12 month period prior to December 31, 2018, which is not anticipated to occur in the next 12 months. The Company, as required by the agreement, repaid in full its outstanding loan with Health Care Royalty Partners on March 10, 2017. On July 1, 2016, the Company also filed a prospectus supplement for an at-the-market (“ATM”) program of up to $25 million. However, if the Company’s anticipated operating results are not achieved in future periods, additional debt or equity financing may need to be raised, or the Company may need to implement an approved plan to reduce planned expenditures.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Basis of Presentation These financial statements have been prepared in accordance with accounting principles generally accepted in the U.S. (U.S. GAAP). Use of Estimates The preparation of 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 as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, management evaluates its estimates, including those related to revenue recognition, fair value of assets and liabilities, inventory, income taxes, common stock, and stock-based compensation. Actual results could differ from those estimates and assumptions. Out-of-period and Other Adjustments In the twelve-months ended December 31, 2015, the Company recorded an out-of-period adjustment to reverse revenue that the Company had originally recorded in the fourth quarter of 2014 associated with sales to a distributor for military facilities. The correction of this error resulted in an increase to the Company’s net loss of $302,000 for the twelve months ended December 31, 2015 and a corresponding decrease to accounts receivable. The distributor returned the underlying inventory, and the Company terminated the relationship with the distributor involved, and started working with a new distributor for military accounts. In addition, d uring the twelve months ended December 31, 2015 , the Company recorded an out-of-period adjustment to increase the fair value of the convertible preferred stock warrant liability, which was incorrectly valued at December 31, 2014 due to an error in the expected term assumption. The correction of this error resulted in an increase to the Company’s net loss of $370,000 for the twelve months ended December 31, 2015 and a corresponding increase to the convertible preferred stock warrant liability. Management assessed the impact of these adjustments and did not believe the amounts were material to any prior period financial statements, and the impact of correcting these errors in the twelve months ended December 31, 2015 was not material to those financial statements. As a result, the Company did not restate any prior period amounts. Cash Equivalents Cash equivalents consist of short-term, highly liquid investments with original maturities of three months or less from the date of purchase. Cash equivalents consist primarily of amounts invested in money market funds. Restricted Cash Restricted cash represents a certificate of deposit held at a financial institution as collateral for the Company credit cards and a letter of credit related to the Company’s facility lease. Short-Term Investments All short-term investments are classified as “available-for-sale” and carried at estimated fair value as determined based upon quoted market prices or pricing models for similar securities. Management determines the appropriate classification of its investments in debt securities at the time of purchase and reevaluates such designation as of each balance sheet date. Unrealized gains and losses are excluded from earnings and are reported as a component of comprehensive loss. Realized gains and losses and declines in fair value judged to be other than temporary, if any, on available-for-sale securities are included in interest and other income (expense), net, respectively, and are derived using the specific identification method for determining the cost of securities sold. Interest on available-for-sale securities is included in interest and other income (expense), net. Unrealized gains and losses and realized gains and losses on sale of short-term investments were not material for the years ended December 31, 2016, 2015, and 2014. The Company did not hold any short-term investments as of either December 31, 2015 and had total short investments of $10.7 million as of December 31, 2016. Accounts Receivable Accounts receivable are recorded at the invoiced amount and do not bear interest. The Company generally does not require collateral or other security in support of accounts receivable. Allowances are provided for individual accounts receivable when the Company becomes aware of a customer’s inability to meet its financial obligations, such as in the case of bankruptcy, deterioration in the customer’s operating results or change in financial position. If circumstances related to customers change, estimates of the recoverability of receivables would be further adjusted. The Company also considers broad factors in evaluating the sufficiency of its allowance for doubtful accounts, including the length of time receivables are past due, significant one-time events, creditworthiness of customers and historical experience. Account balances are charged off against the allowance after all means of collection have been exhausted and the potential for recovery is considered remote. The allowance for doubtful accounts balance was $300,000 and $158,000 as of December 31, 2016 and 2015, respectively. The Company has written off $6,000, $165,000 and $0 as uncollectible accounts receivables to the allowance for doubtful accounts during the twelve months ended December 31, 2016, 2015, and 2014, respectively. Fair Value of Financial Instruments Carrying amounts of the Company’s financial instruments, including cash equivalents, short-term investments, accounts receivable, and accounts payable approximate fair value due to their relatively short maturities. As of December 31, 2016 and 2015, based on Level 2 inputs and the borrowing rates available to the Company for loans with similar terms and consideration of the Company’s credit risk, the carrying value of the Company’s related party debt approximates its fair value. Concentrations of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk at December 31, 2016 and 2015 consist primarily of cash, which is held primarily by one domestic financial institution and exceeds federally insured limits, and cash equivalents. The Company manages its liquidity risk by investing in a variety of money market funds and corporate debt. This diversification of investments is consistent with the Company’s policy to maintain liquidity and ensure the ability to collect principal. All investments are made pursuant to corporate investment policy guidelines which restrict investments to issuers evaluated as creditworthy. Significant customers are those which represent 10% or more of the Company’s total revenue for each period presented in the statements of operations and comprehensive loss or 10% or more of the Company’s net accounts receivable balance at each respective balance sheet date. As of and for the twelve months ended December 31, 2016 and 2015, the Company had no customers that represented 10% or more of its revenue or accounts receivable balances. There was one customer that represented 12% of total revenue for the twelve months ended December 31, 2014. Inventory Inventories are stated at the lower of cost or market (estimated net realizable value). Cost is determined using the standard cost method, which approximates the first-in, first out basis. The Company periodically assesses the recoverability of all inventories, including raw materials and finished goods, to determine whether adjustments to the carrying value are required. Inventory that is obsolete or in excess of forecasted usage is written down to its estimated net realizable value based on assumptions about future demand and market conditions. Inventory write-downs are charged to cost of goods. Property and Equipment Property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation is provided using the straight-line method over the estimated useful lives of the respective assets. The estimated useful lives of the Company’s assets are as follows: Laboratory equipment 3 years Leasehold improvements Shorter of lease term or estimated life of the assets Furniture and fixtures 3 years Computer equipment and software 2 to 3 years Manufacturing equipment 5 years Maintenance and repairs that do not extend the life or improve the asset are expensed when incurred. Impairment of Long-Lived Assets The Company reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset (or asset group) may not be recoverable. An impairment loss is recognized when the total of estimated undiscounted future cash flows expected to result from the use of the asset and its eventual disposition is less than its carrying amount. Impairment, if any, would be assessed using discounted cash flows or other appropriate measures of fair value. The Company has not recorded impairment charges on long-lived assets for the periods presented in these financial statements. Convertible Preferred Stock Warrant Liability Freestanding warrants for shares that were contingently redeemable were classified as liabilities on the balance sheet at their estimated fair value because the shares underlying the warrants may obligate the Company to transfer assets to the holders at a future date under certain circumstances such as a deemed liquidation event. The warrants were subject to re-measurement at each balance sheet date and the change in fair value, if any, was recognized as interest and other income (expense), net in the statements of operations. The Company adjusted the liability for changes in fair value until the completion of its IPO, at which time all convertible preferred stock warrants were converted into warrants to purchase common stock and the liability was reclassified to additional paid-in capital. Other Comprehensive Income (Loss) Other comprehensive income (loss) represents all changes in stockholders’ equity except those resulting from distributions to stockholders. The Company’s unrealized loss on short-term available-for-sale securities represent the components of other comprehensive income (loss) that are excluded from the reported net loss and are presented in the statements of comprehensive loss. Revenue Recognition The Company’s revenue is generated from the sale of its products to hospitals and medical centers through direct sales representatives and independent sales agents. The Company recognizes revenue when all of the following criteria are met: · persuasive evidence of an arrangement exists; · the sales price is fixed or determinable; · collection of the relevant receivable is reasonably assured at the time of sale; and · delivery has occurred or services have been rendered. The Company recognizes revenue when title to the goods and risk of loss transfers to the customer, which is upon shipment of the product under the Company’s standard terms and conditions. Shipping and handling costs billed to the customer are recorded in revenue. Warranty Obligations The Company does not offer rights of return or price protection and has no post-delivery obligations other than its standard warranty which entitles the customer to return defective products for a period of one year after sale. The warranty liability was $50,000 as of December 31, 2016. Historical warranty costs have been insignificant. Medical Device Excise Tax In March 2010, the Affordable Care Act (the ACA) was signed into law which included a deductible 2.3% excise tax on any entity that manufactures or imports medical devices offered for sale in the United States, with limited exceptions, effective January 1, 2013. Subsequently, this excise tax was suspended effective January 1, 2016 through December 31, 2017. Research and Development The Company’s research and development costs are expensed as incurred. Research and development costs includes but are not limited to, payroll and personnel-related expenses, including stock-based compensation, laboratory supplies, consulting costs, and allocated facilities and information services costs. Income Taxes The Company accounts for income taxes under the asset and liability method, whereby deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. A valuation allowance is established when, in management’s estimate, it is more likely than not that the deferred tax asset will not be realized. The tax effects of the Company’s income tax positions are recognized only if they are more likely than not to be sustained based solely on the technical merits as of the reporting date. The Company considers many factors when evaluating and estimating its tax positions and benefits, which may require periodic adjustments and which may not accurately anticipate actual outcomes. Stock-based Compensation The Company measures its stock-based awards made to employees based on the estimated fair values of the awards as of the grant date using the Black-Scholes option-pricing model. Stock-based compensation expense is recognized over the requisite service period using the straight-line method and is based on the value of the portion of stock-based payment awards that is ultimately expected to vest. As such, the Company’s stock-based compensation is reduced for the estimated forfeitures at the date of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. Stock-based compensation expense for options granted to non-employees as consideration for services received is measured on the date of performance at the fair value of the consideration received or the fair value of the equity instruments issued, using the Black-Scholes option-pricing model, whichever can be more reliably measured. Compensation expense for options granted to non-employees is periodically remeasured as the underlying options vest. Segment Reporting The Company manages its operations as a single operating segment for the purposes of assessing performance and making operating decisions. All of the Company’s assets are maintained in the United States. The Company derives its revenue from sales to customers in the United States, based upon the billing address of the customer. Net Loss per Common Share Basic net loss per common share is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period, without consideration of potentially dilutive securities. Diluted net loss per common share is the same as basic net loss per common share since the effect of potentially dilutive securities are anti-dilutive. Shares subject to repurchase are excluded from the weighted-average shares. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (Topic 606) , which supersedes the revenue recognition requirements in ASC 605, Revenue Recognition . This ASU is based on the principle that revenue is recognized to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The ASU also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract. In August 2015, the FASB issued ASU No. 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date , which effectively delayed the adoption date by one year, to an effective date for public entities for annual and interim periods beginning after December 15, 2017. In March 2016, the FASB issued ASU No. 2016-08 , Revenue from Contracts with Customers (Topic 606): Principal Versus Agent Considerations (Reporting Revenue Gross Versus Net), to clarify certain aspects of the principal-versus-agent guidance in its new revenue recognition standard. In April 2016, the FASB issued ASU No. 2016-10 , Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing to clarify on how to identify the performance obligations and the licensing implementation guidance in its new revenue recognition standard. In May 2016, the FASB issued ASU No. 2016-12, Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients, to address certain issues identified by the Transition Resource Group, (the “TRG”) in the guidance on assessing collectability, presentation of sales tax, noncash consideration, and completed contracts and contracts modifications at transition. The Company plans to adopt this standard on January 1, 2018 and is in the process of determining the potential effects of this new guidance on its financial statements. In August 2014, the FASB issued ASU No. 2014-15, Disclosure of Uncertainties About an Entity’s Ability to Continue as a Going Concern . The new standard provides guidance around management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures. The new standard is effective for the annual and interim periods ended after December 15, 2016. The Company has adopted this accounting standard, which is reflected in its liquidity disclosure. In July 2015, the FASB issued ASU No. 2015-11, Inventory (Topic 330): Simplifying the Measurement of Inventory , which permits companies to measure inventory at the lower of cost and realizable value. ASU No.2015-11 applies to all business entities and is effective for public business entities for annual periods, and interim periods within those annual periods, beginning after December 15, 2016. The Company currently plans to adopt this accounting standard in the first quarter of fiscal year 2017 and the standard is not expected to have a material impact on the Company’s financial statements. In January 2016, the FASB issued ASU No. 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 No. 2016-01 is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2017. The Company is in the process of evaluating the impact of the adoption of this new guidance on its financial statements. In February 2016, the FASB issued ASU No. 2016-02 – Leases (“ASC 842”), which sets out the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e. lessees and lessors). The new standard requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase by the lessee. This classification will determine whether lease expense is recognized based on an effective interest method or on a straight line basis over the term of the lease, respectively. A lessee is also required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months regardless of their classification. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases today. ASC 842 supersedes the previous leases standard, ASC 840 Leases. The standard is effective on January 1, 2019, with early adoption permitted. The Company is in the process of evaluating the impact of this new guidance on its financial statements. In March 2016, the FASB issued ASU No. 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. This update simplifies the accounting for employee share-based payment transactions, including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification in the statement of cash flows. ASU No. 2016-09 is effective for public entities for annual periods beginning after December 15, 2016. The Company currently plans to adopt this accounting standard in the first quarter of fiscal year 2017 and the standard is not expected to have a material impact on the Company’s financial statements. In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Statements. This update provides financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. The update replaces the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU No. 2016-13 is effective for public entities for annual periods beginning after December 15, 2019. The Company is in the process of evaluating the impact of this new guidance on its financial statements. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (a consensus of the FASB Emerging Issues Task Force). The new guidance is intended to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. This update addresses the following eight specific cash flow issues: debt prepayment or debt extinguishment costs; settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing; contingent consideration payments made after a business combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies (COLIs) (including bank-owned life insurance policies (BOLIs)); distributions received from equity method investees; beneficial interests in securitization transactions; and separately identifiable cash flows and application of the predominance principle. ASU No. 2016-15 is effective for public entities for annual periods beginning after December 15, 2017. The Company is in the process of evaluating the impact of this new guidance on its financial statements. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash. The amendments in this Update require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The amendments in this Update are effective for public business entities for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The Company is in the process of evaluating the impact of this new guidance on its financial statements.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2016
Fair Value Measurements
Fair Value Measurements	3. The Company discloses and recognizes the fair value of its assets and liabilities using a hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The hierarchy gives the highest priority to valuations based upon unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to valuations based upon unobservable inputs that are significant to the valuation (Level 3 measurements). The guidance establishes three levels of the fair value hierarchy as follows: Level 1 —Inputs are unadjusted quoted prices in active markets for identical assets or liabilities at the measurement date. Level 2 —Inputs (other than quoted market prices included in Level 1) are either directly or indirectly observable for the asset or liability through correlation with market data at the measurement date and for the duration of the instrument’s anticipated life. Level 3 —Inputs reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model. The Company’s financial instruments consist of Level 1 and 2 assets and Level 3 liabilities. Level 1 assets consist primarily of highly liquid money market funds that are included in cash, cash equivalents, and restricted cash. Commercial Paper and corporate debt securities are classified in Level 2 of the fair value hierarchy because these valuation inputs are observable or market-corroborated. Prior to the Company’s IPO, the Company had a convertible preferred stock warrant liability relating to certain prior year financings. See Note 8 for further discussion. Upon the IPO, in June 2015, all convertible preferred stock warrants were converted into common stock warrants and the company recorded expense of $136,000 relating to the change in fair value of this convertible preferred stock warrant. For the periods ended December 31, 2016 and December 31, 2015 respectively, the Company has no other Level 3 assets or liabilities. The following table sets forth the fair value of the Company’s financial assets and liabilities measured at fair value on a recurring basis based on the three-tier fair value hierarchy (in thousands): December 31, 2016 Level 1 Level 2 Level 3 Total Assets Money market funds $ $ — $ — $ Commercial Paper — — Corporate debt securities — — $ $ $ — $ December 31, 2015 Level 1 Level 2 Level 3 Total Assets Money market funds $ $ — $ — $ $ $ — $ — $ As of and for the twelve months ended December 31, 2016, the carrying value of the Company’s short term investments approximates its fair value. There were no short term investments held by the Company for the twelve months ended December 31, 2015 and no related unrecognized gains or losses.

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2016
Balance Sheet Components
Balance Sheet Components	4. Inventory Inventory consisted of the following (in thousands): December 31, 2016 2015 Raw materials $ $ Work-in-process Finished goods Total inventory $ $ Prepaid expenses and other current assets Prepaid expenses and other current assets consisted of the following (in thousands): December 31, 2016 2015 Prepaid expenses $ $ Other Total prepaid expenses and other current assets $ $ Property and Equipment, Net Property and equipment, net consisted of the following (in thousands): December 31, 2016 2015 Computer equipment and software $ $ Laboratory and manufacturing equipment Furniture and fixtures Leasehold improvements Total property and equipment, gross Less: accumulated depreciation and amortization Total property and equipment, net $ $ Depreciation and amortization expense was $2.0 million, $1.7 million, and $0.3 million during the years ended December 31, 2016, 2015, and 2014 respectively. Accrued and Other Current Liabilities Accrued and other current liabilities consisted of the following (in thousands): December 31, 2016 2015 Accrued payroll-related expenses $ $ Accrued independent sales agent commissions Accrued professional fees Deferred rent Other Total accrued and other current liabilities $ $

Related Party Loan Agreement

Related Party Loan Agreement	12 Months Ended
	Dec. 31, 2016
Related Party Loan Agreement
Related Party Loan Agreement	5. In February 2014, the Company entered into a loan agreement with HealthCare Royalty Partners (“HCRP”), a related party due to its equity ownership interest in the Company, and drew down the first tranche of $10.0 million. The second tranche associated with HCRP, of $5.0 million, was drawn down in March 2015. Interest is payable quarterly at a fixed rate of 12.5% per annum with interest-only payments to be made from the effective date of the loan until March 31, 2017. Thereafter, the Company will make principal and interest payments until the maturity of the loan on December 31, 2020. The Company is permitted to make a voluntary prepayment in full, but not in part, prior to December 31, 2020, which prepayment must be made together with accrued and unpaid fixed interest on the amount prepaid and any additional amounts due in respect thereof, including an additional percentage of the aggregate loan amount or outstanding principal amount, depending on the date of prepayment. The Company’s obligations under the loan agreement are secured by a first priority security interest in all of the Company’s assets, other than bank accounts, accounts receivable and inventory. The loan agreement imposes customary affirmative and restrictive covenants, including with respect to fundamental transactions, the incurrence of additional indebtedness or liens and the payment of cash dividends, but does not include any financial covenants. The loan agreement contains a material adverse event clause which provides that an event of default will occur if, among other triggers, there occurs any circumstance that could reasonably be expected to result in a material adverse effect on the Company’s business, operations or condition, or on the Company’s ability to perform its obligations under the loan. The Company recorded interest expense of $2.0 million and $1.8 million on the loan, for the years ended December 31, 2016 and 2015, respectively. As of December 31, 2016, management does not believe that it is probable that the clause will be triggered within the next twelve months, and classified the debt as long-term excluding the portion relating to initial principal payments that are scheduled to be paid beginning March 2017. These principal payments have been reclassified into short term debt on the face of the balance sheet. The loan agreement also includes customary representations and warranties, events of defaults and termination provisions. As of December 31, 2016 and 2015, the Company was in compliance with all covenants. In connection with the loan agreement, the Company issued HCRP a warrant to purchase 84,553 shares of Series E convertible preferred stock at $13.3052 per share. The warrant was recorded on the balance sheet on the date of issuance at its fair value of $572,000 and recorded as a reduction in the carrying value of the debt. Upon completion of the IPO in June 2015, this warrant automatically converted into a warrant to purchase 86,891 shares of common stock and the liability was reclassified to additional paid-in capital. The Company also paid $200,000 in debt issuance costs to HCRP, which were recorded as a debt discount. The total debt discount is being amortized as interest expense in the straight-line method over the term of the loan. Future payments due under the Company’s loan agreements as of December 31, 2016 are as follows (in thousands): Year ending December 31, 2017 2018 2019 2020 Thereafter — Less: Amount representing interest Less: Amount representing debt discount $

Debt

Debt	12 Months Ended
	Dec. 31, 2016
Debt
Debt	6. In December 2010, the Company entered into a loan and security agreement with Silicon Valley Bank (“SVB”) whereby the Company may borrow funds via a series of term loans. In July 2013, the Company entered into the first amendment to the loan and security agreement with SVB. The Company repaid the outstanding balance of $1.9 million on the original loan, including accrued interest, and drew down a new term loan (“Tranche III”) in the amount of $2.5 million. Pursuant to the Tranche III loan agreement, the Company made interest-only payments at a stated rate of 6% per annum for the first eleven months from the funding date. Thereafter, the Company was obligated to pay monthly cash payments of principal and interest for a 30-month period with a balloon payment at maturity which was accreted as interest expense over the term of the loan. The Company was subject to a prepayment penalty equal to 2% of the outstanding principal amount at the prepayment date if the loan was prepaid on or before 18 months after its funding date. The loan balance of $ 2.7 million principal and interest was repaid in February 2014 in connection with the Company entering into a new loan agreement with HCRP (See Note 5 – Related Party Loan Agreement). In connection with Tranche III, in July 2013, the Company granted SVB a warrant to purchase 11,294 shares of Series D convertible preferred stock at $12.395 per share. The warrant was recorded on the balance sheet on the date of issuance at its fair value of $23,000 and recorded as a reduction in the carrying value of the debt. This debt discount was initially amortized to interest expense over the term of the agreement, resulting in an effective interest rate of approximately 13.3% per annum, until the repayment of Tranche III in February 2014 at which time the remaining unamortized balance of the debt discount of $19,000 was recognized in interest expense, together with a prepayment penalty of $50,000 and the unamortized portion of the balloon interest payment of $143,000. Upon completion of the IPO on June 2015, all convertible preferred warrants automatically converted into warrants to purchase shares of common stock and the liability was reclassified to additional paid-in capital. In February 2015, the Company entered into an accounts receivable credit facility with Silicon Valley Bank (SVB) that permits the borrowing of the lesser of $7.5 million or an amount representing up to 80% of eligible accounts receivable. The credit facility terminates in February 2018 and the Company’s obligations under the credit facility are secured by a first priority security interest in the Company’s bank accounts, accounts receivable, and inventory. Interest on borrowed amounts is payable monthly at the prime rate plus 0.75%. The credit facility imposes customary affirmative and restrictive covenants, including with respect to fundamental transactions, changes to the Company’s business, the incurrence of additional indebtedness or liens and the payment of dividends, but does not include any financial covenants. In addition, the credit facility states that if the Company maintains a net cash balance, defined as unrestricted cash held with SVB less any borrowings on the revolving line of credit, of more than $3.0 million, then all collections will be deposited in the Company’s operating account. If the net cash balance is below $3.0 million, then all collections will be held in an SVB-controlled account and applied to reduce the loan balance. The credit facility also includes customary representations and warranties, events of defaults and termination provisions. As of December 31, 2016, the Company has not drawn down on the credit facility.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies.
Commitments and Contingencies	7. Operating Leases The Company leases manufacturing and office space in San Francisco, California, under a non-cancelable operating lease entered into in May 2014. The lease commencement date was November 1, 2014 and the lease expires on October 31, 2024. At the inception of the lease, the Company provided the landlord with a security deposit of $1.1 million in the form of an irrevocable letter of credit, which was recorded in restricted cash on the balance sheet at both December 31, 2016 and December 31, 2015. Rent expense is recognized on a straight-line basis over the term of the leases and accordingly, the Company records the difference between cash rent payments and the recognition of rent expense as a deferred rent liability. Incentives granted under the Company’s facilities leases, including allowances to fund leasehold improvements, are deferred and are recognized as adjustments to rental expense on a straight-line basis over the term of the lease. The Company is entitled to a $2.6 million tenant allowance in connection with the lease entered into in November 2014. The Company has utilized the entire $2.6 million allowance in connection with the qualified costs as of December 31, 2014 and was fully reimbursed by the landlord as of December 31, 2015. The allowance has been recorded on the balance sheet as a leasehold improvement and is being amortized over the term of the lease as a reduction to rent expense. The following table summarizes the Company’s future minimum lease payments as of December 31, 2016 (in thousands): Year ending December 31: 2017 $ 2018 2019 2020 2021 Thereafter Total $ The Company’s rent expense was $2.0 million, $2.0 million and $0.6 million for the years ended December 31, 2016, 2015 and 2014, respectively. Legal Proceedings On February 27, 2017, a purported stockholder class action titled Paciga v. Invuity, Inc., et al., Case No. 3:17-cv-01005, was filed in the United States District Court for the Northern District of California against the Company, its Chief Executive Officer, and its Chief Financial Officer. The complaint alleges that the defendants made false or misleading statements to investors regarding the Company’s business prospects. The complaint purports to assert claims for violation of Sections 10(b) and 20(a) of the Securities Exchange Act of 1934, as amended, and the Securities Exchange Commission Rule 10b-5 on behalf of a purported class consisting of all purchasers of the Company’s common stock between July 19, 2016 and November 3, 2016, and seeks unspecified compensatory damages, attorney fees and costs, and other relief. The Company intends to defend the litigation vigorously. Based on information currently available, the Company has determined that the amount of any possible loss or range of possible loss is not reasonably estimable. In addition, the Company is, and from time to time may become, involved in legal proceedings arising from the ordinary course of its business. Management is currently not aware of any matters that will have a material adverse effect on the financial position, results of operations or cash flows of the Company. Indemnifications In the ordinary course of business, the Company enters into agreements that may include indemnification provisions. Pursuant to such agreements, the Company may indemnify, hold harmless and defend an indemnified party for losses suffered or incurred by the indemnified party. Some of the provisions will limit losses to those arising from third-party actions. In some cases, the indemnification will continue after the termination of the agreement. The maximum potential amount of future payments the Company could be required to make under these provisions is not determinable. The Company has never incurred material costs to defend lawsuits or settle claims related to these indemnification provisions. The Company has also entered into indemnification agreements with its directors and officers that may require the Company to indemnify its directors and officers against liabilities that may arise by reason of their status or service as directors or officers to the fullest extent permitted by Delaware corporate law. The Company currently has directors’ and officers’ insurance. To date, the Company has not paid any claims, and the Company believes that the estimated fair value of these indemnification obligations is minimal and it has not accrued any amounts for these obligations.

Warrants

Warrants	12 Months Ended
	Dec. 31, 2016
Warrants
Warrants	8. Common Stock Warrants In March 2010, the Company issued a warrant to purchase 3,532 shares of common stock at an exercise price of $1.30 per share to a third party in exchange for recruiting services. The Company recorded the warrants in equity at their fair value of $3,000 on the date of issuance using the Black-Scholes option-pricing model. The warrant was fully exercisable upon grant and expired upon the Company’s IPO in June 2015. Preferred Stock Warrants In conjunction with various financings between 2008 and 2014, the Company issued warrants to purchase 130,540 shares of convertible preferred stock. The relative fair value of these warrants was determined using the Black-Scholes model and was amortized to interest expense over the term of each loan, unless subsequently modified. All convertible preferred stock warrants were classified as liabilities on the balance sheet at their estimated fair value because the shares underlying the warrants could obligate the Company to transfer assets to the holders at a future date under certain circumstances such as a deemed liquidation event. The warrants were subject to re-measurement at each balance sheet date and the change in fair value, if any, was recognized as interest and other income, net in the statements of operations and comprehensive loss. The Company adjusted the liability for changes in fair value until the completion of its IPO, at which time all convertible preferred stock warrants were converted into 137,007 warrants to purchase common stock and the liability was reclassified to additional paid-in capital. The Company recorded a loss of $472,000 and a gain of $522,000 during the years ended December 31, 2015 and 2014, respectively, relating to the change in fair value of the convertible preferred stock warrant liability.

Convertible Preferred Stock and

Convertible Preferred Stock and Stockholders' Deficit	12 Months Ended
	Dec. 31, 2016
Convertible Preferred Stock and Stockholders' Deficit
Convertible Preferred Stock and Stockholders' Deficit	9. Convertible Preferred Stock In February and March 2015, the Company issued an aggregate of 1,596,212 shares of Series F convertible preferred stock. Upon the closing of the Company’s IPO in June 2015, all 7,652,615 shares of convertible preferred stock then outstanding converted into 7,979,332 shares of common stock, which includes an aggregate of 326,717 additional shares of common stock related to anti-dilution adjustments upon conversion of the convertible preferred stock.

Stock Option Plans

Stock Option Plans	12 Months Ended
	Dec. 31, 2016
Stock Option Plans
Stock Option Plans	10. In April 2015, the Company’s board of directors approved the 2015 Equity Incentive plan (the “2015 Plan”), effective June 11, 2015, covering incentive stock options (“ISOs”), nonstatutory stock options (“NSOs”), restricted stock, restricted stock awards (“RSU”), stock appreciation rights and performance units that may be granted to employees, directors and consultants. In connection with the approval of the 2015 Plan, all remaining shares available for future award under the 2005 Stock Option Plan (the “2005 Plan”) were transferred to the 2015 Plan, and the 2005 Plan was terminated. The number of shares initially authorized for issuance under the 2015 Plan was 1,494,272 plus 169,529 shares remaining available for future awards under the Company’s 2005 Plan. Any options under the 2005 Plan or 2015 Plan (collectively “the Plans”) that expire or otherwise terminate will revert to the 2015 Plan and again become available for issuance. The number of shares available for issuance under the 2015 Plan will be increased on the first day of each fiscal year in an amount equal to the lessor of (i) 1,494,272 shares; (ii) five percent of the outstanding shares on the last day of the immediately preceding fiscal year or (iii) such number of shares determined by the Company’s board of directors. ISOs may be granted to employees or directors holding more than 10% of the voting power of all classes of stock of the Company at an exercise price of no less than 110% of the fair value of the common stock on the grant date and to all other employees or directors at an exercise price of no less than 100% of the fair value of the common stock on the grant date. NSOs may be granted to employees, directors and consultants at an exercise price no less than 100% of the fair value of the common stock on the grant date. Employee stock options under the 2015 plan generally vest 20% upon one year of continued service to the Company, with the remainder in monthly increments over four additional years. Options expire no more than ten years after the date of grant. The Company’s Board of Directors and stockholders previously approved the 2005 Plan. Pursuant to the 2005 plan, options and restricted stock may be granted to employees, directors and consultants of the Company. Options granted under the Company’s 2005 plan may be either incentive stock options or nonstatutory stock options. ISOs may be granted to employees with exercise prices of no less than 100% the fair value of the common stock on the grant date and NSOs may be granted to employees, directors or consultants at exercise prices of no less than 85% of the fair value of the common stock on the grant date, as determined by the Board of Directors. All options granted under the 2005 plan may be exercised before they are vested. Employee stock options granted under the 2005 plan generally vest 25% upon one year of continued service to the Company, with the remainder in monthly increments over three additional years. Stock options granted to consultants generally vest over the performance period of the consultancy agreement, ranging from two to four years. Options expire no more than ten years after the date of grant. As of December 31, 2016, there were 3,776,263 shares authorized for issuance under the Plans of which 1,198,856 were available for grant. In the event of stock splits and stock dividends, the Board of Directors may increase or decrease proportionately the number of shares and the exercise (purchase) price per share deliverable to the 2015 Plan participants. In the event of a merger in which the Company is not the surviving entity or sale of substantially all the Company’s assets, all outstanding options must be either assumed or substituted by the surviving corporation, or may be required to be exercised or settled. The following table summarizes stock option activity and related information: Options Outstanding Weighted- Average Options Exercise Aggregate Available Options Price Per Intrinsic for Grant Outstanding Share Value (in thousands) Balances at December 31, 2015 $ $ Options authorized — Options granted $ Options exercised — $ Options forfeited $ Balances at December 31, 2016 $ $ Options exercisable—December 31, 2016 $ $ Options vested and expected to vest—December 31, 2016 $ $ The intrinsic value is the difference between the estimated fair value of the Company’s common stock at the date of exercise and the exercise price for in-the-money options. The aggregate intrinsic value of options exercised was $2.3 million, $796,000, and $310,000 for the years ended December 31, 2016, 2015, and 2014 respectively. The weighted-average grant-date fair value of options granted during the years ended December 31, 2016, 2015 and 2014 was $3.43, $4.82, and $5.99 per share, respectively. As of December 31, 2016 and 2015, the weighted-average remaining contractual life of options outstanding was 7.5 and 7.8 years, respectively, and for options vested and expected to vest, was 7.5 and 7.7 years, respectively. The options outstanding, vested and currently exercisable by exercise price under the 2015 Plan at December 31, 2016 are as follows: Options Outstanding Options Exercisable Weighted- Weighted- Weighted- Average Average Average Remaining Exercise Exercise Number of Contractual Price Per Number of Price Per Exercise Price Options Life (years) Share Options Share $1.30-2.78 $ $ $3.15 $ $ $4.81-7.32 $ $ $7.45-11.1 $ $ $11.10-13.00 $ $ $13.47-14.25 $ $ $15.91 $ $ $ $ RSU activity for the year ended December 31, 2016, was as follows: Weighted Weighted Average Aggregate Average Remaining Intrinsic Grant Date Shares Contractual Term Value Fair Value (In thousands) Balances at December 31, 2015 — $ — Awarded $ Released $ Forfeited $ Balances at December 31, 2016 $ $ $ Awards vested and expected to vest—December 31, 2016 $ $ $ Early Exercise of Stock Options The 2005 Plan allowed for the granting of options that may be exercised before the options have vested. Shares issued as a result of early exercise that have not vested are subject to repurchase by the Company upon termination of the purchaser’s employment or services, at the price paid by the purchaser. The Company’s right to repurchase these shares generally lapses 1/48 of the original grant date amount per month over four years. At December 31, 2016 and 2015, there were 2,661 and 8,648 shares of common stock outstanding, respectively, subject to the Company’s right of repurchase at a weighted-average price of $2.59 and $2.49 per share, respectively. Employee Stock-Based Compensation Stock-based compensation expense recognized during the years ended December 31, 2016, 2015, and 2014, includes compensation expense for stock-based awards granted to employees based on the grant date fair value of $2.2 million, $1.1 million, and $0.6 million respectively. As of December 31, 2016 and 2015, there were total unamortized compensation costs of $5.0 million and $4.1 million, respectively related to unvested stock options which the Company expects to recognize over a period of approximately 3.1 years and 3.6 years, respectively. On April 30, 2014, the Company modified the terms of 348,871 vested and unvested stock option awards by reducing their exercise price from $4.81 to $3.15 per share. There was no change in any of the other terms of the option awards. The modification resulted in an incremental value of $226,000 being allocated to the options, of which $158,000 was recognized to expense immediately based on options that were vested at the time of the modification. The remaining incremental value of $68,000 attributable to unvested shares is being recognized over their remaining vesting term of which $1,300 is still unvested as of December 31, 2016. The Company estimates the fair value of stock options using the Black-Scholes option valuation model. The fair value of employee stock options is being amortized on a straight-line basis over the requisite service period of the awards. Prior to our IPO, the fair value of the shares of the Company’s common stock underlying the stock options has historically been determined by the Company’s Board of Directors. Because there had been no public market for the Company’s common stock, its Board of Directors has determined the fair value of the Company’s common stock at the time of grant of the option by considering a number of objective and subjective factors, including the Company’s stage of development, sales of the Company’s convertible preferred stock, the Company’s operating and financial performance, equity market conditions affecting comparable public companies, the lack of liquidity of the Company’s capital stock, and the general and industry-specific economic outlooks. Since the Company’s IPO in June 2015, the fair value of the Company’s common stock is based on the closing price of its common stock, as quoted on the NASDAQ Global Market, on the date of grant. In addition to the value determined by the board and closing price on NASDAQ Global Market, the fair value is estimated using the assumptions below. Each of these inputs is subjective and its determination generally requires significant judgment. Year Ended December 31, 2016 2015 2014 Expected term (in years) 5.0–6.0 5.0–6.0 Expected volatility % 35–50 % 35 – 38 % Risk-free interest rate 1.24–2.26 % 1.31–1.89 % 1.80 – 1.93 % Dividend yield — % — % — % Expected Term. The expected term of stock-based awards represents the weighted-average period that the stock-based awards are expected to remain outstanding. The Company opted to use the “simplified method” for estimating the expected term of the awards, whereby the expected term equals the arithmetic average of the vesting term and the original contractual term of the awards. Expected Volatility. The Company determined the share price volatility for stock-based awards based on an analysis of the historical volatilities of a peer group of publicly traded medical device companies. In evaluating similarity, the Company considered factors such as industry, stage of life cycle and size. Risk-Free Interest Rate. The risk-free interest rate is based on the U.S. Treasury yield in effect at the time of the grant for zero-coupon U.S. Treasury notes with remaining terms similar to the expected term of the stock-based awards. Dividend Rate. The expected dividend was assumed to be zero as the Company has never paid dividends and has no current plans to do so. Expected Forfeiture Rate. The Company is required to estimate forfeitures at the time of grant, and revise those estimates in subsequent periods if actual forfeitures differ from those estimates. The Company uses historical data to estimate pre-vesting option forfeitures and record stock-based compensation expense only for those awards that are expected to vest. To the extent actual forfeitures differ from the estimates, the difference will be recorded as a cumulative adjustment in the period that the estimates are revised. Non-Employee Stock-Based Compensation Stock-based compensation expense related to non-employee awards was $121,000, $103,000 and $57,000 during the years ended December 31, 2016, 2015, and 2014, respectively. Total Stock-Based Compensation The following table summarizes total stock-based compensation expense for the years ended December 31, 2016, 2015, and 2014, which was included in the statements of operations as follows (in thousands): Year Ended December 31, 2016 2015 2014 Cost of goods sold $ $ $ Selling, general and administrative Research and development Total stock-based compensation expense $ $ $

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Taxes
Income Taxes	11. The Company has incurred net operating losses for the years ended December 31, 2016, 2015 and 2014, therefore has no provision for income taxes recorded for such years. For the years ended December 31, 2016, 2015 and 2014, the Company generated losses before taxes in the United States of $40.6 million, $37.6 million and $20.7 million, respectively and no foreign income or losses. The Company’s deferred tax assets are offset by a full valuation allowance. The reconciliation of the statutory federal income tax rate to the Company’s effective tax rate is as follows: Year Ended December 31, 2016 2015 2014 Tax at statutory federal rate % % % State taxes, net of federal benefit Tax credits Change in valuation allowance Other Provision for income taxes % % % The tax effects of temporary differences and carryforwards that give rise to significant portions of the deferred tax assets are as follows (in thousands): December 31, 2016 2015 2014 Deferred tax assets: Net operating loss carryforwards $ $ $ Research and development Accrued liabilities and other Stock-based compensation Fixed assets Tenant improvement allowance Total deferred tax assets Valuation allowance Net deferred tax assets $ — $ — $ — Realization of deferred tax assets is dependent upon future earnings, if any, the timing and amount of which are uncertain. Accordingly, the net deferred tax assets have been fully offset by a valuation allowance. The valuation allowance increased by $15.2 million, $12.7 million and $7.5 million for the years ended December 31, 2016, 2015 and 2014, respectively, and there were no releases of the valuation allowance in these years. As a result of certain realization requirements of ASC 718, Compensation — Stock Compensation, the table of deferred tax assets and liabilities shown above does not include certain deferred tax assets as of December 31, 2016 and December 31, 2015, that arose directly from tax deductions related to equity compensation that are greater than the compensation recognized for financial reporting. Equity will be increased by approximately $1.0 million if and when such deferred tax assets are ultimately realized. The Company uses ASC 740 ordering when determining when excess tax benefits have been realized. As of December 31, 2016, the Company had net operating loss (“NOL”) carryforwards (before tax effects) for federal and state income tax purposes of $131.9 million and $87.4 million, respectively. These federal and state NOL carryforwards will begin to expire in 2026 and 2017, respectively, if not utilized. In addition, the Company has federal and state research and development tax credit carryforwards of $1.0 million and $1.2 million, respectively, to offset future income tax liabilities. The federal research and development tax credits will begin to expire in 2024, if not utilized, while the state research and development tax credit can be carried forward indefinitely. Federal and California tax laws impose substantial restrictions on the utilization of net operating losses and credit carry-forwards in the event of an “ownership change” for tax purposes, as defined in Section 382 of the Internal Revenue Code. Due to ownership changes since inception, the Company’s net operating losses may be limited as to their usage. In the event the Company has additional changes in ownership, utilization of the carryforwards could be further restricted. A reconciliation of the Company’s unrecognized tax benefits for the years ended December 31, 2016, 2015, and 2014 is as follows (in thousands): Year Ended December 31, 2016 2015 2014 Balance at beginning of year $ $ $ Additions for tax positions taken in current year Reductions for tax positions taken in prior years Balance at end of year $ $ $ The unrecognized tax benefits, if recognized, would not have an impact on the Company’s effective tax rate to the extent that the Company continues to maintain a full valuation allowance against its deferred tax assets. The Company does not expect a material change to its unrecognized tax benefits over the next 12 months. The Company’s policy is to include interest and penalties related to unrecognized tax benefits within the provision for income taxes. Management determined that no accrual for interest and penalties was required as of December 31, 2016, 2015, and 2014, respectively. The Company’s tax years 2005-2016 will remain open for examination by the federal and state authorities for three and four years, respectively, from the date of utilization of any NOL or research and development credits.

Net Loss per Common Share

Net Loss per Common Share	12 Months Ended
	Dec. 31, 2016
Net Loss per Common Share
Net Loss per Common Share	12. The following table sets forth the computation of the basic and diluted net loss per share during the years ended December 31, 2016, 2015, and 2014 (in thousands, except share and per share data): Year Ended December 31, 2016 2015 2014 Numerator: Net loss $ $ $ Denominator: Weighted-average common shares outstanding Less: weighted-average unvested common shares subject to repurchase Weighted-average shares used to compute net loss per common share, basic and diluted Net loss per common share, basic and diluted $ $ $ Basic net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding for the period. Diluted net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common shares and potentially dilutive securities outstanding for the period, determined using the treasury-stock method and the as-if converted method, for convertible securities, if inclusion of these is dilutive. Because the Company has reported a net loss for all periods presented, diluted net loss per common share is the same as basic net loss per common share for those periods. The following potentially dilutive securities outstanding at the end of the periods presented have been excluded from the computation of diluted shares outstanding: Year Ended December 31, 2016 2015 2014 Convertible preferred stock on an as-converted basis - - Options to purchase common stock Restricted Stock Units - - Warrants to purchase common stock Warrants to purchase convertible preferred stock on an as-converted basis - - Total

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2016
Subsequent Events
Subsequent Events	13 On March 10, 2017, the Company entered into a credit and security agreement with MidCap, as agent, for up to $30.0 million in term loans. Under the terms of the agreement, the Company borrowed the first term loan of $20.0 million (“Tranche 1”) at closing and will be eligible for an additional term loan of $10.0 million (“Tranche 2”) which can be drawn down prior to December 31, 2018, subject to certain terms and conditions. The term loans accrue interest at a floating rate equal to 6.50% per annum, plus the greater of (i) 1.5% or (ii) one month Libor. Interest shall accrue on the date of the commencement of funding and is payable in arrears on the first day of each month. Principal is payable in 36 equal monthly installments beginning April 1, 2019 until paid in full on March 1, 2022. The Company used $17.2 million of the $20.0 million Tranche 1 term loan to pay off in full the HCRP loan and associated prepayment fees. The Company also entered into a separate credit and security agreement with MidCap that provides for a revolving credit facility of up to $10.0 million based on the eligible accounts receivable and inventory balances. The Company may increase the total commitments under the revolving credit facility by up to an additional $10.0 million, subject to certain conditions. Loans under the revolving credit facility accrue interest at a floating rate equal to 3.25% per annum, plus the greater of (i) 1.5% or (ii) one month LIBOR. Interest is payable in arrears on the first day of each month subsequent to the draw down date. The facility terminates in full on March 1, 2022 unless terminated earlier. This new revolving credit facility replaces the Company’s $7.5 million accounts receivable credit facility that existed with SVB, under which no principal or interest was outstanding. Pursuant to the SVB credit facility, the Company paid a termination fee in an amount equal to $150,000. The term loan facility and the revolving credit facility are secured by substantially all of the Company’s assets, including intellectual property. In addition, under the terms of the agreement, the Company is required to meet certain covenants which if the Company is unable to meet, or if the Company does not make its payments, the Company may be found in default and all obligations may be accelerated and become immediately due and payable upon the sole election of the lenders. The Company must also comply with a financial covenant relating to certain quarterly minimum Net Revenue (as defined in the credit agreements) requirements on a trailing twelve month basis. In connection with the term loan facility, the Company agreed to issue to each lender warrants to purchase shares of the Company’s common stock upon the drawdown of each tranche in an aggregate amount equal to 2.0% of the amount drawn, divided by the exercise price per share for that tranche. In connection with the Tranche 1 term loan, the Company issued warrants to purchase an aggregate of 50,618 shares of the Company’s common stock, at an exercise price equal to $7.90 per share. If the Company borrows the Tranche 2 term loan, it must issue additional warrants to the Tranche 2 lenders in accordance with the formula used to calculate the number of shares subject to the Tranche 1 warrants.

Supplementary Financial Data (U

Supplementary Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2016
Supplementary Financial Data
Supplementary Financial Data	SUPPLEMENTARY FINANCIAL DAT The following table presents selected unaudited financial data for each of the eight quarters in the two-year period ended December 31, 2016. The selected quarterly financial data should be read in conjunction with the Company's financial statements and the related notes and Item 7 “Management's Discussion and Analysis of Financial Condition and Results of Operations." This information has been derived from the Company's unaudited financial statements that, in management's opinion, reflect all recurring adjustments necessary to fairly state this information when read in conjunction with the Company's financial statements and the related notes appearing in the section entitled " Financial Statements and Supplementary Data," Net loss per share-basic and diluted, for the four quarters of each fiscal year may not sum to the total for the fiscal year because of the different number of shares outstanding during each period. The results of operations for any quarter are not necessarily indicative of the results to be expected for any future period. Statements of Operations Data: Three Months Ended December 31, 2016 September 30, 2016 June 30, 2016 March 31, 2016 (in thousands except share and per share data) Revenue $ $ $ $ Gross profit Loss from operations Net loss $ $ $ $ Net loss per common share, basic and diluted $ $ $ $ Weighted-average shares used to compute net loss per common share, basic and diluted Three Months Ended December 31, 2015 September 30, 2015 June 30, 2015 March 31, 2015 (in thousands except share and per share data) Revenue $ $ $ $ Gross profit Loss from operations Net loss $ $ $ $ Net loss per common share, basic and diluted $ $ $ $ Weighted-average shares used to compute net loss per common share, basic and diluted

Summary of Significant Accoun22

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Summary of Significant Accounting Policies
Basis of Presentation	Basis of Presentation These financial statements have been prepared in accordance with accounting principles generally accepted in the U.S. (U.S. GAAP).
Use of Estimates	Use of Estimates The preparation of 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 as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, management evaluates its estimates, including those related to revenue recognition, fair value of assets and liabilities, inventory, income taxes, common stock, and stock-based compensation. Actual results could differ from those estimates and assumptions.
Out-of-period and Other Adjustments	Out-of-period and Other Adjustments In the twelve-months ended December 31, 2015, the Company recorded an out-of-period adjustment to reverse revenue that the Company had originally recorded in the fourth quarter of 2014 associated with sales to a distributor for military facilities. The correction of this error resulted in an increase to the Company’s net loss of $302,000 for the twelve months ended December 31, 2015 and a corresponding decrease to accounts receivable. The distributor returned the underlying inventory, and the Company terminated the relationship with the distributor involved, and started working with a new distributor for military accounts. In addition, d uring the twelve months ended December 31, 2015 , the Company recorded an out-of-period adjustment to increase the fair value of the convertible preferred stock warrant liability, which was incorrectly valued at December 31, 2014 due to an error in the expected term assumption. The correction of this error resulted in an increase to the Company’s net loss of $370,000 for the twelve months ended December 31, 2015 and a corresponding increase to the convertible preferred stock warrant liability. Management assessed the impact of these adjustments and did not believe the amounts were material to any prior period financial statements, and the impact of correcting these errors in the twelve months ended December 31, 2015 was not material to those financial statements. As a result, the Company did not restate any prior period amounts.
Cash Equivalents	Cash Equivalents Cash equivalents consist of short-term, highly liquid investments with original maturities of three months or less from the date of purchase. Cash equivalents consist primarily of amounts invested in money market funds.
Restricted Cash	Restricted Cash Restricted cash represents a certificate of deposit held at a financial institution as collateral for the Company credit cards and a letter of credit related to the Company’s facility lease.
Short Term Investments	Short-Term Investments All short-term investments are classified as “available-for-sale” and carried at estimated fair value as determined based upon quoted market prices or pricing models for similar securities. Management determines the appropriate classification of its investments in debt securities at the time of purchase and reevaluates such designation as of each balance sheet date. Unrealized gains and losses are excluded from earnings and are reported as a component of comprehensive loss. Realized gains and losses and declines in fair value judged to be other than temporary, if any, on available-for-sale securities are included in interest and other income (expense), net, respectively, and are derived using the specific identification method for determining the cost of securities sold. Interest on available-for-sale securities is included in interest and other income (expense), net. Unrealized gains and losses and realized gains and losses on sale of short-term investments were not material for the years ended December 31, 2016, 2015, and 2014. The Company did not hold any short-term investments as of either December 31, 2015 and had total short investments of $10.7 million as of December 31, 2016.
Accounts Receivable	Accounts Receivable Accounts receivable are recorded at the invoiced amount and do not bear interest. The Company generally does not require collateral or other security in support of accounts receivable. Allowances are provided for individual accounts receivable when the Company becomes aware of a customer’s inability to meet its financial obligations, such as in the case of bankruptcy, deterioration in the customer’s operating results or change in financial position. If circumstances related to customers change, estimates of the recoverability of receivables would be further adjusted. The Company also considers broad factors in evaluating the sufficiency of its allowance for doubtful accounts, including the length of time receivables are past due, significant one-time events, creditworthiness of customers and historical experience. Account balances are charged off against the allowance after all means of collection have been exhausted and the potential for recovery is considered remote. The allowance for doubtful accounts balance was $300,000 and $158,000 as of December 31, 2016 and 2015, respectively. The Company has written off $6,000, $165,000 and $0 as uncollectible accounts receivables to the allowance for doubtful accounts during the twelve months ended December 31, 2016, 2015, and 2014, respectively.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Carrying amounts of the Company’s financial instruments, including cash equivalents, short-term investments, accounts receivable, and accounts payable approximate fair value due to their relatively short maturities. As of December 31, 2016 and 2015, based on Level 2 inputs and the borrowing rates available to the Company for loans with similar terms and consideration of the Company’s credit risk, the carrying value of the Company’s related party debt approximates its fair value.
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk at December 31, 2016 and 2015 consist primarily of cash, which is held primarily by one domestic financial institution and exceeds federally insured limits, and cash equivalents. The Company manages its liquidity risk by investing in a variety of money market funds and corporate debt. This diversification of investments is consistent with the Company’s policy to maintain liquidity and ensure the ability to collect principal. All investments are made pursuant to corporate investment policy guidelines which restrict investments to issuers evaluated as creditworthy. Significant customers are those which represent 10% or more of the Company’s total revenue for each period presented in the statements of operations and comprehensive loss or 10% or more of the Company’s net accounts receivable balance at each respective balance sheet date. As of and for the twelve months ended December 31, 2016 and 2015, the Company had no customers that represented 10% or more of its revenue or accounts receivable balances. There was one customer that represented 12% of total revenue for the twelve months ended December 31, 2014.
Inventory	Inventory Inventories are stated at the lower of cost or market (estimated net realizable value). Cost is determined using the standard cost method, which approximates the first-in, first out basis. The Company periodically assesses the recoverability of all inventories, including raw materials and finished goods, to determine whether adjustments to the carrying value are required. Inventory that is obsolete or in excess of forecasted usage is written down to its estimated net realizable value based on assumptions about future demand and market conditions. Inventory write-downs are charged to cost of goods.
Property and Equipment	Property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation is provided using the straight-line method over the estimated useful lives of the respective assets. The estimated useful lives of the Company’s assets are as follows: Laboratory equipment 3 years Leasehold improvements Shorter of lease term or estimated life of the assets Furniture and fixtures 3 years Computer equipment and software 2 to 3 years Manufacturing equipment 5 years Maintenance and repairs that do not extend the life or improve the asset are expensed when incurred.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset (or asset group) may not be recoverable. An impairment loss is recognized when the total of estimated undiscounted future cash flows expected to result from the use of the asset and its eventual disposition is less than its carrying amount. Impairment, if any, would be assessed using discounted cash flows or other appropriate measures of fair value. The Company has not recorded impairment charges on long-lived assets for the periods presented in these financial statements.
Convertible Preferred Stock Warrant Liability	Convertible Preferred Stock Warrant Liability Freestanding warrants for shares that were contingently redeemable were classified as liabilities on the balance sheet at their estimated fair value because the shares underlying the warrants may obligate the Company to transfer assets to the holders at a future date under certain circumstances such as a deemed liquidation event. The warrants were subject to re-measurement at each balance sheet date and the change in fair value, if any, was recognized as interest and other income (expense), net in the statements of operations. The Company adjusted the liability for changes in fair value until the completion of its IPO, at which time all convertible preferred stock warrants were converted into warrants to purchase common stock and the liability was reclassified to additional paid-in capital.
Other Comprehensive Income (Loss)	Other Comprehensive Income (Loss) Other comprehensive income (loss) represents all changes in stockholders’ equity except those resulting from distributions to stockholders. The Company’s unrealized loss on short-term available-for-sale securities represent the components of other comprehensive income (loss) that are excluded from the reported net loss and are presented in the statements of comprehensive loss.
Revenue Recognition	Revenue Recognition The Company’s revenue is generated from the sale of its products to hospitals and medical centers through direct sales representatives and independent sales agents. The Company recognizes revenue when all of the following criteria are met: · persuasive evidence of an arrangement exists; · the sales price is fixed or determinable; · collection of the relevant receivable is reasonably assured at the time of sale; and · delivery has occurred or services have been rendered. The Company recognizes revenue when title to the goods and risk of loss transfers to the customer, which is upon shipment of the product under the Company’s standard terms and conditions. Shipping and handling costs billed to the customer are recorded in revenue.
Warranty Obligations	Warranty Obligations The Company does not offer rights of return or price protection and has no post-delivery obligations other than its standard warranty which entitles the customer to return defective products for a period of one year after sale. The warranty liability was $50,000 as of December 31, 2016. Historical warranty costs have been insignificant.
Medical Device Excise Tax	Medical Device Excise Tax In March 2010, the Affordable Care Act (the ACA) was signed into law which included a deductible 2.3% excise tax on any entity that manufactures or imports medical devices offered for sale in the United States, with limited exceptions, effective January 1, 2013. Subsequently, this excise tax was suspended effective January 1, 2016 through December 31, 2017.
Research and Development	Research and Development The Company’s research and development costs are expensed as incurred. Research and development costs includes but are not limited to, payroll and personnel-related expenses, including stock-based compensation, laboratory supplies, consulting costs, and allocated facilities and information services costs.
Income Taxes	Income Taxes The Company accounts for income taxes under the asset and liability method, whereby deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. A valuation allowance is established when, in management’s estimate, it is more likely than not that the deferred tax asset will not be realized. The tax effects of the Company’s income tax positions are recognized only if they are more likely than not to be sustained based solely on the technical merits as of the reporting date. The Company considers many factors when evaluating and estimating its tax positions and benefits, which may require periodic adjustments and which may not accurately anticipate actual outcomes.
Stock-based Compensation	Stock-based Compensation The Company measures its stock-based awards made to employees based on the estimated fair values of the awards as of the grant date using the Black-Scholes option-pricing model. Stock-based compensation expense is recognized over the requisite service period using the straight-line method and is based on the value of the portion of stock-based payment awards that is ultimately expected to vest. As such, the Company’s stock-based compensation is reduced for the estimated forfeitures at the date of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. Stock-based compensation expense for options granted to non-employees as consideration for services received is measured on the date of performance at the fair value of the consideration received or the fair value of the equity instruments issued, using the Black-Scholes option-pricing model, whichever can be more reliably measured. Compensation expense for options granted to non-employees is periodically remeasured as the underlying options vest.
Segment Reporting	Segment Reporting The Company manages its operations as a single operating segment for the purposes of assessing performance and making operating decisions. All of the Company’s assets are maintained in the United States. The Company derives its revenue from sales to customers in the United States, based upon the billing address of the customer.
Net loss per Common Share	Net Loss per Common Share Basic net loss per common share is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period, without consideration of potentially dilutive securities. Diluted net loss per common share is the same as basic net loss per common share since the effect of potentially dilutive securities are anti-dilutive. Shares subject to repurchase are excluded from the weighted-average shares.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (Topic 606) , which supersedes the revenue recognition requirements in ASC 605, Revenue Recognition . This ASU is based on the principle that revenue is recognized to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The ASU also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract. In August 2015, the FASB issued ASU No. 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date , which effectively delayed the adoption date by one year, to an effective date for public entities for annual and interim periods beginning after December 15, 2017. In March 2016, the FASB issued ASU No. 2016-08 , Revenue from Contracts with Customers (Topic 606): Principal Versus Agent Considerations (Reporting Revenue Gross Versus Net), to clarify certain aspects of the principal-versus-agent guidance in its new revenue recognition standard. In April 2016, the FASB issued ASU No. 2016-10 , Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing to clarify on how to identify the performance obligations and the licensing implementation guidance in its new revenue recognition standard. In May 2016, the FASB issued ASU No. 2016-12, Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients, to address certain issues identified by the Transition Resource Group, (the “TRG”) in the guidance on assessing collectability, presentation of sales tax, noncash consideration, and completed contracts and contracts modifications at transition. The Company plans to adopt this standard on January 1, 2018 and is in the process of determining the potential effects of this new guidance on its financial statements. In August 2014, the FASB issued ASU No. 2014-15, Disclosure of Uncertainties About an Entity’s Ability to Continue as a Going Concern . The new standard provides guidance around management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures. The new standard is effective for the annual and interim periods ended after December 15, 2016. The Company has adopted this accounting standard, which is reflected in its liquidity disclosure. In July 2015, the FASB issued ASU No. 2015-11, Inventory (Topic 330): Simplifying the Measurement of Inventory , which permits companies to measure inventory at the lower of cost and realizable value. ASU No.2015-11 applies to all business entities and is effective for public business entities for annual periods, and interim periods within those annual periods, beginning after December 15, 2016. The Company currently plans to adopt this accounting standard in the first quarter of fiscal year 2017 and the standard is not expected to have a material impact on the Company’s financial statements. In January 2016, the FASB issued ASU No. 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 No. 2016-01 is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2017. The Company is in the process of evaluating the impact of the adoption of this new guidance on its financial statements. In February 2016, the FASB issued ASU No. 2016-02 – Leases (“ASC 842”), which sets out the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e. lessees and lessors). The new standard requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase by the lessee. This classification will determine whether lease expense is recognized based on an effective interest method or on a straight line basis over the term of the lease, respectively. A lessee is also required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months regardless of their classification. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases today. ASC 842 supersedes the previous leases standard, ASC 840 Leases. The standard is effective on January 1, 2019, with early adoption permitted. The Company is in the process of evaluating the impact of this new guidance on its financial statements. In March 2016, the FASB issued ASU No. 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. This update simplifies the accounting for employee share-based payment transactions, including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification in the statement of cash flows. ASU No. 2016-09 is effective for public entities for annual periods beginning after December 15, 2016. The Company currently plans to adopt this accounting standard in the first quarter of fiscal year 2017 and the standard is not expected to have a material impact on the Company’s financial statements. In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Statements. This update provides financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. The update replaces the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU No. 2016-13 is effective for public entities for annual periods beginning after December 15, 2019. The Company is in the process of evaluating the impact of this new guidance on its financial statements. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (a consensus of the FASB Emerging Issues Task Force). The new guidance is intended to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. This update addresses the following eight specific cash flow issues: debt prepayment or debt extinguishment costs; settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing; contingent consideration payments made after a business combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies (COLIs) (including bank-owned life insurance policies (BOLIs)); distributions received from equity method investees; beneficial interests in securitization transactions; and separately identifiable cash flows and application of the predominance principle. ASU No. 2016-15 is effective for public entities for annual periods beginning after December 15, 2017. The Company is in the process of evaluating the impact of this new guidance on its financial statements. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash. The amendments in this Update require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The amendments in this Update are effective for public business entities for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The Company is in the process of evaluating the impact of this new guidance on its financial statements.

Summary of Significant Accoun23

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2016
Summary of Significant Accounting Policies
Property Plant and Equipment, Estimated Useful Lives	Laboratory equipment 3 years Leasehold improvements Shorter of lease term or estimated life of the assets Furniture and fixtures 3 years Computer equipment and software 2 to 3 years Manufacturing equipment 5 years

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Measurements
Financial Assets and Liabilities Measured at Fair Value on Recurring Basis Based on Three-Tier Fair Value Hierarchy	The following table sets forth the fair value of the Company’s financial assets and liabilities measured at fair value on a recurring basis based on the three-tier fair value hierarchy (in thousands): December 31, 2016 Level 1 Level 2 Level 3 Total Assets Money market funds $ $ — $ — $ Commercial Paper — — Corporate debt securities — — $ $ $ — $ December 31, 2015 Level 1 Level 2 Level 3 Total Assets Money market funds $ $ — $ — $ $ $ — $ — $

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2016
Balance Sheet Components
Schedule of Inventory	Inventory consisted of the following (in thousands): December 31, 2016 2015 Raw materials $ $ Work-in-process Finished goods Total inventory $ $
Schedule of Prepaid Expenses and Other Assets	Prepaid expenses and other current assets consisted of the following (in thousands): December 31, 2016 2015 Prepaid expenses $ $ Other Total prepaid expenses and other current assets $ $
Schedule of Property and Equipment, Net	Property and equipment, net consisted of the following (in thousands): December 31, 2016 2015 Computer equipment and software $ $ Laboratory and manufacturing equipment Furniture and fixtures Leasehold improvements Total property and equipment, gross Less: accumulated depreciation and amortization Total property and equipment, net $ $
Schedule of Accrued and Other Current Liabilities	Accrued and other current liabilities consisted of the following (in thousands): December 31, 2016 2015 Accrued payroll-related expenses $ $ Accrued independent sales agent commissions Accrued professional fees Deferred rent Other Total accrued and other current liabilities $ $

Related Party Loan Agreement (T

Related Party Loan Agreement (Tables)	12 Months Ended
	Dec. 31, 2016
Related Party Loan Agreement
Schedule of Future Payments under Company's Loan Agreements	Future payments due under the Company’s loan agreements as of December 31, 2016 are as follows (in thousands): Year ending December 31, 2017 2018 2019 2020 Thereafter — Less: Amount representing interest Less: Amount representing debt discount $

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies.
Summary of Company's Future Minimum Lease Payments	The following table summarizes the Company’s future minimum lease payments as of December 31, 2016 (in thousands): Year ending December 31: 2017 $ 2018 2019 2020 2021 Thereafter Total $

Stock Option Plans (Tables)

Stock Option Plans (Tables)	12 Months Ended
	Dec. 31, 2016
Stock Option Plans
Summary of Stock Option Activity	Options Outstanding Weighted- Average Options Exercise Aggregate Available Options Price Per Intrinsic for Grant Outstanding Share Value (in thousands) Balances at December 31, 2015 $ $ Options authorized — Options granted $ Options exercised — $ Options forfeited $ Balances at December 31, 2016 $ $ Options exercisable—December 31, 2016 $ $ Options vested and expected to vest—December 31, 2016 $ $
Schedule of Options Outstanding, Vested and Currently Exercisable by Exercise Price	Options Outstanding Options Exercisable Weighted- Weighted- Weighted- Average Average Average Remaining Exercise Exercise Number of Contractual Price Per Number of Price Per Exercise Price Options Life (years) Share Options Share $1.30-2.78 $ $ $3.15 $ $ $4.81-7.32 $ $ $7.45-11.1 $ $ $11.10-13.00 $ $ $13.47-14.25 $ $ $15.91 $ $ $ $
Schedule of RSU activity	Weighted Weighted Average Aggregate Average Remaining Intrinsic Grant Date Shares Contractual Term Value Fair Value (In thousands) Balances at December 31, 2015 — $ — Awarded $ Released $ Forfeited $ Balances at December 31, 2016 $ $ $ Awards vested and expected to vest—December 31, 2016 $ $ $
Schedule of Assumptions Used in Estimated Fair Value of Share-based Compensation for Options Granted	Year Ended December 31, 2016 2015 2014 Expected term (in years) 5.0–6.0 5.0–6.0 Expected volatility % 35–50 % 35 – 38 % Risk-free interest rate 1.24–2.26 % 1.31–1.89 % 1.80 – 1.93 % Dividend yield — % — % — %
Summary of Stock-based Compensation Expense Related to Stock Options and Restricted Stock Units Included in Condensed Statements of Operations and Comprehensive Loss	The following table summarizes total stock-based compensation expense for the years ended December 31, 2016, 2015, and 2014, which was included in the statements of operations as follows (in thousands): Year Ended December 31, 2016 2015 2014 Cost of goods sold $ $ $ Selling, general and administrative Research and development Total stock-based compensation expense $ $ $

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Taxes
Schedule of Reconciliation of the Statutory Federal Income Tax Rate to the Company's Effective Tax Rate	Year Ended December 31, 2016 2015 2014 Tax at statutory federal rate % % % State taxes, net of federal benefit Tax credits Change in valuation allowance Other Provision for income taxes % % %
Summary of Significant Portions of the Deferred Tax Assets	The tax effects of temporary differences and carryforwards that give rise to significant portions of the deferred tax assets are as follows (in thousands): December 31, 2016 2015 2014 Deferred tax assets: Net operating loss carryforwards $ $ $ Research and development Accrued liabilities and other Stock-based compensation Fixed assets Tenant improvement allowance Total deferred tax assets Valuation allowance Net deferred tax assets $ — $ — $ —
Schedule of Reconciliation of the Company's Unrecognized Tax Benefits	A reconciliation of the Company’s unrecognized tax benefits for the years ended December 31, 2016, 2015, and 2014 is as follows (in thousands): Year Ended December 31, 2016 2015 2014 Balance at beginning of year $ $ $ Additions for tax positions taken in current year Reductions for tax positions taken in prior years Balance at end of year $ $ $

Net Loss per Common Share (Tabl

Net Loss per Common Share (Tables)	12 Months Ended
	Dec. 31, 2016
Net Loss per Common Share
Schedule of Computation of Basic and Diluted Net Loss per Share	The following table sets forth the computation of the basic and diluted net loss per share during the years ended December 31, 2016, 2015, and 2014 (in thousands, except share and per share data): Year Ended December 31, 2016 2015 2014 Numerator: Net loss $ $ $ Denominator: Weighted-average common shares outstanding Less: weighted-average unvested common shares subject to repurchase Weighted-average shares used to compute net loss per common share, basic and diluted Net loss per common share, basic and diluted $ $ $
Schedule of Potentially Dilutive Securities Outstanding Excluded from Computation of Diluted Shares Outstanding	The following potentially dilutive securities outstanding at the end of the periods presented have been excluded from the computation of diluted shares outstanding: Year Ended December 31, 2016 2015 2014 Convertible preferred stock on an as-converted basis - - Options to purchase common stock Restricted Stock Units - - Warrants to purchase common stock Warrants to purchase convertible preferred stock on an as-converted basis - - Total

Supplementary Financial Data 31

Supplementary Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2016
Supplementary Financial Data
Schedule of Selected Quarterly Information	Three Months Ended December 31, 2016 September 30, 2016 June 30, 2016 March 31, 2016 (in thousands except share and per share data) Revenue $ $ $ $ Gross profit Loss from operations Net loss $ $ $ $ Net loss per common share, basic and diluted $ $ $ $ Weighted-average shares used to compute net loss per common share, basic and diluted Three Months Ended December 31, 2015 September 30, 2015 June 30, 2015 March 31, 2015 (in thousands except share and per share data) Revenue $ $ $ $ Gross profit Loss from operations Net loss $ $ $ $ Net loss per common share, basic and diluted $ $ $ $ Weighted-average shares used to compute net loss per common share, basic and diluted

Organization and Description 32

Organization and Description of Business - Additional Information (Detail) $ / shares in Units, $ in Millions	Mar. 10, 2017USD ($)	Jul. 31, 2016USD ($)	Jun. 30, 2015$ / sharesshares	May 31, 2015	Dec. 31, 2016$ / sharesshares	Dec. 31, 2015$ / sharesshares	Jun. 18, 2015$ / sharesshares
Organization And Nature Of Operations [Line Items]
Authorized capital units							110,000,000
Common stock, shares authorized					100,000,000	100,000,000	100,000,000
Preferred stock, shares authorized					10,000,000	10,000,000	10,000,000
Common Stock Par Or Stated Value Per Share | $ / shares					$ 0.001	$ 0.001	$ 0.001
Preferred Stock Par Or Stated Value Per Share | $ / shares					$ 0.001	$ 0.001	$ 0.001
Preferred stock, shares outstanding					0	0
Second Public Offering [Member]
Organization And Nature Of Operations [Line Items]
ATM Offering | $		$ 25
Subsequent Event | MidCap | Term loan
Organization And Nature Of Operations [Line Items]
Maximum loan amount | $	$ 30
Subsequent Event | MidCap | Tranche 1
Organization And Nature Of Operations [Line Items]
Drawn amont | $	$ 20
Common Stock [Member]
Organization And Nature Of Operations [Line Items]
Reverse split of common stock				0.0541
Description reverse stock split						Reverse Stock SplitIn May 2015, the Company's board of directors and its stockholders approved an amendment to the Company's amended and restated articles of incorporation to effect a reverse split of shares of the Company's common stock on a 1-for-18.5 basis (the "Reverse Stock Split"). All authorized, issued and outstanding shares of common stock, convertible preferred stock, warrants for common stock and preferred stock, options to purchase common stock and the related per share amounts contained in the financial statements have been retroactively adjusted to reflect this Reverse Stock Split for all periods presented. The Reverse Stock Split was effected on May 27, 2015.
Convertible preferred stock converted into shares of common stock			7,979,332
Stock issued, shares					3,220,000	4,600,000
Common Stock [Member] | IPO [Member]
Organization And Nature Of Operations [Line Items]
Convertible preferred stock converted into shares of common stock			7,979,332
Stock issued, shares			4,600,000
Price per share issed | $ / shares			$ 12
Common Stock [Member] | Maximum | IPO [Member]
Organization And Nature Of Operations [Line Items]
Additional shares of common stock			600,000

Summary of Significant Accoun33

Summary of Significant Accounting Policies - Additional Information (Detail)	3 Months Ended								12 Months Ended			24 Months Ended
	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2016USD ($)segmentcustomer	Dec. 31, 2015USD ($)customer	Dec. 31, 2014USD ($)customer	Dec. 31, 2016USD ($)
Significant Accounting Policies [Line Items]
Net loss	$ (9,549,000)	$ (8,821,000)	$ (10,129,000)	$ (12,110,000)	$ (10,055,000)	$ (9,138,000)	$ (9,346,000)	$ (9,031,000)	$ (40,609,000)	$ (37,570,000)	$ (20,662,000)
Short-term Investments	10,737,000				0				10,737,000	0		$ 10,737,000
Allowance For Doubtful Accounts Receivable	300,000				158,000				300,000	158,000		300,000
Write off adjustments charged to allowance									6,000	165,000	$ 0
Warrant Liability	$ 50,000								$ 50,000			$ 50,000
Medical Device Excise Tax Percentage									2.30%
Number of operating segments | segment									1
Restatement Adjustment | Error Corrections That Reverse Revenue Recorded
Significant Accounting Policies [Line Items]
Net loss										(302,000)
Restatement Adjustment | Error Corrections That Increase Fair Value Of Warrant Liability
Significant Accounting Policies [Line Items]
Convertible preferred stock warrant liability					$ 370,000					$ 370,000
Revenue | Customer Concentration Risk
Significant Accounting Policies [Line Items]
Concentration risk, percentage									10.00%
Accounts Receivable, Net
Significant Accounting Policies [Line Items]
Number of Customers | customer									0	0	1
Accounts Receivable, Net | Customer Concentration Risk
Significant Accounting Policies [Line Items]
Concentration risk, percentage											12.00%	10.00%

Summary of Significant Accoun34

Summary of Significant Accounting Policies - Schedule of Revenue as Percentage of Total Revenue for Each Significant Customer (Detail) - Customer Concentration Risk	12 Months Ended		24 Months Ended
	Dec. 31, 2016	Dec. 31, 2014	Dec. 31, 2016
Revenue
Concentration Risk [Line Items]
Concentration risk, percentage	10.00%
Accounts Receivable, Net
Concentration Risk [Line Items]
Concentration risk, percentage		12.00%	10.00%

Summary of Significant Accoun35

Summary of Significant Accounting Policies - Schedule of Estimated Useful Lives of Assets (Detail)	12 Months Ended
	Dec. 31, 2016
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	3 years
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	3 years
Computer Equipment and Software | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	2 years
Computer Equipment and Software | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	3 years
Manufacturing Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	5 years

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Reclassification of convertible preferred stock warrant liability to additional paid-in capital upon conversion of preferred stock warrants into common stock warrants		$ 608,000
Short-term Investments	$ 10,737,000	0
Gains losses on short term investments		$ 0
Level 3 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Reclassification of convertible preferred stock warrant liability to additional paid-in capital upon conversion of preferred stock warrants into common stock warrants	$ 136,000

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis Based on Three-Tier Fair Value Hierarchy (Detail) - Recurring - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Assets
Assets	$ 37,870	$ 44,750
Level 1
Assets
Assets	18,755	44,750
Level 2
Assets
Assets	19,115
Level 3
Assets
Assets	0	0
Money Market Funds
Assets
Assets	18,755	44,750
Money Market Funds | Level 1
Assets
Assets	18,755	$ 44,750
Commercial Paper
Assets
Assets	9,582
Commercial Paper | Level 2
Assets
Assets	9,582
Corporate Debt Securities
Assets
Assets	9,533
Corporate Debt Securities | Level 2
Assets
Assets	$ 9,533

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Inventory (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Balance Sheet Components
Raw materials	$ 699	$ 1,000
Work-in-process	1,144	798
Finished goods	3,209	3,384
Total inventory	$ 5,052	$ 5,182

Balance Sheet Components - Sc39

Balance Sheet Components - Schedule of Prepaid Expenses and Other Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Balance Sheet Components
Prepaid expenses	$ 1,004	$ 907
Other	84	16
Total prepaid expenses and other assets	$ 1,088	$ 923

Balance Sheet Components - Sc40

Balance Sheet Components - Schedule of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	$ 12,394	$ 11,436
Less: accumulated depreciation and amortization	(4,108)	(2,241)
Total property and equipment, net	8,286	9,195
Computer Equipment and Software
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	1,377	1,341
Laboratory and Manufacturing Equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	2,422	1,544
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	1,442	1,445
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	$ 7,153	$ 7,106

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Balance Sheet Components
Depreciation and amortization	$ 1,995	$ 1,710	$ 344

Balance Sheet Components - Sc42

Balance Sheet Components - Schedule of Accrued and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Balance Sheet Components
Accrued payroll-related expenses	$ 5,301	$ 3,052
Accrued independent sales agent commissions	193	158
Accrued professional fees	246	373
Deferred rent	261	261
Other	350	370
Total accrued and other current liabilities	$ 6,351	$ 4,214

Related Party Loan Agreement -

Related Party Loan Agreement - Additional Information (Detail) - HealthCare Royalty Partners - USD ($)	Feb. 28, 2014	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jun. 30, 2015
Related Party Transaction [Line Items]
Payments of debt issuance costs	$ 200,000
Common Stock [Member] | IPO [Member]
Related Party Transaction [Line Items]
Warrants issued to purchase of shares						86,891
Series E Convertible Preferred Stock [Member]
Related Party Transaction [Line Items]
Warrants issued to purchase of shares	84,553
Exercise price of warrants	$ 13.3052
Warrants liability	$ 572,000
Loans Payable [Member] | Loan Agreement [Member]
Related Party Transaction [Line Items]
Debt instrument, fixed interest rate				12.50%
Debt instrument, maturity date			Dec. 31, 2020
Interest expense on the loan				$ 2,000,000	$ 1,800,000
Loans Payable [Member] | Loan Agreement [Member] | Tranche One [Member]
Related Party Transaction [Line Items]
Debt instrument, drawn amount	$ 10,000,000
Loans Payable [Member] | Loan Agreement [Member] | Tranche Two [Member]
Related Party Transaction [Line Items]
Debt instrument, drawn amount		$ 5,000,000

Related Party Loan Agreement 44

Related Party Loan Agreement - Schedule of Future Payments under Company's Loan Agreements (Detail) - HealthCare Royalty Partners $ in Thousands	Dec. 31, 2016USD ($)
Related Party Transaction [Line Items]
2,017	$ 3,305
2,018	4,547
2,019	5,601
2,020	6,469
Total	19,922
Less: Amount representing interest	(4,922)
Less: Amount representing debt discount	(377)
Future payments due, net	$ 14,623

Debt - Additional Information (

Debt - Additional Information (Detail) - Silicon Valley Bank - USD ($)	1 Months Ended			12 Months Ended
	Feb. 28, 2015	Feb. 28, 2014	Jul. 31, 2013	Dec. 31, 2016
Tranche III [Member]
Debt Instrument [Line Items]
Debt instrument, repayment of loan payable		$ 2,700,000	$ 1,900,000
New term loan			$ 2,500,000
Debt instrument, fixed interest rate			6.00%
Loan payment terms				Thereafter, the Company was obligated to pay monthly cash payments of principal and interest for a 30-month period with a balloon payment at maturity which was accreted as interest expense over the term of the loan.
Frequency periodic payment of loan				Monthly
Loan term period			30 months
Percentage of prepayment penalty			2.00%
Loan maturity date				February 2,014
Tranche III [Member] | Series D Convertible Preferred Stock [Member]
Debt Instrument [Line Items]
Debt conversion number of warrants issued			11,294
Debt conversion warrant price per share			$ 12.395
Warrants liability			$ 23,000
Loan interest rate, effective percentage			13.30%
Unamortized balance of debt discount		19,000
Prepayment penalty on debt		50,000
Unamortized portion of balloon interest payment		$ 143,000
Accounts Receivable Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	$ 7,500,000
Credit facility, percentage of maximum borrowings on eligible accounts receivable	80.00%
Line of credit facility maturity month and year				2018-02
Credit facility, interest rate description				Interest on borrowed amounts is payable monthly at the prime rate plus 0.75%.
Credit facility, covenant terms				The credit facility imposes customary affirmative and restrictive covenants, including with respect to fundamental transactions, changes to the Company's business, the incurrence of additional indebtedness or liens and the payment of dividends, but does not include any financial covenants. In addition, the credit facility states that if the Company maintains a net cash balance, defined as unrestricted cash held with SVB less any borrowings on the revolving line of credit, of more than $3.0 million, then all collections will be deposited in the Company's operating account. If the net cash balance is below $3.0 million, then all collections will be held in an SVB-controlled account and applied to reduce the loan balance.
Credit facility, net cash balance	$ 3,000,000
Credit facility, frequency of interest payment				monthly
Accounts Receivable Credit Facility | Revolving Credit Facility | Prime Rate [Member]
Debt Instrument [Line Items]
Credit facility, monthly interest rate				0.75%

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Nov. 01, 2014
Other Commitments [Line Items]
Rent expense	$ 2	$ 2	$ 0.6
Non-Cancelable Facility Lease Agreement [Member]
Other Commitments [Line Items]
Commencement date of lease		Nov. 1, 2014
Lease expiration date		Oct. 31, 2024
Security deposit				$ 1.1
Tenant allowance			2.6
Tenant allowance utilized			$ 2.6

Commitments and Contingencies47

Commitments and Contingencies - Summary of Company's Future Minimum Lease Payments (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Commitments and Contingencies.
2,017	$ 2,114
2,018	2,178
2,019	2,243
2,020	2,310
2,021	2,380
Thereafter	7,131
Total	$ 18,356

Warrants - Additional Informati

Warrants - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016	Mar. 31, 2010
Class Of Warrant Or Right [Line Items]
Changes in fair value of convertible preferred stock warrant liability	$ 472,000	$ (522,000)
Convertible Preferred Stock Warrants [Member]
Class Of Warrant Or Right [Line Items]
Changes in fair value of convertible preferred stock warrant liability	$ (472,000)	$ 522,000
Common Stock Warrants [Member]
Class Of Warrant Or Right [Line Items]
Warrants issued to purchase of shares				3,532
Exercise price of warrants				$ 1.30
Preferred Stock Warrants [Member] | Financings between 2008 and 2014 [Member]
Class Of Warrant Or Right [Line Items]
Warrants issued to purchase of shares			130,540
Convertible Preferred Stock Warrants [Member] | Financings between 2008 and 2014 [Member] | IPO [Member]
Class Of Warrant Or Right [Line Items]
Warrants issued to purchase of shares			137,007
Black Scholes Based Option Pricing Model [Member] | Common Stock Warrants [Member]
Class Of Warrant Or Right [Line Items]
Warrants liability				$ 3,000

Convertible Preferred Stock a49

Convertible Preferred Stock and Stockholders' Deficit - Additional Information (Detail) - shares	2 Months Ended
	Mar. 31, 2013	Jun. 30, 2015	Jun. 14, 2015
Temporary Equity [Line Items]
Convertible preferred stock, shares outstanding			7,652,615
Series F Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Convertible preferred stock, shares issued during period	1,596,212
Common Stock [Member]
Temporary Equity [Line Items]
Convertible preferred stock converted into shares of common stock		7,979,332
Common Stock [Member] | IPO [Member]
Temporary Equity [Line Items]
Convertible preferred stock converted into shares of common stock		7,979,332
Common Stock [Member] | Anti-dilution Adjustments [Member]
Temporary Equity [Line Items]
Convertible preferred stock converted into shares of common stock		326,717

Stock Option Plans - Additional

Stock Option Plans - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Apr. 30, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorised for future issuance	3,776,263
Number of shares available for future awards	1,198,856	1,394,661	1,406,439
Stock-based compensation	$ 2,303,000	$ 1,249,000	$ 663,000
2015 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorised for future issuance				1,494,272
Number of shares available for future awards				169,529
Stock option vesting, description	Employee stock options under the 2015 plan generally vest 20% upon one year of continued service to the Company, with the remainder in monthly increments over four additional years. Options expire no more than ten years after the date of grant.
Increase in number of shares available for issuance, description	The number of shares available for issuance under the 2015 Plan will be increased on the first day of each fiscal year in an amount equal to the lessor of (i) 1,494,272 shares; (ii) five percent of the outstanding shares on the last day of the immediately preceding fiscal year or (iii) such number of shares determined by the Company's board of directors.
2005 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option vesting, description	Employee stock options granted under the 2005 plan generally vest 25% upon one year of continued service to the Company, with the remainder in monthly increments over three additional years. Stock options granted to consultants generally vest over the performance period of the consultancy agreement, ranging from two to four years. Options expire no more than ten years after the date of grant.
Non Statutory Stock Option [Member] | 2005 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price of stock option granted on fair value of common stock at grant date	85.00%
Incentive Stock Options [Member] | 2015 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option granted to employees or director upon minimum percentage of voting right	10.00%
Incentive Stock Options [Member] | 2005 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price of stock option granted on fair value of common stock at grant date	100.00%
Employees | Share-based Compensation Award, Tranche One [Member] | 2015 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option vesting, term		1 year
Restricted stock units, vesting percentage		20.00%
Employees | Share-based Compensation Award, Tranche One [Member] | 2005 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option vesting, term	1 year
Restricted stock units, vesting percentage	25.00%
Employees | Share-based Compensation Award, Tranche Two [Member] | 2015 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option vesting, term		4 years
Employees | Share-based Compensation Award, Tranche Two [Member] | 2005 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option vesting, term		3 years
Non-employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation	$ 121,000	$ 103,000	$ 57,000
Minimum | 2015 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in number of shares available for issuance		1,494,272
Increase in number of shares available for issuance, percentage	5.00%
Minimum | Employees or Directors Holding Less Than 10% of Voting Power [Member] | Incentive Stock Options [Member] | 2015 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent	110.00%
Minimum | Employees or Directors Holding More Than 10% of Voting Power [Member] | Incentive Stock Options [Member] | 2015 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent	100.00%
Minimum | Employees, Directors and Consultants [Member] | Non Statutory Stock Option [Member] | 2015 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent	100.00%
Minimum | Consultants [Member] | 2005 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option vesting, term		2 years
Maximum | 2005 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock units, expiration term		10 years
Maximum | Share-based Compensation Award, Tranche Two [Member] | 2015 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option vesting, term		4 years
Restricted stock units, expiration term		10 years

Stock Option Plans - Summary of

Stock Option Plans - Summary of Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Apr. 30, 2014
Options Available for Grant, Beginning Balances	1,394,661	1,406,439
Options Available for Grant, Options authorized		669,617
Options Available for Grant, Options granted		(963,052)
Options Available for Grant, Options forfeited		281,657
Options Available for Grant, Ending Balances	1,198,856	1,394,661
Options Outstanding, Beginning Balances	2,445,600	2,038,787
Stock options granted		963,052
Options Outstanding, Options exercised		(274,582)
Options Outstanding, Options forfeited		(281,657)
Options Outstanding, Ending Balances		2,445,600
Options Outstanding, Options exercisable		1,083,571
Options Outstanding, Options vested and expected to vest	2,303,316		348,871
Weighted Average Exercise Price Per Share, Beginning Balances	$ 6.86	$ 6.69
Weighted Average Exercise Price Per Share, authorized	$ 6.74
Weighted Average Exercise Price Per Share, granted		7.14
Weighted Average Exercise Price Per Share, exercised		2.67
Weighted Average Exercise Price Per Share, forfeited		10.61
Weighted Average Exercise Price Per Share, Ending Balances		6.86
Weighted Average Exercise Price Per Share, Options exercisable		$ 5.15
Aggregate Intrinsic Value, Beginning Balances	$ 2,920	$ 7,504
Aggregate Intrinsic Value, Options exercisable		$ 2,385
Aggregate Intrinsic Value, Options vested and expected to vest	$ 2,894

Stock Option Plans - Schedule o

Stock Option Plans - Schedule of Options Outstanding, Vested and Currently Exercisable by Exercise Price (Detail) - 2015 Plan [Member]	12 Months Ended
	Dec. 31, 2016$ / sharesshares
Exercise Price Range
Options Outstanding, Number of Options | shares	2,445,600
Options Outstanding, Weighted-Average Remaining Contractual Life (year)	7 years 6 months
Options Outstanding, Weighted Average Exercise Price Per Share	$ 6.86
Options Exercisable, Number of Options | shares	1,083,571
Options Exercisable, Weighted Average Exercise Price Per Share	$ 5.15
1.30-2.78 [Member]
Exercise Price Range
Exercise Price Range, Lower Range Limit	1.30
Exercise Price Range, Upper Range Limit	$ 2.78
Options Outstanding, Number of Options | shares	249,745
Options Outstanding, Weighted-Average Remaining Contractual Life (year)	3 years 10 months 24 days
Options Outstanding, Weighted Average Exercise Price Per Share	$ 1.44
Options Exercisable, Number of Options | shares	248,885
Options Exercisable, Weighted Average Exercise Price Per Share	$ 1.44
$3.15 [Member]
Exercise Price Range
Exercise Price Range, Upper Range Limit	$ 3.15
Options Outstanding, Number of Options | shares	655,436
Options Outstanding, Weighted-Average Remaining Contractual Life (year)	6 years 9 months 18 days
Options Outstanding, Weighted Average Exercise Price Per Share	$ 3.15
Options Exercisable, Number of Options | shares	501,010
Options Exercisable, Weighted Average Exercise Price Per Share	$ 3.15
$4.81-7.32 [Member]
Exercise Price Range
Exercise Price Range, Lower Range Limit	4.81
Exercise Price Range, Upper Range Limit	$ 7.32
Options Outstanding, Number of Options | shares	550,183
Options Outstanding, Weighted-Average Remaining Contractual Life (year)	7 years 10 months 24 days
Options Outstanding, Weighted Average Exercise Price Per Share	$ 6.53
Options Exercisable, Number of Options | shares	44,782
Options Exercisable, Weighted Average Exercise Price Per Share	$ 6.82
$7.45-11.1 [Member]
Exercise Price Range
Exercise Price Range, Lower Range Limit	7.45
Exercise Price Range, Upper Range Limit	$ 11.10
Options Outstanding, Number of Options | shares	398,248
Options Outstanding, Weighted-Average Remaining Contractual Life (year)	8 years 8 months 12 days
Options Outstanding, Weighted Average Exercise Price Per Share	$ 8.33
Options Exercisable, Number of Options | shares	78,727
Options Exercisable, Weighted Average Exercise Price Per Share	$ 9.03
$11.1-13.00 [Member]
Exercise Price Range
Exercise Price Range, Lower Range Limit	11.10
Exercise Price Range, Upper Range Limit	$ 13
Options Outstanding, Number of Options | shares	393,822
Options Outstanding, Weighted-Average Remaining Contractual Life (year)	8 years 6 months
Options Outstanding, Weighted Average Exercise Price Per Share	$ 11.54
Options Exercisable, Number of Options | shares	143,747
Options Exercisable, Weighted Average Exercise Price Per Share	$ 11.36
$13.47-14.25 [Member]
Exercise Price Range
Exercise Price Range, Lower Range Limit	13.47
Exercise Price Range, Upper Range Limit	$ 14.25
Options Outstanding, Number of Options | shares	139,808
Options Outstanding, Weighted-Average Remaining Contractual Life (year)	8 years 9 months 18 days
Options Outstanding, Weighted Average Exercise Price Per Share	$ 14.12
Options Exercisable, Number of Options | shares	35,514
Options Exercisable, Weighted Average Exercise Price Per Share	$ 14.15
$15.91 [Member]
Exercise Price Range
Exercise Price Range, Upper Range Limit	$ 15.91
Options Outstanding, Number of Options | shares	58,358
Options Outstanding, Weighted-Average Remaining Contractual Life (year)	8 years 1 month 6 days
Options Outstanding, Weighted Average Exercise Price Per Share	$ 15.91
Options Exercisable, Number of Options | shares	30,906
Options Exercisable, Weighted Average Exercise Price Per Share	$ 15.91

Stock Option Plans - Addition53

Stock Option Plans - Additional Information 1 (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Compensation Related Costs [Abstract]
Aggregate intrinsic value of options exercised	$ 2,300	$ 796	$ 310
Weighted average grant date fair value of options, granted	$ 3.43	$ 4.82	$ 5.99
Weighted-average remaining contractual life of options outstanding	7 years 6 months	7 years 9 months 18 days
Weighted-average remaining contractual life of options outstanding, vested and expected to vest	7 years 6 months	7 years 8 months 12 days
Stock option repurchase, term	4 years
Common stock outstanding, right to repurchase	2,661	8,648
Weighted average price of stock repurchase	$ 2.59	$ 2.49
Right to repurchase of shares, term	The Company's right to repurchase these shares generally lapses 1/48 of the original grant date amount per month over four years

Stock Option Plans - Summary 54

Stock Option Plans - Summary of Stock-based Compensation Expense Related to Stock Options and Restricted Stock Units Included in Condensed Statements of Operations and Comprehensive Loss (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 2,303	$ 1,249	$ 663
Cost of Goods Sold
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	133	89	23
Research and Development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	419	300	93
Selling, General and Administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 1,751	$ 860	$ 547

Stock Option Plans - Addition55

Stock Option Plans - Additional Information 2 (Detail) - USD ($) $ / shares in Units, $ in Thousands	Apr. 30, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense recognized		$ 2,200	$ 1,100	$ 600
Unrecognized compensation expense related to unvested options		$ 5,000	$ 4,100
Weighted-average expected period to recognize of compensation expense, term		3 years 1 month 6 days	3 years 7 months 6 days
Options Outstanding, Options vested and expected to vest	348,871	2,303,316
Modification, incremental cost	$ 226
Expense recognized based on options vested at the time of modification of terms	158
Incremental value attributed to unvested shares being recognized over the remaining vesting term	$ 68	$ 1,300
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vested and unvested stock option award exercise price	$ 4.81
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vested and unvested stock option award exercise price	$ 3.15

Stock Option Plans - RSU (Detai

Stock Option Plans - RSU (Detail) - Restricted Stock Units $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)$ / sharesshares
Shares
Awarded (in shares) | shares	221,807
Released (in shares) | shares	(64,000)
Forfeited (in shares) | shares	(26,000)
Balances at end of period (in shares) | shares	131,807
Awards vested and expected to vest at end of period (in shares) | shares	114,766
Weighted Average Remaining Contractual Term
Balances at end of period (in years)	1 year 11 months 23 days
Awards vested and expected to vest at end of period (in years)	1 year 10 months 2 days
Aggregate Intrinsic Value
Balances at end of period | $	$ 758
Awards vested and expected to vest at end of period | $	$ 660
Weighted Average Grant Date Fair Value
Awarded (in dollars per share) | $ / shares	$ 6.93
Released (in dollars per share) | $ / shares	4.87
Forfeited (in dollars per share) | $ / shares	7.45
Balances at end of period (in dollars per share) | $ / shares	7.82
Awards vested and expected to vest at end of period (in dollars per share) | $ / shares	$ 7.86

Stock Option Plans - Schedule57

Stock Option Plans - Schedule of Assumptions Used in Estimated Fair Value of Share-based Compensation for Options Granted (Detail) - Employees	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)			6 years
Expected volatility	50.00%
Dividend yield	0.00%	0.00%	0.00%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	5 years	5 years
Expected volatility		50.00%
Risk-free interest rate	1.24%	1.31%	1.80%
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years	6 years
Expected volatility		50.00%
Risk-free interest rate	2.26%	1.89%	1.93%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Line Items]
Provision for income taxes	$ 0	$ 0	$ 0
Income before income taxes, U.S.	40,600,000	37,600,000	20,700,000
Income before income taxes, Foreign	0	0	0
Increase decrease in deferred tax asset valuation allowance	15,200,000	12,700,000	7,500,000
Unrecognized tax benefits, interest and penalties accrued	0	$ 0	$ 0
Excess tax benefit related to stock-based compensation	$ 1,000,000
Earliest Tax Year
Income Tax Disclosure [Line Items]
Tax year open for income tax examination	2,005
Latest Tax Year
Income Tax Disclosure [Line Items]
Tax year open for income tax examination	2,016
Federal
Income Tax Disclosure [Line Items]
Net operating loss carryforwards before tax effects	$ 131,900,000
Net operating loss carryforwards expiration year	2,026
Research and development tax credits carryforwards	$ 1,000,000
Research and development tax credits expiration year	2,024
Tax years under examination	3 years
State
Income Tax Disclosure [Line Items]
Net operating loss carryforwards before tax effects	$ 87,400,000
Net operating loss carryforwards expiration year	2,017
Research and development tax credits carryforwards	$ 1,200,000
Research and development tax credits expiration term		indefinitely
Tax years under examination	4 years

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of the Statutory Federal Income Tax Rate to the Company's Effective Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Taxes
Tax at statutory federal rate	34.00%	34.00%	34.00%
State taxes, net of federal benefit	3.50%	0.40%	3.80%
Tax credits	1.20%	0.90%	1.30%
Change in valuation allowance	(37.70%)	(33.90%)	(37.80%)
Other	(1.00%)	(1.40%)	(1.30%)
Provision for income taxes	0.00%	0.00%	0.00%

Income Taxes - Summary of Signi

Income Taxes - Summary of Significant Portions of the Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Net operating loss carryforwards	$ 49,261	$ 35,474	$ 23,574
Research and development	1,343	986	782
Accrued liabilities and other	1,567	935	590
Stock-based compensation	823	485	259
Fixed assets	477	219	100
Tenant improvement allowance	744	836	970
Total deferred tax assets	54,215	38,935	26,275
Valuation allowance	(54,215)	(38,935)	(26,275)
Net deferred tax assets

Income Taxes - Schedule of Re61

Income Taxes - Schedule of Reconciliation of the Company's Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Taxes
Balance at beginning of year	$ 329	$ 261	$ 209
Additions for tax positions taken in current year	124	86	69
Reductions for tax positions taken in prior years	(5)	(18)	(17)
Balance at end of year	$ 448	$ 329	$ 261

Net Loss per Common Share - Sch

Net Loss per Common Share - Schedule of Computation of Basic and Diluted Net Loss per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Numerator:
Net loss	$ (9,549)	$ (8,821)	$ (10,129)	$ (12,110)	$ (10,055)	$ (9,138)	$ (9,346)	$ (9,031)	$ (40,609)	$ (37,570)	$ (20,662)
Denominator:
Weighted-average common shares outstanding									14,869,691	7,619,696	673,573
Less: weighted-average unvested common shares subject to repurchase									(1,190)	(13,524)	(20,378)
Weighted-average shares used to compute net loss per common share, basic and diluted	14,868,501	15,690,785	13,404,007	13,392,976	13,307,031	13,292,849	2,919,823	703,637	14,868,501	7,606,172	653,195
Net loss per common share, basic and diluted	$ (0.56)	$ (0.56)	$ (0.76)	$ (0.90)	$ (0.76)	$ (0.69)	$ (3.20)	$ (12.84)	$ (2.73)	$ (4.94)	$ (31.63)

Net Loss per Common Share - S63

Net Loss per Common Share - Schedule of Potentially Dilutive Securities Outstanding Excluded from Computation of Diluted Shares Outstanding (Detail) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share	2,714,414	2,175,796	7,763,801
Convertible Preferred Stock As Converted [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share			6,246,196
Options to Purchase Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share	2,445,600	2,038,789	1,379,503
Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share	131,807
Warrants to Purchase Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share	137,007	137,007	3,532
Warrants To Purchase Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share			134,570

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 10, 2017	Dec. 31, 2014
Subsequent Event [Line Items]
Loan paid off		$ 2,500
Subsequent Event
Subsequent Event [Line Items]
Common Stock Drawdown Percent Of Amount Drawn	2.00%
Subsequent Event | Tranche 1
Subsequent Event [Line Items]
Applicable margin (as a percent)	6.50%
Warrants issued to purchase of shares	50,618
Exercise price of warrants	$ 7.90
Subsequent Event | Mid Cap | Revolving Credit Facility
Subsequent Event [Line Items]
Maximum loan amount	$ 10,000
Subsequent Event | Mid Cap | Tranche 1
Subsequent Event [Line Items]
Maximum loan amount	30,000
Drawn amont	20,000
Subsequent Event | Mid Cap | Tranche 1 | HealthCare Royalty Partners
Subsequent Event [Line Items]
Loan paid off	17,200
Subsequent Event | Mid Cap | Tranche 2 | Revolving Credit Facility
Subsequent Event [Line Items]
Maximum loan amount	10,000
Subsequent Event | Silicon Valley Bank | Revolving Credit Facility
Subsequent Event [Line Items]
Loan Termination Fee	150
Subsequent Event | Silicon Valley Bank | Accounts Receivable Credit Facility
Subsequent Event [Line Items]
Drawn amont	$ 7,500

Supplementary Financial Data 65

Supplementary Financial Data (Unaudited) - Schedule of Selected Quarterly Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Supplementary Financial Data
Revenue	$ 9,356	$ 8,478	$ 8,223	$ 6,404	$ 6,246	$ 5,595	$ 4,748	$ 4,442	$ 32,461	$ 21,031	$ 13,103
Gross profit	6,948	6,259	6,132	4,298	4,119	3,561	2,898	2,720	23,637	13,298	8,473
Loss from operations	(9,074)	(8,346)	(9,637)	(11,623)	(9,567)	(8,661)	(8,866)	(8,113)	(38,680)	(35,207)	(19,752)
Net loss	$ (9,549)	$ (8,821)	$ (10,129)	$ (12,110)	$ (10,055)	$ (9,138)	$ (9,346)	$ (9,031)	$ (40,609)	$ (37,570)	$ (20,662)
Net loss per common share, basic and diluted	$ (0.56)	$ (0.56)	$ (0.76)	$ (0.90)	$ (0.76)	$ (0.69)	$ (3.20)	$ (12.84)	$ (2.73)	$ (4.94)	$ (31.63)
Weighted-average shares used to compute net loss per common share, basic and diluted	14,868,501	15,690,785	13,404,007	13,392,976	13,307,031	13,292,849	2,919,823	703,637	14,868,501	7,606,172	653,195