Invuity (IVTY) 10-Q 12 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Nov. 02, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Trading Symbol	IVTY
Entity Registrant Name	Invuity, Inc.
Entity Central Index Key	1,393,020
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		13,306,698

Condensed Balance Sheets

Condensed Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 54,035	$ 6,048
Accounts receivable, net	3,284	2,798
Inventory	4,882	4,271
Prepaid expenses and other current assets	1,372	2,486
Total current assets	63,573	15,603
Restricted cash	1,090	1,125
Property and equipment, net	9,014	8,541
Other non-current assets		55
Total assets	73,677	25,324
Current liabilities:
Accounts payable	1,108	1,075
Accrued and other current liabilities	3,338	4,162
Total current liabilities	4,446	5,237
Deferred rent	2,826	2,676
Convertible preferred stock warrant liability		136
Long-term debt-related party	14,444	9,347
Total liabilities	$ 21,716	$ 17,396
Commitments and contingencies
Convertible preferred stock, $0.001 par value-no and 6,207,320 shares authorized at September 30, 2015 and December 31, 2014, respectively; no and 6,056,403 shares issued and outstanding at September 30, 2015 and December 31, 2014, respectively		$ 73,755
Stockholders' equity (deficit):
Preferred stock, $0.001 par value-10,000,000 and no shares authorized at September 30, 2015 and December 31, 2014, respectively; no shares issued and outstanding at September 30, 2015 and December 31, 2014
Common stock, $0.001 par value-100,000,000 and 9,189,189 shares authorized at September 30, 2015 and December 31, 2014, respectively; 13,305,713 and 711,249 shares issued and outstanding at September 30, 2015 and December 31, 2014, respectively	$ 13	$ 1
Additional paid-in capital	147,501	2,209
Accumulated deficit	(95,553)	(68,037)
Total stockholders' equity (deficit)	51,961	(65,827)
Total liabilities, convertible preferred stock and stockholders' equity (deficit)	$ 73,677	$ 25,324

Condensed Balance Sheets (Paren

Condensed Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Convertible preferred stock, par value	$ 0.001	$ 0.001
Convertible preferred stock, shares authorized	0	6,207,320
Convertible preferred stock, shares issued	0	6,056,403
Convertible preferred stock, shares outstanding	0	6,056,403
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	9,189,189
Common stock, shares issued	13,305,713	711,249
Common stock, shares outstanding	13,305,713	711,249

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Revenue	$ 5,595	$ 3,724	$ 14,784	$ 8,694
Cost of goods sold	2,035	1,294	5,605	3,231
Gross profit	3,560	2,430	9,179	5,463
Operating expenses:
Selling, general and administrative	10,180	6,063	29,020	16,066
Research and development	2,042	1,287	5,799	3,800
Total operating expenses	12,222	7,350	34,819	19,866
Loss from operations	(8,662)	(4,920)	(25,640)	(14,403)
Interest expense	(504)	(348)	(1,377)	(1,070)
Interest and other income (expense), net	28	(22)	(499)	15
Net loss and comprehensive loss	$ (9,138)	$ (5,290)	$ (27,516)	$ (15,458)
Net loss per common share, basic and diluted	$ (0.69)	$ (8.11)	$ (4.84)	$ (23.86)
Weighted-average shares used to compute net loss per common share, basic and diluted	13,292,849	651,959	5,684,755	647,791

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net loss	$ (27,516)	$ (15,458)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,258	225
Stock-based compensation	919	492
Changes in fair value of convertible preferred stock warrant liability	472	15
Provision for doubtful accounts	147	60
Noncash interest expense	107	55
Accretion of premium on marketable securities		173
Changes in operating assets and liabilities:
Accounts receivable	(633)	(1,043)
Inventory	(611)	(369)
Prepaid expenses and other current assets	1,119	(286)
Accounts payable	30	(394)
Accrued and other current liabilities	696	634
Deferred rent	121	(20)
Net cash used in operating activities	(23,891)	(15,916)
Cash flows from investing activities:
Purchases of property and equipment	(3,181)	(577)
Purchases of marketable securities		(17,508)
Sales of marketable securities		4,297
Maturities of marketable securities		851
Change in restricted cash	35	(1,090)
Net cash used in investing activities	(3,146)	(14,027)
Cash flows from financing activities:
Proceeds from issuance of common stock upon initial public offering, net of issuance costs	47,219
Proceeds from issuance of long-term debt -related party, net of issuance costs	5,000	9,800
Repayments of long-term debt		(2,500)
Proceeds from issuance of common stock upon exercise of stock options	36	27
Proceeds from issuance of convertible preferred stock, net of issuance costs	22,769	20,806
Net cash provided by financing activities	75,024	28,133
Net increase (decrease) in cash and cash equivalents	47,987	(1,810)
Cash and cash equivalents, beginning of period	6,048	4,953
Cash and cash equivalents, end of period	54,035	3,143
Supplemental disclosures of cash flow information:
Interest paid		275
Interest paid to related party	1,271	740
Non-cash investing and financing activities:
Purchases of property and equipment in accounts payable and accrued liabilities	12	$ 1,676
Reclassification of convertible preferred stock warrant liability and convertible preferred stock to additional paid-in capital upon conversion of preferred stock warrants into common stock warrants and convertible preferred stock into common stock	$ 73,891

Organization and Description of

Organization and Description of Business	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Organization and Description of Business	1. Organization and Description of Business 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 minimally invasive and minimal access procedures. The Company’s management, development and management 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 (“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 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 September 30, 2015. Basis of Presentation The accompanying unaudited condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and in accordance with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. The unaudited interim condensed financial statements have been prepared on the same basis as the annual financial statements. In the opinion of management, the accompanying unaudited condensed financial statements reflect all adjustments (consisting only of normal recurring adjustments) considered necessary for a fair statement. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the audited financial statements and notes thereto included in the Company’s prospectus dated June 15, 2015 filed with the U.S. Securities and Exchange Commission (the “SEC”) pursuant to Rule 424(b) under the Securities Act of 1933, as amended (the “Securities Act”). The results for the three and nine months ended September 30, 2015 are not necessarily indicative of the results expected for the full fiscal year or any other periods. Reclassifications Certain prior year amounts in the condensed financial statements and notes thereto have been reclassified where necessary to conform to the current presentation. These reclassifications did not affect the prior period’s stockholders’ equity, net loss or net cash used in operating activities. Out-of-Period Adjustments During the three months ended June 30, 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 nine months ended September 30, 2015 and a corresponding decrease to accounts receivable. The distributor has returned the underlying inventory, and the Company has terminated the relationship with the distributor involved, and started working with a new distributor for military accounts. Management has assessed the impact of the adjustment and does not believe the amount is material to any prior period financial statements, and the impact of correcting the error in the nine months ended September 30, 2015 is not material to those financial statements and is not expected to be material to the financial statements for the year ending December 31, 2015. As a result, the Company has not restated any prior period amounts. During the three months ended March 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 three months ended March 31, 2015 and a corresponding increase to the convertible preferred stock warrant liability. Management has assessed the impact of the adjustment and does not believe that the amount is material to any prior period financial statements, and the impact of correcting the error in the nine months ended September 30, 2015 is not material to those financial statements and is not expected to be material to the financial statements for the year ending December 31, 2015. As a result, the Company has not restated any prior period amounts. During the three months ended March 31, 2015, the Company determined that certain expenses relating to research and development in 2014 had been incorrectly classified within selling, general and administrative expenses, due to an erroneous allocation of departmental expenses. The company has not revised the statement of operations for the three months ended September 30, 2014 or for the nine months ended September 30, 2014. The reclassification would have resulted in an increase to research and development expenses of $386,000 and $613,000, with a corresponding decrease to selling, general and administrative expenses for the respective periods. Management has assessed the impact of the correction and has concluded that it is not material to the financial statements being presented.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Use of Estimates The Company’s financial statements have been prepared in conformity with U.S. GAAP. The preparation of the 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, convertible preferred stock and related warrants, common stock prior to the Company’s IPO, and stock-based compensation. Actual results could differ from those estimates and assumptions. 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 a letter of credit related to the Company’s facility lease in San Francisco, California. Fair Value of Financial Instruments Carrying amounts of the Company’s financial instruments, including cash equivalents, accounts receivable and accounts payable approximate fair value due to their relatively short maturities. As of September 30, 2015 and December 31, 2014, 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 long-term debt approximates its fair value. Customer Concentration Significant customers are those which represent 10% or more of the Company’s total revenue for each period presented in the condensed statements of operations and comprehensive loss or 10% or more of the Company’s net accounts receivable balance at each respective balance sheet date. For each significant customer, revenue as a percentage of total revenue and accounts receivable, net as a percentage of total accounts receivable, net were as follows: Revenue Accounts Receivable, net Three Months Ended Nine Months Ended September 30, September 30, December 31, 2015 2014 2015 2014 2015 2014 Customers: Customer A * 13 % * 14 % * 12 % Customer B * * * * * 12 % * Less than 10% 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, net in the condensed 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 warrants to purchase common stock and the liability was reclassified to additional paid-in capital. 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. 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 (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”). Areas of revenue recognition that will be affected include, but are not limited to, transfer of control, variable consideration, allocation of transfer pricing, licenses, time value of money, contract costs and disclosures. On July 9, 2015, the FASB deferred the implementation of this standard by one year so that the guidance is effective for fiscal years and interim reporting periods beginning after December 15, 2017, at which time the Company may adopt the new standard under the full retrospective method or the modified retrospective method. The Company is currently evaluating the impact that the adoption of ASU 2014-09 will have on its financial statements and related disclosures. In April 2015, the FASB issued ASU No. 2015-03, Interest-Imputation of Interest In July 2015, the FASB issued ASU 2015-11, Inventory (Topic 330): Simplifying the Measurement of Inventory. ASU 2015-11 amends guidance on the measurement of inventory from lower of cost or market to net realizable (“ASU 2015-11”) value. The amendment applies to all inventory other than those measured by Last-In-First-Out and the Retail Inventory Method. The amendment is effective for fiscal years beginning after December 15, 2016, including interim periods within that reporting period. Early adoption is permitted. The Company is currently evaluating the impact, if any, that the adoption of ASU 2015-11 will have on its financial statements and related disclosures.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements 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 Level 2 Level 3 The Company’s financial instruments consist of Level 1 assets and at December 31, 2014, Level 3 liabilities. Where quoted prices are available in an active market, securities are classified as Level 1. Level 1 assets consist primarily of highly liquid money market funds that are included in cash and cash equivalents and restricted cash. Level 3 liabilities that were measured at fair value on a recurring basis consisted of the convertible preferred stock warrant liability, which was measured using the probability weighted expected return method that calculated the probability of the Company going public or being acquired, and the option-pricing method for remaining private in the near to mid-term. Upon completion of the Company’s IPO, the convertible preferred stock warrants were converted into common stock warrants and the fair value of the liability of $0.6 million was transferred to additional paid-in capital. The warrants are no longer subject to remeasurement. 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): September 30, 2015 Level 1 Level 2 Level 3 Total Assets Money market funds $ 52,738 $ — $ — $ 52,738 $ 52,738 $ — $ — $ 52,738 December 31, 2014 Level 1 Level 2 Level 3 Total Assets Money market funds (a) $ 5,768 $ — $ — $ 5,768 $ 5,768 $ — $ — $ 5,768 Liabilities Convertible preferred stock warrant liability $ — $ — $ 136 $ 136 $ — $ — $ 136 $ 136 (a) - Balances include $35,000 classified as non-current restricted cash as of December 31, 2014. The following table sets forth a summary of the changes in the fair value of the convertible preferred stock warrant liability, the Company’s Level 3 financial liability, which is measured on a recurring basis (in thousands): Three Months ended Nine Months ended September 30, 2015 2014 2015 2014 Beginning balance $ — $ 657 $ 136 $ 86 Issuance of convertible preferred stock warrants — — — 572 Change in fair value recorded in interest and other income (expense), net — 16 472 15 Reclassification of liability to additional paid-in capital upon conversion to common stock warrants — — (608 ) — Ending balance $ — $ 673 $ — $ 673

Balance sheet components

Balance sheet components	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance sheet components	4. Balance sheet components Inventory Inventory consisted of the following (in thousands): September 30, 2015 December 31, 2014 Raw materials $ 827 $ 894 Work-in-process 799 768 Finished goods 3,256 2,609 Total inventory $ 4,882 $ 4,271 Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following (in thousands): September 30, 2015 December 31, 2014 Prepaid expenses $ 1,366 $ 420 Tenant improvement allowance receivable — 2,064 Other 6 2 Total prepaid expenses and other current assets $ 1,372 $ 2,486 Property and Equipment, Net Property and equipment, net, consisted of the following (in thousands): September 30, December 31, 2014 Computer equipment and software $ 1,113 $ 633 Laboratory and manufacturing equipment 1,356 816 Furniture and fixtures 1,445 1,409 Leasehold improvements 6,889 6,541 Total property and equipment, gross 10,803 9,399 Less: accumulated depreciation and amortization (1,789 ) (858 ) Total property and equipment, net $ 9,014 $ 8,541 Depreciation and amortization expense was $439,000 and $90,000 for the three months ended September 30, 2015 and 2014 respectively, and $1,258,000 and $225,000 for the nine months ended September 30, 2015 and 2014 respectively. Accrued and Other Current Liabilities Accrued and other current liabilities consisted of the following (in thousands): September 30, December 31, 2014 Accrued payroll-related expenses $ 2,460 $ 1,599 Accrued independent sales agent commissions 156 227 Accrued professional fees 182 89 Accrued costs for property and equipment — 1,453 Deferred rent 261 290 Other 279 504 Total accrued and other current liabilities $ 3,338 $ 4,162

Related Party Loan Agreement

Related Party Loan Agreement	9 Months Ended
	Sep. 30, 2015
Related Party Transactions [Abstract]
Related Party Loan Agreement	5. Related Party Loan Agreement In March 2015, the Company drew down the second tranche of $5.0 million from its $15.0 million loan agreement with HealthCare Royalty Partners (“HCRP”), a related party due to its equity ownership interest in the Company resulting in outstanding borrowings of $15.0 million as of September 30, 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. As of September 30, 2015, management does not believe that it is probable that the clause will be triggered within the next twelve months, and therefore the debt is classified as long-term. The loan agreement also includes customary representations and warranties, events of defaults and termination provisions. As of December 31, 2014 and September 30, 2015, the Company was in compliance with all covenants.

Credit Facility

Credit Facility	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Credit Facility	6. Credit Facility 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 matures 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 September 30, 2015, the Company has not drawn down on the credit facility and has $2.8 million available.

Convertible Preferred Stock

Convertible Preferred Stock	9 Months Ended
	Sep. 30, 2015
Text Block [Abstract]
Convertible Preferred Stock	7. Convertible Preferred Stock Convertible preferred stock as of December 31, 2014 consisted of the following (in thousands except share data): December 31, 2014 Shares Shares Net Aggregate Series A 396,605 396,590 $ 2,646 $ 2,715 Series B 493,385 478,718 8,141 8,240 Series C 1,586,392 1,566,352 17,412 17,592 Series D 2,028,236 2,016,929 24,750 25,000 Series E 1,702,702 1,597,814 20,806 21,259 Total 6,207,320 6,056,403 $ 73,755 $ 74,806 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 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, as follows (in thousands except share data): Shares Shares Net As-Converted Series A 396,605 396,590 $ 2,646 396,590 Series B 493,385 478,718 8,141 568,615 Series C 1,586,392 1,566,352 17,412 1,666,248 Series D 2,028,236 2,016,929 24,750 2,034,709 Series E 1,702,702 1,597,814 20,806 1,642,002 Series F 1,654,594 1,596,212 22,769 1,671,168 Total 7,861,914 7,652,615 $ 96,524 7,979,332 As of September 30, 2015, there was no convertible preferred stock outstanding.

Stock Option Plans

Stock Option Plans	9 Months Ended
	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Option Plans	8. Stock Option Plans Pursuant to the Company’s 2005 Stock Incentive Plan (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. Incentive stock options 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 nonstatutory options 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 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. In connection with the Board of Directors’ and stockholders’ approval of the 2015 Plan, all remaining shares available for future award under the 2005 Plan were transferred to the 2015 Plan, and the 2005 Plan was terminated. In April 2015, the Company’s board of directors and stockholders approved the 2015 Equity Incentive plan (“2015 Plan”), effective June 11, 2015, covering options, restricted stock, restricted stock units, stock appreciation rights, performance units and performance shares that may be granted to employees, directors and consultants. The number of shares authorized for issuance under the 2015 Plan is 3,597,794 at September 30, 2015 of which 1,512,552 shares were available for grant. 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 at least (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. Incentive stock options 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. Nonstatutory stock options 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 generally vest 25% 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. Any options under the 2015 Plan that expire or otherwise terminate will revert to the 2015 Plan and again become available for issuance. The 2015 Plan also includes the granting of restricted stock, restricted stock units, stock appreciation rights and performance units. The following table summarizes stock option activity under the plans and related information: Options Outstanding Options Options Weighted- Aggregate (in thousands) Balances at December 31, 2014 315,876 1,379,503 $ 2.56 $ 9,483 Options authorized 1,851,517 — Options granted (736,595 ) 736,595 $ 12.60 Options exercised — (15,605 ) $ 2.30 Options forfeited 81,754 (81,754 ) $ 6.24 Balances at September 30, 2015 1,512,552 2,018,739 $ 6.08 $ 16,345 Options exercisable at September 30, 2015 1,813,302 $ 6.08 $ 16,102 Options vested and expected to vest at September 30, 2015 1,895,687 $ 5.81 $ 15,828 The aggregate intrinsic values of options outstanding, exercisable, vested and expected to vest were calculated as the difference between the exercise price of the options and the fair value of the Company’s common stock, as of September 30, 2015 and December 31, 2014. During the three months ended September 30, 2015 and 2014, the Company granted options with a weighted average grant date fair value of $12.88 and $6.97 per share respectively. During the nine months ended September 30, 2015 and 2014, the Company granted options with a weighted average grant date fair value of $12.60 and $4.53 per share respectively. The aggregate intrinsic value of options exercised was $11,000 and $0 during the three months ended September 30, 2015 and 2014, respectively, and $71,000 and $24,000 during the nine months ended September 30, 2015 and 2014. The total fair value of options vested was $367,000 and $140,000 for the three months ended September 30, 2015 and 2014, and $879,000 respectively, and $402,000 for the nine months ended September 30, 2015 and 2014, respectively. The weighted-average remaining contractual life of options outstanding was 7.8 years at both September 30, 2015 and December 31, 2014. For both September 30, 2015 and December 31, 2014, the weighted-average remaining contractual life was 7.7 years, for vested and expected to vest options. 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 September 30, 2015 and December 31, 2014, there were 10,878 and 17,566 shares of common stock outstanding subject to the Company’s right of repurchase at a weighted-average price of $2.43 and $2.34 per share. Stock-Based The fair value of share-based Black-Scholes option- Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Expected term (in years) 5.0-6.32 6.0 5.0-6.32 6.0 Expected volatility 33.4-34.1 % 37 % 32.8-34.1 % 37-38 % Risk-free 1.61-1.80 % 1.80-1.93 % 1.31-1.80 % 1.80%-1.93 % Dividend yield — — — — Stock-based Black-Scholes Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Expected term (in years) 8.1-9.9 8.0-9.5 8.1-9.9 8.0-10.0 Expected volatility 39-39.5 % 38 % 34-39.5 % 38%-43 % Risk-free 1.85-2.06 % 2.53 % 1.79-3.03 % 2.53%-2.72 % Dividend yield — — — — The following table summarizes stock-based Three Months Ended Nine Months Ended 2015 2014 2015 2014 Cost of revenue $ 25 $ 5 $ 66 $ 9 Research and development 76 19 223 52 Selling, general and administrative 257 145 630 430 Total stock-based $ 358 $ 169 $ 919 $ 491 As of September 30, 2015, unrecognized compensation expense related to unvested options, net of estimated forfeitures, was $3.9 million, which the Company expects to recognize on a straight-line weighted-average

Net Loss per Common Share

Net Loss per Common Share	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Net Loss per Common Share	9. Net Loss per Common Share The Company computes net income (loss) per share of common stock in conformity with the two-class method required for participating securities. The Company considers all series of the Company’s convertible preferred stock to be participating securities as the holders of the convertible preferred stock are entitled to receive a noncumulative dividend on a pari passu basis in the event that a dividend is paid on common stock. In accordance with the two-class method, earnings allocated to convertible preferred stock are excluded from the computation of net income per common share, basic and diluted. The holders of all series of convertible preferred stock do not have a contractual obligation to share in the losses of the Company. As such, the Company’s net losses for the three months and nine months ended September 30, 2015 and 2014 were not allocated to these participating securities. As the Company had net losses for all the periods presented, all potentially dilutive common securities were determined to be anti-dilutive. The following table sets forth the computation of the basic and diluted net loss per share (in thousands, except share and per share data): Three Months Ended Nine months Ended 2015 2014 2015 2014 Numerator: Net loss $ (9,138 ) $ (5,290 ) $ (27,516 ) $ (15,458 ) Denominator: Weighted-average common shares outstanding 13,305,057 672,635 5,699,512 668,830 Less: weighted-average unvested common shares subject to repurchase (12,208 ) (20,676 ) (14,757 ) (21,039 ) Weighted-average shares used to compute net loss per common share, basic and diluted 13,292,849 651,959 5,684,755 647,791 Net loss per common share, basic and diluted $ (0.69 ) $ (8.11 ) $ (4.84 ) $ (23.86 ) The following outstanding shares of potentially dilutive securities have been excluded from diluted net loss per share for the three months and nine months ended September 30, 2015 and 2014 because their inclusion would be anti-dilutive: September 30, 2015 2014 Convertible preferred stock on an as-converted basis — 6,246,196 Options to purchase common stock 2,018,739 1,199,689 Warrants to purchase common stock 137,007 3,532 Warrants to purchase convertible preferred stock on an as-converted basis — 134,570 Total 2,155,746 7,583,987

Organization and Description 15

Organization and Description of Business (Policies)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Reclassifications	Reclassifications Certain prior year amounts in the condensed financial statements and notes thereto have been reclassified where necessary to conform to the current presentation. These reclassifications did not affect the prior period’s stockholders’ equity, net loss or net cash used in operating activities.
Use of Estimates	Use of Estimates The Company’s financial statements have been prepared in conformity with U.S. GAAP. The preparation of the 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, convertible preferred stock and related warrants, common stock prior to the Company’s IPO, and stock-based compensation. Actual results could differ from those estimates and assumptions.
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 a letter of credit related to the Company’s facility lease in San Francisco, California.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Carrying amounts of the Company’s financial instruments, including cash equivalents, accounts receivable and accounts payable approximate fair value due to their relatively short maturities. As of September 30, 2015 and December 31, 2014, 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 long-term debt approximates its fair value.
Customer Concentration	Customer Concentration Significant customers are those which represent 10% or more of the Company’s total revenue for each period presented in the condensed statements of operations and comprehensive loss or 10% or more of the Company’s net accounts receivable balance at each respective balance sheet date. For each significant customer, revenue as a percentage of total revenue and accounts receivable, net as a percentage of total accounts receivable, net were as follows: Revenue Accounts Receivable, net Three Months Ended Nine Months Ended September 30, September 30, December 31, 2015 2014 2015 2014 2015 2014 Customers: Customer A * 13 % * 14 % * 12 % Customer B * * * * * 12 % * Less than 10%
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, net in the condensed 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 warrants to purchase common stock and the liability was reclassified to additional paid-in capital.
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.
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 (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”). Areas of revenue recognition that will be affected include, but are not limited to, transfer of control, variable consideration, allocation of transfer pricing, licenses, time value of money, contract costs and disclosures. On July 9, 2015, the FASB deferred the implementation of this standard by one year so that the guidance is effective for fiscal years and interim reporting periods beginning after December 15, 2017, at which time the Company may adopt the new standard under the full retrospective method or the modified retrospective method. The Company is currently evaluating the impact that the adoption of ASU 2014-09 will have on its financial statements and related disclosures. In April 2015, the FASB issued ASU No. 2015-03, Interest-Imputation of Interest In July 2015, the FASB issued ASU 2015-11, Inventory (Topic 330): Simplifying the Measurement of Inventory. ASU 2015-11 amends guidance on the measurement of inventory from lower of cost or market to net realizable (“ASU 2015-11”) value. The amendment applies to all inventory other than those measured by Last-In-First-Out and the Retail Inventory Method. The amendment is effective for fiscal years beginning after December 15, 2016, including interim periods within that reporting period. Early adoption is permitted. The Company is currently evaluating the impact, if any, that the adoption of ASU 2015-11 will have on its financial statements and related disclosures.

Summary of Significant Accoun16

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Schedule of Revenue as Percentage of Total Revenue for Each Significant Customer	For each significant customer, revenue as a percentage of total revenue and accounts receivable, net as a percentage of total accounts receivable, net were as follows: Revenue Accounts Receivable, net Three Months Ended Nine Months Ended September 30, September 30, December 31, 2015 2014 2015 2014 2015 2014 Customers: Customer A * 13 % * 14 % * 12 % Customer B * * * * * 12 % * Less than 10%

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
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): September 30, 2015 Level 1 Level 2 Level 3 Total Assets Money market funds $ 52,738 $ — $ — $ 52,738 $ 52,738 $ — $ — $ 52,738 December 31, 2014 Level 1 Level 2 Level 3 Total Assets Money market funds (a) $ 5,768 $ — $ — $ 5,768 $ 5,768 $ — $ — $ 5,768 Liabilities Convertible preferred stock warrant liability $ — $ — $ 136 $ 136 $ — $ — $ 136 $ 136 (a) - Balances include $35,000 classified as non-current restricted cash as of December 31, 2014.
Summary of Changes in Fair Value of Convertible Preferred Stock Warrant Liability	The following table sets forth a summary of the changes in the fair value of the convertible preferred stock warrant liability, the Company’s Level 3 financial liability, which is measured on a recurring basis (in thousands): Three Months ended Nine Months ended September 30, 2015 2014 2015 2014 Beginning balance $ — $ 657 $ 136 $ 86 Issuance of convertible preferred stock warrants — — — 572 Change in fair value recorded in interest and other income (expense), net — 16 472 15 Reclassification of liability to additional paid-in capital upon conversion to common stock warrants — — (608 ) — Ending balance $ — $ 673 $ — $ 673

Balance sheet components (Table

Balance sheet components (Tables)	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Inventory	Inventory consisted of the following (in thousands): September 30, 2015 December 31, Raw materials $ 827 $ 894 Work-in-process 799 768 Finished goods 3,256 2,609 Total inventory $ 4,882 $ 4,271
Schedule of Prepaid Expenses and Other Current Assets	Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following (in thousands): September 30, 2015 December 31, 2014 Prepaid expenses $ 1,366 $ 420 Tenant improvement allowance receivable — 2,064 Other 6 2 Total prepaid expenses and other current assets $ 1,372 $ 2,486
Schedule of Property and Equipment, Net	Property and equipment, net, consisted of the following (in thousands): September 30, December 31, 2014 Computer equipment and software $ 1,113 $ 633 Laboratory and manufacturing equipment 1,356 816 Furniture and fixtures 1,445 1,409 Leasehold improvements 6,889 6,541 Total property and equipment, gross 10,803 9,399 Less: accumulated depreciation and amortization (1,789 ) (858 ) Total property and equipment, net $ 9,014 $ 8,541
Schedule of Accrued and Other Current Liabilities	Accrued and other current liabilities consisted of the following (in thousands): September 30, December 31, 2014 Accrued payroll-related expenses $ 2,460 $ 1,599 Accrued independent sales agent commissions 156 227 Accrued professional fees 182 89 Accrued costs for property and equipment — 1,453 Deferred rent 261 290 Other 279 504 Total accrued and other current liabilities $ 3,338 $ 4,162

Convertible Preferred Stock (Ta

Convertible Preferred Stock (Tables)	9 Months Ended
	Sep. 30, 2015
Text Block [Abstract]
Components of Convertible Preferred Stock	Convertible preferred stock as of December 31, 2014 consisted of the following (in thousands except share data): December 31, 2014 Shares Shares Net Aggregate Series A 396,605 396,590 $ 2,646 $ 2,715 Series B 493,385 478,718 8,141 8,240 Series C 1,586,392 1,566,352 17,412 17,592 Series D 2,028,236 2,016,929 24,750 25,000 Series E 1,702,702 1,597,814 20,806 21,259 Total 6,207,320 6,056,403 $ 73,755 $ 74,806 Shares Shares Net As-Converted Series A 396,605 396,590 $ 2,646 396,590 Series B 493,385 478,718 8,141 568,615 Series C 1,586,392 1,566,352 17,412 1,666,248 Series D 2,028,236 2,016,929 24,750 2,034,709 Series E 1,702,702 1,597,814 20,806 1,642,002 Series F 1,654,594 1,596,212 22,769 1,671,168 Total 7,861,914 7,652,615 $ 96,524 7,979,332

Stock Option Plans (Tables)

Stock Option Plans (Tables)	9 Months Ended
	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option Activity	The following table summarizes stock option activity under the plans and related information: Options Outstanding Options Available Grant Options Weighted- Average Exercise Price Per Share Aggregate Value (in thousands) Balances at December 31, 2014 315,876 1,379,503 $ 2.56 $ 9,483 Options authorized 1,851,517 — Options granted (736,595 ) 736,595 $ 12.60 Options exercised — (15,605 ) $ 2.30 Options forfeited 81,754 (81,754 ) $ 6.24 Balances at September 30, 2015 1,512,552 2,018,739 $ 6.08 $ 16,345 Options exercisable at September 30, 2015 1,813,302 $ 6.08 $ 16,102 Options vested and expected to vest at September 30, 2015 1,895,687 $ 5.81 $ 15,828
Schedule of Assumptions Used in Estimated Fair Value of Share-based Compensation for Options Granted	The fair value of share-based Black-Scholes option- Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Expected term (in years) 5.0-6.32 6.0 5.0-6.32 6.0 Expected volatility 33.4-34.1 % 37 % 32.8-34.1 % 37-38 % Risk-free 1.61-1.80 % 1.80-1.93 % 1.31-1.80 % 1.80%-1.93 % Dividend yield — — — — Stock-based Black-Scholes Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Expected term (in years) 8.1-9.9 8.0-9.5 8.1-9.9 8.0-10.0 Expected volatility 39-39.5 % 38 % 34-39.5 % 38%-43 % Risk-free 1.85-2.06 % 2.53 % 1.79-3.03 % 2.53%-2.72 % Dividend yield — — — —
Summary of Stock-based Compensation Expense Related to Stock Options Included in Condensed Statements of Operations and Comprehensive Loss	The following table summarizes stock-based Three Months Ended Nine Months Ended 2015 2014 2015 2014 Cost of revenue $ 25 $ 5 $ 66 $ 9 Research and development 76 19 223 52 Selling, general and administrative 257 145 630 430 Total stock-based $ 358 $ 169 $ 919 $ 491

Net Loss per Common Share (Tabl

Net Loss per Common Share (Tables)	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
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 (in thousands, except share and per share data): Three Months Ended Nine months Ended 2015 2014 2015 2014 Numerator: Net loss $ (9,138 ) $ (5,290 ) $ (27,516 ) $ (15,458 ) Denominator: Weighted-average common shares outstanding 13,305,057 672,635 5,699,512 668,830 Less: weighted-average unvested common shares subject to repurchase (12,208 ) (20,676 ) (14,757 ) (21,039 ) Weighted-average shares used to compute net loss per common share, basic and diluted 13,292,849 651,959 5,684,755 647,791 Net loss per common share, basic and diluted $ (0.69 ) $ (8.11 ) $ (4.84 ) $ (23.86 )
Schedule of Outstanding Shares of Potentially Dilutive Securities Excluded from Diluted Net Loss per Share	The following outstanding shares of potentially dilutive securities have been excluded from diluted net loss per share for the three months and nine months ended September 30, 2015 and 2014 because their inclusion would be anti-dilutive: September 30, 2015 2014 Convertible preferred stock on an as-converted basis — 6,246,196 Options to purchase common stock 2,018,739 1,199,689 Warrants to purchase common stock 137,007 3,532 Warrants to purchase convertible preferred stock on an as-converted basis — 134,570 Total 2,155,746 7,583,987

Organization and Description 22

Organization and Description of Business - Additional Information (Detail) $ / shares in Units, $ in Millions	1 Months Ended		9 Months Ended
	Jun. 30, 2015USD ($)$ / sharesshares	May. 31, 2015	Sep. 30, 2015$ / sharesshares	Jun. 18, 2015$ / sharesshares	Dec. 31, 2014$ / sharesshares
Organization And Nature Of Operations [Line Items]
Capital stock authorized				110,000,000
Common stock, shares authorized			100,000,000	100,000,000	9,189,189
Preferred stock, shares authorized			10,000,000	10,000,000	0
Common stock, par value | $ / shares			$ 0.001	$ 0.001	$ 0.001
Preferred stock, par value | $ / shares			$ 0.001	$ 0.001	$ 0.001
Preferred stock, shares outstanding			0		0
Common Stock [Member]
Organization And Nature Of Operations [Line Items]
Description 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.
Reverse stock split ratio		0.0541
Convertible preferred stock converted into shares of common stock	7,979,332
Common Stock [Member] | IPO [Member]
Organization And Nature Of Operations [Line Items]
Stock issued, shares	4,600,000
Public offering price | $ / shares	$ 12
Stock issued, value | $	$ 47.2
Option to purchase additional shares	600,000
Convertible preferred stock converted into shares of common stock	7,979,332

Organization and Description 23

Organization and Description of Business - Additional Information 1 (Detail) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	$ (9,138,000)		$ (5,290,000)	$ (27,516,000)	$ (15,458,000)
Accounts receivable, net	3,284,000			3,284,000		$ 2,798,000
Convertible preferred stock warrant liability						$ 136,000
Research and development	2,042,000		1,287,000	5,799,000	3,800,000
Selling, general and administrative	10,180,000		6,063,000	29,020,000	16,066,000
Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Research and development			386,000		613,000
Selling, general and administrative			$ (386,000)		$ (613,000)
Error Correction [Member] | Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss		$ (370,000)		(302,000)
Accounts receivable, net	$ (302,000)			$ (302,000)
Convertible preferred stock warrant liability		$ 370,000

Summary of Significant Accoun24

Summary of Significant Accounting Policies - Schedule of Revenue as Percentage of Total Revenue for Each Significant Customer (Detail)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2014	Dec. 31, 2014
Customer Concentration Risk [Member] | Customer A [Member] | Revenue [Member]
Concentration Risk [Line Items]
Customer concentration, percentage	13.00%	14.00%
Credit Concentration Risk [Member] | Customer A [Member] | Accounts Receivable, Net [Member]
Concentration Risk [Line Items]
Customer concentration, percentage			12.00%
Credit Concentration Risk [Member] | Customer B [Member] | Accounts Receivable, Net [Member]
Concentration Risk [Line Items]
Customer concentration, percentage			12.00%

Summary of Significant Accoun25

Summary of Significant Accounting Policies - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2015Segments
Accounting Policies [Abstract]
Number of operating segments	1

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)
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	$ 73,891
Level 3 [Member] | Recurring [Member]
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	$ 600

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) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Assets
Assets	$ 52,738	$ 5,768
Liabilities
Liabilities		136
Convertible Preferred Stock Warrant Liability [Member]
Liabilities
Liabilities		136
Money Market Funds [Member]
Assets
Assets	52,738	5,768
Level 1 [Member] | Recurring [Member]
Assets
Assets	52,738	5,768
Level 1 [Member] | Money Market Funds [Member] | Recurring [Member]
Assets
Assets	$ 52,738	5,768
Level 3 [Member] | Recurring [Member]
Liabilities
Liabilities		136
Level 3 [Member] | Recurring [Member] | Convertible Preferred Stock Warrant Liability [Member]
Liabilities
Liabilities		$ 136

Fair Value Measurements - Fin28

Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis Based on Three-Tier Fair Value Hierarchy (Parenthetical) (Detail) - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$ 52,738,000	$ 5,768,000
Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$ 52,738,000	5,768,000
Money Market Funds [Member] | Non-current Restricted Cash [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		$ 35,000

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Changes in Fair Value of Convertible Preferred Stock Warrant Liability (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Fair Value Disclosures [Abstract]
Beginning balance	$ 657	$ 136	$ 86
Issuance of convertible preferred stock warrants			572
Change in fair value recorded in interest and other income (expense), net	16	472	15
Reclassification of liability to additional paid-in capital upon conversion to common stock warrants		$ (608)
Ending balance	$ 673		$ 673

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Inventory (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Raw materials	$ 827	$ 894
Work-in-process	799	768
Finished goods	3,256	2,609
Total inventory	$ 4,882	$ 4,271

Balance Sheet Components - Sc31

Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid expenses	$ 1,366	$ 420
Tenant improvement allowance receivable		2,064
Other	6	2
Total prepaid expenses and other current assets	$ 1,372	$ 2,486

Balance Sheet Components - Sc32

Balance Sheet Components - Schedule of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	$ 10,803	$ 9,399
Less: accumulated depreciation and amortization	(1,789)	(858)
Total property and equipment, net	9,014	8,541
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	1,113	633
Laboratory and Manufacturing Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	1,356	816
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	1,445	1,409
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	$ 6,889	$ 6,541

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Property, Plant and Equipment [Abstract]
Depreciation and amortization	$ 439	$ 90	$ 1,258	$ 225

Balance Sheet Components - Sc34

Balance Sheet Components - Schedule of Accrued and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Payables and Accruals [Abstract]
Accrued payroll-related expenses	$ 2,460	$ 1,599
Accrued independent sales agent commissions	156	227
Accrued professional fees	182	89
Accrued costs for property and equipment		1,453
Deferred rent	261	290
Other	279	504
Total accrued and other current liabilities	$ 3,338	$ 4,162

Related Party Loan Agreement -

Related Party Loan Agreement - Additional Information (Detail) - HealthCare Royalty Partners [Member] - Loans Payable [Member] - Loan Agreement [Member] - USD ($)	1 Months Ended	9 Months Ended
	Mar. 31, 2015	Sep. 30, 2015
Related Party Transaction [Line Items]
Debt instrument, drawn amount	$ 5,000,000
Debt instrument, amount		$ 15,000,000
Debt instrument, outstanding borrowings amount		$ 15,000,000
Debt instrument, fixed interest rate		12.50%
Debt instrument, payment terms		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.
Debt instrument, maturity date		Dec. 31, 2020

Credit Facility - Additional In

Credit Facility - Additional Information (Detail) - Revolving Credit Facility [Member] - Silicon Valley Bank [Member] - Accounts Receivable Credit Facility [Member] - USD ($)	1 Months Ended	9 Months Ended
	Feb. 28, 2015	Sep. 30, 2015
Line of Credit Facility [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 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
Credit facility, available borrowing capacity		$ 2,800,000
Prime Rate [Member]
Line of Credit Facility [Line Items]
Credit facility, monthly interest rate in addition to prime rate		0.75%

Convertible Preferred Stock - C

Convertible Preferred Stock - Components of Convertible Preferred Stock (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Jun. 14, 2015	Dec. 31, 2014
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized	0	7,861,914	6,207,320
Convertible preferred stock, shares issued	0	7,652,615	6,056,403
Convertible preferred stock, net carrying value		$ 96,524	$ 73,755
Convertible preferred stock, aggregate liquidation preference			$ 74,806
Convertible preferred stock, as-converted shares		7,979,332
Convertible preferred stock, shares outstanding	0	7,652,615	6,056,403
Series A Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized		396,605	396,605
Convertible preferred stock, shares issued		396,590	396,590
Convertible preferred stock, net carrying value		$ 2,646	$ 2,646
Convertible preferred stock, aggregate liquidation preference			$ 2,715
Convertible preferred stock, as-converted shares		396,590
Convertible preferred stock, shares outstanding		396,590	396,590
Series B Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized		493,385	493,385
Convertible preferred stock, shares issued		478,718	478,718
Convertible preferred stock, net carrying value		$ 8,141	$ 8,141
Convertible preferred stock, aggregate liquidation preference			$ 8,240
Convertible preferred stock, as-converted shares		568,615
Convertible preferred stock, shares outstanding		478,718	478,718
Series C Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized		1,586,392	1,586,392
Convertible preferred stock, shares issued		1,566,352	1,566,352
Convertible preferred stock, net carrying value		$ 17,412	$ 17,412
Convertible preferred stock, aggregate liquidation preference			$ 17,592
Convertible preferred stock, as-converted shares		1,666,248
Convertible preferred stock, shares outstanding		1,566,352	1,566,352
Series D Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized		2,028,236	2,028,236
Convertible preferred stock, shares issued		2,016,929	2,016,929
Convertible preferred stock, net carrying value		$ 24,750	$ 24,750
Convertible preferred stock, aggregate liquidation preference			$ 25,000
Convertible preferred stock, as-converted shares		2,034,709
Convertible preferred stock, shares outstanding		2,016,929	2,016,929
Series E Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized		1,702,702	1,702,702
Convertible preferred stock, shares issued		1,597,814	1,597,814
Convertible preferred stock, net carrying value		$ 20,806	$ 20,806
Convertible preferred stock, aggregate liquidation preference			$ 21,259
Convertible preferred stock, as-converted shares		1,642,002
Convertible preferred stock, shares outstanding		1,597,814	1,597,814
Series F Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized		1,654,594
Convertible preferred stock, shares issued		1,596,212
Convertible preferred stock, net carrying value		$ 22,769
Convertible preferred stock, as-converted shares		1,671,168
Convertible preferred stock, shares outstanding		1,596,212

Convertible Preferred Stock - A

Convertible Preferred Stock - Additional Information (Detail) - shares	2 Months Ended
	Mar. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Jun. 14, 2015	Dec. 31, 2014
Temporary Equity [Line Items]
Convertible preferred stock, shares outstanding		0		7,652,615	6,056,403
Series F Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Convertible preferred stock, shares issued during period	1,596,212
Convertible preferred stock, shares outstanding				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] | 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) - shares	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant	1,512,552	315,876
The 2005 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting, description	Employee stock options 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.
The 2005 Plan [Member] | Incentive Stock Options [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%
The 2005 Plan [Member] | Nonstatutory Options [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%
The 2005 Plan [Member] | Employee [Member] | Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting, percentage	25.00%
Stock option vesting, term	1 year
The 2005 Plan [Member] | Employee [Member] | Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting, term	3 years
The 2005 Plan [Member] | Minimum [Member] | Consultants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting, term	2 years
The 2005 Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option expiration period	10 years
The 2005 Plan [Member] | Maximum [Member] | Consultants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting, term	4 years
2015 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting, description	Employee stock options generally vest 25% 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.
Number of shares authorized for issuance	3,597,794
Number of shares available for grant	1,512,552
Increase in number of shares available for issuance, description	The number of shares authorized for issuance under the 2015 Plan is 3,597,794 at September 30, 2015 of which 1,512,552 shares were available for grant. 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 at least (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.
2015 Plan [Member] | Incentive Stock Options [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%
2015 Plan [Member] | Employee [Member] | Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting, percentage	25.00%
Stock option vesting, term	1 year
2015 Plan [Member] | Employee [Member] | Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vesting, term	4 years
2015 Plan [Member] | Minimum [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%
2015 Plan [Member] | Minimum [Member] | Employees or Directors Holding Less Than 10% of Voting Power [Member] | Incentive Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of fair value of common stock on grant date	110.00%
2015 Plan [Member] | Minimum [Member] | Employees or Directors Holding More Than 10% of Voting Power [Member] | Incentive Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of fair value of common stock on grant date	100.00%
2015 Plan [Member] | Minimum [Member] | Employees, Directors and Consultants [Member] | Nonstatutory Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of fair value of common stock on grant date	100.00%
2015 Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option expiration period	10 years

Stock Option Plans - Summary of

Stock Option Plans - Summary of Stock Option Activity (Detail) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)$ / sharesshares
Compensation Related Costs [Abstract]
Options Available for Grant, Beginning Balances	315,876
Options Available for Grant, Options authorized	1,851,517
Options Available for Grant, Options granted	(736,595)
Options Available for Grant, Options exercised	0
Options Available for Grant, Options forfeited	81,754
Options Available for Grant, Ending Balances	1,512,552
Options Outstanding, Beginning Balances	1,379,503
Options Outstanding, Options granted	736,595
Options Outstanding, Options exercised	(15,605)
Options Outstanding, Options forfeited	(81,754)
Options Outstanding, Ending Balances	2,018,739
Options Outstanding, Options exercisable	1,813,302
Options Outstanding, Options vested and expected to vest	1,895,687
Weighted Average Exercise Price Per Share, Beginning Balances | $ / shares	$ 2.56
Weighted Average Exercise Price Per Share, authorized | $ / shares	0
Weighted Average Exercise Price Per Share, granted | $ / shares	12.60
Weighted Average Exercise Price Per Share, exercised | $ / shares	2.30
Weighted Average Exercise Price Per Share, forfeited | $ / shares	6.24
Weighted Average Exercise Price Per Share, Ending Balances | $ / shares	6.08
Weighted Average Exercise Price Per Share, Options exercisable | $ / shares	6.08
Weighted Average Exercise Price Per Share, Options vested and expected to vest | $ / shares	$ 5.81
Aggregate Intrinsic Value, Beginning Balances | $	$ 9,483
Aggregate Intrinsic Value , Ending Balances | $	16,345
Aggregate Intrinsic Value, Options exercisable | $	16,102
Aggregate Intrinsic Value, Options vested and expected to vest | $	$ 15,828

Stock Option Plans - Addition41

Stock Option Plans - Additional Information 1 (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Compensation Related Costs [Abstract]
Weighted average grant date fair value of options, granted	$ 12.88	$ 6.97	$ 12.60	$ 4.53
Aggregate intrinsic value of options exercised	$ 11,000	$ 0	$ 71,000	$ 24,000
Fair value of option vested	$ 367,000	$ 140,000	$ 879,000	$ 402,000
Weighted-average remaining contractual life of options outstanding			7 years 9 months 18 days		7 years 9 months 18 days
Weighted-average remaining contractual life of options outstanding, vested and expected to vest			7 years 8 months 12 days		7 years 8 months 12 days
Stock option repurchase, term			4 years
Common stock outstanding, right to repurchase	10,878		10,878		17,566
Weighted average price of stock repurchase	$ 2.43		$ 2.43		$ 2.34
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.
Unrecognized compensation expense related to unvested options	$ 3,900,000		$ 3,900,000
Weighted-average expected period to recognize of compensation expense, term			3 years 7 months 6 days

Stock Option Plans - Schedule o

Stock Option Plans - Schedule of Assumptions Used in Estimated Fair Value of Share-based Compensation for Options Granted (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Employees and Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)		6 years		6 years
Expected volatility		37.00%
Dividend yield	0.00%	0.00%	0.00%	0.00%
Employees and Directors [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	5 years		5 years
Expected volatility	33.40%		32.80%	37.00%
Risk-free interest rate	1.61%	1.80%	1.31%	1.80%
Employees and Directors [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 years 3 months 26 days		6 years 3 months 26 days
Expected volatility	34.10%		34.10%	38.00%
Risk-free interest rate	1.80%	1.93%	1.80%	1.93%
Non-employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility		38.00%
Dividend yield	0.00%	0.00%	0.00%	0.00%
Risk-free interest rate		2.53%
Non-employees [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	8 years 1 month 6 days	8 years	8 years 1 month 6 days	8 years
Expected volatility	39.00%		34.00%	38.00%
Risk-free interest rate	1.85%		1.79%	2.53%
Non-employees [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	9 years 10 months 24 days	9 years 6 months	9 years 10 months 24 days	10 years
Expected volatility	39.50%		39.50%	43.00%
Risk-free interest rate	2.06%		3.03%	2.72%

Stock Option Plans - Summary 43

Stock Option Plans - Summary of Stock-based Compensation Expense Related to Stock Options Included in Condensed Statements of Operations and Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 358	$ 169	$ 919	$ 492
Cost of Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	25	5	66	9
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	76	19	223	52
Selling, General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 257	$ 145	$ 630	$ 430

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		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Numerator:
Net loss	$ (9,138)	$ (5,290)	$ (27,516)	$ (15,458)
Denominator:
Weighted-average common shares outstanding	13,305,057	672,635	5,699,512	668,830
Less: weighted-average unvested common shares subject to repurchase	(12,208)	(20,676)	(14,757)	(21,039)
Weighted-average shares used to compute net loss per common share, basic and diluted	13,292,849	651,959	5,684,755	647,791
Net loss per common share, basic and diluted	$ (0.69)	$ (8.11)	$ (4.84)	$ (23.86)

Net Loss per Common Share - S45

Net Loss per Common Share - Schedule of Outstanding Shares of Potentially Dilutive Securities Excluded from Diluted Net Loss per Share (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share	2,155,746	7,583,987	2,155,746	7,583,987
Convertible Preferred Stock on an as-Converted Basis [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		6,246,196
Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share	2,018,739	1,199,689	2,018,739	1,199,689
Warrants to Purchase Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share	137,007	3,532	137,007	3,532
Warrants to Purchase Convertible Preferred Stock on an as-Converted Basis [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		134,570