ChemoCentryx (CCXI) 10-Q 6 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	Apr. 30, 2019
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Entity Registrant Name	ChemoCentryx, Inc.
Entity Central Index Key	0001340652
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Trading Symbol	CCXI
Entity Common Stock, Shares Outstanding		58,047,961
Entity Emerging Growth Company	false
Entity Small Business	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 79,333,000	$ 28,088,000
Short-term investments	142,777,000	148,896,000
Accounts receivable from related party	167,000	2,058,000
Prepaid expenses and other current assets	4,399,000	2,342,000
Total current assets	226,676,000	181,384,000
Property and equipment, net	1,441,000	1,536,000
Long-term investments	11,968,000	0
Operating Lease, Right-of-Use Asset	1,062,000	0
Other assets	210,000	390,000
Total assets	241,357,000	183,310,000
Current liabilities:
Accounts payable	1,293,000	966,000
Accrued and other current liabilities	12,865,000	12,969,000
Deferred revenue from related party	51,950,000	50,461,000
Total current liabilities	66,108,000	64,396,000
Long-term debt, net	19,714,000	19,689,000
Noncurrent deferred revenue from related party	74,451,000	84,100,000
Other non-current liabilities	445,000	387,000
Total liabilities	160,718,000	168,572,000
Commitments
Stockholders' equity:
Preferred stock, $0.001 par value, 10,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $0.001 par value, 200,000,000 shares authorized; 57,725,915 and 50,652,238 shares issued and outstanding at March 31, 2019 and December 31, 2018, respectively	58,000	51,000
Additional paid-in capital	467,047,000	389,398,000
Note receivable	(16,000)	(16,000)
Accumulated other comprehensive loss	(4,000)	(198,000)
Accumulated deficit	(386,446,000)	(374,497,000)
Total stockholders' equity	80,639,000	14,738,000
Total liabilities and stockholders' equity	$ 241,357,000	$ 183,310,000

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
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	200,000,000	200,000,000
Common stock, shares issued	57,725,915	50,652,238
Common stock, shares outstanding	57,725,915	50,652,238

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue:
Collaboration and license revenue from related party	$ 8,327	$ 9,546
Total revenue	8,327	9,546
Operating expenses:
Research and development	15,354	14,742
General and administrative	5,501	4,660
Total operating expenses	20,855	19,402
Loss from operations	(12,528)	(9,856)
Other income (expense):
Interest income	1,121	613
Interest expense	(542)	(174)
Total other income, net	579	439
Net loss	$ (11,949)	$ (9,417)
Basic and diluted net loss per common share	$ (0.23)	$ (0.19)
Shares used to compute basic and diluted net loss per common share	52,395	48,853

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net loss	$ (11,949)	$ (9,417)
Unrealized gain (loss) on available-for-sale securities	194	(183)
Comprehensive loss	$ (11,755)	$ (9,600)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Note Receivable [Member]	Accumulated Other Comprehensive Loss [Member]	Accumulated Deficit [Member]
Beginning Balance at Dec. 31, 2017	$ 79,267	$ 49	$ 368,553	$ (16)	$ (119)	$ (289,200)
Beginning Balance, shares at Dec. 31, 2017		48,837,060
Net loss	(9,417)					(9,417)
Adoption of ASC Topic 606, Revenue from Contracts with Customers	(47,331)					(47,331)
Unrealized gain / (loss) on investments	(183)				(183)
Issuance of common stock under equity incentive plans	1,128		1,128
Issuance of common stock under equity incentive plans, shares		313,886
Repurchased shares upon vesting of restricted stock units for tax withholdings	(473)		(473)
Repurchased shares upon vesting of restricted stock units for tax withholdings, shares		(79,585)
Employee stock-based compensation	2,206		2,206
Compensation expense related to options granted to consultants	335		335
Ending Balance at Mar. 31, 2018	25,532	$ 49	371,749	(16)	(302)	(345,948)
Ending Balance, shares at Mar. 31, 2018		49,071,361
Beginning Balance at Dec. 31, 2018	$ 14,738	$ 51	389,398	(16)	(198)	(374,497)
Beginning Balance, shares at Dec. 31, 2018	50,652,238	50,652,238
Net loss	$ (11,949)					(11,949)
Unrealized gain / (loss) on investments	194				194
Issuance of common stock through Equity Distribution Agreement, net of issuance costs (Note 9)	$ 73,276	$ 6	73,270
Issuance of common stock through Equity Distribution Agreement, net of issuance costs (Note 9), shares	6,491,196	6,491,196
Issuance of common stock under equity incentive plans	$ 2,852	$ 1	2,851
Issuance of common stock under equity incentive plans, shares		690,100
Repurchased shares upon vesting of restricted stock units for tax withholdings	(1,174)		(1,174)
Repurchased shares upon vesting of restricted stock units for tax withholdings, shares		(107,619)
Employee stock-based compensation	2,662		2,662
Compensation expense related to options granted to consultants	40		40
Ending Balance at Mar. 31, 2019	$ 80,639	$ 58	$ 467,047	$ (16)	$ (4)	$ (386,446)
Ending Balance, shares at Mar. 31, 2019	57,725,915	57,725,915

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Operating activities
Net loss		$ (11,949)	$ (9,417)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Stock-based compensation		2,702	2,541
Depreciation of property and equipment		141	111
Amortization of right-of-use assets		239
Noncash interest income, net		(436)	(366)
Changes in assets and liabilities:
Accounts receivable due from related party		1,891	49,392
Prepaids and other current assets		(1,778)	(83)
Other assets		180	32
Accounts payable		327	(951)
Other liabilities		(1,443)	(1,372)
Deferred revenue from related party		(8,160)	1,061
Net cash provided by (used in) operating activities		(18,286)	40,948
Investing activities
Purchases of property and equipment, net		(46)	(32)
Purchases of investments		(75,235)	(77,941)
Sales of investments		4,967
Maturities of investments		65,170	26,900
Net cash used in investing activities		(5,144)	(51,073)
Financing activities
Proceeds from issuance of common stock		73,276
Proceeds from exercise of stock options		2,573	1,128
Employees' tax withheld and paid for restricted stock units		(1,174)	(473)
Net cash provided by financing activities		74,675	655
Net increase (decrease) in cash and cash equivalents		51,245	(9,470)
Cash and cash equivalents at beginning of period		28,088	40,020
Cash and cash equivalents at end of period		79,333	30,550
Supplemental disclosures of cash flow information
Cash paid for interest		422	$ 70
Right-of-use assets obtained in exchange for lease obligations	[1]	$ 1,301
[1]	Amounts for the three months ended March 31, 2019 include the transition adjustment for the adoption of Topic 842.

Description of Business

Description of Business	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	1. Description of Business ChemoCentryx, Inc. (the Company) commenced operations in 1997. The Company is a clinical-stage biopharmaceutical company focused on developing new medications targeted at inflammatory disorders, autoimmune diseases and cancer. The Company’s principal operations are in the United States and it operates in one segment. Unaudited Interim Financial Information The financial information filed is unaudited. The Condensed Consolidated Financial Statements included in this report reflect all adjustments (consisting only of normal recurring adjustments) that the Company considers necessary for the fair statement of the results of operations for the interim periods covered and of the financial condition of the Company at the date of the interim balance sheet. The December 31, 2018 Condensed Consolidated Balance Sheet was derived from audited financial statements. The results for interim periods are not necessarily indicative of the results for the entire year or any other interim period. The Condensed Consolidated Financial Statements should be read in conjunction with the Company’s financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 filed with the Securities and Exchange Commission on March 11, 2019.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States (GAAP) requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from these estimates. Concentration of Credit Risk The Company invests in a variety of financial instruments and, by its policy, limits the amount of credit exposure with any one issuer, industry or geographic area. Accounts receivable are typically unsecured and are concentrated in the pharmaceutical industry and government sector. Accordingly, the Company may be exposed to credit risk generally associated with pharmaceutical companies and government funded entities. The Company has not historically experienced any significant losses due to concentration of credit risk. Accounts receivable consists of the following (in thousands): March 31, 2019 December 31, 2018 Vifor (International) Ltd., and/or its affiliates, or collectively, Vifor $ 167 $ 2,058 Net Loss Per Share Basic net loss per common share is computed by dividing net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration for common stock equivalents. Diluted net loss per share is computed by dividing net loss attributable to common stockholders by the sum of the weighted-average number of common shares outstanding and dilutive common stock equivalent shares outstanding for the period. The Company’s potentially dilutive common stock equivalent shares, which include incremental common shares issuable upon (i) the exercise of outstanding stock options and warrants, (ii) vesting of restricted stock units (RSUs) and restricted stock awards (RSAs), and (iii) the purchase from contributions to the 2012 Employee Stock Purchase Plan (the ESPP), (calculated based on the treasury stock method), are only included in the calculation of diluted net loss per share when their effect is dilutive. For the three months ended March 31, 2019 and 2018, the following potentially dilutive securities were excluded from the calculation of diluted net loss per share due to their anti-dilutive effect: Three Months Ended March 31, 2019 2018 Options to purchase common stock, including purchases from contributions to ESPP 11,073,806 11,824,877 Restricted stock units 374,352 459,682 Restricted stock awards 27,278 85,431 Warrants to purchase common stock 150,000 150,000 11,625,436 12,519,990 Comprehensive Loss Comprehensive loss comprises net loss and other comprehensive loss. For the periods presented, other comprehensive loss consists of unrealized gains and losses on the Company’s available-for-sale securities. For the three months ended March 31, 2019, amounts reclassified from accumulated other comprehensive loss to net loss for unrealized gains (losses) on available-for-sale securities were not significant, and were recorded as part of other income, net in the Condensed Consolidated Statements of Operations. For the three months ended March 31, 2018, there were no sales of investments and therefore there were no reclassifications. Leases The Company determines if an arrangement includes a lease at inception. Operating leases are included in operating lease right-of-use (ROU) assets, accrued and other current liabilities and other non-current liabilities on the Company’s Condensed Consolidated Balance Sheets. Operating lease ROU assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. The Company uses the incremental borrowing rate based on the information available at lease commencement date in determining the present value of future payments. The operating lease ROU asset also excludes lease incentives. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise any such options. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. The Company has elected not to apply the recognition requirements for short-term leases. For lease agreements with lease and non-lease components, the Company generally accounts for them separately. Recent Accounting Pronouncements In February 2016, the Financial Accounting Standard Board (FASB) issued Accounting Standards Update (ASU) No. 2016-02, Leases (Topic 842). The new standard requires the Company to recognize the assets and liabilities that arise from leases on the balance sheet and disclose qualitative and quantitative information about its leasing arrangements. On January 1, 2019, the Company adopted this new standard using the modified retrospective approach in accordance with Leases – Targeted Improvements (ASU No. 2018-11). The Company elected the package of practical expedients permitted under the transition guidance within ASU No. 2018-11, which among other things, allowed the Company to carry forward the historical lease classification of those leases in place as of January 1, 2019. Results for the three months ended March 31, 2019 are presented under Topic 842. Prior period amounts have not been adjusted and continue to be reported in accordance with the Company’s historical accounting under previous lease guidance, ASC Topic 840, Leases (Topic 840). The impact of the adoption of Topic 842 on the accompanying Condensed Consolidated Balance Sheet as of January 1, 2019 was as follows (in thousands): December 31, 2018 Adjustments Due to the Adoption of Topic 842 January 1, 2019 Balance Sheet Assets: Operating lease right-of-use assets $ — $ 1,301 $ 1,301 Liabilities: Operating lease liabilities: Accrued and other current liabilities (1) 12,969 955 13,924 Other non-current liabilities (2) 387 346 733 (1) Includes deferred rent and current portion of operating lease liabilities (2) Includes deferred rent and non-current portion of operating lease liabilities In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments. The new standard replaces the incurred loss impairment methodology under the current standard 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. The Company will be required to use a forward-looking expected credit loss model for accounts receivables and other financial instruments. Credit losses relating to available-for-sale debt securities will also be recorded through an allowance for credit losses rather than as a reduction in the amortized cost basis of the securities. The new standard will be effective for the Company on January 1, 2020, with early adoption permitted on January 1, 2019. The Company is currently evaluating the impact of the adoption of this standard on its financial statements and does not expect the adoption of this accounting guidance to have a material impact on the consolidated financial statements. In June 2018, the FASB issued ASU No. 2018-07, Compensation – Stock Compensation (Topic 718). The new standard simplifies the accounting for share-based payments to nonemployees by aligning it with the accounting for share-based payments to employees, with certain exceptions. The Company adopted this new standard on January 1, 2019. The adoption of this accounting guidance did not have a material impact on the consolidated financial statements. The Company has reviewed other recent accounting pronouncements and concluded they are either not applicable to the business or that no material effect is expected on the consolidated financial statements as a result of future adoption. In August 2018, the SEC adopted amendments to certain disclosure requirements in Securities Act Release No. 33-10532, Form 10-Q. The analysis, which can be presented as a footnote or separate statement, is required for the current and comparative quarter and year-to-date interim periods. March 31, 2019. The adoption of these SEC amendments did not have a material effect on the Company’s financial position, results of operations, cash flows or stockholders’ equity.

Cash Equivalents and Investment

Cash Equivalents and Investments	3 Months Ended
	Mar. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Cash Equivalents and Investments	3. Cash Equivalents and Investments The amortized cost and fair value of cash equivalents and investments at March 31, 2019 and December 31, 2018 were as follows (in thousands): March 31, 2019 Amortized Gross Unrealized Fair Cost Gains Losses Value Money market fund $ 71,368 $ — $ — $ 71,368 U.S. treasury securities 35,798 12 (1 ) 35,809 Commercial paper 49,638 — — 49,638 Asset-backed securities 27,147 6 — 27,153 Corporate debt securities 46,046 20 (41 ) 46,025 Total available-for-sale securities $ 229,997 $ 38 $ (42 ) $ 229,993 Classified as: Cash equivalents $ 75,248 Short-term investments 142,777 Long-term investments 11,968 Total available-for-sale securities $ 229,993 December 31, 2018 Amortized Gross Unrealized Fair Cost Gains Losses Value Money market fund $ 22,073 $ — $ — $ 22,073 U.S. treasury securities 23,013 — (13 ) 23,000 Commercial paper 45,683 — — 45,683 Asset-backed securities 29,127 — (34 ) 29,093 Corporate debt securities 55,228 — (151 ) 55,077 Total available-for-sale securities $ 175,124 $ — $ (198 ) $ 174,926 Classified as: Cash equivalents $ 26,030 Short-term investments 148,896 Long-term investments — Total available-for-sale securities $ 174,926 Cash equivalents in the tables above exclude cash of $4.1 million and $2.1 million as of March 31, 2019 and December 31, 2018, respectively. All available-for-sale securities held as of March 31, 2019 had contractual maturities of less than two years No significant available-for-sale securities held as of March 31, 2019 have been in a continuous unrealized loss position for more than 12 months. As of March 31, 2019, unrealized losses on available-for-sale investments are not attributed to credit risk and are considered to be temporary. The Company believes that it is more-likely-than-not that investments in an unrealized loss position will be held until maturity or the recovery of the cost basis of the investment. The Company believes it has no other-than-temporary impairments on its securities because it does not intend to sell these securities and it believes it is not more likely than not that it will be required to sell these securities before the recovery of their amortized cost basis. To date, the Company has not recorded any impairment charges on marketable securities related to other-than-temporary declines in market value.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value Measurements The Company determines the fair value of financial assets and liabilities using three levels of inputs as follows: Level 1—Inputs which include quoted prices in active markets for identical assets and liabilities. Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Recurring Fair Value Measurements The Company’s financial assets subject to fair value measurements on a recurring basis and the level of inputs used in such measurements were as follows as of March 31, 2019 and December 31, 2018 (in thousands): March 31, 2019 Description Level 1 Level 2 Level 3 Total Money market fund $ 71,368 $ — $ — $ 71,368 U.S. treasury securities — 35,809 — 35,809 Commercial paper — 49,638 — 49,638 Asset-backed securities — 27,153 — 27,153 Corporate debt securities — 46,025 — 46,025 Total assets $ 71,368 $ 158,625 $ — $ 229,993 December 31, 2018 Description Level 1 Level 2 Level 3 Total Money market fund $ 22,073 $ — $ — $ 22,073 U.S. treasury securities — 23,000 — 23,000 Commercial paper — 45,683 — 45,683 Asset-backed securities — 29,093 — 29,093 Corporate debt securities — 55,077 — 55,077 Total assets $ 22,073 $ 152,853 $ — $ 174,926 During the three months ended March 31, 2019, there were no transfers between Level 1 and Level 2 financial assets. When the Company uses observable market prices for identical securities that are traded in less active markets, the Company classifies its marketable debt instruments as Level 2. When observable market prices for identical securities are not available, the Company prices its marketable debt instruments using non-binding market consensus prices that are corroborated with observable market data; quoted market prices for similar instruments; or pricing models, such as a discounted cash flow model, with all significant inputs derived from or corroborated with observable market data. Non-binding market consensus prices are based on the proprietary valuation models of pricing providers or brokers. These valuation models incorporate a number of inputs, including non-binding and binding broker quotes; observable market prices for identical or similar securities; and the internal assumptions of pricing providers or brokers that use observable market inputs and, to a lesser degree, unobservable market inputs. The Company corroborates non-binding market consensus prices with observable market data using statistical models when observable market data exists. The discounted cash flow model uses observable market inputs, such as LIBOR-based yield curves, currency spot and forward rates, and credit ratings. Other Fair Value Measurements The carrying amount and estimated fair value of financial instruments not recorded at fair value at March 31, 2019 and December 31, 2018 were as follows (in thousands): March 31, 2019 December 31, 2018 Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value Long-term debt, net (1) $ 19,714 $ 19,954 $ 19,689 $ 19,847 (1) Carrying amounts of long-term debt were net of unamortized debt discounts of $286,000 and $311,000 as of March 31, 2019 and December 31, 2018, respectively. The fair value of the Company’s long-term debt is estimated using the net present value of future debt payments, discounted at an interest rate that is consistent with market interest rates, which is a Level 2 input.

Accrued and Other Current Liabi

Accrued and Other Current Liabilities	3 Months Ended
	Mar. 31, 2019
Payables and Accruals [Abstract]
Accrued And Other Liabilities Current Disclosure [Text Block]	5. Accrued and Other Current Liabilities Accrued and other current liabilities consist of the following (in thousands): March 31, 2019 December 31, 2018 Research and development related $ 8,220 $ 8,466 Compensation related 1,460 2,767 Consulting and professional services 779 811 Current portion of operating lease liability 1,357 — Other 1,049 925 $ 12,865 $ 12,969

Long-term Debt

Long-term Debt	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Long-term Debt	6. Long-term Debt On December 28, 2017 (the Closing Date), the Company entered into a Loan and Security Agreement with Hercules Capital, Inc. (Hercules) which the Company amended in December 2018, pursuant to which term loans in an aggregate principal amount of up to $50.0 million (the Credit Facility) are available to the Company in three tranches, subject to certain terms and conditions. As of March 31, 2019, the Company had borrowed $20.0 million under the Credit Facility with up to $25.0 million remaining available for future borrowing, subject to Hercules’ approval, through June 15, 2019. Advances under the Credit Facility bear an interest rate equal to the greater of either (i) 8.05% plus the prime rate as reported from time to time in The Wall Street Journal minus 4.75%, and (ii) 8.05%. At March 31, 2019, the interest rate on the outstanding borrowings under the Credit Facility was 8.80%. For advances made under the first and second tranches, the Company will make interest-only payments through July 1, 2021, and will then repay the principal balance and interest on the advances in equal monthly installments after the interest-only period and continuing through December 1, 2022. For advances made under the third tranche, the Company will make interest-only payments for the first 30 months, and will then repay the principal balance and interest on the advances in equal monthly installments after the interest-only period with each advance repaid 48 months after it is drawn. The Company may prepay advances under the Credit Facility, in whole or in part, at any time, subject to a prepayment charge equal to: (a) 1.5% of the amount so prepaid, if such prepayment occurs during the second year following the Closing Date; and (b) 1.0% of the amount so prepaid, if such prepayment occurs after the second year following the Closing Date. The Credit Facility is secured by substantially all of the Company’s assets, excluding intellectual property. In addition, Hercules has the right to participate, in an amount up to $2.0 million, in any subsequent equity financing broadly marketed to multiple investors in an amount greater than $20.0 million. The Credit Facility also includes customary affirmative restrictions on the payment of dividends and negative covenants, and events of default, the occurrence and continuance of which provide Hercules with the right to demand immediate repayment of all principal and unpaid interest under the Credit Facility, and to exercise remedies against the Company and the collateral securing the Credit Facility. The Company was in compliance with all loan covenants for all periods presented. The Company will pay an end-of-term charge for each tranche which will occur on the earliest of (i) the applicable tranche maturity date; (ii) the date that the Company prepays all of the outstanding principal under each tranche in full, or (iii) the date the loan payments are accelerated due to an event of default. For the first and second tranches, the end of term charge is $0.9 million and $0.3 million, respectively. In the case of the third tranche, the charge is 6.25% of the aggregate amount of the advances applicable to such tranche. In addition, the Company pays a commitment charge of 1% of the advances made under the Credit Facility, with a minimum charge of $162,500 paid on the Closing Date. Also, the Company reimbursed Hercules for costs incurred related to the Credit Facility. These charges were recorded as discounts to the carrying value of the loan and are amortized over the term of the loan using the effective interest method. As of March 31, 2019, the Company had outstanding borrowings under the Credit Facility of $19.7 million, net of discounts of $0.3 million. Future minimum principal payments, which exclude the end of term charge, related to the Credit Facility as of March 31, 2019 are as follows (in thousands): Amounts Year ending December 31: Remaining of fiscal year 2019 $ — 2020 — 2021 6,363 2022 13,637 Total minimum payments 20,000 Less: amount representing debt discount (286 ) Present value of remaining debt payments 19,714 Less: current portion — Noncurrent portion $ 19,714

Commitments

Commitments	3 Months Ended
	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments	7. Commitments Operating Leases As described further in “Note 2. Summary of Significant Accounting Policies”, the Company adopted Topic 842 as of January 1, 2019. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. In May 2004, the Company entered into a noncancelable operating lease for its current office and primary research facility located in Mountain View, California. The Company received a discounted lease rate during the first year of the agreement. In August 2012, the Company entered into an amendment to the lease agreement for the same facility to extend the term through April 2019. In April 2017, the Company entered into a second amendment to the lease agreement for the same facility to extend the term of the lease through April 2020. The balance sheet classification of the Company’s operating lease liabilities was as follows (in thousands): March 31, 2019 December 31, 2018 Accrued and other current liabilities (1) $ 1,357 $ 244 Other non-current liabilities (2) 124 143 Total lease liabilities $ 1,481 $ 387 (1) Includes current portion of operating lease liabilities as of March 31, 2019 and deferred rent as of December 31, 2018 (2) Includes non-current portion of operating lease liabilities as of March 31, 2019 and deferred rent as of December 31, 2018 The component of lease costs, which was included in operating expenses in the Company’s Condensed Consolidated Statements of Operations, was as follows (in thousands): Three Months Ended March 31, 2019 2018 Operating lease cost $ 268 $ 268 Cash paid for amounts included in the measurement of lease liabilities for the three months ended March 31, 2019 was $236,000 Future minimum lease payments under all noncancelable operating leases as of March 31, 2019 are as follows (in thousands): Operating leases Year ending December 31: Remaining of fiscal year 2019 $ 1,080 2020 501 Total minimum payments 1,581 Less: interest (100 ) Present value of lease liabilities $ 1,481 As of March 31, 2019, the weighted-average remaining lease term was 1.1 years and the weighted-average operating discount rate used to determine the operating lease liability was 11.0%.

Related-Party Transactions

Related-Party Transactions	3 Months Ended
	Mar. 31, 2019
Related Party Transactions [Abstract]
Related-Party Transactions	8. Related-Party Transactions Vifor Vifor held 10,676,825 shares of the Company’s common stock as of March 31, 2019. The Company has collaboration agreements with Vifor: the Avacopan Agreements and the . See “Note 2. Summary of Significant Accounting Policies – Concentration of Credit Risk” for additional information on accounts receivable balance due from Vifor. Avacopan Agreements In May 2016, the Company entered into an exclusive collaboration and license agreement with Vifor pursuant to which the Company granted Vifor exclusive rights to commercialize avacopan in Europe and certain other markets (the Avacopan Agreement). Avacopan is the Company’s lead drug candidate for the treatment of patients with anti-neutrophil cytoplasmic auto-antibody associated vasculitis (AAV) and other rare diseases. The Avacopan Agreement also provided Vifor with an exclusive option to negotiate during 2016 a worldwide license agreement for one of the Company’s other drug candidates, CCX140, an orally-administered inhibitor of the chemokine receptor known as CCR2. In connection with the Avacopan Agreement, the Company received a non-refundable upfront payment of $85.0 million, comprising $60.0 million in cash and $25.0 million in the form of an equity investment to purchase 3,333,333 shares of the Company’s common stock at a price of $7.50 per share. In February 2017, Vifor and the Company expanded the Vifor territories under the Avacopan Agreement to include all markets outside the United States and China (the Avacopan Amendment). In connection with this February 2017 arrangement, the Company received a $20.0 $5.0 million payment for the expanded rights. Upon achievement of certain regulatory and commercial milestones with avacopan, the Company will receive additional payments of up to $460.0 million under the Avacopan Agreement. In addition, the Company will receive royalties, with rates ranging from the low teens to the mid-twenties, on future potential net sales of avacopan by Vifor in the licensed territories. In December 2017, the Company achieved a $50.0 million regulatory milestone when the European Medicines Agency (EMA) validated the Company’s Conditional marketing authorisation (CMA) application for avacopan for the treatment of AAV. The Company identified the following material promises under the Avacopan Agreements: (1) the license related to avacopan; (2) the development and regulatory services for the submission of the marketing authorisation application (MAA); and (3) an exclusive option to negotiate a worldwide license agreement for CCX140, which expired in 2016. The Company considered that the license has standalone functionality and is capable of being distinct. However, the Company determined that the license is not distinct from the development and regulatory services within the context of the agreement because Vifor is dependent on the Company to execute the development and regulatory activities in order for Vifor to benefit from the license. As such, the license is combined with the development and regulatory services into a single performance obligation. The exclusive option related to CCX140 is a separate performance obligation and the Company determined that its transaction price is not material. As such, the transaction price under this arrangement is allocated to the license and the development and regulatory services. As of March 31, 2019, the transaction price of $153.0 million consists of the following: • $78.0 million upfront payment under the May 2016 Avacopan Agreement. Of the total $85.0 million upfront payment received under the May 2016 Avacopan Agreement, $7.0 million was allocated to the issuance of 3,333,333 shares of the Company’s common stock valued at $2.10 per share, the closing stock price on the effective date of the agreement, May 9, 2016. The remaining $78.0 million was allocated to the transaction price under this arrangement; • $20.0 million upfront payment under the February 2017 Avacopan Amendment; • $50.0 million regulatory milestone payment achieved upon the validation of the Company’s CMA application by the EMA, for avacopan for the treatment of AAV in December 2017; and • $5.0 The Company will re-evaluate the transaction price in each reporting period and as uncertain events are resolved or other changes in circumstances occur. The Company determined that the combined performance obligation will be performed over the duration of the contract, which began on the effective date of May 9, 2016 and ends upon completion of development and regulatory services. The Company uses a cost-based input method to measure proportional performance and to calculate the corresponding amount of revenue to recognize. The Company believes this is the best measure of progress because other measures do not reflect how the Company transfers its performance obligation to Vifor. In applying the cost-based input method of revenue recognition, the Company measures actual costs incurred relative to budgeted costs to fulfill the combined performance obligation. These costs consist primarily of third-party contract costs. Revenue is recognized based on actual costs incurred as a percentage of total budgeted costs as the Company completes its performance obligations. For the three months ended March 31, 2019 and 2018, the Company recognized $6.6 million and $8.2 million of collaboration and license revenue under the Avacopan Agreements, respectively. CCX140 Agreements In December 2016, the Company entered into a second collaboration and license agreement with Vifor pursuant to which the Company granted Vifor exclusive rights to commercialize CCX140 (the CCX140 Agreement) in markets outside the United States and China. CCX140 is an orally-administered inhibitor of the chemokine receptor known as CCR2. The Company retains marketing rights in the United States and China, while Vifor has commercialization rights in the rest of the world. Pursuant to the CCX140 Agreement, the Company is responsible for the clinical development of CCX140 in rare renal diseases and is reimbursed for Vifor’s equal share of such development cost. Vifor retains an option to solely develop and commercialize CCX140 in more prevalent forms of chronic kidney disease (CKD). Should Vifor later exercise the CKD option, the Company would receive co-promotion rights for CKD in the United States. Under the terms of the CCX140 Agreement, the Company received a non-refundable upfront payment of $50.0 million in 2017. In June 2018, the Company and Vifor entered into a letter agreement to expand Vifor’s rights to include the right to exclusively commercialize CCX140 in China (the CCX140 Letter Agreement). In connection with the CCX140 Letter Agreement, the Company received a non-refundable payment of $5.0 $11.5 million. The Company retains control of ongoing and future development of CCX140 (other than country-specific development in the licensed territories), and all commercialization rights to CCX140 in the United States. Upon achievement of certain regulatory and commercial milestones with CCX140, the Company will receive additional payments of up to $625.0 million under the CCX140 Agreement. In addition, the Company will receive tiered royalties, with rates ranging from ten to the mid-twenties, on net sales of CCX140 in the licensed territories. The Company identified the following material promises under the CCX140 Agreements: (1) the license related to CCX140; and (2) the development and regulatory services for the submission of the MAA . The Company considered that the license has standalone functionality and is capable of being distinct. However, the Company determined that the license is not distinct from the development and regulatory services within the context of the agreement because Vifor is dependent on the Company to execute the development and regulatory activities in order for Vifor to benefit from the license. As such, the license is combined with the development and regulatory services into a single performance obligation. As of March 31, 2019, the transaction price of $113.5 million consists of the following: • $50.0 • $58.5 million of CCX140 development funding by Vifor; and • $5.0 The Company will re-evaluate the transaction price in each reporting period and as uncertain events are resolved or other changes in circumstances occur. The Company determined that the combined performance obligation will be performed over the duration of the contract, which began on the effective date of December 22, 2016 and ends upon completion of development and regulatory services. The Company uses a cost-based input method to measure proportional performance and to calculate the corresponding amount of revenue to recognize. The Company believes this is the best measure of progress because other measures do not reflect how the Company transfers its performance obligation to Vifor. In applying the cost-based input method of revenue recognition, the Company measures actual costs incurred relative to budgeted costs to fulfill the combined performance obligation. These costs consist primarily of third-party contract costs. Revenue is recognized based on actual costs incurred as a percentage of total budgeted costs as the Company completes its performance obligations. For the three months ended March 31, 2019 and 2018, the Company recognized $1.7 million and $1.3 million of collaboration and license revenue under the CCX140 Agreements, respectively. The following table presents the contract assets and liabilities for all of the Company’s revenue contracts as of the following dates (in thousands): March 31, 2019 December 31, 2018 Contract asset: Accounts receivable $ 167 $ 2,058 Contract liability: Deferred revenue (126,401 ) (134,561 ) During the three months ended March 31, 2019, the Company recognized the following revenue as a result of changes in the contract asset and the contract liability balances (in thousands): Three Months Ended March 31, 2019 Revenue recognized in the period from: Amount included in contract liability at the beginning of the period $ 8,160 Performance obligations satisfied (or partially satisfied) in previous periods $ (896 )

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stockholders' Equity	9. Stockholders’ Equity Stock Options During the three months ended March 31, 2019, the Company had the following activities under its equity incentive plans: Available for Grant Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Balance at December 31, 2018 1,708,516 10,720,200 $ 8.39 Shares authorized 2,000,000 — Granted (1) (1,529,886 ) 1,384,133 11.44 Exercised (2) 107,619 (485,012 ) 5.88 Forfeited and expired (3) 584,832 (578,165 ) 6.85 Outstanding at March 31, 2019 2,871,081 11,041,156 $ 8.96 6.40 $ 55,107,905 Vested and expected to vest, net of estimated forfeiture at March 31, 2019 10,648,497 $ 8.91 6.29 $ 53,745,822 Exercisable at March 31, 2019 7,200,618 $ 8.56 5.00 $ 39,078,897 (1) The difference between shares granted in the number of shares available for grant and outstanding options represents the RSUs and RSAs granted for the period. (2) Shares presented as available for grant represents shares repurchased for tax withholding upon vesting of RSUs. (3) The difference between shares forfeited and expired in the number of shares available for grant and outstanding options represents the RSUs canceled during the period. Restricted Stock During the three months ended March 31, 2019, the activity for restricted stock is summarized as follows: Shares Weighted Average Grant-Date Fair Value Balance at December 31, 2018 467,632 $ 8.47 Granted 145,753 11.23 Vested (205,088 ) 7.38 Canceled (6,667 ) 10.86 Unvested at March 31, 2019 401,630 $ 9.99 Stock-based Compensation Total stock-based compensation expense was $2.7 million and $2.5 million during the three months ended March 31, 2019 and 2018, respectively. As of March 31, 2019, $19.4 million, $2.7 million and $38,000 of total unrecognized compensation expenses associated with outstanding employee stock options, unvested restricted stock, and the ESPP, net of estimated forfeitures, were expected to be recognized over a weighted-average period of 2.74, 1.66 and 0.12 years, respectively. Equity Distribution Agreement In December 2018, $0.001 per share, having an aggregate offering price of up to $75.0 million. For the three months ended March 31, 2019, the Company sold 6,491,196 shares of its common stock pursuant to its EDA for net proceeds of $73.3 million. These sales fully exhausted the amount available under the EDA. Accordingly, no further sales will be made under the EDA.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States (GAAP) requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from these estimates.
Concentration of Credit Risk	Concentration of Credit Risk The Company invests in a variety of financial instruments and, by its policy, limits the amount of credit exposure with any one issuer, industry or geographic area. Accounts receivable are typically unsecured and are concentrated in the pharmaceutical industry and government sector. Accordingly, the Company may be exposed to credit risk generally associated with pharmaceutical companies and government funded entities. The Company has not historically experienced any significant losses due to concentration of credit risk. Accounts receivable consists of the following (in thousands): March 31, 2019 December 31, 2018 Vifor (International) Ltd., and/or its affiliates, or collectively, Vifor $ 167 $ 2,058
Net Loss Per Share	Net Loss Per Share Basic net loss per common share is computed by dividing net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration for common stock equivalents. Diluted net loss per share is computed by dividing net loss attributable to common stockholders by the sum of the weighted-average number of common shares outstanding and dilutive common stock equivalent shares outstanding for the period. The Company’s potentially dilutive common stock equivalent shares, which include incremental common shares issuable upon (i) the exercise of outstanding stock options and warrants, (ii) vesting of restricted stock units (RSUs) and restricted stock awards (RSAs), and (iii) the purchase from contributions to the 2012 Employee Stock Purchase Plan (the ESPP), (calculated based on the treasury stock method), are only included in the calculation of diluted net loss per share when their effect is dilutive. For the three months ended March 31, 2019 and 2018, the following potentially dilutive securities were excluded from the calculation of diluted net loss per share due to their anti-dilutive effect: Three Months Ended March 31, 2019 2018 Options to purchase common stock, including purchases from contributions to ESPP 11,073,806 11,824,877 Restricted stock units 374,352 459,682 Restricted stock awards 27,278 85,431 Warrants to purchase common stock 150,000 150,000 11,625,436 12,519,990
Comprehensive Loss	Comprehensive Loss Comprehensive loss comprises net loss and other comprehensive loss. For the periods presented, other comprehensive loss consists of unrealized gains and losses on the Company’s available-for-sale securities. For the three months ended March 31, 2019, amounts reclassified from accumulated other comprehensive loss to net loss for unrealized gains (losses) on available-for-sale securities were not significant, and were recorded as part of other income, net in the Condensed Consolidated Statements of Operations. For the three months ended March 31, 2018, there were no sales of investments and therefore there were no reclassifications.
Lease, Policy	Leases The Company determines if an arrangement includes a lease at inception. Operating leases are included in operating lease right-of-use (ROU) assets, accrued and other current liabilities and other non-current liabilities on the Company’s Condensed Consolidated Balance Sheets. Operating lease ROU assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. The Company uses the incremental borrowing rate based on the information available at lease commencement date in determining the present value of future payments. The operating lease ROU asset also excludes lease incentives. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise any such options. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. The Company has elected not to apply the recognition requirements for short-term leases. For lease agreements with lease and non-lease components, the Company generally accounts for them separately.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In February 2016, the Financial Accounting Standard Board (FASB) issued Accounting Standards Update (ASU) No. 2016-02, Leases (Topic 842). The new standard requires the Company to recognize the assets and liabilities that arise from leases on the balance sheet and disclose qualitative and quantitative information about its leasing arrangements. On January 1, 2019, the Company adopted this new standard using the modified retrospective approach in accordance with Leases – Targeted Improvements (ASU No. 2018-11). The Company elected the package of practical expedients permitted under the transition guidance within ASU No. 2018-11, which among other things, allowed the Company to carry forward the historical lease classification of those leases in place as of January 1, 2019. Results for the three months ended March 31, 2019 are presented under Topic 842. Prior period amounts have not been adjusted and continue to be reported in accordance with the Company’s historical accounting under previous lease guidance, ASC Topic 840, Leases (Topic 840). The impact of the adoption of Topic 842 on the accompanying Condensed Consolidated Balance Sheet as of January 1, 2019 was as follows (in thousands): December 31, 2018 Adjustments Due to the Adoption of Topic 842 January 1, 2019 Balance Sheet Assets: Operating lease right-of-use assets $ — $ 1,301 $ 1,301 Liabilities: Operating lease liabilities: Accrued and other current liabilities (1) 12,969 955 13,924 Other non-current liabilities (2) 387 346 733 (1) Includes deferred rent and current portion of operating lease liabilities (2) Includes deferred rent and non-current portion of operating lease liabilities In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments. The new standard replaces the incurred loss impairment methodology under the current standard 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. The Company will be required to use a forward-looking expected credit loss model for accounts receivables and other financial instruments. Credit losses relating to available-for-sale debt securities will also be recorded through an allowance for credit losses rather than as a reduction in the amortized cost basis of the securities. The new standard will be effective for the Company on January 1, 2020, with early adoption permitted on January 1, 2019. The Company is currently evaluating the impact of the adoption of this standard on its financial statements and does not expect the adoption of this accounting guidance to have a material impact on the consolidated financial statements. In June 2018, the FASB issued ASU No. 2018-07, Compensation – Stock Compensation (Topic 718). The new standard simplifies the accounting for share-based payments to nonemployees by aligning it with the accounting for share-based payments to employees, with certain exceptions. The Company adopted this new standard on January 1, 2019. The adoption of this accounting guidance did not have a material impact on the consolidated financial statements. The Company has reviewed other recent accounting pronouncements and concluded they are either not applicable to the business or that no material effect is expected on the consolidated financial statements as a result of future adoption. In August 2018, the SEC adopted amendments to certain disclosure requirements in Securities Act Release No. 33-10532, Form 10-Q. The analysis, which can be presented as a footnote or separate statement, is required for the current and comparative quarter and year-to-date interim periods. March 31, 2019. The adoption of these SEC amendments did not have a material effect on the Company’s financial position, results of operations, cash flows or stockholders’ equity.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Summary of Accounts Receivable	Accounts receivable consists of the following (in thousands): March 31, 2019 December 31, 2018 Vifor (International) Ltd., and/or its affiliates, or collectively, Vifor $ 167 $ 2,058
Potentially Dilutive Securities Excluded from Calculation of Diluted Net Income (Loss) per Share Due to Anti-Dilutive Effect	For the three months ended March 31, 2019 and 2018, the following potentially dilutive securities were excluded from the calculation of diluted net loss per share due to their anti-dilutive effect: Three Months Ended March 31, 2019 2018 Options to purchase common stock, including purchases from contributions to ESPP 11,073,806 11,824,877 Restricted stock units 374,352 459,682 Restricted stock awards 27,278 85,431 Warrants to purchase common stock 150,000 150,000 11,625,436 12,519,990
Schedule of Impact of Adoption on Consolidated Statement of Operations and Balance Sheet	The impact of the adoption of Topic 842 on the accompanying Condensed Consolidated Balance Sheet as of January 1, 2019 was as follows (in thousands): December 31, 2018 Adjustments Due to the Adoption of Topic 842 January 1, 2019 Balance Sheet Assets: Operating lease right-of-use assets $ — $ 1,301 $ 1,301 Liabilities: Operating lease liabilities: Accrued and other current liabilities (1) 12,969 955 13,924 Other non-current liabilities (2) 387 346 733 (1) Includes deferred rent and current portion of operating lease liabilities (2) Includes deferred rent and non-current portion of operating lease liabilities

Cash Equivalents and Investme_2

Cash Equivalents and Investments (Tables)	3 Months Ended
	Mar. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Amortized Cost and Fair Value of Cash Equivalents and Investments	The amortized cost and fair value of cash equivalents and investments at March 31, 2019 and December 31, 2018 were as follows (in thousands): March 31, 2019 Amortized Gross Unrealized Fair Cost Gains Losses Value Money market fund $ 71,368 $ — $ — $ 71,368 U.S. treasury securities 35,798 12 (1 ) 35,809 Commercial paper 49,638 — — 49,638 Asset-backed securities 27,147 6 — 27,153 Corporate debt securities 46,046 20 (41 ) 46,025 Total available-for-sale securities $ 229,997 $ 38 $ (42 ) $ 229,993 Classified as: Cash equivalents $ 75,248 Short-term investments 142,777 Long-term investments 11,968 Total available-for-sale securities $ 229,993 December 31, 2018 Amortized Gross Unrealized Fair Cost Gains Losses Value Money market fund $ 22,073 $ — $ — $ 22,073 U.S. treasury securities 23,013 — (13 ) 23,000 Commercial paper 45,683 — — 45,683 Asset-backed securities 29,127 — (34 ) 29,093 Corporate debt securities 55,228 — (151 ) 55,077 Total available-for-sale securities $ 175,124 $ — $ (198 ) $ 174,926 Classified as: Cash equivalents $ 26,030 Short-term investments 148,896 Long-term investments — Total available-for-sale securities $ 174,926

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements of Company's Financial Assets	The Company’s financial assets subject to fair value measurements on a recurring basis and the level of inputs used in such measurements were as follows as of March 31, 2019 and December 31, 2018 (in thousands): March 31, 2019 Description Level 1 Level 2 Level 3 Total Money market fund $ 71,368 $ — $ — $ 71,368 U.S. treasury securities — 35,809 — 35,809 Commercial paper — 49,638 — 49,638 Asset-backed securities — 27,153 — 27,153 Corporate debt securities — 46,025 — 46,025 Total assets $ 71,368 $ 158,625 $ — $ 229,993 December 31, 2018 Description Level 1 Level 2 Level 3 Total Money market fund $ 22,073 $ — $ — $ 22,073 U.S. treasury securities — 23,000 — 23,000 Commercial paper — 45,683 — 45,683 Asset-backed securities — 29,093 — 29,093 Corporate debt securities — 55,077 — 55,077 Total assets $ 22,073 $ 152,853 $ — $ 174,926
Summary of Carrying Amount And Estimated Fair Value of Financial Instruments	The carrying amount and estimated fair value of financial instruments not recorded at fair value at March 31, 2019 and December 31, 2018 were as follows (in thousands): March 31, 2019 December 31, 2018 Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value Long-term debt, net (1) $ 19,714 $ 19,954 $ 19,689 $ 19,847 (1) Carrying amounts of long-term debt were net of unamortized debt discounts of $286,000 and $311,000 as of March 31, 2019 and December 31, 2018, respectively.

Accrued and Other Current Lia_2

Accrued and Other Current Liabilities (Tables)	3 Months Ended
	Mar. 31, 2019
Payables and Accruals [Abstract]
Schedule of Accrued And Other Liabilities Current [Table Text Block]	Accrued and other current liabilities consist of the following (in thousands): March 31, 2019 December 31, 2018 Research and development related $ 8,220 $ 8,466 Compensation related 1,460 2,767 Consulting and professional services 779 811 Current portion of operating lease liability 1,357 — Other 1,049 925 $ 12,865 $ 12,969

Long-term Debt (Tables)

Long-term Debt (Tables)	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Schedule of Future Minimum Principal Payments Related to the Credit Facility	Future minimum principal payments, which exclude the end of term charge, related to the Credit Facility as of March 31, 2019 are as follows (in thousands): Amounts Year ending December 31: Remaining of fiscal year 2019 $ — 2020 — 2021 6,363 2022 13,637 Total minimum payments 20,000 Less: amount representing debt discount (286 ) Present value of remaining debt payments 19,714 Less: current portion — Noncurrent portion $ 19,714

Commitments (Tables)

Commitments (Tables)	3 Months Ended
	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Schedule of balance Sheet Classification of Operating LeaseTable Text Block	The balance sheet classification of the Company’s operating lease liabilities was as follows (in thousands): March 31, 2019 December 31, 2018 Accrued and other current liabilities (1) $ 1,357 $ 244 Other non-current liabilities (2) 124 143 Total lease liabilities $ 1,481 $ 387
Lease, Cost [Table Text Block]	The component of lease costs, which was included in operating expenses in the Company’s Condensed Consolidated Statements of Operations, was as follows (in thousands): Three Months Ended March 31, 2019 2018 Operating lease cost $ 268 $ 268
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	Future minimum lease payments under all noncancelable operating leases as of March 31, 2019 are as follows (in thousands): Operating leases Year ending December 31: Remaining of fiscal year 2019 $ 1,080 2020 501 Total minimum payments 1,581 Less: interest (100 ) Present value of lease liabilities $ 1,481

Related-Party Transactions (Tab

Related-Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2019
Related Party Transactions [Abstract]
Schedule of Contract Assets and Liabilities and Changes in Contract Balances	The following table presents the contract assets and liabilities for all of the Company’s revenue contracts as of the following dates (in thousands): March 31, 2019 December 31, 2018 Contract asset: Accounts receivable $ 167 $ 2,058 Contract liability: Deferred revenue (126,401 ) (134,561 ) During the three months ended March 31, 2019, the Company recognized the following revenue as a result of changes in the contract asset and the contract liability balances (in thousands): Three Months Ended March 31, 2019 Revenue recognized in the period from: Amount included in contract liability at the beginning of the period $ 8,160 Performance obligations satisfied (or partially satisfied) in previous periods $ (896 )

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option Activity under its Stock Plans	During the three months ended March 31, 2019, the Company had the following activities under its equity incentive plans: Available for Grant Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Balance at December 31, 2018 1,708,516 10,720,200 $ 8.39 Shares authorized 2,000,000 — Granted (1) (1,529,886 ) 1,384,133 11.44 Exercised (2) 107,619 (485,012 ) 5.88 Forfeited and expired (3) 584,832 (578,165 ) 6.85 Outstanding at March 31, 2019 2,871,081 11,041,156 $ 8.96 6.40 $ 55,107,905 Vested and expected to vest, net of estimated forfeiture at March 31, 2019 10,648,497 $ 8.91 6.29 $ 53,745,822 Exercisable at March 31, 2019 7,200,618 $ 8.56 5.00 $ 39,078,897 (1) The difference between shares granted in the number of shares available for grant and outstanding options represents the RSUs and RSAs granted for the period. (2) Shares presented as available for grant represents shares repurchased for tax withholding upon vesting of RSUs. (3) The difference between shares forfeited and expired in the number of shares available for grant and outstanding options represents the RSUs canceled during the period.
Restricted Stock Activity	During the three months ended March 31, 2019, the activity for restricted stock is summarized as follows: Shares Weighted Average Grant-Date Fair Value Balance at December 31, 2018 467,632 $ 8.47 Granted 145,753 11.23 Vested (205,088 ) 7.38 Canceled (6,667 ) 10.86 Unvested at March 31, 2019 401,630 $ 9.99

Description of Business - Addit

Description of Business - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of operating segment	1

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Summary of Accounts Receivable (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Vifor [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 167	$ 2,058

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Potentially Dilutive Securities Excluded from Calculation of Diluted Net Income (Loss) per Share Due to Anti-Dilutive Effect (Detail) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	11,625,436	12,519,990
Options to Purchase Common Stock, Including Purchases from Contributions to ESPP [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	11,073,806	11,824,877
Unvested Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	374,352	459,682
Restricted Stock Awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	27,278	85,431
Warrants to Purchase Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	150,000	150,000

Summary Of Significant Accoun_6

Summary Of Significant Accounting Policies - Schedule Of Impact Of Accompanying Consolidated Statement of Balance Sheet (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Assets:
Operating lease right-of-use assets	$ 1,062	$ 1,301	$ 0
Operating lease liabilities:
Accrued and other current liabilities	12,865	13,924	12,969
Other non-current liabilities	$ 445	733	$ 387
Accounting Standards Update 2016-02 [Member]
Assets:
Operating lease right-of-use assets		1,301
Accounting Standards Update 2016-02 [Member] | Accrued and other current liabilities [Member]
Operating lease liabilities:
Accrued and other current liabilities		955
Accounting Standards Update 2016-02 [Member] | Other non-current liabilities [Member]
Operating lease liabilities:
Other non-current liabilities		$ 346

Cash Equivalents and Investme_3

Cash Equivalents and Investments - Amortized Cost and Fair Value of Cash Equivalents and Investments (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 229,997	$ 175,124
Gross Unrealized Gains	38	0
Gross Unrealized Losses	(42)	(198)
Available-for-sale Securities	229,993	174,926
Money Market Fund [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	71,368	22,073
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Available-for-sale Securities	71,368	22,073
U.S. Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	35,798	23,013
Gross Unrealized Gains	12	0
Gross Unrealized Losses	(1)	(13)
Available-for-sale Securities	35,809	23,000
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	49,638	45,683
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Available-for-sale Securities	49,638	45,683
Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	27,147	29,127
Gross Unrealized Gains	6	0
Gross Unrealized Losses	0	(34)
Available-for-sale Securities	27,153	29,093
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	46,046	55,228
Gross Unrealized Gains	20	0
Gross Unrealized Losses	(41)	(151)
Available-for-sale Securities	$ 46,025	$ 55,077

Cash Equivalents and Investme_4

Cash Equivalents and Investments - Amortized Cost and Fair Value of Cash Equivalents and Investments 2 (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Cash and Cash Equivalents [Abstract]
Cash equivalents	$ 75,248	$ 26,030
Short-term investments	142,777	148,896
Long-term investments	11,968	0
Total available-for-sale securities	$ 229,993	$ 174,926

Cash Equivalents and Investme_5

Cash Equivalents and Investments - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2019USD ($)Investment	Dec. 31, 2018USD ($)
Cash and Cash Equivalents [Abstract]
Maturity period available-for-sale securities	less than two years
Significant realized gains or losses on available-for-sale securities	$ 0
Cash	$ 4,100,000	$ 2,100,000
Number of available-for-sale securities in a continuous unrealized loss position for more than 12 months | Investment	0
Number of available-for-sale securities in a continuous unrealized loss position for more than 12 months	$ 0

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Measurements of Company's Financial Assets (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	$ 229,993	$ 174,926
Money Market Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	71,368	22,073
U.S. Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	35,809	23,000
Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	49,638	45,683
Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	27,153	29,093
Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	46,025	55,077
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	71,368	22,073
Level 1 [Member] | Money Market Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	71,368	22,073
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	158,625	152,853
Level 2 [Member] | U.S. Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	35,809	23,000
Level 2 [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	49,638	45,683
Level 2 [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	27,153	29,093
Level 2 [Member] | Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	$ 46,025	$ 55,077

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail)	Mar. 31, 2019USD ($)
Fair Value Disclosures [Abstract]
Transfers from Level 1 to Level 2 financial assets	$ 0
Transfers from Level 2 to Level 1 financial assets	$ 0

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Carrying Amount and Estimated Fair Value of Financial Instruments (Detail) - Term Loan [Member] - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Amount	$ 19,714	$ 19,689
Estimated Fair Value	$ 19,954	$ 19,847

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Carrying Amount and Estimated Fair Value of Financial Instruments (Parenthetical) (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Term Loan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unamortized debt discounts	$ 286	$ 311

Accrued and Other Current Lia_3

Accrued and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Payables and Accruals [Abstract]
Research and development related	$ 8,220		$ 8,466
Compensation related	1,460		2,767
Consulting and professional services	779		811
Current portion of operating lease liability	1,357
Current portion of operating lease liability			0
Other	1,049		925
Accrued liabilities	$ 12,865	$ 13,924	$ 12,969

Long-term Debt - Additional Inf

Long-term Debt - Additional Information (Detail) - USD ($)	Dec. 28, 2017	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Line of credit facility, advance amount		$ 20,000,000
Line of credit facility, interest rate	8.05%
Line of credit facility, interest rate description		Advances under the Credit Facility bear an interest rate equal to the greater of either (i) 8.05% plus the prime rate as reported from time to time in The Wall Street Journal minus 4.75%, and (ii) 8.05%. At March 31, 2019, the interest rate on the outstanding borrowings under the Credit Facility was 8.80%. For advances made under the first and second tranches, the Company will make interest-only payments through July 1, 2021, and will then repay the principal balance and interest on the advances in equal monthly installments after the interest-only period and continuing through December 1, 2022. For advances made under the third tranche, the Company will make interest-only payments for the first 30 months, and will then repay the principal balance and interest on the advances in equal monthly installments after the interest-only period with each advance repaid 48 months after it is drawn.
Proceeds from issuance of common stock		$ 73,276,000
Term Loan [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 50,000,000
Line of credit facility, current borrowing capacity		$ 25,000,000
Line of credit facility, interest rate		8.80%
Line of credit facility, prepayment description	The Company may prepay advances under the Credit Facility, in whole or in part, at any time, subject to a prepayment charge equal to: (a) 1.5% of the amount so prepaid, if such prepayment occurs during the second year following the Closing Date; and (b) 1.0% of the amount so prepaid, if such prepayment occurs after the second year following the Closing Date. The Credit Facility is secured by substantially all of the Company’s assets, excluding intellectual property.
Loan commitment charge, percentage	1.00%
Borrowings outstanding		$ 19,714,000	$ 19,689,000
Discount on borrowings		$ 286,000	$ 311,000
Term Loan [Member] | Minimum [Member]
Debt Instrument [Line Items]
Aggregate proceeds to be received from equity offering	$ 20,000,000
Loan commitment charge	162,500
Hercules Capital Inc [Member] | Term Loan [Member] | Maximum [Member]
Debt Instrument [Line Items]
Proceeds from issuance of common stock	2,000,000
Tranche One [Member] | Term Loan [Member]
Debt Instrument [Line Items]
End of term charge amount for loan	900,000
Tranche Two And Tranche Three [Member] | Term Loan [Member]
Debt Instrument [Line Items]
End of term charge amount for loan	$ 300,000
End of term charge for loan	The charge is 6.25% of the aggregate amount of the advances applicable to such tranche.
End of term charge for loan, percentage	6.25%

Long-term Debt - Schedule of Fu

Long-term Debt - Schedule of Future Minimum Principal Payments Related to the Credit Facility (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Long-term debt, Non current portion	$ 19,714	$ 19,689
Term Loan [Member]
Debt Instrument [Line Items]
Remaining of fiscal year 2019	0
2020	0
2021	6,363
2022	13,637
Total minimum payments	20,000
Less: amount representing debt discount	(286)	(311)
Long-term debt, net	19,714	$ 19,689
Less: current portion	0
Long-term debt, Non current portion	$ 19,714

Commitments - Schedule of Balan

Commitments - Schedule of Balance Sheet Classification of our Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Total operating lease liabilities	$ 1,357
Total operating lease liabilities		$ 0
Total operating lease liabilities	1,481
Total operating lease liabilities		387
Accrued And Other Liabilities Current [Member]
Total operating lease liabilities	1,357
Total operating lease liabilities		244
Other Noncurrent Liabilities [Member]
Total operating lease liabilities	$ 124
Total operating lease liabilities		$ 143

Commitments - Schedule of Opera

Commitments - Schedule of Operating Expenses in the Company's Condensed Consolidated Statements of Operations (Details 1) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating lease cost	$ 268	$ 268

Commitments - Schedule of Futur

Commitments - Schedule of Future Minimum Lease Payments Under all Noncancelable Operating Leases (Details 2) $ in Thousands	Mar. 31, 2019USD ($)
Remaining of fiscal year 2019	$ 1,080
2020	501
Total minimum payments	1,581
Less: interest	(100)
Present value of lease liabilities	$ 1,481

Commitments - Additional Inform

Commitments - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2019USD ($)
Operating Leased Assets [Line Items]
Discounted lease	The Company received a discounted lease rate during the first year of the agreement.
Operating Lease, Weighted Average Remaining Lease Term	1 year 1 month 6 days
Operating Lease, Weighted Average Discount Rate, Percent	11.00%
Operating Lease, Payments	$ 236,000
First Amendment August 2012 [Member]
Operating Leased Assets [Line Items]
Expiration date	2019-04
Second Amendment April 2017 [Member]
Operating Leased Assets [Line Items]
Expiration date	2020-04

Related-Party Transactions - Ad

Related-Party Transactions - Additional Information (Detail) - USD ($)	Jan. 01, 2018	Dec. 28, 2017	Jun. 30, 2018	Dec. 31, 2017	Feb. 28, 2017	May 31, 2016	Mar. 31, 2019	Mar. 31, 2018
Related Party Transaction [Line Items]
Non refundable upfront payments received						$ 85,000,000
Non refundable upfront payment received in equity investment, shares						3,333,333
Performance obligations satisfied (or partially satisfied) in previous periods							$ (896,000)
Upfront payments received						$ 78,000,000
Non refundable upfront payments allocated for issuance of common stock						$ 7,000,000
Issuance of common stock, per share value						$ 2.10
Collaboration and license revenue from related party							8,327,000	$ 9,546,000
Avacopan Agreement [Member]
Related Party Transaction [Line Items]
Non refundable upfront payments received						$ 85,000,000
Non refundable upfront payment received in cash						60,000,000
Non refundable upfront payment received in equity investment						$ 25,000,000
Share price of common stock in equity investment						$ 7.50
Non refundable upfront payment received in equity investment, shares						3,333,333
Performance obligations satisfied (or partially satisfied) in previous periods				$ 50,000,000
Transaction price							153,000,000
Collaboration and license revenue from related party							6,600,000	8,200,000
Avacopan Amendment [Member]
Related Party Transaction [Line Items]
Non refundable upfront payments received							20,000,000
Upfront cash commitment					$ 20,000,000
Avacopan Letter Agreement [Member]
Related Party Transaction [Line Items]
Non refundable payment for expanded rights		$ 5,000,000	$ 5,000,000
CCX140 Agreement [Member]
Related Party Transaction [Line Items]
Non refundable payment for expanded rights			$ 5,000,000				5,000,000	5,000,000
Transaction price							113,500,000
Upfront payments received	$ 50,000,000						50,000,000
Collaboration and license revenue from related party							1,700,000	$ 1,300,000
Non refundable upfront commitment				$ 50,000,000			11,500,000
CCX140 Agreement [Member] | Vifor [Member]
Related Party Transaction [Line Items]
Development funding							58,500,000
Maximum [Member] | Avacopan Agreement [Member]
Related Party Transaction [Line Items]
Potential milestone payments receivable							460,000,000
Maximum [Member] | CCX140 Agreement [Member]
Related Party Transaction [Line Items]
Potential milestone payments receivable							$ 625,000,000

Related-Party Transactions - Sc

Related-Party Transactions - Schedule of Contract Assets and Liabilities and Changes in Contract Balances (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Accounts Receivable Net [Member]
Contract asset:
Contract asset	$ 167	$ 2,058
Deferred Revenue [Member]
Contract liability:
Contract liability	$ (126,401)	$ (134,561)

Related-Party Transactions - _2

Related-Party Transactions - Schedule of Contract Assets and Liabilities Changes (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Contract with Customer Asset and Liability [Line Items]
Amount included in contract liability at the beginning of the period	$ 8,160
Performance obligations satisfied (or partially satisfied) in previous periods	$ (896)

Stockholders' Equity - Stock Op

Stockholders' Equity - Stock Options - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, Par or Stated Value Per Share	$ 0.001		$ 0.001
Stock Issued During Period, Shares, New Issues	6,491,196
Proceeds from Issuance of Common Stock	$ 73,276,000
Equity Distribution Agreement [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity Distribution Agreement Aggregate Offering Price	75,000,000
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expenses	$ 38,000
Unrecognized compensation expense, weighted-average period	1 month 13 days
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expenses	$ 19,400,000
Unrecognized compensation expense, weighted-average period	2 years 8 months 26 days
Allocated Share-based Compensation Expense	$ 2,700,000	$ 2,500,000
Restricted Stocks [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expenses	$ 2,700,000
Unrecognized compensation expense, weighted-average period	1 year 7 months 27 days

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Stock Option Activity under its Stock Plans (Detail)	3 Months Ended
	Mar. 31, 2019USD ($)$ / sharesshares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shares Available for Grant, Outstanding Beginning Balance	1,708,516
Available for Grant, Shares authorized	2,000,000
Shares Available for Grant, Granted	(1,529,886)
Shares Available for Grant, Exercised	107,619
Shares Available for Grant, Forfeited and expired	584,832
Shares Available for Grant, Outstanding Ending Balance	2,871,081
Shares, Options Outstanding, Beginning Balance	10,720,200
Shares, Options Outstanding, authorized	0
Shares, Options Outstanding, Granted	1,384,133
Shares, Options Outstanding, Exercised	(485,012)
Shares, Options Outstanding, Forfeited and expired	(578,165)
Shares, Options Outstanding, Ending Balance	11,041,156
Shares, Vested and expected to vest, net of estimated forfeiture at March 31, 2019	10,648,497
Shares, Exercisable at March 31, 2019	7,200,618
Weighted Average Exercise Price, Options Outstanding, Beginning Balance | $ / shares	$ 8.39
Weighted Average Exercise Price, Options Outstanding, Granted | $ / shares	11.44
Weighted Average Exercise Price, Options Outstanding, Exercised | $ / shares	5.88
Weighted Average Exercise Price, Options Outstanding, Forfeited and expired | $ / shares	6.85
Weighted Average Exercise Price, Options Outstanding, Ending Balance | $ / shares	8.96
Weighted Average Exercise Price, Vested and expected to vest, net of estimated forfeiture at March 31, 2019 | $ / shares	8.91
Weighted Average Exercise Price, Exercisable at March 31, 2019 | $ / shares	$ 8.56
Options Outstanding, Weighted Average Remaining Contractual Term	6 years 4 months 24 days
Weighted Average Remaining Contractual Term, Vested and expected to vest, net of estimated forfeiture at March 31, 2019	6 years 3 months 14 days
Weighted Average Remaining Contractual Term, Exercisable at March 31, 2019	5 years
Aggregate Intrinsic Value, Outstanding, Ending Balance | $	$ 55,107,905
Aggregate Intrinsic Value, Vested and expected to vest, net of estimated forfeiture at March 31, 2019 | $	53,745,822
Aggregate Intrinsic Value, Exercisable at March 31, 2019 | $	$ 39,078,897

Stockholders' Equity - Restrict

Stockholders' Equity - Restricted Stock Activity (Detail) - Restricted Stocks [Member]	3 Months Ended
	Mar. 31, 2019$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Unvested, Beginning Balance | shares	467,632
Shares, Granted | shares	145,753
Shares, Vested | shares	(205,088)
Shares, Canceled | shares	(6,667)
Shares, Unvested, Ending Balance | shares	401,630
Weighted Average Grant-Date Fair Value, Unvested, Beginning Balance | $ / shares	$ 8.47
Weighted Average Grant-Date Fair Value, Granted | $ / shares	11.23
Weighted Average Grant-Date Fair Value, Vested | $ / shares	7.38
Weighted Average Grant-Date Fair Value, Canceled | $ / shares	10.86
Weighted Average Grant-Date Fair Value, Unvested, Ending Balance | $ / shares	$ 9.99