Gyre Therapeutics (GYRE) 10-Q 5 Nov 20 2020 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2020	Oct. 29, 2020
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Trading Symbol	CBIO
Entity Registrant Name	Catalyst Biosciences, Inc.
Entity Central Index Key	0001124105
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		22,097,820
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	000-51173
Entity Tax Identification Number	56-2020050
Entity Address, Address Line One	611 Gateway Blvd.
Entity Address, Address Line Two	Suite 710
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	650
Local Phone Number	871-0761
Entity Interactive Data Current	Yes
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false
Title of 12(b) Security	Common Stock

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 24,923	$ 15,369
Short-term investments	77,959	61,496
Accounts receivable	1,555	15,000
Prepaid and other current assets	3,535	4,201
Total current assets	107,972	96,066
Long-term investments	1,171
Other assets, noncurrent	698	257
Right-of-use assets	1,524	1,927
Property and equipment, net	439	304
Total assets	111,804	98,554
Current liabilities:
Accounts payable	4,244	4,279
Accrued compensation	2,543	2,106
Deferred revenue	764	15,000
Other accrued liabilities	8,750	7,031
Operating lease liability	519	483
Total current liabilities	16,820	28,899
Operating lease liability, noncurrent	925	1,319
Total liabilities	17,745	30,218
Stockholders’ equity:
Preferred stock, $0.001 par value, 5,000,000 shares authorized; zero shares issued and outstanding
Common stock, $0.001 par value, 100,000,000 shares authorized; 22,082,924 and 12,040,835 shares issued and outstanding at September 30, 2020 and December 31, 2019, respectively	22	12
Additional paid-in capital	389,883	326,810
Accumulated other comprehensive income	8	34
Accumulated deficit	(295,854)	(258,520)
Total stockholders’ equity	94,059	68,336
Total liabilities and stockholders’ equity	$ 111,804	$ 98,554

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	22,082,924	12,040,835
Common stock, shares outstanding	22,082,924	12,040,835

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
License and collaboration revenue	$ 893		$ 18,917
Operating expenses:
Total operating expenses	16,993	$ 13,195	57,446	$ 43,290
Research and development	12,249	9,927	38,419	33,066
General and administrative	3,833	3,268	11,895	10,224
Loss from operations	(16,100)	(13,195)	(38,529)	(43,290)
Interest and other income, net	67	489	1,195	1,722
Net loss	$ (16,033)	$ (12,706)	$ (37,334)	$ (41,568)
Net loss per share attributable to common stockholders, basic and diluted	$ (0.73)	$ (1.06)	$ (2.05)	$ (3.47)
Shares used to compute net loss per share attributable to common stockholders, basic and diluted	22,072,243	12,022,620	18,199,575	11,992,240
License
License and collaboration revenue	$ 32		$ 15,100
Collaboration
License and collaboration revenue	861		3,817
Cost of license
Operating expenses:
Total operating expenses	32		3,102
Cost of collaboration
Operating expenses:
Total operating expenses	$ 879		$ 4,030

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (16,033)	$ (12,706)	$ (37,334)	$ (41,568)
Other comprehensive (loss) income:
Unrealized (loss) gain on available-for-sale debt securities	(33)	(26)	(26)	35
Total comprehensive loss	$ (16,066)	$ (12,732)	$ (37,360)	$ (41,533)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Balance at Dec. 31, 2018	$ 119,945	$ 12	$ 323,279	$ (4)	$ (203,342)
Balance (in shares) at Dec. 31, 2018		11,954,528
Stock-based compensation expense	829		829
Issuance of common stock from stock grants and option exercises	106		106
Issuance of common stock from stock grants and option exercises, shares		19,576
Unrealized (loss) gain on available-for-sale debt securities	17			17
Net loss	(15,082)				(15,082)
Balance at Mar. 31, 2019	105,815	$ 12	324,214	13	(218,424)
Balance (in shares) at Mar. 31, 2019		11,974,104
Balance at Dec. 31, 2018	119,945	$ 12	323,279	(4)	(203,342)
Balance (in shares) at Dec. 31, 2018		11,954,528
Unrealized (loss) gain on available-for-sale debt securities	35
Net loss	(41,568)
Balance at Sep. 30, 2019	81,272	$ 12	326,139	31	(244,910)
Balance (in shares) at Sep. 30, 2019		12,029,992
Balance at Mar. 31, 2019	105,815	$ 12	324,214	13	(218,424)
Balance (in shares) at Mar. 31, 2019		11,974,104
Stock-based compensation expense	903		903
Stock-based compensation expense		5,999
Issuance of common stock from stock grants and option exercises	129		129
Issuance of common stock from stock grants and option exercises, shares		28,425
Unrealized (loss) gain on available-for-sale debt securities	44			44
Net loss	(13,780)				(13,780)
Balance at Jun. 30, 2019	93,111	$ 12	325,246	57	(232,204)
Balance (in shares) at Jun. 30, 2019		12,008,528
Stock-based compensation expense	801		801
Stock-based compensation expense		7,393
Issuance of common stock from stock grants and option exercises	92		92
Issuance of common stock from stock grants and option exercises, shares		14,071
Unrealized (loss) gain on available-for-sale debt securities	(26)			(26)
Net loss	(12,706)				(12,706)
Balance at Sep. 30, 2019	81,272	$ 12	326,139	31	(244,910)
Balance (in shares) at Sep. 30, 2019		12,029,992
Balance at Dec. 31, 2019	68,336	$ 12	326,810	34	(258,520)
Balance (in shares) at Dec. 31, 2019		12,040,835
Stock-based compensation expense	805		805
Stock-based compensation expense		7,817
Issuance of common stock from stock grants and option exercises	339		339
Issuance of common stock from stock grants and option exercises, shares		62,969
Issuance of common stock for public offering, net of issuance costs of $2,514 and $ [ ]	31,986	$ 5	31,981
Issuance of common stock for public offering, net of issuance costs of $2,514, shares		5,307,692
Unrealized (loss) gain on available-for-sale debt securities	106			106
Net loss	(4,053)				(4,053)
Balance at Mar. 31, 2020	97,519	$ 17	359,935	140	(262,573)
Balance (in shares) at Mar. 31, 2020		17,419,313
Balance at Dec. 31, 2019	68,336	$ 12	326,810	34	(258,520)
Balance (in shares) at Dec. 31, 2019		12,040,835
Unrealized (loss) gain on available-for-sale debt securities	(26)
Net loss	(37,334)
Balance at Sep. 30, 2020	94,059	$ 22	389,883	8	(295,854)
Balance (in shares) at Sep. 30, 2020		22,082,924
Balance at Mar. 31, 2020	97,519	$ 17	359,935	140	(262,573)
Balance (in shares) at Mar. 31, 2020		17,419,313
Stock-based compensation expense	834		834
Stock-based compensation expense		16,048
Issuance of common stock for public offering, net of issuance costs of $2,514 and $ [ ]	27,955	$ 5	27,950
Issuance of common stock for public offering, net of issuance costs of $2,514, shares		4,615,384
Unrealized (loss) gain on available-for-sale debt securities	(99)			(99)
Net loss	(17,248)				(17,248)
Balance at Jun. 30, 2020	108,961	$ 22	388,719	41	(279,821)
Balance (in shares) at Jun. 30, 2020		22,050,745
Stock-based compensation expense	1,068		1,068
Stock-based compensation expense		12,295
Issuance of common stock from stock grants and option exercises	96		96
Issuance of common stock from stock grants and option exercises, shares		19,884
Unrealized (loss) gain on available-for-sale debt securities	(33)			(33)
Net loss	(16,033)				(16,033)
Balance at Sep. 30, 2020	$ 94,059	$ 22	$ 389,883	$ 8	$ (295,854)
Balance (in shares) at Sep. 30, 2020		22,082,924

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2020	Mar. 31, 2020
Statement Of Stockholders Equity [Abstract]
Issuance costs of issuance of common stock for public offering	$ 2,045	$ 2,514

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating Activities
Net loss	$ (37,334)	$ (41,568)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	2,707	2,533
Depreciation and amortization	93	112
Changes in operating assets and liabilities:
Accounts receivable	13,445
Prepaid and other assets	225	(477)
Accounts payable	(35)	875
Accrued compensation and other accrued liabilities	2,156	2,944
Operating lease liability and right-of-use asset	45	57
Deferred revenue	(14,236)
Net cash flows used in operating activities	(32,934)	(35,524)
Investing Activities
Proceeds from maturities of short-term investments	74,082	133,967
Purchases of short-term and long-term investments	(91,742)	(106,950)
Purchases of property and equipment	(228)	(65)
Net cash flows (used in) provided by investing activities	(17,888)	26,952
Financing Activities
Issuance of common stock for public offering, net of issuance costs	59,941
Issuance of common stock from stock grants and option exercises	435	327
Net cash flow provided by financing activities	60,376	327
Net increase (decrease) in cash, cash equivalents and restricted cash	9,554	(8,245)
Cash, cash equivalents and restricted cash at beginning of the period	15,369	31,263
Cash, cash equivalents and restricted cash at end of the period	$ 24,923	23,018
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Right-of-use asset and operating lease liability recorded upon the adoption of ASC 842, net		$ 2,052

Nature of Operations and Liquid

Nature of Operations and Liquidity	9 Months Ended
	Sep. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Operations and Liquidity	1. Catalyst Biosciences, Inc. and its subsidiary (the “Company” or “Catalyst”) is a fully integrated research and clinical development biopharmaceutical company with expertise in protease engineering, discovery, translational research, clinical development, and manufacturing. The Company is focused on advancing its protease product candidates in the fields of hemostasis and complement regulation. The Company had a net loss of $37.3 million for the nine months ended September 30, 2020 and an accumulated deficit of $295.9 million as of September 30, 2020. The Company expects to continue to incur losses for the next several years. As of September 30, 2020, the Company had $104.1 million of cash, cash equivalents and investments. Its primary uses of cash are to fund operating expenses, including research and development expenditures and general and administrative expenditures. Based on the current status of its research and development plans, the Company believes that its existing cash, cash equivalents and investments as of September 30, 2020 will be sufficient to fund its cash requirements for at least the next 12 months from the date of the filing of this quarterly report. If, at any time, the Company’s prospects for financing its research and development programs decline, the Company may decide to reduce research and development expenses by delaying, discontinuing or reducing its funding of one or more of its research or development programs. Alternatively, the Company might raise funds through strategic collaborations, public or private financings or other arrangements. Such funding, if needed, may not be available on favorable terms, or at all.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Basis of Presentation The Company’s condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) and following the requirements of the Securities and Exchange Commission (the “SEC”) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP can be condensed or omitted. These financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments, which are necessary for a fair presentation of the Company’s financial information. These interim results and cash flows for any interim period are not necessarily indicative of the results to be expected for the full year. The accompanying condensed consolidated financial statements and related financial information should be read in conjunction with the consolidated financial statements filed with the Company’s Annual Report on Form 10-K for the year ended December 31, 2019 (“Annual Report”). Accounting Pronouncements Recently Adopted The Company’s significant accounting policies are included in “Part II - Item 8 - Financial Statements and Supplementary Data - Note 3 – Summary of Significant Accounting Policies” in the Company’s Annual Report. In November 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction Between Topic 808 and Topic 606 (“ASU 2018-18”). The amended guidance precludes presenting consideration from a transaction in a collaborative arrangement as revenue from contracts with customers if the counterparty is not a customer for that transaction. The new guidance is effective for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. Early adoption is permitted. The Company adopted ASU 2018-18 as of January 1, 2020. The adoption of ASU 2018-18 did not have a material impact on the Company’s condensed consolidated financial statements. New Accounting Pronouncements Recently Issued But Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, 13. In May 2019, the FASB issued ASU 2019-05, Financial Instruments – Credit Losses (Topic 326): Targeted Transition Relief, to provide entities with more flexibility in applying the fair value option on adoption of the credit impairment standard. ASU 2018-19 and ASU 2019-05 have the same effective date and transition requirements as ASU 2016-13. ASU 2016-13 will be effective for the Company for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years, using a modified retrospective approach. Early adoption is permitted. The Company plans to adopt ASU 2016-13 and related updates as of January 1, 2023. The Company will assess the impact of adoption of this standard on its consolidated financial statements . In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes . of adopting this new accounting guidance . Cost of License and Collaboration Revenue Cost of license revenue includes sublicense fees paid or payable to Mosaic Biosciences, Inc. (“Mosaic”), incurred in the period, under the terms of the Mosaic collaboration agreement, and fees for patent development and protection paid or payable to other third-party vendors corresponding to the recognition of license revenue from the Biogen Agreement. See Notes 7 and 11. Cost of license revenue does not include any allocated overhead costs. Cost of collaboration revenue includes fees for research and development services paid or payable to Mosaic and other third-party vendors and personnel cost, incurred in the period pertaining to the Biogen Agreement. See Notes 7 and 11. Cost of collaboration revenue does not include any allocated overhead costs.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. For a description of the fair value hierarchy and the Company’s fair value methodology, see “Part II - Item 8 - Financial Statements and Supplementary Data - Note 2 – Summary of Significant Accounting Policies” in the Company’s Annual Report. There were no significant changes in these methodologies during the nine months ended September 30, 2020. There were no transfers in or out of Level 1 or 2 during the periods presented. The following tables present the fair value hierarchy for assets and liabilities measured at fair value on a recurring basis as of September 30, 2020 and December 31, 2019 ( in thousands September 30, 2020 Level 1 Level 2 Level 3 Total Financial assets: Money market funds (1) $ 24,923 $ — $ — $ 24,923 U.S. government agency securities (2) 55,042 — — 55,042 Federal agency securities (2) — 24,088 — 24,088 Total financial assets $ 79,965 $ 24,088 $ — $ 104,053 (1) Included in cash and cash equivalents on the accompanying condensed consolidated balance sheets. ( 2 ) Included in short-term investments on the accompanying condensed consolidated balance sheets and classified as available-for-sale debt securities. $1.2 million of Federal agency securities are included in long-term investments on the accompanying condensed consolidated balance sheets due to the maturity being more than 12 months. December 31, 2019 Level 1 Level 2 Level 3 Total Financial assets: Money market funds (1) $ 15,369 $ — $ — $ 15,369 U.S. government agency securities (2) 51,490 — — 51,490 Federal agency securities (2) — 10,006 — 10,006 Total financial assets $ 66,859 $ 10,006 $ — $ 76,865 (1) Included in cash and cash equivalents on the accompanying condensed consolidated balance sheets. ( 2 ) Included in short-term investments on the accompanying condensed consolidated balance sheets and classified as available-for-sale debt securities.

Financial Instruments

Financial Instruments	9 Months Ended
	Sep. 30, 2020
Investments All Other Investments [Abstract]
Financial Instruments	4. Cash equivalents and investments (debt securities) which are classified as available-for-sale debt securities, consisted of the following ( in thousands September 30, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Money market funds (cash equivalents) $ 24,923 $ — $ — $ 24,923 U.S. government agency securities 55,038 4 — 55,042 Federal agency securities 24,084 4 — 24,088 Total financial assets $ 104,045 $ 8 $ — $ 104,053 Classified as: Cash and cash equivalents $ 24,923 Short-term investments 77,959 Long-term investments 1,171 $ 104,053 December 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Money market funds (cash equivalents) $ 15,369 $ — $ — $ 15,369 U.S. government agency securities 51,467 23 — 51,490 Federal agency securities 9,995 11 — 10,006 Total financial assets $ 76,831 $ 34 $ — $ 76,865 Classified as: Cash and cash equivalents $ 15,369 Short-term investments 61,496 $ 76,865 There have been no material realized gains or losses on available-for-sale debt securities for the periods presented. As of September 30, 2020, the remaining contractual maturities of $78.0 million of available-for-sale debt securities was less than one year and $1.2 million of available-for-sale debt securities were less than two years. The carrying amounts of cash, accounts receivable, accounts payable, and accrued liabilities approximate their fair values due to the short-term maturity of these instruments.

Lease

Lease	9 Months Ended
	Sep. 30, 2020
Lessee Disclosure [Abstract]
Lease	5. The Company leases office space for its corporate headquarters, located in South San Francisco, CA. The lease term is through April 30, 2023 and there are no stated renewal options. Operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term. In calculating the present value of the lease payments, the Company has elected to utilize its incremental borrowing rate based on the original lease term and not the remaining lease term. The lease includes non-lease components ( e.g. On July 17, 2020, the Company entered into an amendment to the existing lease agreement to lease additional office space for an aggregated undiscounted future payment of $0.4 million. This amendment will be treated as a separate lease with a lease term of 2.6 years and is expected to commence during the fourth quarter of 2020. For the three and nine months ended September 30, 2020, the Company’s operating lease expense was $0.2 million and $0.6 million, respectively. For the three and nine months ended September 30, 2019, the Company’s operating lease expense was $0.2 million and $0.5 million, respectively. September 30, December 31, 2020 2019 Weighted-average remaining lease term 2.58 years 3.33 years Weighted-average discount rate 6.0 % 6.0 % The maturity of the Company’s operating lease liabilities as of September 30, 2020 were as follows (in thousands) Year Undiscounted lease payments Remaining in 2020 $ 145 2021 596 2022 614 2023 209 Total undiscounted lease payments $ 1,564 Less imputed interest (120 ) Total operating lease liability $ 1,444 Supplemental cash flow information related to operating leases was as follows (in thousands) Nine Months Ended September 30, 2020 2019 Cash paid for leases that were included in operating cash outflows $ 433 $ 420

Stock Based Compensation

Stock Based Compensation	9 Months Ended
	Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Based Compensation	6. 2018 Omnibus Incentive Plan In June 2018, stockholders of the Company approved the Company’s 2018 Omnibus Incentive Plan (the “2018 Plan”). The 2018 Plan had previously been approved by the Company’s Board of Directors (the “Board”) and the Compensation Committee of the Board, subject to stockholder approval. The 2018 Plan became effective on June 13, 2018. On June 11, 2020, the stockholders of the Company approved an amendment previously approved by the Board to increase the number of shares of common stock reserved for issuance under the 2018 Plan by 1,300,000 to a total of 2,800,000 shares. The amendment became effective immediately upon stockholder approval. The following table summarizes stock option activity under the Company’s equity incentive plans and related information: Number of Shares Underlying Outstanding Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (Years) Outstanding — December 31, 2019 1,577,541 $ 10.85 8.15 Options granted 971,250 $ 6.25 Options exercised (44,605 ) $ 5.04 Options forfeited (223,708 ) $ 9.61 Options expired (16,337 ) $ 49.67 Outstanding — September 30, 2020 2,264,141 $ 8.84 8.09 Exercisable — September 30, 2020 1,032,133 $ 10.99 Valuation Assumptions The Company estimated the fair value of stock options granted using the Black-Scholes option-pricing formula and a single option award approach. Due to its limited history as a public company and limited number of sales of its common stock, the Company estimated its volatility considering a number of factors including the use of the volatility of comparable public companies. The expected term of options granted under the Plan, all of which qualify as “plain vanilla” per SEC Staff Accounting Bulletin 107, is determined based on the simplified method due to the Company’s limited operating history. The risk-free rate is based on the yield of a U.S. Treasury security with a term consistent with the option. This fair value is being amortized ratably over the requisite service periods of the awards, which is generally the vesting period. The fair value of employee stock options was estimated using the following weighted-average assumptions: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Employee Stock Options: Risk-free interest rate 0.39% 1.65% 0.96% 2.39% Expected term (in years) 6.06 5.90 5.78 5.98 Dividend yield — — — — Volatility 115.62% 109.47% 112.87% 89.76% Weighted-average fair value of stock options granted $ 4.61 $ 5.60 $ 5.17 $ 5.93 Total stock-based compensation recognized was as follows ( in thousands Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Research and development $ 493 $ 284 $ 1,151 $ 805 General and administrative (1) 575 517 1,556 1,728 Total stock-based compensation $ 1,068 $ 801 $ 2,707 $ 2,533 (1) Included in general and administrative stock-based compensation for the three and nine months ended September 30, 2020 is expense related to 12,295 shares and 36,160 shares of common stock, respectively, issued to certain board members in lieu of their cash compensation. As of September 30, 2020, 1,373,834 shares of common stock were available for future grant and 2,264,141

Collaborations

Collaborations	9 Months Ended
	Sep. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Collaborations	7 . Pfizer Pursuant to the termination agreement entered into on December 8, 2016, in connection with the termination of a prior license and development agreement, Pfizer granted the Company an exclusive license to Pfizer’s proprietary rights for manufacturing materials and processes that apply to Factor VIIa variants, CB 813a and marzeptacog alfa (activated) - MarzAA. Pfizer also transferred to the Company the IND application and documentation related to the development, manufacturing and testing of the Factor VIIa products as well as the orphan drug designation. The Company agreed to make contingent cash payments to Pfizer in an aggregate amount up to $17.5 million, payable upon the achievement of certain clinical, regulatory and commercial milestones. Following commercialization of any covered product, Pfizer will also receive a single-digit royalty on net product sales on a country-by-country basis for a predefined royalty term. In February 2018, the Company paid Pfizer a $1.0 million milestone payment based on the dosing of the first patient in its Phase 2 study; the amount was recorded as a research and development expense. No payments were made to Pfizer in the nine months ended September 30, 2020. ISU Abxis In December 2018, the Company entered into an amended and restated license agreement with ISU Abxis (the “A&R ISU Abxis Agreement”), which amended and restated its previous license and collaboration agreement with ISU Abxis previously entered into in September 2013, as subsequently amended in October 2014 and December 2016 (the “Original ISU Abxis Agreement”) ISU Abxis will receive commercialization rights in South Korea to the Company’s engineered Factor IX dalcinonacog alfa - DalcA and the Company will receive clinical development and commercialization rights in the rest of world (excluding South Korea) and manufacturing development and manufacturing rights worldwide (including South Korea) The eliminates the profit-sharing arrangement in the Original ISU Abxis Agreement and rovides for a low single-digit royalty payment to ISU Abxis, on a country-by-country basis, for net product sales of DalcA by the Company or its affiliates in each country other than South Korea. Pursuant to the A&R , the Company will also pay up to an aggregate of $19.5 million in milestone payments to ISU Abxis, including $2.5 million in regulatory and development milestone payments and up to $17.0 million in commercial milestone payments, if the applicable milestones are met. As of September 30, 2020, no milestones have been met. Biogen On December 18, 2019, the Company and Biogen International GmbH (“Biogen”) entered into a License and Collaboration Agreement (the “Biogen Agreement”), under which the Company granted Biogen a worldwide, royalty-bearing, exclusive, with the right to sublicense, license (“Exclusive License”) to develop and commercialize CB 2782-PEG and other anti-C3 proteases for potential treatment of dry age-related macular degeneration (“ twelve-month Under the terms of the Biogen Agreement, the Company received an up-front payment for the transfer of the Exclusive License (inclusive of certain know-how) of $15.0 million in January 2020. The Company is eligible to receive development milestones and sales milestones of up to $340.0 million. In addition, the Company is eligible to receive royalties in the range of single-digit to low double-digit percentage rates of annual net sales on a product-by-product and country-by-country basis. The Company will also receive reimbursements for costs associated with the performance of the Research Services. The Company determined that the performance obligations under the Biogen Agreement were the Exclusive License and the Research Services. For the Exclusive License, the Company used the residual approach in determining the standalone selling price, or SSP, which includes the upfront payments, milestones and royalties. For the Research Services, the Company used the historical pricing approach for determining the SSP, which includes the reimbursement of personnel and out-of-pocket costs. The Biogen Agreement will continue on a product-by-product and country-by-country basis until the tenth anniversary of the first commercial sale of the first product in a country, unless terminated earlier by either party as specified under the agreement. For the nine months ended September 30, 2020, the Company recognized the $15.0 million in license revenue upon the transfer of the Exclusive License and the related know-how, and $0.1 million in license revenue for reimbursable out-of-pocket costs incurred. For the three and nine months ended September 30, 2020, the Company recognized $0.9 million and $3.8 million, respectively, in collaboration revenue for reimbursable out-of-pocket and personnel costs incurred related to research services.

Net Loss per Share Attributable

Net Loss per Share Attributable to Common Stockholders	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Net Loss per Share Attributable to Common Stockholders	8. The following table sets forth the computation of the basic and diluted net loss per common share as follows ( in thousands, except share and per share data Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Net loss attributable to common stockholders $ (16,033 ) $ (12,706 ) $ (37,334 ) $ (41,568 ) Weighted-average number of shares used in computing net loss per share, basic and diluted 22,072,243 12,022,620 18,199,575 11,992,240 Net loss available for common stockholders per share, basic and diluted $ (0.73 ) $ (1.06 ) $ (2.05 ) $ (3.47 ) Since the Company was in a loss position for all periods presented, diluted net loss per share is the same as basic net loss per share for all periods as the inclusion of all potential common shares outstanding would have been anti-dilutive. Potentially dilutive securities on an as-if converted basis that were not included in the diluted per share calculations because they would be anti-dilutive were as follows: September 30, 2020 2019 Options to purchase common stock 2,264,141 1,569,838 Common stock warrants 722 7,857 Total 2,264,863 1,577,695

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Stockholders' Equity	9. Stockholders’ Equity In February 2020, In June 2020, the Company completed an underwritten public offering of 4,615,384 shares of its common stock at a price of $6.50 per share. The net proceeds to the Company, after deducting $2.0 million in underwriting discounts and commissions and offering expenses payable by the Company, were approximately $28.0 million.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	10. Commitments and Contingencies Manufacturing Agreements On May 20, 2016, the Company signed a development and manufacturing services agreement with AGC Biologics, Inc. (“AGC”), formerly known as CMC ICOS Biologics, Inc., pursuant to which AGC will conduct manufacturing development of agreed upon product candidates. The Company currently has firm work orders with AGC to manufacture MarzAA and DalcA to support its clinical trials totaling $21.6 million and the payment obligations remaining as of September 30, 2020 were $13.4 million. On October 9, 2019, the Company and Catalent Indiana, LLC (“Catalent”) signed a clinical supply services agreement, effective October 4, 2019, pursuant to which Catalent will conduct drug product development of agreed upon product candidates. The Company had firm work orders with Catalent to manufacture DalcA to support its clinical trial totaling $0.5 million and all outstanding amounts were paid during the nine months ended September 30, 2020. The COVID-19 pandemic may disrupt the operations of the Company’s manufacturers or disrupt supply logistics, which could impact the timing of deliveries and potentially increase expenses under our agreements. All required MarzAA supplies for the MAA-304 and MAA-202 studies have been manufactured.

Related Parties

Related Parties	9 Months Ended
	Sep. 30, 2020
Related Party Transactions [Abstract]
Related Parties	11. Related Parties On October 24, 2017, the Company announced a strategic research collaboration with Mosaic to develop intravitreal anti-complement factor C3 products for the treatment of dry AMD and other retinal diseases. Dr. Usman, the Company’s Chief Executive Officer and a member of the Company’s board of directors, and Mr. Lawlor, a member of the Company’s board of directors, were also members of the board of directors of Mosaic. On December 21, 2018, the Company amended its collaboration agreement with Mosaic to, among other things, include certain additional products. Pursuant to the Mosaic collaboration agreement, as amended, the Company and Mosaic co-funded certain research. On December 18, 2019, the Company entered into the second amendment to the Mosaic collaboration agreement following completion of the co-funded research. Pursuant to the second amendment, any future services provided by Mosaic will be performed on a fee-for-service basis. In connection with the Biogen Agreement, the Company received a $15.0 million upfront license fee on January 10, 2020, see Note 7. The Company paid Mosaic a $3.0 million sublicense fee and recorded such payment as cost of license revenue for the nine months ended September 30, 2020. On May 8, 2020, the Company entered into a subsequent amendment to the Mosaic collaboration agreement. As part of this amendment, the Company paid a one-time $0.8 million cash payment, and Mosaic is eligible to receive up to $4.0 million in potential future milestone payments related to regulatory and clinical development events for CB 2782-PEG and an additional anti-complement product candidate in lieu of the Company’s obligations to pay Mosaic a double-digit percentage of funds the Company receives from Biogen or any other amounts the Company receives related to sublicense fees, research and development payments, or any other research, regulatory, clinical or commercial milestones and royalties on any other development candidates. The Company now owns one hundred percent of all future payment streams related to these product candidates. The one-time $0.8 million cash payment was recorded to research and development expenses for the nine months ended September 30, 2020.

Interest and Other Income, Net

Interest and Other Income, Net	9 Months Ended
	Sep. 30, 2020
Other Income And Expenses [Abstract]
Interest and Other Income, Net	12. Interest and Other Income, Net The following table shows the detail of interest and other income, net as follows ( in thousands Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Interest income $ 74 $ 489 $ 536 $ 1,763 Miscellaneous income — — 679 — Other (7 ) — (20 ) (41 ) Total interest and other income, net $ 67 $ 489 $ 1,195 $ 1,722

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Company’s condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) and following the requirements of the Securities and Exchange Commission (the “SEC”) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP can be condensed or omitted. These financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments, which are necessary for a fair presentation of the Company’s financial information. These interim results and cash flows for any interim period are not necessarily indicative of the results to be expected for the full year. The accompanying condensed consolidated financial statements and related financial information should be read in conjunction with the consolidated financial statements filed with the Company’s Annual Report on Form 10-K for the year ended December 31, 2019 (“Annual Report”).
Accounting Pronouncements Recently Adopted and Not Yet Adopted	Accounting Pronouncements Recently Adopted The Company’s significant accounting policies are included in “Part II - Item 8 - Financial Statements and Supplementary Data - Note 3 – Summary of Significant Accounting Policies” in the Company’s Annual Report. In November 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction Between Topic 808 and Topic 606 (“ASU 2018-18”). The amended guidance precludes presenting consideration from a transaction in a collaborative arrangement as revenue from contracts with customers if the counterparty is not a customer for that transaction. The new guidance is effective for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. Early adoption is permitted. The Company adopted ASU 2018-18 as of January 1, 2020. The adoption of ASU 2018-18 did not have a material impact on the Company’s condensed consolidated financial statements. New Accounting Pronouncements Recently Issued But Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, 13. In May 2019, the FASB issued ASU 2019-05, Financial Instruments – Credit Losses (Topic 326): Targeted Transition Relief, to provide entities with more flexibility in applying the fair value option on adoption of the credit impairment standard. ASU 2018-19 and ASU 2019-05 have the same effective date and transition requirements as ASU 2016-13. ASU 2016-13 will be effective for the Company for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years, using a modified retrospective approach. Early adoption is permitted. The Company plans to adopt ASU 2016-13 and related updates as of January 1, 2023. The Company will assess the impact of adoption of this standard on its consolidated financial statements . In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes . of adopting this new accounting guidance .
Cost of License and Collaboration Revenue	Cost of License and Collaboration Revenue Cost of license revenue includes sublicense fees paid or payable to Mosaic Biosciences, Inc. (“Mosaic”), incurred in the period, under the terms of the Mosaic collaboration agreement, and fees for patent development and protection paid or payable to other third-party vendors corresponding to the recognition of license revenue from the Biogen Agreement. See Notes 7 and 11. Cost of license revenue does not include any allocated overhead costs. Notes 7 and 11. Cost of collaboration revenue does not include any allocated overhead costs.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following tables present the fair value hierarchy for assets and liabilities measured at fair value on a recurring basis as of September 30, 2020 and December 31, 2019 ( in thousands September 30, 2020 Level 1 Level 2 Level 3 Total Financial assets: Money market funds (1) $ 24,923 $ — $ — $ 24,923 U.S. government agency securities (2) 55,042 — — 55,042 Federal agency securities (2) — 24,088 — 24,088 Total financial assets $ 79,965 $ 24,088 $ — $ 104,053 (1) Included in cash and cash equivalents on the accompanying condensed consolidated balance sheets. ( 2 ) Included in short-term investments on the accompanying condensed consolidated balance sheets and classified as available-for-sale debt securities. $1.2 million of Federal agency securities are included in long-term investments on the accompanying condensed consolidated balance sheets due to the maturity being more than 12 months. December 31, 2019 Level 1 Level 2 Level 3 Total Financial assets: Money market funds (1) $ 15,369 $ — $ — $ 15,369 U.S. government agency securities (2) 51,490 — — 51,490 Federal agency securities (2) — 10,006 — 10,006 Total financial assets $ 66,859 $ 10,006 $ — $ 76,865 (1) Included in cash and cash equivalents on the accompanying condensed consolidated balance sheets. ( 2 ) Included in short-term investments on the accompanying condensed consolidated balance sheets and classified as available-for-sale debt securities.

Financial Instruments (Tables)

Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2020
Investments All Other Investments [Abstract]
Cash Equivalents and Investments Classified as Available-for-Sale Securities	Cash equivalents and investments (debt securities) which are classified as available-for-sale debt securities, consisted of the following ( in thousands September 30, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Money market funds (cash equivalents) $ 24,923 $ — $ — $ 24,923 U.S. government agency securities 55,038 4 — 55,042 Federal agency securities 24,084 4 — 24,088 Total financial assets $ 104,045 $ 8 $ — $ 104,053 Classified as: Cash and cash equivalents $ 24,923 Short-term investments 77,959 Long-term investments 1,171 $ 104,053 December 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Money market funds (cash equivalents) $ 15,369 $ — $ — $ 15,369 U.S. government agency securities 51,467 23 — 51,490 Federal agency securities 9,995 11 — 10,006 Total financial assets $ 76,831 $ 34 $ — $ 76,865 Classified as: Cash and cash equivalents $ 15,369 Short-term investments 61,496 $ 76,865

Lease (Tables)

Lease (Tables)	9 Months Ended
	Sep. 30, 2020
Lessee Disclosure [Abstract]
Summary of Present Value Assumptions used in Calculating Present Value of Lease Payments	For the three and nine months ended September 30, 2019, the Company’s operating lease expense was $0.2 million and $0.5 million, respectively. September 30, December 31, 2020 2019 Weighted-average remaining lease term 2.58 years 3.33 years Weighted-average discount rate 6.0 % 6.0 %
Schedule of Maturity of Operating Lease Liabilities	The maturity of the Company’s operating lease liabilities as of September 30, 2020 were as follows (in thousands) Year Undiscounted lease payments Remaining in 2020 $ 145 2021 596 2022 614 2023 209 Total undiscounted lease payments $ 1,564 Less imputed interest (120 ) Total operating lease liability $ 1,444
Schedule of Supplemental Cash Flow Information	Supplemental cash flow information related to operating leases was as follows (in thousands) Nine Months Ended September 30, 2020 2019 Cash paid for leases that were included in operating cash outflows $ 433 $ 420

Stock Based Compensation (Table

Stock Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Option Activity Under Company's Equity Incentive Plans	The following table summarizes stock option activity under the Company’s equity incentive plans and related information: Number of Shares Underlying Outstanding Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (Years) Outstanding — December 31, 2019 1,577,541 $ 10.85 8.15 Options granted 971,250 $ 6.25 Options exercised (44,605 ) $ 5.04 Options forfeited (223,708 ) $ 9.61 Options expired (16,337 ) $ 49.67 Outstanding — September 30, 2020 2,264,141 $ 8.84 8.09 Exercisable — September 30, 2020 1,032,133 $ 10.99
Summary of Weighted Average Valuation Assumptions Used to Estimate Fair Value of Employee Stock Options	The fair value of employee stock options was estimated using the following weighted-average assumptions: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Employee Stock Options: Risk-free interest rate 0.39% 1.65% 0.96% 2.39% Expected term (in years) 6.06 5.90 5.78 5.98 Dividend yield — — — — Volatility 115.62% 109.47% 112.87% 89.76% Weighted-average fair value of stock options granted $ 4.61 $ 5.60 $ 5.17 $ 5.93
Summary of Stock-Based Compensation Recognized	Total stock-based compensation recognized was as follows ( in thousands Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Research and development $ 493 $ 284 $ 1,151 $ 805 General and administrative (1) 575 517 1,556 1,728 Total stock-based compensation $ 1,068 $ 801 $ 2,707 $ 2,533 (1) Included in general and administrative stock-based compensation for the three and nine months ended September 30, 2020 is expense related to 12,295 shares and 36,160 shares of common stock, respectively, issued to certain board members in lieu of their cash compensation.

Net Loss per Share Attributab_2

Net Loss per Share Attributable to Common Stockholders (Tables)	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Basic and Diluted Net Loss Per Common Share	The following table sets forth the computation of the basic and diluted net loss per common share as follows ( in thousands, except share and per share data Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Net loss attributable to common stockholders $ (16,033 ) $ (12,706 ) $ (37,334 ) $ (41,568 ) Weighted-average number of shares used in computing net loss per share, basic and diluted 22,072,243 12,022,620 18,199,575 11,992,240 Net loss available for common stockholders per share, basic and diluted $ (0.73 ) $ (1.06 ) $ (2.05 ) $ (3.47 )
Anti-dilutive Security not Included In Diluted per Share Calculations	Since the Company was in a loss position for all periods presented, diluted net loss per share is the same as basic net loss per share for all periods as the inclusion of all potential common shares outstanding would have been anti-dilutive. Potentially dilutive securities on an as-if converted basis that were not included in the diluted per share calculations because they would be anti-dilutive were as follows: September 30, 2020 2019 Options to purchase common stock 2,264,141 1,569,838 Common stock warrants 722 7,857 Total 2,264,863 1,577,695

Interest and Other Income, Net

Interest and Other Income, Net (Tables)	9 Months Ended
	Sep. 30, 2020
Other Income And Expenses [Abstract]
Detail of Interest and Other Income, Net	The following table shows the detail of interest and other income, net as follows ( in thousands Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Interest income $ 74 $ 489 $ 536 $ 1,763 Miscellaneous income — — 679 — Other (7 ) — (20 ) (41 ) Total interest and other income, net $ 67 $ 489 $ 1,195 $ 1,722

Nature of Operations and Liqu_2

Nature of Operations and Liquidity - Additional Information (Detail) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Sep. 30, 2020USD ($)Segment	Sep. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Accounting Policies [Abstract]
Number of operating segment | Segment							1
Net loss	$ 16,033	$ 17,248	$ 4,053	$ 12,706	$ 13,780	$ 15,082	$ 37,334	$ 41,568
Accumulated deficit	295,854						295,854		$ 258,520
Cash, cash equivalents and short-term investments	$ 104,100						$ 104,100

Assets and Liabilities Measured

Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands		Sep. 30, 2020		Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value		$ 104,053		$ 76,865
Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	[1]	24,923		15,369
U.S. Government Agency Securities | Short-Term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value		55,042	[2]	51,490	[3]
Federal Agency Securities | Short-Term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	[3]			10,006
Federal Agency Securities | Short-Term and Long-Term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	[2]	24,088
Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value		79,965		66,859
Fair Value, Inputs, Level 1 | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	[1]	24,923		15,369
Fair Value, Inputs, Level 1 | U.S. Government Agency Securities | Short-Term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value		55,042	[2]	51,490	[3]
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value		24,088		10,006
Fair Value, Inputs, Level 2 | Federal Agency Securities | Short-Term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	[3]			$ 10,006
Fair Value, Inputs, Level 2 | Federal Agency Securities | Short-Term and Long-Term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	[2]	$ 24,088
[1]	Included in cash and cash equivalents on the accompanying condensed consolidated balance sheets.
[2]	Included in short-term investments on the accompanying condensed consolidated balance sheets and classified as available-for-sale debt securities. $1.2 million of Federal agency securities are included in long-term investments on the accompanying condensed consolidated balance sheets due to the maturity being more than 12 months.
[3]	Included in short-term investments on the accompanying condensed consolidated balance sheets and classified as available-for-sale debt securities.

Assets and Liabilities Measur_2

Assets and Liabilities Measured at Fair Value - Additional Information (Detail) $ in Millions	Sep. 30, 2020USD ($)
Long Term Investments | Federal Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale, debt securities	$ 1.2

Cash Equivalents and Short-Term

Cash Equivalents and Short-Term Investments Classified as Available-for-sale Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 104,045	$ 76,831
Gross Unrealized Gains	8	34
Estimated Fair Value	104,053	76,865
Money Market Funds | Cash Equivalents
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	24,923	15,369
Estimated Fair Value	24,923	15,369
U.S. Government Agency Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	55,038	51,467
Gross Unrealized Gains	4	23
Estimated Fair Value	55,042	51,490
Cash and Cash Equivalents
Schedule Of Available For Sale Securities [Line Items]
Estimated Fair Value	24,923	15,369
Short-Term Investments
Schedule Of Available For Sale Securities [Line Items]
Estimated Fair Value	77,959	61,496
Long-Term Investments
Schedule Of Available For Sale Securities [Line Items]
Estimated Fair Value	1,171
Federal Agency Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	24,084	9,995
Gross Unrealized Gains	4	11
Estimated Fair Value	$ 24,088	$ 10,006

Financial Instruments - Additio

Financial Instruments - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2020USD ($)
Fair Value Disclosures [Abstract]
Material realized gains or losses on available-for-sale securities	$ 0
Available-for-sale debt securities current	78,000,000
Available-for-sale-debt securities noncurrent	$ 1,200,000

Lease - Additional Information

Lease - Additional Information (Detail) - USD ($) $ in Thousands	Jul. 17, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Lessee Disclosure [Abstract]
Lease expiration date				Apr. 30, 2023
Lessee operating lease renewal term description				no stated renewal options
Total undiscounted lease payments	$ 400	$ 1,564		$ 1,564
Operating lease term of contract	2 years 7 months 6 days
Operating lease not yet commenced description	expected to commence during the fourth quarter of 2020
Operating lease expense		$ 200	$ 200	$ 600	$ 500

Summary of Present Value Assump

Summary of Present Value Assumptions used in Calculating Present Value of Lease Payments (Detail)	Sep. 30, 2020	Dec. 31, 2019
Lessee Disclosure [Abstract]
Weighted-average remaining lease term	2 years 6 months 29 days	3 years 3 months 29 days
Weighted-average discount rate	6.00%	6.00%

Schedule of Maturity of Operati

Schedule of Maturity of Operating Lease Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Jul. 17, 2020
Operating Lease Liabilities Payments Due [Abstract]
Remaining in 2020	$ 145
2021	596
2022	614
2023	209
Total undiscounted lease payments	1,564	$ 400
Less imputed interest	(120)
Total operating lease liability	$ 1,444

Schedule of Supplemental Cash F

Schedule of Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating Lease Liabilities Payments Due [Abstract]
Cash paid for leases that were included in operating cash outflows	$ 433	$ 420

Stock Based Compensation - Addi

Stock Based Compensation - Additional Information (Detail) - USD ($) $ in Millions	Jun. 11, 2020	Sep. 30, 2020	Sep. 30, 2020	Dec. 31, 2019
Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table]
Number of shares of common stock issued to certain board members in lieu of cash compensation		12,295	36,160
Number of common stock available for future grant		1,373,834	1,373,834
Shares remaining outstanding		2,264,141	2,264,141	1,577,541
Employee Stock Option
Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table]
Unrecognized employee stock based compensation expense		$ 6.7	$ 6.7
Unrecognized employee stock based compensation expense, period for recognition			2 years 8 months 1 day
2018 Omnibus Incentive Plan
Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table]
Increase in number of shares of common stock reserved for issuance.	1,300,000
Common Stock, Capital Shares Reserved for Future Issuance	2,800,000

Summary of Option Activity Unde

Summary of Option Activity Under Company's Equity Incentive Plans (Detail) - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Number of Shares Underlying Outstanding Options
Number of Shares Underlying Outstanding Options, Beginning Balance	1,577,541
Number of Shares Underlying Outstanding Options, Options granted	971,250
Number of Shares Underlying Outstanding Options, Options exercised	(44,605)
Number of Shares Underlying Outstanding Options, Options forfeited	(223,708)
Number of Shares Underlying Outstanding Options, Options expired	(16,337)
Number of Shares Underlying Outstanding Options, Ending Balance	2,264,141	1,577,541
Number of Shares Underlying Outstanding Options, Exercisable - September 30, 2020	1,032,133
Weighted- Average Exercise Price
Weighted- Average Exercise Price, Beginning Balance	$ 10.85
Weighted- Average Exercise Price, Options granted	6.25
Weighted- Average Exercise Price, Options exercised	5.04
Weighted- Average Exercise Price, Options forfeited	9.61
Weighted- Average Exercise Price, Options expired	49.67
Weighted- Average Exercise Price, Ending Balance	8.84	$ 10.85
Weighted- Average Exercise Price, Exercisable - September 30, 2020	$ 10.99
Weighted-Average Remaining Contractual Term (Years)
Weighted-Average Remaining Contractual Term (Years), Outstanding Balance	8 years 1 month 2 days	8 years 1 month 24 days

Fair Values of Stock Options Es

Fair Values of Stock Options Estimated Using Black-Scholes Valuation Model (Detail) - Employee Stock Option - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Black Scholes Method Used [Line Items]
Risk-free interest rate	0.39%	1.65%	0.96%	2.39%
Expected term (in years)	6 years 22 days	5 years 10 months 25 days	5 years 9 months 11 days	5 years 11 months 23 days
Volatility	115.62%	109.47%	112.87%	89.76%
Weighted-average fair value of stock options granted	$ 4.61	$ 5.60	$ 5.17	$ 5.93

Summary of Stock-Based Compensa

Summary of Stock-Based Compensation Recognized (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation		$ 1,068	$ 801	$ 2,707	$ 2,533
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation		493	284	1,151	805
General and Administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	[1]	$ 575	$ 517	$ 1,556	$ 1,728
[1]	Included in general and administrative stock-based compensation for the three and nine months ended September 30, 2020 is expense related to 12,295 shares and 36,160 shares of common stock, respectively, issued to certain board members in lieu of their cash compensation.

Collaborations - Additional Inf

Collaborations - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 18, 2019	Jan. 31, 2020	Dec. 31, 2018	Feb. 28, 2018	Sep. 30, 2020	Sep. 30, 2020	Dec. 08, 2016
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
License and collaboration revenue					$ 893	$ 18,917
License
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
License and collaboration revenue					32	15,100
License | Transfer of Exclusive License and Related Know-How
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
License and collaboration revenue						15,000
Exclusive License
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
License and collaboration revenue						100
Collaboration
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
License and collaboration revenue					861	3,817
Collaboration | Reimbursable Out-of-Pocket and Personnel Costs Incurred Related to Research Services
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
License and collaboration revenue					$ 900	3,800
Pfizer Inc | Collaboration Agreement
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Milestone payment				$ 1,000		0
Pfizer Inc | Collaboration Agreement | Maximum
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Contingent cash payments upon achievement of certain clinical, regulatory and commercial milestones							$ 17,500
ISU Abxis | Amended and Restated License Agreement
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Regulatory and development milestone payment			$ 2,500			0
ISU Abxis | Amended and Restated License Agreement | Maximum
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Milestone payment			19,500			0
Commercial milestone payments			$ 17,000			$ 0
Biogen | License and Collaboration Agreement (the “Biogen Agreement”)
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Research services	30 months
Research services option to extend	12 months
Biogen | Exclusive License
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Up-front payments received		$ 15,000
Biogen | Exclusive License | Maximum
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Development and sales milestone payments		$ 340,000

Basic and Diluted Net Loss Per

Basic and Diluted Net Loss Per Common Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Net loss attributable to common stockholders	$ (16,033)	$ (12,706)	$ (37,334)	$ (41,568)
Weighted-average number of shares used in computing net loss per share, basic and diluted	22,072,243	12,022,620	18,199,575	11,992,240
Net loss available for common stockholders per share, basic and diluted	$ (0.73)	$ (1.06)	$ (2.05)	$ (3.47)

Anti-dilutive Security not Incl

Anti-dilutive Security not Included In Diluted per Share Calculations (Detail) - shares	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti dilutive securities	2,264,863	1,577,695
Options To Purchase Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti dilutive securities	2,264,141	1,569,838
Common Stock Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti dilutive securities	722	7,857

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Jun. 30, 2020	Feb. 29, 2020	Jun. 30, 2020	Mar. 31, 2020
Stockholders Equity Disclosure [Line Items]
Net proceeds from sale of common stock after deducting underwriting commissions and offering expenses payable	$ 28	$ 32
Underwriting discounts, commissions and offering expenses payable	$ 2	$ 2.5
Common Stock
Stockholders Equity Disclosure [Line Items]
Firm commitment underwritten public offering shares	4,615,384	5,307,692
Issuance of stock, shares			4,615,384	5,307,692
Common stock price, per share	$ 6.50	$ 6.50	$ 6.50
Common Stock | Overallotment Option
Stockholders Equity Disclosure [Line Items]
Issuance of stock, shares		692,307

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Millions	Sep. 30, 2020USD ($)
AGC Biologics, Inc | Marzeptacog Alfa Activated and Dalcinonacog Alfa
Commitments And Contingencies Disclosure [Line Items]
Firm work order supporting clinical trials	$ 21.6
Contractual obligation payments	13.4
Catalent Indiana, LLC. | Dalcinonacog alfa.
Commitments And Contingencies Disclosure [Line Items]
Firm work order supporting clinical trials	$ 0.5

Related Parties - Additional In

Related Parties - Additional Information (Detail) - USD ($) $ in Millions	May 08, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jan. 10, 2020
Mosaic
Related Party Transaction [Line Items]
Expenses related to collaboration	$ 0.8
Payment related to collaboration				$ 3
Mosaic | Maximum
Related Party Transaction [Line Items]
Milestone payments , clinical development events				4
Mosaic | Research and development
Related Party Transaction [Line Items]
Cash research and development expense				0.8
Mosaic | Collaboration Agreement | Intravitreal Anti-Complement Factor 3
Related Party Transaction [Line Items]
Expenses related to collaboration		$ 0.2	$ 0.3	$ 1.5	$ 0.8
Biogen | License and Collaboration Agreement (the “Biogen Agreement”)
Related Party Transaction [Line Items]
Upfront license fee received from collaboration agreement						$ 15

Detail of Interest and Other In

Detail of Interest and Other Income, Net (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Other Income And Expenses [Abstract]
Interest income	$ 74	$ 489	$ 536	$ 1,763
Miscellaneous income			679
Other	(7)		(20)	(41)
Total interest and other income, net	$ 67	$ 489	$ 1,195	$ 1,722