0000950170-22-007846 | 10-Q | XBRL Viewer

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Fair Value Measurements - Summary of Financial Assets Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Money Market Funds \| Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents and marketable securities, Amortized Cost	$ 359,789	$ 218,451
Cash equivalents and marketable securities, Unrealized Gains	0	0
Cash equivalents and marketable securities, Unrealized Losses	0	0
Cash equivalents and marketable securities, Fair Market Value	359,789	218,451
U.S Government Treasury Securities \| Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents and marketable securities, Amortized Cost	417,885	407,041
Cash equivalents and marketable securities, Unrealized Gains	0	8
Cash equivalents and marketable securities, Unrealized Losses	(3,934)	(950)
Cash equivalents and marketable securities, Fair Market Value	413,951	406,099
Cash Equivalents and Marketable Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents and marketable securities, Amortized Cost	777,674	625,492
Cash equivalents and marketable securities, Unrealized Gains	0	8
Cash equivalents and marketable securities, Unrealized Losses	(3,934)	(950)
Cash equivalents and marketable securities, Fair Market Value	$ 773,740	$ 624,550

Summary of Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2022

Accounting Policies [Abstract]

Basis of Presentation

The condensed consolidated financial statements have been prepared in conformity with generally accepted accounting principles in the United States (GAAP) as defined by the Financial Accounting Standards Board (FASB). In the opinion of management, these unaudited condensed consolidated financial statements include all normal, recurring adjustments that are necessary to present fairly the results of the interim periods presented. The condensed consolidated financial statements include the accounts of Alector, Inc. and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.

The results of operations for the interim periods are not necessarily indicative of the results of operations to be expected for the full year. These interim financial statements should be read in conjunction with the audited financial statements as of and for the year ended December 31, 2021, and the notes thereto, which are included in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC) on February 24, 2022.

Use of Estimates

The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenue and expense during the reporting period. The Company evaluates its estimates, including those related to revenue recognition, manufacturing accruals, clinical accruals, fair value of assets and liabilities, income taxes uncertainties, stock-based compensation, and related assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could materially differ from those estimates.

Concentration of Credit Risk

Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents, and short-term marketable securities. Cash and cash equivalents are deposited in checking and sweep accounts at financial institutions. Such deposits may, at times, exceed federally insured limits.

Cash, Cash Equivalents, and Restricted Cash

The Company considers all highly liquid investments with original maturities of three months or less at the date of purchase to be cash and cash equivalents. Cash equivalents, which consist of amounts invested in money market funds, are stated at fair value.

Restricted cash as of March 31, 2022 relates to a letter of credit established for a lease entered into in June 2018.

The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the condensed consolidated balance sheets that sum to the total of the same amounts shown in the condensed consolidated statements of cash flows:


	Three Months Ended March 31,
	2022		2021
	(In thousands)
Cash and cash equivalents	$	454,620	$	110,703
Restricted cash		1,472		1,472
Total cash, cash equivalents, and restricted cash	$	456,092	$	112,175

Marketable Securities Policy

Marketable Securities

All marketable securities have been classified as “available-for-sale” and are carried at fair value, based upon quoted market prices. The Company considers its available-for-sale portfolio as available for use in current operations. Accordingly, the Company may classify certain investments as short-term marketable securities, even though the stated maturity date may be one year or more beyond the current balance sheet date. For available-for-sale debt securities, unrealized gains, net of any related tax effects, are excluded from earnings and are included in other comprehensive income and reported as a separate component of stockholders’ equity until realized. The Company assesses available-for-sale debt securities on a quarterly basis to see if any unrealized loss is due to credit-related factors. Factors considered in determining whether an impairment is credit-related include the extent to which the investment’s fair value is less than its cost basis, declines in published credit ratings, changes in interest rates, and any other adverse factors related to the security. If it is determined that a credit-related impairment exists, the Company will measure the credit loss based on a discounted cash flows model. Credit-related impairments on available-for-sale debt securities are recognized as an allowance for credit losses with a corresponding adjustment to other income, net in the Company’s consolidated statement of operations. The unrealized loss position that is not credit-related is recorded, net of any related tax effects, in other comprehensive income until realized. There were no credit-related losses recognized for the periods presented.

The cost of securities sold is based on the specific-identification method. The amortized cost of securities is adjusted for amortization of premiums and accretion of discounts to maturity. In accordance with our investment policy, management invests in money market funds, U.S. treasury securities, and corporate bonds. The Company has not experienced any losses on its deposits of cash, cash equivalents, and marketable securities.

Fair Value of Financial Instruments

The Company’s financial instruments include cash and cash equivalents, marketable securities, receivable from collaboration partner, current and noncurrent prepaid expenses, accounts payable, and accrued liabilities. The Company’s financial instruments approximate fair value due to their relatively short maturities.

The Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible. The Company determines the fair value of its financial instruments based on assumptions that market participants would use in pricing an asset or liability in the principal or most advantageous market. When considering market participant assumptions in fair value measurements, the following fair value hierarchy distinguishes between observable and unobservable inputs, which are categorized in one of the following levels:

Level 1 – Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date;

Level 2 – Inputs are observable, unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities 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 related assets or liabilities; and

Level 3 – Unobservable inputs that are significant to the measurement of the fair value of the assets or liabilities that are supported by little or no market data.

Revenue Recognition

The Company recognizes revenue when control of promised goods or services is transferred to customers in an amount that reflects the consideration that is expected to be received for those goods or services. In determining the appropriate amount of revenue to be recognized as the Company fulfills its obligations under arrangements, the Company performs the following steps: (i) identify the contract(s) with a customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations in the contract, and (v) recognize revenue when (or as) the entity satisfies the performance obligation. If it is determined that multiple performance obligations exist, the transaction price is allocated at the inception of the agreement to all identified performance obligations based on the relative standalone selling price (SSP). The relative SSP for each deliverable is estimated using external sourced evidence if it is available. If external sourced evidence is not available, we use our best estimate of the SSP for the deliverable.

The Company recognizes collaboration revenue at a point in time if control of the promised good or service has been transferred to the customer. The Company recognizes collaboration revenue over time by measuring the progress toward complete satisfaction of the performance obligation using an input measure. In order to recognize revenue over the research and development period, the Company measures actual costs incurred to date compared to the overall total expected costs to satisfy the performance obligation. Revenues are recognized as the program costs are incurred. The Company re-evaluates the estimate of expected costs to satisfy the performance obligation each reporting period.

Stock-based Compensation

Stock-based compensation is measured on the grant date based on the fair value of the awards. The fair value of options to purchase common stock is measured using the Black-Scholes option-pricing model. Stock-based compensation associated with restricted stock units (RSUs) is based on the fair value of the Company's common stock on the grant date, which equals the closing price of the Company's common stock on the grant date. The Company recognizes expense over the vesting period of the awards. Expense for options and RSUs that vest based only on a service condition is recognized on a straight-line basis.

In 2021, the Company began granting RSUs with market conditions to certain executives. The fair value of RSUs with market conditions is estimated using a Monte Carlo simulation model. Assumptions and estimates utilized in the model include the stock price on grant date, risk-free interest rate, dividend yield, expected stock volatility, and estimated period to achieve the market condition. The expense is recognized based on continued employment of the participants, regardless of achievement of the market condition. Expense related to the RSUs with market conditions is recognized using the accelerated attribution method.

The Company accounts for forfeitures as they occur for all awards.

Comprehensive Loss

Comprehensive Loss includes net loss and certain changes in stockholders’ equity that are the result of transactions and economic events other than those with stockholders. The Company’s only element of other comprehensive loss was net unrealized loss on marketable securities.

Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2022

Share-based Payment Arrangement [Abstract]

Summary of Recognized Stock-Based Compensation

The Company recognized stock-based compensation as follows:


	Three Months Ended March 31,
	2022		2021
	(In thousands)
Research and development	$	6,626	$	4,363
General and administrative		5,313		4,437
Total stock-based compensation	$	11,939	$	8,800

Summary of Options to Purchase Common Stock


	Number of Options			Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Term		Aggregate Intrinsic Value
						(In years)		(In thousands)
Outstanding as of December 31, 2021		11,644,070		$	16.41
Granted		1,575,780			17.27
Exercised		(234,117	)		10.61
Forfeited		(460,926	)		18.38
Outstanding as of March 31, 2022		12,524,807		$	16.55	$	8.3	$	19,371
Exercisable as of March 31, 2022		5,152,851		$	14.95	$	7.5	$	12,167
Vested and expected to vest as of March 31, 2022		12,524,807		$	16.55	$	8.3	$	19,371

Summary of Restricted Stock Awards and Restricted Stock Units

Activity for the restricted stock awards and RSUs is shown below. In May 2021, the Company began to issue RSUs with market conditions to certain executives, which are included in the table below. The RSUs with market conditions are earned based on stock price performance and continued service by the employee.


	Number of Shares			Weighted Average Grant Date Fair Value per Share
Unvested restricted stock units as of December 31, 2021		1,373,874		$	18.35
Granted		118,000			19.14
Vested		(104,368	)		19.67
Forfeited		(52,136	)		20.31
Unvested restricted stock units as of March 31, 2022		1,335,370		$	18.24

Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2022

Fair Value Disclosures [Abstract]

Summary of Financial Assets Measured at Fair Value on a Recurring Basis

The following tables summarize the Company’s financial assets measured at fair value on a recurring basis by level within the fair value hierarchy:


	March 31, 2022
	Fair Value Hierarchy	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Market Value
	(In thousands)
Money market funds	Level 1	$	359,789	$	—	$	—		$	359,789
U.S. government treasury securities	Level 1		417,885		—		(3,934	)		413,951
Total cash equivalents and marketable securities		$	777,674	$	—	$	(3,934	)	$	773,740

	December 31, 2021
	Fair Value Hierarchy	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Market Value
	(In thousands)
Money market funds	Level 1	$	218,451	$	—	$	—		$	218,451
U.S. government treasury securities	Level 1		407,041		8		(950	)		406,099
Total cash equivalents and marketable securities		$	625,492	$	8	$	(950	)	$	624,550

Stock-based Compensation - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Jan. 01, 2022
Restricted Stock subject to future vesting
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation	$ 21.3
Expected weighted average period	2 years 1 month 6 days
2019 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected weighted average period	2 years 8 months 12 days
Common stock reserved for issuance	22,451,254	4,099,309
Common stock, shares available for issuance	7,829,077
Unrecognized stock-based compensation	$ 84.3
2019 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance	2,979,129
Purchase price of common stock, percentage	85.00%
Subsequent offering period	6 months
2022 Inducement Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance		1,630,000
Common stock, shares available for issuance		762,000

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - $ / shares	Mar. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	82,324,677	82,324,677
Common stock, shares outstanding	81,986,192	81,986,192

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities:
Net loss	$ (44,617)	$ (52,171)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation and amortization	1,589	1,541
Stock-based compensation	11,939	8,800
Amortization of premiums and accretion of discounts on marketable securities	570	594
Amortization of right-of-use assets	670	461
Changes in operating assets and liabilities:
Receivable from collaboration partner	(5,428)	0
Prepaid expenses and other current assets	(2,465)	(3,790)
Other assets	(358)	25
Accounts payable	2,043	2,592
Accrued liabilities and accrued clinical supply costs	(3,383)	(5,500)
Deferred revenue	175,526	(4,110)
Lease liabilities	(995)	(821)
Other long-term liabilities	0	(314)
Net cash provided by (used in) operating activities	135,091	(52,693)
Cash flows from investing activities:
Purchase of property and equipment	(692)	(947)
Purchase of marketable securities	(30,114)	0
Maturities of marketable securities	18,700	110,500
Net cash provided by (used in) investing activities	(12,106)	109,553
Cash flows from financing activities:
Proceeds from the exercise of options to purchase common stock	2,483	3,874
Net cash provided by financing activities	2,483	3,874
Net increase in cash, cash equivalents, and restricted cash	125,468	60,734
Cash, cash equivalents, and restricted cash at beginning of period	330,624	51,441
Cash, cash equivalents, and restricted cash at end of period	456,092	112,175
Non-cash investing and financing activities:
Property and equipment purchases included in accounts payable and accrued liabilities	$ 499	$ 628

Stock-based Compensation - Summary of Recognized Stock-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 11,939	$ 8,800
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	6,626	4,363
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 5,313	$ 4,437

Stock-based Compensation - Summary of Options to Purchase Common Stock (Details) - 2019 Equity Incentive Plan $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022 USD ($) $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Options, Outstanding, beginning balance \| shares	11,644,070
Number of Options, Granted \| shares	1,575,780
Number of Options, Exercised \| shares	(234,117)
Number of Options, Forfeited \| shares	(460,926)
Number of Options, Outstanding, ending balance \| shares	12,524,807
Number of Options, Exercisable \| shares	5,152,851
Number of Options, Vested and expected to vest \| shares	12,524,807
Weighted average exercise price, Outstanding, beginning balance \| $ / shares	$ 16.41
Weighted average exercise price, Granted \| $ / shares	17.27
Weighted average exercise price, Exercised \| $ / shares	10.61
Weighted average exercise price, Forfeited \| $ / shares	18.38
Weighted average exercise price, Outstanding, ending balance \| $ / shares	16.55
Weighted average exercise price, Exercisable \| $ / shares	14.95
Weighted average exercise price, Vested and expected to vest \| $ / shares	$ 16.55
Weighted Average Remaining Contractual Term, Outstanding (in years)	8 years 3 months 18 days
Weighted Average Remaining Contractual Term, Exercisable (In years)	7 years 6 months
Weighted Average Remaining Contractual Term, Vested and expected to vest (In years)	8 years 3 months 18 days
Aggregate Intrinsic Value, Outstanding \| $	$ 19,371
Aggregate Intrinsic Value, Exercisable \| $	12,167
Aggregate Intrinsic Value, Vested or expected to vest \| $	$ 19,371

Related Party Transactions

3 Months Ended

Mar. 31, 2022

Related Party Transactions

7. Related Party Transactions

In 2014, the Company entered into a collaboration agreement with Adimab, LLC (Adimab) under which the Company is developing antibodies discovered by Adimab in its latozinemab and AL101 programs and is developing antibodies optimized by Adimab in its AL002 and AL003 programs (2014 Adimab Agreement). In August 2019, the Company signed a collaboration agreement with Adimab for research and development of additional antibodies (2019 Adimab Agreement). In December 2021, the Company signed another collaboration agreement with Adimab for antibody engineering research programs (2021 Adimab Agreement). The Chief Executive Officer of Adimab is a Co-founder and Chairperson of the board of directors of Alector. For the three months ended March 31, 2022, the Company incurred expenses of $0.1 million. For the three months ended March 31, 2021, the Company incurred expenses of $1.0 million for milestone payments for progress of programs through clinical trials. The Company had $0.1 million and zero accrued liabilities due to Adimab as of March 31, 2022 and 2021. Under the 2014 Adimab Agreement, the Company will owe up to $3.5 million in milestone payments per program to Adimab for its product candidates and will also owe low- to mid- single-digit royalty payments for commercial sales of such product candidates. Under the 2019 and 2021 Adimab Agreements, the Company will owe certain milestone payments and low single-digit royalty payments for commercial sales of covered product candidates.

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 454,620	$ 329,152
Marketable securities	413,951	406,099
Receivable from Collaboration partner	12,819	7,391
Prepaid expenses and other current assets	9,536	7,071
Total current assets	890,926	749,713
Property and equipment, net	26,228	27,330
Operating lease right-of-use assets	29,899	30,569
Restricted cash	1,472	1,472
Other assets	5,932	5,574
Total assets	954,457	814,658
Current liabilities:
Accounts payable	6,752	4,749
Accrued clinical supply costs	12,618	8,748
Accrued liabilities	20,042	27,460
Deferred revenue, current portion	95,611	90,803
Operating lease liabilities, current portion	7,855	7,795
Total current liabilities	142,878	139,555
Deferred revenue, long-term portion	505,133	334,415
Operating lease liabilities, long-term portion	38,751	39,806
Other long-term liabilities	158	158
Total liabilities	686,920	513,934
Commitments and Contingencies
Stockholders' equity:
Common stock, $0.0001 par value; 200,000,000 shares authorized; 81,248,646 and 79,316,261 shares issued and outstanding as of September 30, 2021 and December 31, 2020	8	8
Additional paid-in capital	762,458	748,036
Accumulated other comprehensive loss	(3,935)	(943)
Accumulated deficit	(490,994)	(446,377)
Total stockholders' equity	267,537	300,724
Total liabilities and stockholders’ equity	$ 954,457	$ 814,658

Net Loss Per Share - Schedule of Dilutive Shares Excluded from Calculation of Diluted Net Loss Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive shares	13,930,583	12,821,991
Restricted Stock subject to future vesting
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive shares	1,335,370	100,881
Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive shares	12,524,807	12,634,433
Shares Committed Under 2019 ESPP
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive shares	70,406	86,677

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	1 Months Ended		3 Months Ended
	Jan. 31, 2018	Oct. 31, 2017	Mar. 31, 2022	Mar. 31, 2021
Summary Of Significant Accounting Policies [Line Items]
Increase in expected cost percentage			2.00%
Reduced revenue			$ 1,800,000
Deferred revenue			486,700,000
AbbVie Biotechnology Limited
Summary Of Significant Accounting Policies [Line Items]
Upfront payments		$ 205,000,000
Upfront payment received	$ 200,000,000	5,000,000
Exclusive option rights exercised for each program		250,000,000
Collaboration revenue			3,300,000	$ 4,100,000
Deferred revenue			114,100,000	$ 128,200,000
AbbVie Biotechnology Limited \| Maximum
Summary Of Significant Accounting Policies [Line Items]
Additional milestone payments per program related to initiation of certain clinical studies and regulatory approval		$ 242,800,000
Innovent
Summary Of Significant Accounting Policies [Line Items]
Collaboration revenue			0
Development milestone			11,500,000
Sales milestone			$ 112,500,000

Collaboration Agreements

3 Months Ended

Mar. 31, 2022

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Collaboration Agreements

4. Collaboration Agreements

GSK

On July 1, 2021, the Company entered into a Collaboration and License Agreement with Glaxo Wellcome UK Limited, a subsidiary of GlaxoSmithKline plc (GSK), pursuant to which the Company and GSK will collaborate on the global development and commercialization of progranulin-elevating monoclonal antibodies, including AL001 (latozinemab) and AL101 (GSK Agreement). The GSK Agreement was made effective on August 17, 2021.

Under the terms of the GSK Agreement, the Company received $700 million in upfront payments, of which $500 million was received in August 2021 and $200 million was received in January 2022. In addition, based on the development and commercialization plan for latozinemab and AL101, the Company may be eligible to receive up to an additional $1.5 billion in clinical development, regulatory, and commercial launch-related milestone payments. In the United States, the Company and GSK will equally share profits and losses from commercialization of latozinemab and AL101. Outside of the United States, the Company will be eligible for double-digit tiered royalties.

The Company and GSK will jointly develop latozinemab and AL101. The Company will lead the global clinical development of latozinemab and AL101, other than with respect to Phase 3 clinical trials for Alzheimer’s disease and Parkinson’s disease and other non-orphan indications, which will be led by GSK. The Company and GSK will share development costs 60% by GSK and 40% by the Company, except that the Company will solely bear the development costs of the initial Phase 2 clinical trials under the development plan, and the parties will share manufacturing development costs equally.

In the United States, the Company and GSK will be jointly responsible for commercialization of latozinemab and AL101, with the Company leading the commercialization for orphan indications and GSK leading the commercialization for Alzheimer’s disease and Parkinson’s disease and other non-orphan indications. Outside of the United States, GSK will be solely responsible for commercialization of latozinemab and AL101 for all indications. The Company may opt out of the sharing of development costs and of profit and losses from commercialization in the United States on a product-by-product basis. In such case, the Company will no longer conduct development or

commercialization of that product and the Company will receive tiered royalties on net sales in the United States instead of a share of profits or losses. GSK may terminate the agreement at any time with 180 days' notice, but the Company does not need to repay any portion of the payments received.

The Company concluded that the GSK Agreement is within the scope of ASC 808, Collaborative Arrangements, as both parties are active participants in the activities and are exposed to significant risks and rewards dependent on the success of the commercialization of latozinemab and AL101. Certain elements are required to be accounted for under ASC 606, Revenue From Contracts With Customers, where the counterparty is a customer for a good or service that is a distinct unit of account.

The Company concluded that the GSK Agreement contained the following units of account: (i) license and know-how for frontotemporal dementia due to a progranulin gene mutation (FTD-GRN) in Phase 3 clinical development, (ii) research and development activities, including license rights and know-how, relating to products in Phase 2 or earlier stages of development, and (iii) research and development services under the co-development plan to be accounted for outside of ASC 606, including all products that move into Phase 3 clinical development. The Company determined that the distinct performance obligations under ASC 606 consisted of: (i) license and know-how to latozinemab FTD-GRN, which is currently in Phase 3 clinical development and (ii) the research and development activities, including license rights and know-how, relating to products in Phase 2 or earlier stages of development.

The transaction price at inception included fixed consideration consisting of the upfront payments of $700 million. All potential future milestones and other payments were considered constrained at the inception of the GSK Agreement since the Company could not conclude it was probable that a significant reversal in the amount of revenue recognized would not occur.

The respective standalone value for each of the performance obligations was allocated to the transaction price. The estimated SSP of each performance obligation was determined using discounted cash flows from the expected commercialization of latozinemab and AL101 and estimated research and development costs to be incurred by the Company in the initial Phase 2 clinical trials. The estimate of SSP for each performance obligation reflects management's assumptions, which may include forecasted revenues, development timelines, discount rates, and probabilities of technical and regulatory success. For the license for FTD-GRN, the Company determined that GSK could benefit from the license at the time the license was granted and therefore, the related performance obligation was satisfied at a point in time. For the product candidates in Phase 2 or earlier stages of development, the Company determined that GSK could not benefit from the licenses without the corresponding development services that the Company has committed to perform due the earlier stage of development for these licenses. The Company will perform research and development activities through the end of the initial Phase 2 clinical trials. Revenue will be recognized over time as the research and development activities are performed. The Company will measure progress based on actual costs incurred to date compared to the overall total expected costs to satisfy the performance obligations.

The research and development activities for products in Phase 3 clinical development were determined to be within the scope of ASC 808. Both parties will be active participants in the development, manufacturing, and commercialization of the product and are exposed to significant risks and rewards that are dependent on the commercial success of the products. The Company and GSK participate in profit and loss sharing for each program commensurate with each party's cost-sharing responsibilities during research and development. ASC 808 does not provide recognition and measurement guidance. As such, the Company determined that ASC 730, Research and Development, was appropriate to analogize to based on the nature of the cost-sharing provision of the agreement. The Company has concluded that payments to or reimbursements from GSK related to these services will be accounted for as an increase to or reduction of research and development expenses, respectively.

Collaboration revenue under the GSK Agreement during the three months ended March 31, 2022 was $21.2 million, all of which was included in deferred revenue at the beginning of the period. No revenue was recognized during the three months ended March 31, 2021 as the GSK Agreement was not yet effective. The deferred revenue related to the GSK Agreement was $486.7 million as of March 31, 2022. The deferred revenue is expected to be recognized over the research and development period of the programs through the completion of initial Phase 2 clinical trials.

Costs associated with co-development activities performed under the agreement are included in research and development expenses in the condensed consolidated statements of operations, with any reimbursement of costs by GSK reflected as a reduction of such expenses. For the three months ended March 31, 2022, the Company recognized a reduction of research and development expense of $5.4 million under the GSK Agreement. No reimbursement of research and development expense was recognized during the three months ended March 31, 2021 as the GSK Agreement was not yet effective.

AbbVie

The Company entered into an agreement in October 2017 with AbbVie Biotechnology, Ltd. (AbbVie) to co-develop antibodies to two program targets in preclinical development (AbbVie Agreement). Under the terms of the AbbVie Agreement, AbbVie made $205 million in upfront payments, of which $5 million and $200 million were received by the Company in October 2017 and January 2018, respectively. The Company will perform research and development services for the two programs through the end of Phase 2 clinical trials. After completion of the Phase 2 clinical trial for each program, AbbVie will then have the exclusive right to exercise an option under the license and collaboration agreement with the Company for that program for $250 million. If AbbVie exercises its option for a program, AbbVie will take over the development of the product candidates for such program and costs will be split between the parties. The Company will also share in profits and losses upon commercialization of any products from such program. However, following AbbVie’s exercise of its option for a program, the Company may opt out of sharing in development costs and profits or losses for that program and instead receive tiered royalties. Additionally, under the terms of the AbbVie Agreement, the Company will be eligible to earn up to an additional $242.8 million in milestone payments per program related to the initiation of certain clinical studies and regulatory approval for up to three indications per program. The Company assessed its collaboration agreement with AbbVie in the context of the delivery of the research and development services.

Collaboration revenue under the Company’s collaboration agreement with AbbVie during the three months ended March 31, 2022 and 2021 was $3.3 million and $4.1 million, respectively, the entire amount of which was included in deferred revenue at the beginning of the period. The deferred revenue related to the AbbVie Agreement was $114.1 million and $128.2 million as of March 31, 2022 and 2021, respectively. The deferred revenue is expected to be recognized over the research and development period of the programs through the completion of Phase 2 clinical trials. The Company has had changes to the overall expected costs to satisfy the performance obligations from period to period for the AbbVie Agreement. For the three months ended March 31, 2022, the Company had a 2% increase in the forecast of the total expected costs. As a result of the cumulative catch up for the change in estimate, revenue was reduced by approximately $1.8 million compared to if the expected costs had remained the same.

Innovent

The Company entered into an agreement in March 2020 with Innovent Biologics (Innovent) to license, develop, and commercialize AL008 in China (Innovent Agreement). AL008 is the Company’s novel antibody targeting the CD47-SIRP-alpha pathway, a potent survival pathway co-opted by tumors to evade the innate immune system. Under the terms of the Innovent Agreement, Innovent may pay the Company up to $11.5 million in development milestones, $112.5 million in sales milestones, and future royalties on sales. The Company retains the rights to develop and commercialize AL008 outside of China. The Company has determined there is one performance obligation for the delivery of the license and will recognize revenue when it is probable that there will not be significant reversal of cumulative revenue. Development and sales milestones under the Innovent Agreement have not been included in the transaction price, as all these amounts were fully constrained as of March 31, 2022. As of March 31, 2022, no revenue has been recognized and no payments have been received under the Innovent Agreement.

Income Taxes

3 Months Ended

Mar. 31, 2022

Income Tax Disclosure [Abstract]

Income Taxes

6. Income Taxes

For the three months ended March 31, 2022 and 2021, the Company's effective tax rate was (1.1)% and zero, respectively. Section 174 of the Internal Revenue Code requires capitalization of research and development expenses to then be amortized over five years for U.S. based research and 15 years for research conducted outside of the U.S., which limits the amount of research and development expenses that can be used to offset income in the current year. The difference between the effective tax rate as of March 31, 2022 and 2021, respectively, and the U.S. federal statutory rate of 21% was primarily due to the anticipatory recognition of a certain amount of current year income tax as a result of this capitalization effective this year.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 21
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details

Fair Value Measurements - Additional Information (Details) $ in Millions	Mar. 31, 2022 USD ($)
Fair Value Disclosures [Abstract]
Remaining contractual maturities of investments were less than one year	$ 649.5
Remaining contractual maturities of investments were less than one year through two years	$ 124.2

The Company and Liquidity

3 Months Ended

Mar. 31, 2022

Organization, Consolidation and Presentation of Financial Statements [Abstract]

The Company and Liquidity

1. The Company and Liquidity

Alector, Inc. (Alector or the Company) is a Delaware corporation headquartered in South San Francisco, California. Alector is a clinical stage biopharmaceutical company pioneering immuno-neurology, a novel therapeutic approach for the treatment of neurodegeneration.

Net Loss Per Share

3 Months Ended

Mar. 31, 2022

Earnings Per Share [Abstract]

Net Loss Per Share

8. Net Loss Per Share

The following outstanding potentially dilutive shares have been excluded from the calculation of diluted net loss per share for the periods presented due to their anti-dilutive effect:


	Three Months Ended March 31,
	2022		2021
Restricted stock subject to future vesting		1,335,370		100,881
Options to purchase common stock		12,524,807		12,634,433
Shares committed under 2019 ESPP		70,406		86,677
Total		13,930,583		12,821,991

Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2022

Accounting Policies [Abstract]

Schedule of Reconciliation of Cash, Cash Equivalents, and Restricted Cash


	Three Months Ended March 31,
	2022		2021
	(In thousands)
Cash and cash equivalents	$	454,620	$	110,703
Restricted cash		1,472		1,472
Total cash, cash equivalents, and restricted cash	$	456,092	$	112,175

Stock-based Compensation

3 Months Ended

Mar. 31, 2022

Share-based Payment Arrangement [Abstract]

Stock-Based Compensation

5. Stock-based Compensation

The Company recognized stock-based compensation as follows:


	Three Months Ended March 31,
	2022		2021
	(In thousands)
Research and development	$	6,626	$	4,363
General and administrative		5,313		4,437
Total stock-based compensation	$	11,939	$	8,800

2019 Equity Incentive Plan and 2022 Inducement Plan

On January 1, 2022, the Company added 4,099,309 shares to the shares reserved for issuance under the 2019 Equity Incentive Plan (2019 Plan). As of March 31, 2022, the Company had reserved 22,451,254 shares of common stock for issuance under the 2019 Plan, of which 7,829,077 shares were available for issuance of future awards. On January 1, 2022, the Company adopted the 2022 Inducement Plan (Inducement Plan) and reserved 1,630,000 shares for issuance

under the Inducement Plan for the grant of equity-based awards to individuals who were not previously employees or non-employee directors of the Company. As of March 31, 2022, 762,000 shares were available for issuance of future awards under the Inducement Plan.

Option activity is shown below:


	Number of Options			Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Term		Aggregate Intrinsic Value
						(In years)		(In thousands)
Outstanding as of December 31, 2021		11,644,070		$	16.41
Granted		1,575,780			17.27
Exercised		(234,117	)		10.61
Forfeited		(460,926	)		18.38
Outstanding as of March 31, 2022		12,524,807		$	16.55	$	8.3	$	19,371
Exercisable as of March 31, 2022		5,152,851		$	14.95	$	7.5	$	12,167
Vested and expected to vest as of March 31, 2022		12,524,807		$	16.55	$	8.3	$	19,371

The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying stock options and the fair value of the Company’s common stock for stock options that were in-the-money. As of March 31, 2022, total unrecognized stock-based compensation related to unvested stock options was $84.3 million, which the Company expects to recognize over a remaining weighted-average period of 2.7 years.

Restricted Stock Activity


	Number of Shares			Weighted Average Grant Date Fair Value per Share
Unvested restricted stock units as of December 31, 2021		1,373,874		$	18.35
Granted		118,000			19.14
Vested		(104,368	)		19.67
Forfeited		(52,136	)		20.31
Unvested restricted stock units as of March 31, 2022		1,335,370		$	18.24

As of March 31, 2022, total unrecognized stock-based compensation related to unvested restricted stock awards and restricted stock units was $21.3 million, which the Company expects to recognize over a remaining weighted-average period of 2.1 years.

2019 Employee Stock Purchase Plan

The 2019 Employee Stock Purchase Plan (2019 ESPP) enables eligible employees of the Company to purchase shares of common stock at a discount. As of March 31, 2022, the Company has reserved for issuance 2,979,129 shares of common stock pursuant to the 2019 ESPP. Each offering period is approximately six months long. 2019 ESPP participants will purchase shares of common stock at a price per share equal to 85% of the lesser of (1) the fair market value per share of the common stock on the first trading day of the offering period or (2) the fair market value of the common stock on the purchase date.

Collaboration Agreements - Additional Information (Details)			1 Months Ended			3 Months Ended
	Aug. 17, 2021 USD ($)	Jul. 01, 2021 USD ($)	Jan. 31, 2022 USD ($)	Jan. 31, 2018 USD ($)	Oct. 31, 2017 USD ($)	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Deferred revenue						$ 486,700,000
Research and development expense						$ 53,043,000	$ 45,733,000
Increase in expected cost percentage						2.00%
Reduced revenue						$ 1,800,000
GlaxoSmithKline plc
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Effective date of agreement	Aug. 17, 2021
Upfront payments		$ 700,000,000				$ 700,000,000
Upfront payment received	$ 500,000,000		$ 200,000,000
Percentage of development cost						0.60
Collaboration revenue						$ 21,200,000
Research and development expense						5,400,000
GlaxoSmithKline plc \| Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Additional milestone payments per program related to initiation of certain clinical studies and regulatory approval						$ 1,500,000,000
Alector
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Percentage of development cost						0.40
AbbVie Biotechnology Limited
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront payments					$ 205,000,000
Upfront payment received				$ 200,000,000	5,000,000
Exclusive option rights exercised for each program					250,000,000
Collaboration revenue						$ 3,300,000	4,100,000
Deferred revenue						114,100,000	$ 128,200,000
AbbVie Biotechnology Limited \| Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Additional milestone payments per program related to initiation of certain clinical studies and regulatory approval					$ 242,800,000
Innovent
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaboration revenue						0
Development milestone						11,500,000
Sales milestone						$ 112,500,000

Net Loss Per Share (Tables)

3 Months Ended

Mar. 31, 2022

Earnings Per Share [Abstract]

Schedule of Dilutive Shares Excluded from Calculation of Diluted Net Loss Per Share

The following outstanding potentially dilutive shares have been excluded from the calculation of diluted net loss per share for the periods presented due to their anti-dilutive effect:


	Three Months Ended March 31,
	2022		2021
Restricted stock subject to future vesting		1,335,370		100,881
Options to purchase common stock		12,524,807		12,634,433
Shares committed under 2019 ESPP		70,406		86,677
Total		13,930,583		12,821,991

Related Party Transactions - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Two Thousand Fourteen Adimab Agreement
Related Party Transaction [Line Items]
Related party transaction expenses	$ 100,000
Future milestone payments owed	1,000,000.0
Two Thousand Fourteen Adimab Agreement \| Maximum
Related Party Transaction [Line Items]
Future milestone payments owed	3,500,000
Adimab
Related Party Transaction [Line Items]
Accrued liabilities due to related parties	$ 100,000	$ 0

- Definition

Carrying amount as of the balance sheet date of obligations due all related parties. For classified balance sheets, represents the current portion of such liabilities (due within one year or within the normal operating cycle if longer).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(C))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(5))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
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-Paragraph 1
-Subparagraph (SX 210.4-08(k)(1))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
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-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iv))
-URI http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756

+ Details

Fair Value Measurements

3 Months Ended

Mar. 31, 2022

Fair Value Disclosures [Abstract]

Fair Value Measurements

3. Fair Value Measurements

The following tables summarize the Company’s financial assets measured at fair value on a recurring basis by level within the fair value hierarchy:


	March 31, 2022
	Fair Value Hierarchy	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Market Value
	(In thousands)
Money market funds	Level 1	$	359,789	$	—	$	—		$	359,789
U.S. government treasury securities	Level 1		417,885		—		(3,934	)		413,951
Total cash equivalents and marketable securities		$	777,674	$	—	$	(3,934	)	$	773,740

	December 31, 2021
	Fair Value Hierarchy	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Market Value
	(In thousands)
Money market funds	Level 1	$	218,451	$	—	$	—		$	218,451
U.S. government treasury securities	Level 1		407,041		8		(950	)		406,099
Total cash equivalents and marketable securities		$	625,492	$	8	$	(950	)	$	624,550

The Company’s Level 2 securities are valued using third-party pricing sources. The pricing services utilize industry standard valuation models for which all significant inputs are observable. The Company classifies marketable securities available to fund current operations as current assets. As of March 31, 2022, the remaining contractual maturities of $649.5 million of investments were less than one year and $124.2 million of investments were after one year through two years. The Company does not intend to sell the investments that are currently in an unrealized loss position, and it is highly unlikely that the Company will be required to sell the investments before recovery of their amortized cost basis, which may be maturity. As of March 31, 2022, the Company considered any unrealized losses on our marketable securities to be driven by factors other than credit risk.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Total revenue	$ 24,474	$ 4,110
Type of Revenue [Extensible List]	Collaboration Revenue [Member]	Collaboration Revenue [Member]
Operating expenses:
Research and development	$ 53,043	$ 45,733
General and administrative	15,554	11,012
Total operating expenses	68,597	56,745
Loss from operations	(44,123)	(52,635)
Other income, net	264	464
Loss before income taxes	(43,859)	(52,171)
Income tax expense	758	0
Net loss	(44,617)	(52,171)
Unrealized loss on marketable securities	(2,992)	(204)
Comprehensive loss	$ (47,609)	$ (52,375)
Net loss per share, basic and diluted	$ (0.54)	$ (0.66)
Shares used in computing net loss per share, basic and diluted	82,102,191	79,386,836

Summary of Significant Accounting Policies - Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 454,620	$ 329,152	$ 110,703
Restricted cash	1,472	1,472	1,472
Total cash, cash equivalents, and restricted cash	$ 456,092	$ 330,624	$ 112,175	$ 51,441

Summary of Significant Accounting Policies

3 Months Ended

Mar. 31, 2022

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Basis of Presentation

Use of Estimates

Concentration of Credit Risk

Cash, Cash Equivalents, and Restricted Cash

Restricted cash as of March 31, 2022 relates to a letter of credit established for a lease entered into in June 2018.


	Three Months Ended March 31,
	2022		2021
	(In thousands)
Cash and cash equivalents	$	454,620	$	110,703
Restricted cash		1,472		1,472
Total cash, cash equivalents, and restricted cash	$	456,092	$	112,175

Marketable Securities

Fair Value of Financial Instruments

Level 1 – Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date;

Level 3 – Unobservable inputs that are significant to the measurement of the fair value of the assets or liabilities that are supported by little or no market data.

Revenue Recognition

Stock-based Compensation

The Company accounts for forfeitures as they occur for all awards.

Comprehensive Loss

Condensed Consolidated Statement of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance at Dec. 31, 2020	$ 267,530	$ 8	$ 676,956	$ 614	$ (410,048)
Beginning balance (in shares) at Dec. 31, 2020		79,316,261
Exercise of stock options	3,874		3,874
Exercise of stock options (in shares)		415,386
Stock-based compensation	8,800		8,800
Unrealized loss on marketable securities	(204)			(204)
Net income (loss)	(52,171)				(52,171)
Ending balance at Mar. 31, 2021	227,829	$ 8	689,630	410	(462,219)
Ending balance (in shares) at Mar. 31, 2021		79,731,647
Beginning balance at Dec. 31, 2021	$ 300,724	$ 8	748,036	(943)	(446,377)
Beginning balance (in shares) at Dec. 31, 2021	81,986,192	81,986,192
Exercise of stock options	$ 2,483		2,483
Exercise of stock options (in shares)		234,117
Vesting of restricted stock units		104,368
Stock-based compensation	11,939		11,939
Unrealized loss on marketable securities	(2,992)			(2,992)
Net income (loss)	(44,617)				(44,617)
Ending balance at Mar. 31, 2022	$ 267,537	$ 8	$ 762,458	$ (3,935)	$ (490,994)
Ending balance (in shares) at Mar. 31, 2022	81,986,192	82,324,677

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(22))
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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+ Details

Income Taxes - Additional Information (Details)	3 Months Ended
Income Taxes - Additional Information (Details)	Mar. 31, 2022	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Federal statutory income tax rate	21.00%
Effective tax rate	1.10%	0.00%

Stock-based Compensation - Summary of Restricted Stock Awards and Restricted Stock Units (Details) - Restricted Stock Units	3 Months Ended
	Mar. 31, 2022 $ / shares shares
Number of Shares
Number of Shares, Unvested, beginning balance \| shares	1,373,874
Number of Shares, Granted \| shares	118,000
Number of Shares, Vested \| shares	(104,368)
Number of Shares, Forfeited \| shares	(52,136)
Number of Shares, Unvested, ending balance \| shares	1,335,370
Weighted-average grant-date fair value
Weighted Average Grant Date Fair Value per Share, Unvested, beginning balance \| $ / shares	$ 18.35
Weighted Average Grant Date Fair Value per Share, Granted \| $ / shares	19.14
Weighted Average Grant Date Fair Value per Share, Vested \| $ / shares	19.67
Weighted Average Grant Date Fair Value per Share, Forfeited \| $ / shares	20.31
Weighted Average Grant Date Fair Value per Share, Unvested, ending balance \| $ / shares	$ 18.24