Basis of Presentation (Tables)

9 Months Ended

Sep. 30, 2020

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Summary of Financial Instruments Measured at Fair Value on Recurring Basis

The following tables summarize the Company’s financial instruments measured at fair value on a recurring basis:

			Fair Value Measurements At Reporting Date Using
	Total		Quoted Prices in Active Markets For Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
As of September 30, 2020
Assets:
Commercial paper	$	3,249	$	—	$	3,249	$	—
Corporate debt securities		4,707		—		4,707		—
Asset backed securities		3,002		—		3,002		—
Total assets measured at fair value	$	10,958	$	—	$	10,958	$	—
As of December 31, 2019
Assets:
Commercial paper	$	9,694	$	—	$	9,694	$	—
Corporate debt securities		24,781		—		24,781		—
Asset backed securities		5,508		—		5,508		—
Total assets measured at fair value	$	39,983	$	—	$	39,983	$	—
Liabilities:
Preferred stock warrant liability	$	184	$	—	$	—	$	184

Summary of Assumptions Used in Black-Scholes Option Pricing Model to Determine Fair Value of Warrant Liability

The assumptions used in the Black-Scholes option pricing model to determine the fair value of the warrant liability were as follows:

	September 15, 2020 (Conversion Date)			December 31, 2019
Fair value of underlying preferred stock	$	13.00		$	9.79
Exercise price	$	10.812		$	10.812
Risk-free interest rate		0.7	%		1.9	%
Expected volatility		93.3	%		80.0	%
Expected term (in years)		9.0			9.7
Expected dividend yield		—			—

Summary of Reconciliation of Warrant Liability Measured at Fair Value Using Level 3 Significant Unobservable Inputs

The following table provides a reconciliation of the warrant liability measured at fair value using Level 3 significant unobservable inputs:

	Warrant Liability
Balance at December 31, 2019	$	184
Change in fair value of warrant liability		75
Conversion to common stock warrant upon completion of IPO		(259	)
Balance at September 30, 2020		-

Summary of Short-Term Investments

The following tables summarize short-term investments (in thousands):

	As of September 30, 2020
			Unrealized
	Amortized Cost		Gains		Losses		Estimated Fair Value
Commercial paper	$	3,243	$	6	$	—	$	3,249
Corporate debt securities		4,701		6		—		4,707
Asset backed securities		3,000		2		—		3,002
Total	$	10,944	$	14	$	—	$	10,958

	As of December 31, 2019
			Unrealized
	Amortized Cost		Gains		Losses			Estimated Fair Value
Commercial paper	$	9,680	$	14	$	—		$	9,694
Corporate debt securities		24,762		20		(1	)		24,781
Asset backed securities		5,500		8		—			5,508
Total	$	39,942	$	42	$	(1	)	$	39,983

Summary of Potentially Dilutive Securities Not Included in Calculation of Diluted Net Loss Per Share

Potentially dilutive securities not included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows (in common stock equivalent shares):

	September 30,		December 31,
	2020		2019
Convertible preferred stock		—		16,685,014
Preferred stock warrant		—		23,122
Common stock warrant		23,122		—
Common stock options		3,332,545		1,684,630
Unvested common stock		47,920		197,549
Total		3,403,587		18,590,315

Schedule of Property and Equipment

Property and equipment consist of the following (in thousands):

	September 30,			December 31,
	2020			2019
Laboratory equipment	$	1,088		$	945
Computer equipment and software		207			182
Furniture and fixtures		178			178
Leasehold improvements		136			132
Property and equipment, gross		1,609			1,437
Less accumulated depreciation and amortization		(919	)		(702	)
Property and equipment, net	$	690		$	735

Schedule of Accrued liabilities

Accrued liabilities consist of the following (in thousands):

	September 30,		December 31,
	2020		2019
Accrued compensation	$	1,099	$	976
Accrued research and development		846		2,369
Other accrued liabilities		780		204
	$	2,725	$	3,549