Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

Schedule of Income before Income Tax, Domestic and Foreign

Loss before the provision for income taxes for the years ended December 31, 2019, 2018 and 2017 consisted of the following:


	Year Ended December 31,
(in thousands)	2019		2018		2017
United States	$	(52,314)	$	(33,285)	$	(21,994)
Foreign (Austria)	(493)		—		—
	$	(52,807)	$	(33,285)	$	(21,994)

Schedule of Effective Income Tax Rate Reconciliation

A reconciliation of the U.S. federal statutory income tax rate to the Company's effective income tax rate is as follows:


	Year Ended December 31,
	2019		2018		2017
U.S. federal statutory income tax rate	(21.0)	%	(21.0)	%	(34.0)	%
State income taxes, net of federal benefit	(5.8)		(6.2)		(8.4)
Foreign rate differential	(0.1)		—		—
Research and development tax credits	(1.1)		(3.7)		(1.8)
Change in fair value of preferred stock warrant liability	0.1		2.4		(2.2)
Other permanent differences	1.4		0.9		0.5
Remeasurement of deferred taxes due to tax reform	—		—		27.8
Change in deferred tax asset valuation allowance	26.8		27.8		18.1
Other	(0.3)		(0.2)		—
Effective income tax rate	—	%	—	%	—	%

Schedule of Deferred Tax Assets and Liabilities

Net deferred tax assets as of December 31, 2019 and 2018 consisted of the following:


	December 31,
(in thousands)	2019		2018
Net operating loss carryforwards	$	65,487	$	15,482
Research and development tax credit carryforwards	3,654		2,710
Capitalized research and development expenses	2,626		2,837
Capitalized license fees	—		221
Accrual-to-cash basis conversion	—		1,367
Lease liabilities	765		—
Other	1,413		180
Total deferred tax assets	73,945		22,797
Valuation allowance	(73,410)		(22,797)
Deferred tax assets, net of valuation allowance	$	535	$	—
Right of use assets	535		—
Total deferred tax liabilities	$	535	$	—
Total deferred tax assets, net	$	—	$	—

Summary of Valuation Allowance

Changes in the valuation allowance for deferred tax assets during the years ended December 31, 2019, 2018 and 2017 related primarily to the increases in net operating loss carryforwards and research and development tax credit carryforwards and were as follows:


	Year Ended December 31,
(in thousands)	2019		2018		2017
Valuation allowance, beginning of year	$	(22,797)	$	(13,546)	$	(9,738)
Increases recorded to income tax provision	(14,485)		(9,251)		(3,808)
Acquisition of business	(36,128)		—		—
Valuation allowance, end of year	$	(73,410)	$	(22,797)	$	(13,546)