Income taxes (Tables)

12 Months Ended

Dec. 31, 2019

Income taxes

Schedule of current and deferred tax provision

	Year ended December 31,
	2019		2018
Current income tax provision:
Federal	$	—	$	—
State		24		—
Total current income tax provision		24		—
Deferred income tax benefit:
Federal		(9,400)		(4,199)
State		688		(1,239)
Total deferred income tax benefit		(8,712)		(5,438)
Change in deferred tax asset valuation allowance		(8,712)		(5,438)
Total provision for income taxes	$	24	$	—

Schedule of reconciliation of the U.S. federal statutory income tax

	Year Ended December 31,
	2019		2018
Federal statutory income tax rate	21.0	%	21.0	%
State income taxes, net of federal benefit	(1.6)		1.5
Research and development tax credits	1.9		0.1
Change in preferred stock tranche obligation	-		(16.0)
Change in deferred tax asset valuation allowance	(19.9)		(6.6)
Effect of Section 382 limitation	(1.5)		-
Effective income tax rate	(0.1)	%	0.0	%

Schedule of Net deferred tax assets

	December 31,
	2019		2018
Deferred tax assets
Net operating loss carry forwards	$	11,380	$	2,899
Research and development tax credit carry forwards		969		231
License fees		3,232		3,669
Stock based compensation		196		—
Accruals, reserves and other		44		1
Total deferred tax assets		15,821		6,800
Deferred tax liabilities
Prepaid expenses		(309)		—
Total deferred tax liabilities		(309)		—
Net deferred tax assets		15,512		6,800
Valuation allowance		(15,512)		(6,800)
Total net deferred tax assets	$	—	$	—

Schedule of changes in the valuation allowance for deferred tax assets

	2019		2018
Valuation allowance as of January 1,	$	(6,800)	$	(1,362)
Increases recorded to income tax provision		—		—
Decreases recorded as a benefit to income tax provision		(8,712)		(5,438)
Valuation allowance as of December 31,	$	(15,512)	$	(6,800)

Schedule of unrecognized tax benefits roll Forward

	2019
Balance as of December 31, 2018	$	—
Increases related to prior year tax positions		—
Decreases related to prior year tax positions		—
Increases related to current year tax positions		237
Settlements		—
Lapse of statute of limitations		—
Balance as of December 31, 2019	$	237