Income taxes (Tables)

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Schedule of Income Tax Reconciliation

A reconciliation of income tax expense computed at the U.S. federal statutory income tax rate to the Company’s income tax expense is as follows (in thousands):

	Years Ended December 31,
	2022			2021
Tax computed at the federal statutory rate	$	(22,361	)	$	(20,034	)
State income taxes, net of federal tax benefit		(6	)		—
Deferred impact of conversion to C Corporation		—			(2,131	)
Nondeductible executive compensation		685			4,145
Stock-based compensation		1,132			(1,021	)
Research and development and orphan drug credits		(3,692	)		(3,091	)
Uncertain tax positions		910			757
Other, net		(23	)		793
Valuation allowance		23,355			20,582
Income tax expense	$	—		$	—

Schedule of Deferred Tax Assets and Liabilities

The Company’s net deferred tax assets (liabilities) are as follows (in thousands):

	Years Ended December 31,
	2022			2021
Deferred tax assets:
Net operating loss carryforwards	$	17,430		$	21,935
Liability to licensor		4,159			4,159
Goodwill		3,193			3,449
Lease liability		836			1,128
Accrued compensation		659			485
Research credit carryforwards		5,760			2,945
Section 174 cost capitalization		14,523			—
Section 59(e) cost capitalization		9,450			—
Stock-based compensation		1,628			697
Other		3			2
Gross deferred tax assets		57,641			34,800
Less: valuation allowance		(56,706	)		(33,351	)
Total deferred tax assets		935			1,449
Deferred tax liabilities:
Fixed assets		(426	)		(756	)
Operating lease right-of-use asset		(509	)		(693	)
Total deferred tax liabilities		(935	)		(1,449	)
Net deferred tax assets	$	—		$	—

Schedule of Unrecognized Tax Benefits

	Years Ended December 31,
	2022		2021
Unrecognized tax benefits - beginning	$	1,011	$	210
Gross increases - tax positions in prior period		11		0
Gross increase – current-period tax positions		946		801
Unrecognized tax benefits - ending	$	1,968	$	1,011