Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Common stock/Ordinary shares	Additional paid in capital	Accumulated other comprehensive income	Accumulated deficit	Total
Stockholders' equity, beginning balance at Dec. 31, 2018	$ 67	$ 462,514	$ 27	$ (393,978)	$ 68,630
Stockholders' equity, beginning balance (in shares) at Dec. 31, 2018	6,702
Consolidated Statements of Changes in Stockholders' Equity
Issuance of common stock & ordinary shares	$ 26	48,056			48,082
Issuance of common stock & ordinary shares (in shares)	2,584
Shares issued in connection with the vesting of restricted share units	$ 1	(1)
Shares issued in connection with the vesting of restricted share units (in shares)	66
Shares issued in connection with the employee stock purchase plan		372			372
Shares issued in connection with the employee stock purchase plan (in shares)	21
Shares issued in connection with the acquisition of Zavante Therapeutics, Inc.	$ 1	(1)
Shares issued in connection with the acquisition of Zavante Therapeutics, Inc. (in shares)	82
Equity transaction costs		(2,794)			(2,794)
Stock-based compensation expense		9,748			9,748
Net loss				(82,764)	(82,764)
Stockholders' equity, ending balance at Dec. 31, 2019	$ 95	517,894	27	(476,742)	41,274
Stockholders' equity, ending balance (in shares) at Dec. 31, 2019	9,455
Consolidated Statements of Changes in Stockholders' Equity
Issuance of common stock & ordinary shares	$ 116	60,944			61,060
Issuance of common stock & ordinary shares (in shares)	11,571
Shares issued in connection with the vesting of restricted share units (in shares)	44
Shares issued in connection with the employee stock purchase plan		43			43
Shares issued in connection with the employee stock purchase plan (in shares)	9
Equity transaction costs		(4,977)			(4,977)
Stock-based compensation expense		5,219			5,219
Net loss				(69,484)	(69,484)
Stockholders' equity, ending balance at Dec. 31, 2020	$ 211	579,123	27	(546,226)	33,135
Stockholders' equity, ending balance (in shares) at Dec. 31, 2020	21,079
Consolidated Statements of Changes in Stockholders' Equity
Issuance of common stock & ordinary shares	$ 348	69,790			70,138
Issuance of common stock & ordinary shares (in shares)	34,922
Shares issued in connection with the vesting of restricted share units	$ 2				2
Shares issued in connection with the vesting of restricted share units (in shares)	82
Equity transaction costs, shares issued, value	$ 6	(3,772)			(3,766)
Equity transaction costs, shares issued (in shares)	632
Stock-based compensation expense		3,291			3,291
Net loss				(49,450)	(49,450)
Stockholders' equity, ending balance at Dec. 31, 2021	$ 567	$ 648,432	$ 27	$ (595,676)	$ 53,350
Stockholders' equity, ending balance (in shares) at Dec. 31, 2021	56,715