CONSOLIDATED STATEMENTS OF SHAREHOLDERS’ EQUITY - USD ($) $ in Thousands	Common Shares Follow-On Offering	Common Shares Private Placement	Common Shares	Additional Paid-In Capital Follow-On Offering	Additional Paid-In Capital Private Placement	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit	Follow-On Offering	Private Placement	Total
Balance at the beginning of the period at Dec. 31, 2018			$ 13			$ 473,483	$ (4)	$ (194,225)			$ 279,267
Balance at the beginning of the period (in shares) at Dec. 31, 2018			49,489,647
Changes in equity
Issuance of common shares upon completion of offering, net of underwriting discounts and commissions and offering costs	$ 2			$ 48,474	$ 34,511				$ 48,476	$ 34,511
Issuance of common shares upon completion of offering, net of underwriting discounts and commissions and offering costs (in shares)	2,816,110	2,000,000
Common shares issued or to be issued in connection with the acquisition of all issued and outstanding equity securities of Primatope Therapeutics, Inc.						7,000					7,000
Common shares issued or to be issued in connection with the acquisition of all issued and outstanding equity securities of Primatope Therapeutics, Inc. (in shares)			337,008
Exercise of options						181					181
Exercise of options (in shares)			50,070
Share-based compensation expense						2,893					2,893
Unrealized gain on short-term investments							12				12
Net loss								(65,821)			(65,821)
Balance at the end of the period at Mar. 31, 2019			$ 15			566,542	8	(260,046)			306,519
Balance at the end of the period (in shares) at Mar. 31, 2019			54,692,835
Balance at the beginning of the period at Dec. 31, 2019			$ 15			581,467	33	(356,092)			225,423
Balance at the beginning of the period (in shares) at Dec. 31, 2019			54,937,628
Changes in equity
Exercise of options						2,414					2,414
Exercise of options (in shares)			643,867
Share-based compensation expense						4,209					4,209
Unrealized gain on short-term investments							207				207
Net loss								(26,419)			(26,419)
Balance at the end of the period at Mar. 31, 2020			$ 15			$ 588,090	$ 240	$ (382,511)			$ 205,834
Balance at the end of the period (in shares) at Mar. 31, 2020			55,581,495