CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenues:
Total revenues	$ 174	$ 685
Operating expenses:
Research and development	17,056	12,720
General and administrative	6,911	4,121
(Gain) loss on fair value remeasurement of contingent consideration	(536)	483
Total operating expenses	23,431	17,324
Operating loss	(23,257)	(16,639)
Investment and other income, net	207	101
Net loss	(23,050)	(16,538)
Net loss	$ (23,050)	$ (16,538)
Basic net loss per common share	$ (0.49)	$ (0.42)
Diluted net loss per common share	$ (0.49)	$ (0.42)
Shares used in calculating basic net loss per share	46,739	39,614
Shares used in calculating diluted net loss per share	46,739	39,614
Comprehensive loss:
Net loss	$ (23,050)	$ (16,538)
Other comprehensive income (loss):
Unrealized loss on marketable securities	(1,782)	(2)
Comprehensive loss	(24,832)	(16,540)
Product development and licensing agreements
Revenues:
Total revenues	30	3
Contracts and grants
Revenues:
Total revenues	$ 144	$ 682