Note 9 - Net Loss Per Share of Common Stock (Tables)

3 Months Ended

Mar. 31, 2022

Notes Tables

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

	Three Months Ended
	March 31,
	2022			2021
Net loss	$	(13,057	)	$	(8,004	)
Basic and diluted net loss per share	$	(0.62	)	$	(0.44	)
Weighted-average shares used to compute basic and diluted net loss per share		21,130			18,067

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

	Three Months Ended
	March 31,
	2022		2021
Options to purchase common stock		3,677,075		2,540,737
Pre-funded warrants to purchase common stock		4,545,455		—
Common stock warrants		4,850,241		—