Net Loss per Share - Summary of Basic and Diluted Net Loss per Share Attributable to Common Stockholders (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Net loss	$ (19,423)	$ (23,258)
Deemed dividend		(549)
Net loss attributable to common stockholders	$ (19,423)	$ (23,807)
Denominator:
Weighted average common shares outstanding, basic and diluted	29,414,148	19,557,418
Net loss per share, basic and diluted	$ (0.66)	$ (1.22)