Net Loss Per Share Attributable to Common Stockholders

12 Months Ended

Dec. 31, 2020

Net Loss Per Share Attributable to Common Stockholders

10. Net Loss Per Share Attributable to Common Stockholders

Basic and diluted net loss per common share is calculated as follows (in thousands except share and per share amounts):

	Year Ended December 31,
	2020			2019
Net loss	$	(27,531	)	$	(37,037	)
Cumulative dividends on convertible preferred stock		(7,189	)		(7,055	)
Net loss attributable to common stockholders	$	(34,720	)	$	(44,092	)
Net loss per common share—basic and diluted	$	(5.25	)	$	(33.41	)
Weighted-average number of shares used in computing net loss per common share—basic and diluted		6,618,445			1,319,912

The following outstanding potentially dilutive shares have been excluded from the calculation of diluted net loss per share due to their anti-dilutive effect:

	As of December 31,
	2020		2019
Convertible preferred stock		—		117,809,883
Stock options to purchase common stock		2,756,102		2,117,106
Restricted stock awards		80,000		—
Warrants to purchase common stock		27,759		27,759

Under the Series C Financing, up to 17,014,902 shares of convertible preferred stock could have been contingently issued upon achievement of certain development milestones. However, in September 2020, the board of directors and the Series C investors amended the Series C stock purchase agreement such that the Preferred Stock Tranche Obligation was no longer exercisable and expired upon the effectiveness of the Company’s IPO registration statement.