Quarterly report pursuant to Section 13 or 15(d)

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDER'S EQUITY

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDER'S EQUITY - USD ($) $ in Thousands	Total	Follow On Offering	At The Market	Common Stock	Common Stock Follow On Offering	Common Stock At The Market	Additional Paid-In Capital	Additional Paid-In Capital Follow On Offering	Additional Paid-In Capital At The Market	Accumulated Other Comprehensive (Loss) Gain	Accumulated Deficit
Balance at Dec. 31, 2019	$ 79,184			$ 43			$ 372,100			$ 24	$ (292,983)
Balance (in shares) at Dec. 31, 2019				43,367,801
Exercise of stock options	212						212
Exercise of stock options, Shares				49,100
Vesting of restricted stock units				103,462
Issuance of shares under Employee Stock Purchase Plan	223						223
Issuance of shares under Employee Stock Purchase Plan, Shares				36,708
Stock-based compensation expense	5,186						5,186
Issuance of common stock / preferred stock, warrants, net of issuance costs			$ 11,919			$ 2			$ 11,917
Issuance of common stock / preferred stock, net of issuance costs (in shares)						2,201,810
Issuance of warrants	128						128
Other comprehensive loss	(24)									(24)
Net loss	(34,422)										(34,422)
Balance at Jun. 30, 2020	62,406			$ 45			389,766				(327,405)
Balance (in shares) at Jun. 30, 2020				45,758,881
Balance at Dec. 31, 2019	79,184			$ 43			372,100			24	(292,983)
Balance (in shares) at Dec. 31, 2019				43,367,801
Net loss	(84,000)
Balance at Dec. 31, 2020	$ 90,553			$ 56			467,518				(377,021)
Balance (in shares) at Dec. 31, 2020	56,222,746			56,222,746
Balance at Mar. 31, 2020	$ 76,543			$ 45			386,704			3	(310,209)
Balance (in shares) at Mar. 31, 2020				45,690,718
Exercise of stock options	112						112
Exercise of stock options, Shares				18,505
Vesting of restricted stock units				12,950
Issuance of shares under Employee Stock Purchase Plan	223						223
Issuance of shares under Employee Stock Purchase Plan, Shares				36,708
Stock-based compensation expense	2,727						2,727
Other comprehensive loss	(3)									(3)
Net loss	(17,196)										(17,196)
Balance at Jun. 30, 2020	62,406			$ 45			389,766				(327,405)
Balance (in shares) at Jun. 30, 2020				45,758,881
Balance at Dec. 31, 2020	$ 90,553			$ 56			467,518				(377,021)
Balance (in shares) at Dec. 31, 2020	56,222,746			56,222,746
Exercise of stock options	$ 157						157
Exercise of stock options, Shares	20,134			20,134
Vesting of restricted stock units				244,312
Issuance of shares under Employee Stock Purchase Plan	$ 153						153
Issuance of shares under Employee Stock Purchase Plan, Shares				33,058
Stock-based compensation expense	5,383						5,383
Issuance of common stock / preferred stock, warrants, net of issuance costs		$ 70,468			$ 5			$ 70,463
Issuance of common stock / preferred stock, net of issuance costs (in shares)					5,400,000
Other comprehensive loss	(19)									(19)
Net loss	(36,718)										(36,718)
Balance at Jun. 30, 2021	$ 129,977			$ 61			543,674			(19)	(413,739)
Balance (in shares) at Jun. 30, 2021	61,920,250			61,920,250
Balance at Mar. 31, 2021	$ 149,880			$ 61			541,068				(391,249)
Balance (in shares) at Mar. 31, 2021				61,849,642
Vesting of restricted stock units				37,550
Issuance of shares under Employee Stock Purchase Plan	153						153
Issuance of shares under Employee Stock Purchase Plan, Shares				33,058
Stock-based compensation expense	2,453						2,453
Other comprehensive loss	(19)									(19)
Net loss	(22,490)										(22,490)
Balance at Jun. 30, 2021	$ 129,977			$ 61			$ 543,674			$ (19)	$ (413,739)
Balance (in shares) at Jun. 30, 2021	61,920,250			61,920,250