Additional

Accumulated Other

Total

Common

Paid-In

Comprehensive

Accumulated

Stockholders’

Shares

Amount

Capital

Loss

Deficit

Equity

Balance at December 31, 2021

74,485,883

$

7

$

1,745,870

$

(2,632

)

$

(703,001

)

$

1,040,244

Issuance of common stock through 
   at-the-market offerings, net of 
   issuance costs of $164

579,788

1

38,885

-

-

38,886

Exercise of stock options

503,830

-

8,435

-

-

8,435

Vesting of restricted stock units

54,666

-

-

-

-

Equity-based compensation

-

-

18,491

-

-

18,491

Other comprehensive loss - unrealized loss on marketable securities

-

-

-

(5,128

)

-

(5,128

)

Other comprehensive loss - equity method investment

-

-

-

(302

)

-

(302

)

Net loss

-

-

-

-

(146,872

)

(146,872

)

Balance at March 31, 2022

75,624,167

8

1,811,681

(8,062

)

(849,873

)

953,754

Exercise of stock options

315,747

-

4,827

-

-

4,827

Vesting of restricted stock units

36,515

-

-

-

-

-

Issuance of shares under employee 
   stock purchase plan

24,316

-

1,068

-

-

1,068

Equity-based compensation

-

-

23,068

-

-

23,068

Other comprehensive loss - unrealized loss on marketable securities

-

-

-

(932

)

-

(932

)

Other comprehensive loss - equity method investment

-

-

-

(560

)

-

(560

)

Net loss

-

-

-

-

(100,678

)

(100,678

)

Balance at June 30, 2022

76,000,745

$

8

$

1,840,644

$

(9,554

)

$

(950,551

)

$

880,547

Additional

Accumulated Other

Total

Common

Paid-In

Comprehensive

Accumulated

Stockholders’

Shares

Amount

Capital

Loss

Deficit

Equity

Balance at December 31, 2020

66,234,056

$

7

$

962,173

$

1

$

(435,109

)

$

527,072

Issuance of common stock through 
   at-the-market offerings, net of 
   issuance costs of $52

641,709

-

45,255

-

-

45,255

Exercise of stock options

1,014,569

-

13,340

-

-

13,340

Equity-based compensation

-

-

6,424

-

-

6,424

Other comprehensive loss - unrealized loss on marketable securities

-

-

-

(13

)

-

(13

)

Net loss

-

-

-

-

(46,205

)

(46,205

)

Balance at March 31, 2021

67,890,334

7

1,027,192

(12

)

(481,314

)

545,873

Exercise of stock options

394,801

-

6,163

-

-

6,163

Vesting of restricted stock units

26,235

-

-

-

-

-

Issuance of shares under employee 
   stock purchase plan

20,410

-

970

-

-

970

Equity-based compensation

-

-

10,614

-

-

10,614

Other comprehensive loss - unrealized loss on marketable securities

-

-

-

(1

)

-

(1

)

Net loss

-

-

-

-

(68,806

)

(68,806

)

Balance at June 30, 2021

68,331,780

$

7

$

1,044,939

$

(13

)

$

(550,120

)

$

494,813