XML 40 R28.htm IDEA: XBRL DOCUMENT v3.21.1
Stock award plan - (Tables)
3 Months Ended
Mar. 31, 2021
Share-based Payment Arrangement [Abstract]  
Summary of stock option activity

    

    

    

Weighted-

    

  

Weighted-

average

Aggregate

average

remaining

intrinsic

Number of

exercise

contractual

value(in 

options

price

term

thousands)

 

Outstanding at December 31, 2020

 

9,663,677

$

38.72

 

  

 

  

Granted

 

1,954,690

66.49

 

  

 

  

Exercised

 

(415,783)

28.32

 

  

 

  

Forfeited/Cancelled

 

(213,382)

48.58

 

  

 

  

Outstanding at March 31, 2021

 

10,989,202

$

43.86

 

7.59

years

$

92,033

Vested or Expected to vest at March 31, 2021

 

5,591,504

$

48.46

 

8.69

years

$

31,047

Exercisable at March 31, 2021

 

4,750,569

$

37.14

 

6.07

years

$

58,970

Schedule of assumptions used to estimate fair values of grants made on the date of grant

    

Three months ended

    

March 31, 2021

Risk-free interest rate

 

0.51%

Expected volatility

 

88.61%

Expected term

 

5.5 years

Summary of information on the Company's restricted stock

Restricted Stock Awards and Units

Weighted

Average

Grant

Number of

Date

    

Shares

    

Fair Value

Unvested at December 31, 2020

982,058

$

41.78

Granted

 

850,365

66.49

Vested

 

(298,982)

34.13

Forfeited

 

(38,803)

56.13

Unvested at March 31, 2021

 

1,494,638

$

57.00

Schedule of share-based compensation expense recorded in the statement of operations

Three Months Ended March 31, 

    

2021

    

2020

Research and development

$

13,725

$

8,179

Selling, general and administrative

 

11,982

 

7,041

Total

$

25,707

$

15,220