Share-based compensation (Tables)

3 Months Ended

Mar. 31, 2020

Share-based compensation

Schedule of share-based compensation expense by classification included in consolidated statements of operations and comprehensive loss

	Three months ended March 31,
	2020		2019
	(in thousands)
Research and development	$	2,382	$	1,980
Selling, general and administrative		1,958		2,298
Total	$	4,340	$	4,278

Schedule of share-based compensation expense

	Three months ended March 31,
	2020		2019
	(in thousands)
Award type
Share options	$	2,208	$	2,076
Restricted share units (“RSUs”)		1,444		930
Performance share units (“PSUs”)		688		1,272
Total	$	4,340	$	4,278

Schedule of unrecognized compensation cost related to unvested awards

	Unrecognized		Weighted average
	share-based		remaining
	compensation		period for
	expense		recognition
	(in thousands)		(in years)
Award type
Share options	$	28,880	3.10
Restricted share units		16,746	2.40
Performance share units		4,278	1.58
Total	$	49,904	2.73

Schedule of weighted-average assumptions for fair value of option issued

	Three months ended March 31,
Assumptions	2020	2019
Expected volatility	70%	75%
Expected terms	10 years	10 years
Risk free interest rate	1.44%	2.80% - 2.87%
Expected dividend yield	0%	0%

Summary of RSUs activity

	RSU
		Weighted average
	Number of	grant-date fair
	ordinary shares	value
Non-vested at December 31, 2019	370,830	$	28.62
Granted	216,749	$	51.81
Vested	(166,974)	$	18.90
Forfeited	(1,535)	$	48.07
Non-vested at March 31, 2020	419,070	$	44.41
Total weighted average grant date fair value of RSUs granted during the period (in $ millions)		$	11.2

Summary of PSUs activity

	PSU
		Weighted average
	Number of	grant-date fair
	ordinary shares	value
Non-vested at December 31, 2019	479,422	$	21.17
Granted	91,003	$	57.56
Vested	(354,105)	$	17.44
Non-vested at March 31, 2020	216,320	$	42.58
Total weighted average grant date fair value of PSUs granted during the period (in $ millions)		$	5.2

2014 Plan

Share-based compensation

Summary of option activity

	Options
	Number of	Weighted average
	ordinary shares	exercise price
Outstanding at December 31, 2019	2,683,104	$	21.29
Granted	393,302	$	51.81
Forfeited	(8,214)	$	40.82
Exercised	(64,762)	$	14.38
Outstanding at March 31, 2020	3,003,430	$	25.38
Thereof, fully vested and exercisable at March 31, 2020	1,528,351	$	15.75
Thereof, outstanding and expected to vest at March 31, 2020	1,475,079	$	35.36

Total weighted average grant date fair value of options issued during the period (in $ millions)	$	11.5
Proceeds from option sales during the period (in $ millions)	$	0.9