Share-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2020

Share-based Payment Arrangement [Abstract]

Schedule of non-cash share-based compensation expense

Non-cash share-based compensation expense, consisting of expense for both stock options, Restricted Share Units ("RSUs") and Employee Share Purchase Plan ("ESPP"), was classified in the condensed consolidated statements of operations and comprehensive loss as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2019		2020		2019
Research and development expenses	$	6,426	$	10,330	$	12,677	$	14,030
Selling, general and administrative expenses	5,336		7,224		15,964		10,854
	$	11,762	$	17,554	$	28,641	$	24,884

Schedule of stock option activity

The following table is a summary of the Company's stock option activity for the six months ended June 30, 2020:

	Number of Shares	Weighted Average Exercise Price	Weighted Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value
Outstanding at December 31, 2019	9,423,015	$24.58
Granted	262,838	$51.79
Exercised	(1,518,142)	$10.81
Forfeited	(47,063)	$37.46
Outstanding at June 30, 2020	8,120,648	$27.96	7.49	$	366,753
Options exercisable at June 30, 2020	4,482,647	$19.46	6.63	$	240,550
Vested at June 30, 2020 and expected to vest in the future	8,120,648	$27.96	7.49	$	366,753

Schedule of RSU activity

The following table is a summary of the RSU activity for the six months ended June 30, 2020:

	Number of Shares	Weighted Average Grant Date Fair Value
Unvested outstanding as of December 31, 2019	88,950	$57.40
Granted	482,975	$54.89
Forfeited	(7,619)	$54.14
Vested	(86,508)	$55.82
Unvested outstanding as of June 30, 2020	477,798	$55.20