Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2022

Stock Option Activity

The following summarizes stock option activity under the 2017 Inducement Plan, 2015 Plan and 2012 Plan:

	Number of Options			Weighted-Average Exercise Price
Outstanding—December 31, 2021		3,553,763		$	42.00
Options granted		671,701			29.32
Options exercised		(36,668	)		14.73
Options canceled		(150,247	)		50.13
Outstanding—June 30, 2022		4,038,549		$	39.84

Valuation Assumptions for Stock Awards

The fair values of stock options granted to employees were calculated using the following assumptions:

	Three Months Ended June 30,		Six Months Ended June 30,
	2022	2021	2022	2021
Expected term (in years)	5.3	5.3-6.1	5.3-6.1	5.3-6.1
Volatility	65.50%	68.1%-72.2%	65.5%-70.5%	68.1%-72.7%
Risk-free interest rate	3.6%	1.0%-1.1%	1.4%-3.6%	0.9%-1.1%
Dividend yield	—	—	—	—

Non-Vested Restricted Stock Activity

The following table summarizes activity of restricted stock units, or RSUs, granted to employees with service-based vesting under the 2017 Inducement Plan and 2015 Plan and related information:

				Weighted-
				Average
	Number			Grant Date
	of RSUs			Fair Value
Non-vested units — December 31, 2021		2,986,269		$	45.37
RSUs granted		1,886,774			29.83
RSUs vested		(482,023	)		51.13
RSUs forfeited		(300,044	)		40.03
Non-vested units — June 30, 2022		4,090,976		$	37.92

Summary of Activity of Market-Condition Awards

The compensation cost for the RSUs with a market condition is not reversed when the market condition is not satisfied. The target prices and vesting tranches are set forth in the following table:

Stock Price Targets		Number of Units Allowed
$	109.20		90,160
$	145.60		157,780
$	182.00		202,860

Valuation Assumptions of Total Shareholder Return RSU Awards

The following table summarizes the 2020 Market-Condition RSU Awards granted and forfeited during the six months ended June 30, 2022:

					Weighted-
			Weighted-		Average
			Average		Remaining		Aggregate
	Number		Grant Date		Vesting		Intrinsic
	of RSUs		Fair Value		Period (years)		Value
Non-vested market-condition awards — December 31, 2021		450,800	$	43.17		0.30	$	13,195
Granted		—		—		—
Vested		—		—		—
Forfeited		—		—		—
Non-vested market condition awards — June 30, 2022		450,800	$	43.15		0.21	$	14,403

Stock-based Compensation Expense Recognized

Total stock-based compensation recognized by function included in the condensed consolidated statements of operations and comprehensive loss was as follows (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Research and development	$	5,926	$	4,906	$	11,457	$	10,216
Selling, general and administrative		13,917		15,064		27,527		30,134
Total stock-based compensation expense	$	19,843	$	19,970	$	38,984	$	40,350

Schedule of Market - Based Share Awards

The TSR percentile rankings and performance multipliers for the TSR RSU Awards are set forth in the following table:

Total Shareholder Return Percentile Rank within the Performance Measurement Index	Performance Multiplier if Total Shareholder Return is ≥ 0%	Performance Multiplier if Total Shareholder Return is < 0%
100th Percentile or higher	200%	100%
50th Percentile	100%	100%
25th Percentile	50%	50%
Below 25th Percentile	0%	0%

Summary of the TSR RSU Awards Granted

The following table summarizes the TSR RSU Awards granted during the six months ended June 30, 2022:

					Weighted-
			Weighted-		Average
			Average		Remaining		Aggregate
	Number		Grant Date		Vesting		Intrinsic
	of RSUs		Fair Value		Period (years)		Value
Total Shareholder Return awards — December 31, 2021		—	$	—		—	$	—
Granted		98,276		47.34		2.59
Vested		—		—		—
Forfeited		—		—		—
Total Shareholder Return awards— June 30, 2022		98,276	$	47.34		2.59	$	3,140

Schedule of Performance Based RSU Awards Granted

The following table summarizes the Patient Share RSU Awards granted during the six months ended June 30, 2022:

					Weighted-
			Weighted-		Average
			Average		Remaining		Aggregate
	Number		Grant Date		Vesting		Intrinsic
	of RSUs		Fair Value		Period (years)		Value
Performance-based awards — December 31, 2021		—	$	—		—	$	—
Granted		98,277		29.87		2.59
Vested		—		—		—
Forfeited		—		—		—
Performance-based awards— June 30, 2022		98,277	$	29.87		2.59	$	3,140

Summary of Assumptions used to Estimate the Fair Value of the TSR RSU Awards

The following table summarizes the assumptions used to estimate the fair value of the TSR RSU Awards as of the grant date:

	Six Months Ended June 30,
	2022
Expected term (in years)	2.84
Volatility	66.01%
Risk-free interest rate	1.4%
Dividend yield	—

Schedule of Patient Share Percentage And Performance Multiplier

The patient share percentages and performance multipliers for the Patient Share RSU Awards are set forth in the following table:

Patient Share	Performance Multiplier
19.80%	200%
18%	100%
16.20%	50%
Below 16.2%	0%