Stock-Based Awards (Tables)

12 Months Ended

Sep. 30, 2019

Data Used to Determine Value of Stock Option Grants, Presented on Weighted Average Basis

The relevant data used to determine the value of the stock option awards are as follows, presented on a weighted average basis:

	Years Ended September 30,
	2019			2018			2017
Risk-free interest rate		2.76	%		2.29	%		1.97	%
Expected term (in years)		6.05			6.05		6.05
Expected volatility		55	%		57	%		60	%
Expected dividends		0	%		0	%		0	%

Stock Option Activity

The following table summarizes stock option activity, including aggregate intrinsic value for the year ended September 30, 2019:

	Shares Issuable Under Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term in years		Aggregate Intrinsic Value
	(in thousands)							(in thousands)
Outstanding as of September 30, 2018		2,624		$	36.65		7.1	$	129,115
Granted		653			82.41
Exercised		(231	)		29.68
Forfeited		(79	)		63.68
Outstanding as of September 30, 2019		2,967		$	46.54		6.7	$	57,336
Options vested and expected to vest as of September 30, 2019		2,967		$	46.54		6.7	$	57,336
Options exercisable as of September 30, 2019		1,954		$	37.09		5.7	$	48,839

Summary of Additional Exercise and Grant Date Information

The aggregate intrinsic value of options is calculated as the difference between the exercise price of the options and the fair value of the Company’s common stock. The following tables summarize additional exercise and grant date information:

	Years Ended September 30,
	2019		2018		2017
	(in thousands)
Aggregate intrinsic value of stock options exercised	$	13,855	$	14,180	$	1,503
Proceeds to Company from stock options exercised	$	6,848	$	6,243	$	1,079

Summary of Restricted Stock Unit Activity

The following table summarizes the restricted stock unit activity for the year to date period ending September 30, 2019:

	Restricted Stock Units			Weighted Average Grant Date Fair Value per Share
	(in thousands, except per share data)
Unvested at September 30, 2018		109		$	30.00
Granted		—			—
Vested		—			—
Cancelled		(14	)		30.00
Unvested at September 30, 2019		95		$	30.00

Stock-Based Compensation Expense

The Company recorded the following stock-based compensation expense for the years ended September 30, 2019, 2018, and 2017:

	Years Ended September 30,
	2019		2018		2017
	(in thousands)
Research and development	$	8,833	$	6,160	$	4,078
General and administrative		10,393		9,685		8,993
	$	19,226	$	15,845	$	13,071

	Years Ended September 30,
	2019		2018		2017
	(in thousands)
Stock options	$	15,854	$	12,694	$	10,442
rTSRUs		1,568		1,721		1,267
PSUs		1,278		641		668
Restricted stock units		526		789		694
	$	19,226	$	15,845	$	13,071

Relative Total Stockholder Return Units [Member]

Data Used to Determine Value of Stock Option Grants, Presented on Weighted Average Basis

. The table below sets forth the weighted average grant date fair value assumptions used to value the rTSRUs:

	Years Ended September 30,
	2019			2018			2017
Risk-free interest rate		2.65	%		2.18	%		1.24	%
Dividend yield		0	%		0	%		0	%
Expected volatility		62	%		62	%		66	%
Remaining performance period (years)		2.03			1.83			1.99

Performance Share Units and Relative Total Stockholder Return Units [Member]

Summary of PSUs and rTSRUs Activity

The following table summarizes PSU and rTSRU activity (at target) for the year ended September 30, 2019:

	PSUs					rTSRUs
	Shares			Weighted Average Grant Date Fair Value per Share		Shares			Weighted Average Grant Date Fair Value per Share
	(in thousands, except per share data)
Unvested at September 30, 2018		70		$	50.97		70		$	59.96
Granted		21			67.13		21			47.42
Vested		(36	)		35.89		(45	)		46.11
Cancelled		(14	)		49.20		(5	)		68.13
Unvested at September 30, 2019		41		$	73.02		41		$	67.76