Stock-Based Awards (Tables)

12 Months Ended

Sep. 30, 2023

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,
	2023			2022			2021
Risk-free interest rate		3.88	%		1.72	%		0.61	%
Expected term (in years)		6.04			6.04			6.05
Expected volatility		48	%		47	%		52	%
Expected dividends		0	%		0	%		0	%
Weighted average grant date fair value	$	22.71		$	33.22		$	21.76

Summary of Stock Option Activity Including Performance Based Options

The following table summarizes stock option activity, including aggregate intrinsic value for the year ended September 30, 2023:

	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, 2022		3,993		$	53.57		6.2	$	28,778
Granted		765			44.47
Exercised		(124	)		17.83
Forfeited		(269	)		58.64
Outstanding as of September 30, 2023		4,365		$	52.68		5.9	$	—
Options vested and expected to vest as of    September 30, 2023		4,365		$	52.68		5.9	$	—
Options exercisable as of September 30, 2023		3,086		$	52.20		4.9	$	—

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,
	2023		2022		2021
	(in thousands)
Aggregate intrinsic value of stock options exercised	$	3,295	$	17,650	$	2,704
Proceeds to Company from stock options exercised	$	2,208	$	21,262	$	3,614

Summary of Restricted Stock Unit Activity

The following table summarizes the restricted stock unit activity for the year ending September 30, 2023:

	Restricted Stock Units			Weighted Average Grant Date Fair Value per Share
	(in thousands, except per share data)
Unvested at September 30, 2022		219		$	64.03
Granted		280			44.63
Vested		(61	)		61.94
Cancelled		(27	)		53.98
Unvested at September 30, 2023		411		$	51.78

Stock-Based Compensation Expense

The Company recorded the following stock-based compensation expense for the years ended September 30, 2023, 2022, and 2021:

	Years Ended September 30,
	2023		2022		2021
	(in thousands)
Research and development	$	9,551	$	9,728	$	10,075
General and administrative		18,665		17,241		10,916
	$	28,216	$	26,969	$	20,991

	Years Ended September 30,
	2023		2022		2021
	(in thousands)
Stock options	$	19,784	$	19,615	$	18,004
rTSRUs		1,893		1,597		1,537
PSUs		542		2,628		235
Restricted stock units		5,997		3,129		1,215
	$	28,216	$	26,969	$	20,991

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,
	2023			2022			2021
Risk-free interest rate		4.19	%		0.94	%		0.13	%
Dividend yield		0	%		0	%		0	%
Expected volatility		77	%		80	%		74	%
Performance period (years)		2.03			1.97			1.97

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, 2023:

	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, 2022		101		$	54.50		101		$	36.14
Granted		50			47.24		50			40.32
Vested		(70	)		44.58		(70	)		27.88
Cancelled		—			—		—			—
Unvested at September 30, 2023		81		$	58.58		81		$	45.82