Leases (Tables)

3 Months Ended

Dec. 31, 2023

Leases [Abstract]

Schedule of Lease Assets and Liabilities and Lease Cost

The components of lease assets and liabilities along with their classification on the Company’s consolidated balance sheets were as follows:

Lease Assets and Liabilities	Classification	December 31, 2023		September 30, 2023
		(in thousands)
Operating lease assets	Right-of-use assets	$	44,907	$	45,297
Current operating lease liabilities	Lease liabilities	3,421		10,563
Non-current operating lease liabilities	Lease liabilities, net of current portion	115,157		104,608

		Three Months Ended December 31,
Lease Cost	Classification	2023		2022
Operating lease cost	Research and development	$	2,994	$	2,069
	General and administrative expense	476		533
Variable lease cost (1)	Research and development	779		210
	General and administrative expense	—		—
Total		$	4,249	$	2,812

(1) Variable lease cost is primarily related to operating expenses associated with the Company’s operating leases.

Summary of Maturities of Operating Lease Liabilities on an Undiscounted Basis

The following table presents maturities of operating lease liabilities on an undiscounted basis as of December 31, 2023:

Year	Amounts
	(in thousands)
2024 (remainder of fiscal year)	$	9,044
2025	15,356
2026	15,696
2027	14,869
2028	13,511
2029 and thereafter	128,356
Total	$	196,832
Less imputed interest	$	(78,254)
Total operating lease liabilities (includes current portion)	$	118,578

Supplemental cash flow and other information related to leases was as follows:

	Three Months Ended December 31,
	2023			2022
	(in thousands)
Cash received for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	3,099		$	—
Right-of-use assets obtained in exchange for amended operating lease liabilities	$	64		$	—
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	2,080		$	1,331
	December 31,
	2023			2022
Weighted-average remaining lease term (in years)	13.3			6.9
Weighted-average discount rate	8.0		%	8.5		%