In May 2018, the Company entered into a lease agreement for office, laboratory, and manufacturing space located at 5403 Betsy Ross Drive in Santa Clara, California, which consists of approximately 35,000 square feet (the “5403 Lease”). The term of the 5403 Lease commenced in September 2018 and ends in August 2022. In connection with the 5403 Lease, the Company maintains a letter of credit for the benefit of the landlord in the amount of $0.5 million, which is secured by restricted cash recorded as other assets on the consolidated balance sheets. In connection with the 5403 Lease, the Company has an operating lease right-of-use asset of $0.7 million as of September 30, 2021 and an aggregate lease liability of $0.8 million on its consolidated balance sheet. The remaining lease term is eleven months.

In December 2019, the Company entered into a lease agreement (i) for additional office, laboratory and manufacturing space located at 5353 Betsy Ross Drive in Santa Clara, California, which consists of approximately 50,200 square feet (the “5353 Lease”); and (ii) to modify the terms of the 5403 Lease. The 5403 Lease will continue in its existing terms (and with no changes to its terms, including its base rent) until its expiration on August 31, 2022, at which point the leased space under the 5403 Lease will become subject to the terms of the 5353 Lease. The initial term of the 5353 Lease began in December 2019 and was initially for 96 months.

The base rent of the first floor of the premises for the 5353 Betsy Ross building shall be abated for the first 19 months, and the base rent for the second floor of the 5353 Betsy Ross building shall be abated for the first four months. The landlord provided the Company with a tenant improvement allowance of up to $1.8 million for both 5403 and 5353 Betsy Ross buildings. In connection with the 5353 Lease, the Company provided an initial security deposit of $1.0 million in the form of a letter of credit, which is secured by restricted cash recorded as other assets on the consolidated balance sheets. While this amount will increase to $1.5 million on September 1, 2022 when the office, laboratory and manufacturing space of the 5403 Lease is included under the terms of the 5353 Lease, the letter of credit will be reduced annually from and after September 1, 2022 until the expiration of the 5353 Lease.

In September 2021, the Company amended the 5353 Lease (the “Amended Lease”), which extended the initial lease terms for both 5403 and 5353 Betsy Ross buildings by approximately 48.5 months to December 31, 2031. The Company accounted for this amendment as a lease modification for the lease of the 5353 Building. As of September 30, 2021, the lease of the 5403 Betsy Ross building under the modified terms has not yet commenced. The Amended Lease also contains an expansion option, which can be exercised after June 1, 2023, to lease an adjacent building consisting of approximately 35,000 square feet.

In connection with the lease of the 5353 Betsy Ross building, the Company has recorded an operating lease right-of-use asset of $10.9 million as of September 30, 2021 and an aggregate lease liability of $11.9 million on its consolidated balance sheet. The remaining lease term is ten years and three months.

Additionally, in September 2021, the Company entered into a ten-year lease for additional office space located at 3003 Bunker Hill Lane in Santa Clara, California which consists of approximately 81,000 square feet (the “3003 Lease”). The base rent for the premises of the 3003 Bunker Hill building shall be abated for the first six months. The landlord provided the Company with a tenant

improvement allowance of up to $5.5 million. In connection with the lease, the Company shall provide an initial security deposit of $0.2 million in the form of a letter of credit and a prepayment for the same amount which will be applied to the first month’s rent. The lease is due to expire in December 2031, and contains two optional extension periods of sixty months each at the then fair market rent for the space. As of September 30, 2021, the Company has not taken control of the leased facility and anticipates that it will take control of the leased facility in the fourth quarter of 2021.

The Company also leases vehicles for use by certain of its employees. In connection with the vehicle leases, the Company has an operating lease right-of-use asset and an aggregate lease liability of $0.2 million as of September 30, 2021 on its consolidated balance sheet. The weighted average remaining lease term for these vehicle leases is one year and seven months.

The weighted average incremental borrowing rate used to measure the operating lease liability is 5.14%. As of September 30, 2021, the Company has no material finance leases.

Short-term leases are leases having a term of 12 months or less. The Company recognizes short-term leases on a straight-line basis and does not record a related lease asset or liability for such leases.

The following are minimum future rental payments owed under these agreements which have commenced as of September 30, 2021:

Year ending December 31,	(in thousands)
2021 (remainder)	$	602
2022		2,128
2023		1,535
2024		1,552
2025		1,600
2026		1,643
Thereafter		8,787
Total minimum lease payments	$	17,847
Less: imputed interest and adjustments		(5,041	)
Total lease liability	$	12,806

The following are minimum undiscounted future rental payments owed for the modified 5403 Betsy Ross Lease and 3003 Bunker Hill Lease which have not yet commenced as of September 30, 2021:

Year ending December 31,	(in thousands)
2021 (remainder)	$	215
2022		1,420
2023		3,704
2024		3,815
2025		3,926
2026		4,047
Thereafter		22,004
Total minimum lease payments	$	39,131

Operating lease cost for the three and nine months ended September 30, 2021 and 2020 was $0.5 million and $1.5 million, respectively, and $0.5 million and $1.5 million, respectively.