The Company adopted ASC 842, Leases, as of January 1, 2019. In accordance with ASC 842, the Company determines if an arrangement is a finance lease, operating lease or short-term lease at inception, or as applicable, and accounts for the arrangement under the relevant accounting literature. During the periods presented, the Company was party to various non-cancellable office and laboratory space operating leases and short-term leases. Currently, the Company is only party to a non-cancellable office and laboratory space operating lease. Under the relevant guidance, the Company recognizes operating lease right-of-use (ROU) assets and liabilities based on the present value of the future minimum lease payments over the lease term at the commencement date, using the Company’s assumed incremental borrowing rate of 5.5%, and amortizes the ROU assets and liabilities over the lease term. Lease expense for operating leases is recognized on a straight-line basis over the lease term. The Company’s short-term leases are not subject to recognition of an ROU asset or liability or straight-line lease expense requirements.

In March 2014, the Company entered into a non-cancellable operating lease for office and laboratory space with a lease term through November 2017. In July 2017, the Company entered into an amendment to this lease to extend the lease term through December 2021.

On June 1, 2020, the Company entered into a second amendment to its existing operating lease (as amended, the 2014 Lease) and entered into a new non-cancellable temporary operating lease in connection with a newly executed non-cancellable operating lease for its new headquarters location, with a projected commencement date of July 1, 2021.

On December 18, 2020, the Company entered into an amendment to the non-cancellable operating lease for its new headquarters location (as amended, the New Lease), which increased the square footage by adding adjacent space and extended the projected commencement date to November 1, 2021. Additionally, the non-cancellable temporary operating lease was amended (as amended, the Temporary Lease) to accommodate the projected commencement date of the New Lease. The lease term under both the 2014 Lease and the Temporary Lease ends 15 days after the commencement date of the New Lease in November 2021. The remaining monthly rental payments under the 2014 Lease and the rent under the Temporary Lease were abated beginning on June 1, 2020, given the execution of the New Lease. The New

Lease has a five-year term upon commencement in November 2021 and a renewal option for an additional five years. Under the terms of the New Lease, the initial monthly base rent of approximately $251,000 will increase to approximately $282,000 during the last year of the New Lease's initial term, and the first year includes five months of rent abatement. The total lease payments under the initial term of the New Lease of $14.7 million were allocated amongst the 2014 Lease, Temporary Lease and New Lease based on the relative standalone price of the separate lease components. Furthermore, pursuant to the terms of the New Lease, the Company is required to maintain a letter of credit totaling $251,000 throughout the lease term.

In June 2020, in accordance with the lease terms applicable at that time, the Company adjusted the ROU asset and liability of the 2014 Lease to conform to the modification terms and recorded an ROU asset and liability for the Temporary Lease upon occupancy. In December 2020, in connection with the lease amendments described above, the Company adjusted the ROU asset and liability of the 2014 Lease and Temporary Lease to conform to the modification terms. In November 2021, the Company recognized an ROU asset and liability related to the New Lease in connection with obtaining control of the asset upon occupancy of the new space.

As of December 31, 2021, the Company’s ROU assets and liabilities related to the New Lease are as follows (in thousands):

ROU assets	$	10,784

Lease liabilities, current portion	$	1,769
Lease liabilities, net of current portion		9,960
Total lease liabilities	$	11,729

As of December 31, 2021, maturities of the lease liabilities due under the New Lease are as follows (in thousands):

Year ending December 31,
2022	$	1,769
2023		3,113
2024		3,207
2025		3,303
2026		3,111
Total lease payments		14,503
Less imputed interest		(2,774	)
Total operating lease liabilities		11,729
Less lease liabilities, current portion		(1,769	)
Lease liabilities, net of current portion	$	9,960

Supplemental cash flow information related to cash paid for amounts included in the measurement of operating lease liabilities was as follows (in thousands):

	Year Ended December 31,
	2021		2020		2019
Cash paid included in operating cash flows	$	234	$	163	$	382

	Year Ended December 31,
	2021		2020		2019
Operating leases	$	946	$	453	$	302
Short-term leases		216		36		6
Total rent expense	$	1,162	$	489	$	308

As of December 31, 2021, the weighted-average remaining term of the Company’s operating lease was 4.9 years.

Liabilities for loss contingencies arising from claims, assessments, litigation, fines, penalties and other sources are recorded when it is probable that a liability has been incurred and the amount can be reasonably estimated. There are no matters currently outstanding for which any liabilities have been accrued.

The Company enters into contracts in the normal course of business for contract research services, contract manufacturing services, professional services, and other services and products for operating purposes. These contracts may include certain provisions that could require payments for early termination. The amount of the termination payments vary depending on the timing of the termination and the specific terms of the contract.