In June 2018, the Company entered into a three-year lease agreement with no renewal options with an investor in the Series B redeemable convertible preferred stock. The lease began on July 16, 2018 and provides 3,185 square feet of office and laboratory space in South San Francisco, California. The Company issued 114,437 shares of its Series B redeemable convertible preferred stock with a fair value of $1.1 million in exchange for the leased facility. No other payments were due under the lease. The common area maintenance and other operating costs are included in the base rent. 100% of the issued shares were initially subject to a repurchase option. Pursuant to the terms of the lease, each month beginning on the one-month anniversary of the commencement date of the lease, 1/36th of the total shares are released from the repurchase option until all shares are released over the lease period of three years. The scheduled release of shares ceased immediately upon the IPO which was a terminating event.

The Company completed its IPO on May 13, 2019 and as a result, pursuant to the terms of the lease agreement, all previously unvested shares were fully vested and as part of the IPO process, all outstanding shares of the Company’s redeemable convertible preferred stock including the Series B redeemable convertible preferred stock issued in connection with the lease agreement were converted into shares of the Company’s common stock on a 1-for-1 basis and the operating lease liability was extinguished.

In May 2019, the Company entered into an amendment to the lease agreement to rent additional space in the same facility under the same terms as its existing facility lease except the terms of payment. Under the terms of the amendment, the Company paid a one-time fee of approximately $63,000 for the additional space and the lease agreement will terminate in July 2021. No other payments are due under the lease agreement and no renewal option is available. As the entire lease is prepaid, there is no associated lease liability.

In May 2020, the Company entered into a second amendment to the lease agreement to rent additional space in the same facility under the same terms as its existing facility lease except the terms of payment. Under the terms of the amendment, the Company will pay rent monthly for the additional space and the lease agreement will terminate in July 2021. The Company recorded an operating lease asset and liability of $172,000.

In May 2021, the Company entered into a third amendment to the lease agreement to extend the term of its existing facility space to July 15, 2022 under the same terms as its existing facility lease except the terms of payment. The lease amendment provides for one-year extension period under the same terms. The Company paid a security deposit of $105,000, which is included in Other Assets on the December 31, 2021 consolidated balance sheets. As a result of this amendment, the Company recognized an additional right-of-use asset and corresponding lease liability of $1.2 million. In the same agreement, the Company also agreed to rent additional space effective July 16, 2021 for a period of 12 months. The lease amendment provides for one-year extension period and is included in the lease term as it is reasonably certain that the Company will exercise the option. The Company recognized an additional right of use asset and corresponding lease liability of $44,000 in July 2021. Total payments under the third amendment to the lease including the additional space will be $1.3 million.

In May 2020, the Company entered into a lease agreement to rent space in San Diego, California for our clinical operations team. The lease agreement is for three years which commenced August 1, 2020. Total payments under the lease will be $337,000. The Company paid a security deposit of $29,000 and is included in Other Assets on our December 31, 2021 consolidated balance sheets. At the commencement of the lease, the Company recorded an operating lease asset of $326,000, which consists of an operating lease liability of $317,000 and cash rent prepayment of $9,000. The Company recognizes lease expense on a straight-line basis over the term of its operating lease.

The Company recognizes lease expense on a straight-line basis over the term of its operating lease. As of December 31, 2021, total future rent expense from all real estate operating leases of $1.1 million will be recognized over the remaining terms of 19 months on a straight-line basis over the respective lease period.

The Company uses certain vendor supplied equipment in connection with its on-going clinical trial. The Company has analyzed the vendor agreement and determined that it contains an embedded operating lease. The Company recognizes monthly the leases costs in our research and development expenses. The right of use asset and lease liability are recognized at the lease commencement date based on the present value of lease payments over the lease term. The Company’s lease does not provide an implicit rate. The Company used an adjusted historical incremental borrowing rate, based on the information available at the approximate lease commencement date, to determine the present value of lease payments. As of December 31, 2021 the lease expense has been fully recognized.

The Company uses certain vendor supplied equipment in connection with its on-going clinical trial. The Company has analyzed the vendor agreements and determined that they contain embedded finance leases. The Company recognizes the depreciation expense in research and development expenses in the statements of operations and comprehensive loss and recognizes expense on a straight-line basis starting when the equipment is placed into service until the end of the contract term ranging from 20 to 34 months. Depreciation expense of the financing lease right of use asset for the years ended December 31, 2021, 2020, and 2019 were $220,000, $230,000, and $107,000, respectively.

Supplemental balance sheet information related to leases as follows (in thousands except lease terms and discount rates):


	December 31, 2021			December 31, 2020
Operating lease right of use asset, net	$	1,165		$	674
Short-term operating lease liability		741			238
Long-term operating lease liability		420			208
	$	1,161		$	446

Finance lease right of use asset		557			557
Finance lease accumulated amortization		(557	)		(337	)
Total finance lease right of use asset, net	$	—		$	220

Weighted average remaining lease term
Operating leases	1.6 years			1.6 years
Finance leases	— years			0.9 years

Weighted average discount rate
Operating leases		1.87	%		2.10	%
Finance leases		—	%		—	%

Year ended December 31,	Operating Lease
2022		757
2023		422
Total lease payments		1,179
Less: imputed interest		(18	)
Total remaining lease liability		1,161

Lease costs for the years ended December 31, 2021, 2020, and 2019 were approximately:


	Years ended December 31,
	2021		2020		2019
Lease costs:
Finance lease amortization of right of use assets	$	220	$	230	$	107
Operating lease costs		729		578		374
Short-term lease costs		66		92		11
Total lease costs	$	1,015	$	900	$	492