The Company enters into contracts in the normal course of business with CROs for preclinical studies and clinical trials. These agreements provide for notice of termination by either party and are, therefore, cancelable contracts.

In May 2015, the Company entered into an operating lease for 30,376 square feet of laboratory and office facilities in South San Francisco, California, which expires in May 2022. In April 2018, the Company amended the lease agreement to include an additional 6,378 square feet of laboratory and office space increasing the total leased premises to 36,754 square feet. The lease amendment extended the lease term to November 2026 and contained scheduled rent increases over the lease term and an option for the Company to extend the lease for an additional five-year term.

In February 2019, the Company entered into an agreement to sublease its facility lease of 6,378 square feet of laboratory and office space, which terminated in July 2020.

As of December 31, 2021, future minimum non-cancelable lease payments, are as follows (in thousands):

Year ending December 31:
2022	$	2,037
2023		2,109
2024		2,183
2025		2,259
2026		2,137
Thereafter		—
Total minimum lease payments	$	10,725

The terms of the lease agreement provide for rental payments on a monthly basis and on a graduated scale. The Company recognizes rent expense on a straight-line basis over the lease period and has accrued for rent expense incurred but not paid. Rent expense includes certain monthly charges that do not represent non-cancelable obligations, as defined. These costs are determined based on actual charges incurred. In addition, tenant improvement allowances recorded are amortized as a reduction to rent expense on a straight-line basis over the lease term. Rent expense was $2.3 million and $2.1 million in the years ended December 31, 2021 and 2020, respectively.

From time to time, the Company may be subject to various legal proceedings and claims arising in the ordinary course of business. The Company assesses contingencies to determine the degree of probability and range of possible loss for potential accrual in its financial statements. An estimated loss contingency is accrued in the financial statements if it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. The Company is not subject to any current pending legal matters or claims and no contingency losses were accrued at either December 31, 2021 or 2020.