Balance Sheet Details

6 Months Ended

Jun. 30, 2022

Organization, Consolidation and Presentation of Financial Statements [Abstract]

4. Balance Sheet Details

Short-term investments consisted of the following (dollar amounts in thousands):


	June 30, 2022
Description	Maturity	Amortized Costs		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Commercial paper	1 year or less	$	55,366	$	—	$	(182	)	$	55,184
U.S. Treasury securities	1 year or less		33,836		—		(160	)		33,676
		$	89,202	$	—	$	(342	)	$	88,860


	December 31, 2021
Description	Maturity	Amortized Costs		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Commercial paper	1 year or less	$	78,456	$	5	$	(3	)	$	78,458
U.S. Treasury securities	1 year or less		5,025		—		—			5,025
U.S. government agency debt securities	1 year or less		5,002		—		—			5,002
		$	88,483	$	5	$	(3	)	$	88,485

The Company concluded that the declines in market value of available-for-sale securities were temporary in nature and did not consider any of the investments to be other-than-temporarily impaired. In accordance with its investment policy, the Company invests in investment grade securities with high credit quality issuers, and generally limits the amount of credit exposure to any one issuer. The Company evaluates securities for other-than-temporary impairment at the end of each reporting period. Impairment is evaluated considering numerous factors, and their relative significance varies depending on the situation. Factors considered include the length of time and extent to which fair value has been less than the cost basis, the financial condition and near-term prospects of the issuer, and the Company’s intent and ability to hold the investment to allow for an anticipated recovery in fair value. Furthermore,

the aggregate of individual unrealized losses that had been outstanding for 12 months or less was not significant as of June 30, 2022 and December 31, 2021. The Company does not intend to sell these investments and it is not more likely than not that the Company will be required to sell the investments before a recovery of their amortized cost bases, which may be maturity. The Company also believes that it will be able to collect both principal and interest amounts due at maturity.

Prepaid expenses and other current assets consisted of the following (dollar amounts in thousands):


	At June 30, 2022		At December 31, 2021
Interest receivable	$	106	$	62
Prepaid insurance		312		1,728
Prepaid research studies		926		1,190
Prepaid other		924		561
Total	$	2,268	$	3,541

Prepaid expenses, net of current portion, consisted of the following (dollar amounts in thousands):


	At June 30, 2022		At December 31, 2021
Prepaid clinical trial and other	$	3,810	$	3,409
	$	3,810	$	3,409

Property and equipment consisted of the following (dollar amounts in thousands):


	At June 30, 2022			At December 31, 2021
Laboratory equipment and manufacturing equipment	$	657		$	591
Furniture and fixtures		258			258
Computer equipment and software		556			440
Leasehold improvements		2,095			2,095
		3,566			3,384
Less accumulated depreciation		(1,358	)		(1,001	)
Total	$	2,208		$	2,383

Depreciation expense for the three months ended June 30, 2022 and 2021 was $179 thousand and $167 thousand, respectively. Depreciation expense for the six months ended June 30, 2022 and 2021 was $357 thousand and $325 thousand, respectively.

Accrued expenses consisted of the following (dollar amounts in thousands):


	At June 30, 2022		At December 31, 2021
Payroll and related liabilities	$	1,679	$	2,379
Professional fees		469		727
Research and development costs		5,852		5,066
Other		461		336
Total	$	8,461	$	8,508

The Company had $0.4 million of restricted cash at June 30, 2022 and June 30, 2021. This amount is included in the "other assets" line item on the balance sheets.