Note 5 - Balance Sheet Components

12 Months Ended

Dec. 31, 2023

Notes to Financial Statements

Supplemental Balance Sheet Disclosures [Text Block]

NOTE 5.  Balance Sheet Components

(a)     Cash, Cash Equivalents, Restricted Cash and Investments

Cash, cash equivalents, restricted cash and investments consisted of the following (in thousands):

	Amortized		Gross Unrealized					Estimated		Cash and Cash		Short-Term
	Cost		Gains		Losses			Fair Value		Equivalents		Investments
December 31, 2023
Cash at banks	$	3,352	$	—	$	—		$	3,352	$	3,352	$	—
Money market funds		31,403		—		—			31,403		31,403		—
U.S. Treasury securities		4,959		—		(1	)		4,958		—		4,958
Total	$	39,714	$	—	$	(1	)	$	39,713	$	34,755	$	4,958

	Amortized		Gross Unrealized					Estimated		Cash, Cash Equivalents		Short-Term
	Cost		Gains		Losses			Fair Value		and Restricted Cash		Investments
December 31, 2022
Cash at banks	$	15,179	$	—	$	—		$	15,179	$	15,179	$	—
Money market funds		30,834		—		—			30,834		30,834		—
U.S. Treasury securities		41,812		—		(270	)		41,542		—		41,542
Corporate securities		8,191		—		(29	)		8,162		—		8,162
Total	$	96,016	$	—	$	(299	)	$	95,717	$	46,013	$	49,704

As of December 31, 2023 and 2022, all investments were available-for-sale debt securities with remaining maturities of 12 months or less. As of December 31, 2023 and 2022, the Company held 1 and 18 securities, respectively, in an unrealized loss position for 12 months or less. Interest receivable as of December 31, 2023 and 2022, was $0.1 million and $0.2 million, respectively and is recorded as a component of prepaid expenses and other current assets on the consolidated balance sheets.

(b)     Accounts Receivable

Accounts receivable comprises royalties receivable of $3.0 million and $20,000 as of  December 31, 2023 and 2022, respectively. The Company has provided no allowance for credit losses as of  December 31, 2023 and 2022, based on past events and subsequent receipts.

(c)     Property and Equipment, Net

Property and equipment, net consists of the following (in thousands):

	December 31, 2023			December 31, 2022
Laboratory equipment	$	13,448		$	12,035
Office and computer equipment		1,105			1,078
Leasehold improvements		3,985			1,760
Construction in progress		24			3,984
Total property and equipment		18,562			18,857
Less: accumulated depreciation		(6,831	)		(3,272	)
Property and equipment, net	$	11,731		$	15,585

Depreciation expense was $3.8 million, and $2.0 million for the years ended December 31, 2023 and 2022, respectively. There were no impairments of the Company’s property and equipment recorded for the years ended  December 31, 2023 or 2022.

(d)     Right-of-Use Assets, Net

Right-of-use assets, net comprises facilities of $24.8 million and $25.7 million as of  December 31, 2023 and 2022, respectively. The right of use of additional leased premises in California commenced in 2023 and 2022, resulting in an additional $3.1 million and $15.0 million right-of-use assets recorded in the year ended December 31, 2023 and 2022 respectively.

(e)     Intangible Assets, Net

Intangible assets comprise developed technology, intellectual property and, until it was considered fully impaired, in-process research and development. Intangible assets are carried at cost less accumulated amortization. As of December 31, 2023, developed technology and intellectual property had remaining lives of 5.9 and 4.0 years, respectively. Intangible assets consist of the following (in thousands):

	December 31, 2023			December 31, 2022
Developed technology	$	5,000		$	5,000
Intellectual property		80			80
Total cost		5,080			5,080
Less: accumulated amortization		(791	)		(60	)
Intangible assets, net	$	4,289		$	5,020

Intangible asset amortization expense was $0.7 million and $1.3 million for the years ended  December 31, 2023 and 2022, respectively. The Company assessed its developed technology as not impaired in the year ended December 31, 2023. Due to a decline in royalties earned since the outbreak of COVID-19 (see Note 7), developed technology was assessed as partially impaired as of December 31, 2022, and accordingly an impairment charge of $4.3 million were recorded within operating expenses.

As of December 31, 2023, the estimated future amortization expense by year is as follows (in thousands):

Year Ending December 31,	Amount
2024	$	731
2025		732
2026		731
2027		731
2028		727
Thereafter		637
Total	$	4,289

(f)     Goodwill

Goodwill, which represents the excess of the purchase price over the fair value of assets acquired, comprises $4.5 million for both years ended  December 31, 2023 and 2022. For the years ended December 31, 2023 and 2022, there was no change in goodwill. As of December 31, 2023 and 2022, there have been no indicators of impairment.

(g)     Other Accrued Liabilities

Other accrued liabilities consist of the following (in thousands):

	December 31, 2023		December 31, 2022
Accrued compensation	$	4,576	$	3,112
Accrued clinical and manufacturing expenses		312		2,413
Accrued professional and consulting services		211		691
Accrued other expenses		535		1,868
Total	$	5,634	$	8,084