Note 4 - Balance Sheet Components

3 Months Ended

Mar. 31, 2024

Notes to Financial Statements

Supplemental Balance Sheet Disclosures [Text Block]

NOTE 4.  Balance Sheet Components

(a) Cash, Cash Equivalents and Investments

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

	Amortized		Gross Unrealized					Estimated		Cash and		Short-Term
	Cost		Gains		Losses			Fair Value		Cash Equivalents		Investments
March 31, 2024
Cash at banks	$	4,078	$	—	$	—		$	4,078	$	4,078	$	—
Money market funds		17,710		—		—			17,710		17,710		—
U.S. Treasury securities		14,886		—		(10	)		14,876		4,947		9,929
Total	$	36,674	$	—	$	(10	)	$	36,664	$	26,735	$	9,929

	Amortized		Gross Unrealized					Estimated		Cash and		Short-Term
	Cost		Gains		Losses			Fair Value		Cash 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

As of March 31,2024 and December 31, 2023, all investments were available-for-sale debt securities with remaining maturities of 12 months or less.

(b) Accounts Receivable

Accounts receivable comprises royalties receivable of $0.6 million and $3.0 million as of March 31, 2024 and December 31, 2023, respectively. The Company has provided no allowance for credit losses as of March 31, 2024 and December 31, 2023, based on past events and subsequent receipts.

(c) Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consists of the following (in thousands):

	March 31, 2024		December 31, 2023
Prepaid clinical and manufacturing expenses	$	1,762	$	984
Unbilled revenue from government contracts		1,596		—
Prepaid insurance		933		258
Prepaid rent		528		488
Interest receivable		140		127
Other		2,105		958
Prepaid expenses and other current assets	$	7,064	$	2,815

(d) Property and Equipment, Net

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

	March 31, 2024			December 31, 2023
Laboratory equipment	$	13,507		$	13,448
Office and computer equipment		1,105			1,105
Leasehold improvements		3,998			3,985
Construction in progress		226			24
Total property and equipment		18,836			18,562
Less: accumulated depreciation		(7,734	)		(6,831	)
Property and equipment, net	$	11,102		$	11,731

Depreciation expense was $0.9 million for the three months ended March 31, 2024 and 2023. There were no impairments of the Company’s property and equipment recorded in the three months ended March 31, 2024 or 2023.

(e) Right-of-Use Assets, Net

Right-of-use assets, net comprises facilities of $23.8 million and $24.8 million as of March 31, 2024 and December 31, 2023, respectively. The right-of-use of additional leased premises in California commenced in 2023, resulting in an additional $3.1 million right-of-use assets recorded in the year ended December 31, 2023.

(f) Intangible Assets, Net

Intangible assets comprise developed technology and intellectual property. Intangible assets are carried at cost less accumulated amortization. As of March 31, 2024, developed technology and intellectual property had remaining lives of 5.6 and 3.75 years, respectively. As of March 31, 2024, there have been no indicators of impairment. Intangible assets consist of the following (in thousands):

	March 31, 2024			December 31, 2023
Developed technology	$	5,000		$	5,000
Intellectual property		80			80
Total cost		5,080			5,080
Less: accumulated amortization		(974	)		(791	)
Intangible assets, net	$	4,106		$	4,289

Intangible asset amortization expense was $0.2 million for the three months ended March 31, 2024 and 2023.

As of March 31, 2024, the estimated future amortization expense by year is as follows (in thousands):

Year Ending December 31,	Amount
2024 (nine months remaining)	$	548
2025		732
2026		731
2027		731
2028		727
Thereafter		637
Total	$	4,106

(g) Goodwill

Goodwill, which represents the excess of the purchase price over the fair value of assets acquired, comprises $4.5 million as of March 31, 2024 and December 31, 2023. As of March 31, 2024, there have been no indicators of impairment.

(h) Other Accrued Current Liabilities

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

	March 31, 2024		December 31, 2023
Accrued compensation	$	3,199	$	4,576
Accrued clinical and manufacturing expenses		180		312
Accrued professional and consulting services		707		211
Other liabilities, current portion		894		535
Total	$	4,980	$	5,634