Balance Sheet Details

12 Months Ended

Dec. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Short-Term Investments

The following is a summary of our short-term investments (in thousands):


	December 31, 2023
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
U.S. treasury bills and government agency obligations	$	31,625	$	11	$	—		$	31,636
U.S. corporate debt securities		11,652		1		—			11,653
Foreign corporate debt securities		5,459		1		—			5,460
U.S. commercial paper		1,991		—		(1	)		1,990
Foreign commercial paper		993		—		—			993
Total	$	51,720	$	13	$	(1	)	$	51,732


	December 31, 2022
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
U.S. treasury bills and agency obligations	$	35,734	$	—	$	(19	)	$	35,715
U.S. commercial paper		5,481		—		—			5,481
Foreign commercial paper		28,292		—		—			28,292
Total	$	69,507	$	—	$	(19	)	$	69,488

The amortized cost of debt securities is adjusted for amortization of premiums and accretion of discounts to maturity. We regularly monitor and evaluate the realizable value of our marketable securities. We did not recognize any impairment losses for the years ended December 31, 2023 and 2022.

Unrealized gains and losses associated with our investments are reported in accumulated other comprehensive income (loss). For the year ended December 31, 2023, we recorded $32,000 in net unrealized gains associated with our short-term investments. For the year ended December 31, 2022, we recorded $13,000 in net unrealized losses associated with our short-term investments.

Realized gains and losses associated with our investments, if any, are reported in the statements of operations and comprehensive loss. We recognized $1,000 in realized losses during the year ended December 31, 2023. We did not recognize any realized gains or losses during the year ended December 31, 2022.

Inventory

Inventory consists of the following (in thousands):


	December 31,
	2023		2022
Raw materials	$	17,643	$	15,137
Work in process		14,550		20,723
Finished goods		9,917		18,713
Total inventory	$	42,110	$	54,573

As of December 31, 2023, total inventory included $11.2 million related to ZYNRELEF, $26.4 million related to CINVANTI, $4.1 million related to SUSTOL and $0.4 million related to APONVIE. As of December 31, 2022, total inventory included $30.9 million related to ZYNRELEF, $19.9 million related to CINVANTI, $2.6 million related to SUSTOL and $1.2 million related to APONVIE. Cost of product sales for the years ended December 31, 2023 and 2022 included charges of $20.3 million and $8.9 million, respectively, resulting primarily from the write-off of ZYNRELEF inventory.

Prepaid Expenses and Other Assets

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


	December 31,
	2023		2022
Prepaid expenses	$	11,731	$	21,120
Prepaid insurance		1,910		1,947
Interest receivables		310		154
Deposits		274		254
Other receivables		21		6,197
Total prepaid expenses and other assets	$	14,246	$	29,672

Property and Equipment

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


	December 31,
	2023			2022
Scientific equipment	$	34,027		$	33,318
Leasehold improvements		647			647
Computer equipment and software		1,506			1,506
Furniture, fixtures and office equipment		1,014			982
Property and equipment, gross		37,194			36,453
Less: accumulated depreciation and amortization		(17,028	)		(14,293	)
Property and equipment, net	$	20,166		$	22,160

Depreciation and amortization expense for the years ended December 31, 2023 and 2022 was $2.9 million for both periods. As of December 31, 2023 and 2022, $6.3 million and $5.4 million of property and equipment, respectively, was in process and not depreciated during the respective years.

Accrued Payroll and Employee Liabilities and Other Accrued Liabilities

Accrued payroll and employee liabilities consist of the following (in thousands):


	December 31,
	2023		2022
Accrued employee salaries and benefits	$	1,371	$	2,134
Accrued bonuses		5,499		7,783
Accrued vacation		2,354		3,499
Total accrued payroll and employee liabilities	$	9,224	$	13,416

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


	December 31,
	2023		2022
Accrued product sales allowances	$	36,529	$	33,317
Accrued consulting and professional fees		3,940		4,236
Accrued accounts payable		559		363
Accrued interest		412		94
Other accrued liabilities		415		542
Total other accrued liabilities	$	41,855	$	38,552