Investments and Fair Value Instruments (Tables)

12 Months Ended

Dec. 31, 2023

Investments And Fair Value Instruments [Abstract]

Summary of Amortized Cost and Fair Value of Investment Securities Portfolio

(Dollars in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses		Estimated Fair Value
December 31, 2023
Cash equivalents:
Money market funds	$	4,925	$	—	$	—	$	4,925
Short-term investments:
Treasury bills		5,023		101		—		5,124
Total Assets at Fair Value	$	9,948	$	101	$	—	$	10,049

(Dollars in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses		Estimated Fair Value
December 31, 2022
Cash equivalents:
Money market funds	$	18,620	$	—	$	—	$	18,620
Total Assets at Fair Value	$	18,620	$	—	$	—	$	18,620

Summary of Fair Value of Investment Securities

The fair value of the investment securities at December 31, 2023 were as follows:

	Fair Value Measurements at December 31, 2023
(Dollars in thousands)	Level 1		Level 2		Level 3		Total
Assets at Fair Value
Cash equivalents:
Money market funds	$	4,925	$	—	$	—	$	4,925
Short-term investments:
Treasury bills		5,124		—		—		5,124
Total Assets at Fair Value	$	10,049	$	—	$	—	$	10,049

The fair value of the investment securities at December 31, 2022 were as follows:

	Fair Value Measurements at December 31, 2022
(Dollars in thousands)	Level 1		Level 2		Level 3		Total
Assets at Fair Value
Cash equivalents:
Money market funds	$	18,620	$	—	$	—	$	18,620
Total Assets at Fair Value	$	18,620	$	—	$	—	$	18,620

Summary of Preferred Investment Option Liabilities Measured and Recorded on Recurring Basis using Black-Scholes Model

The preferred investment option liabilities were measured and recorded on a recurring basis using the Black-Scholes Model with the following assumptions at December 31, 2023 and 2022:

	March 2023 Options - Series A & March 2023 Placement Agent Options					March 2023 Options - Series B					August 2022 Options & August 2022 Placement Agent Options
	December 31, 2023			December 31, 2022		December 31, 2023			December 31, 2022		December 31, 2023			December 31, 2022
Remaining term (in years)		4.16			—		0.61			—		3.67			4.67
Expected volatility		91.7	%		—		78.7	%		—		90.5	%		106.2	%
Risk-free interest rate		3.9	%		—		5.2	%		—		4.0	%		4.0	%
Expected dividend yield		0	%		—		0	%		—		0	%		0	%

Summary of Changes in Fair Value and Other Adjustments of Liabilities

The following table sets forth the establishment of the Company’s Level 3 liabilities, as well as a summary of the changes in the fair value and other adjustments (in thousands):

(Dollars in thousands)	March 2023 Options - Series A			March 2023 Options - Series B			March 2023 Placement Agent Options			August 2022 Options			August 2022 Placement Agent Options			Contingent Liabilities		Total
Balance as of December 31, 2022	$	—		$	—		$	—		$	767		$	39		$	2,000	$	2,806
Initial recognition		4,324			2,274			212			—			—			—		6,810
Change in fair value and    other adjustments		(3,316	)		(2,233	)		(166	)		(608	)		(36	)		—		(6,359	)
Balance as of December 31, 2023	$	1,008		$	41		$	46		$	159		$	3		$	2,000	$	3,257