XML 43 R28.htm IDEA: XBRL DOCUMENT v3.24.1

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

Summary of All Option Activity Under 2007 Plan, 2014 Plan, 2020 Plan and Inducement Grants

The following table summarizes all option activity under the 2007 Plan, 2014 Plan, 2020 Plan and inducement grants:

		Shares Issuable Under Options				Weighted Average Exercise Price				Weighted Average Remaining Contractual Term				Aggregate Intrinsic Value (in thousands)
										(In years)
Outstanding as of January 1, 2022			4,213,977			$	10.33				8.4			$	—
Granted			1,267,700				3.81				—				—
Forfeited / Canceled			(263,644	)			12.12				—				—
Outstanding as of December 31, 2022			5,218,033			$	8.69				8.1			$	—
Granted			11,026,451				2.10				—				—
Forfeited / Canceled			(862,631	)			8.07				—				—
Outstanding as of December 31, 2023			15,381,853			$	4.21				8.9			$	235
Options vested and expected to vest as of    December 31, 2023			9,476,369			$	5.40				8.2			$	235
Options exercisable as of December 31, 2023			4,065,023			$	8.54				7.0			$	—

Schedule of Assumptions Used in Black-Scholes Option Pricing Model to Determine the Fair Value of Stock Options Granted

The Company estimates the fair value of stock option awards on the grant date using the Black-Scholes option pricing model with the following weighted-average assumptions:

		Year Ended December 31,
		2023		2022
Expected stock price volatility		90.5%		83.9%
Risk-free interest rate		3.7%		2.0%
Expected life of options		6.08 years		6.27 years
Estimated dividend yield		0%		0%

Summary of RSU Activity

The following table shows the RSU activity, as follows:

		Shares Issuable Under RSUs				Weighted Average Grant Date Fair Value
						(In years)
Outstanding as of January 1, 2022			20,000			$	5.07
Granted			15,000				2.47
RSUs Vested			(20,000	)			5.07
Forfeited / Canceled			—				—
Outstanding as of December 31, 2022			15,000			$	2.47
Granted			—				—
RSUs Vested			(15,000	)			2.47
Forfeited / Canceled			—				—
Outstanding as of December 31, 2023			—			$	—

Schedule of Stock-Based Compensation Expense Related to Stock-Based Awards

Total compensation expense related to all of the Company’s stock-based awards for the years ended December 31, 2023 and 2022 was comprised of the following (in thousands):

		Year Ended December 31,
		2023				2022
Stock-based compensation classified as:
Research and development expense		$	1,491			$	3,230
General and administrative expense			5,054				4,923
Total stock-based compensation expense		$	6,545			$	8,153

X

- References

No definition available.

+ Details

Name:	us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of cost recognized for award under share-based payment arrangement by plan. Includes, but is not limited to, related tax benefit.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_ScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of the significant assumptions used during the year to estimate the fair value of stock options, including, but not limited to: (a) expected term of share options and similar instruments, (b) expected volatility of the entity's shares, (c) expected dividends, (d) risk-free rate(s), and (e) discount for post-vesting restrictions.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 718
-SubTopic 10
-Subparagraph (f)(2)
-Name Accounting Standards Codification
-Paragraph 2
-Section 50
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of the change in stock options.

+ References

No definition available.

+ Details

Name:	us-gaap_ScheduleOfStockOptionsRollForwardTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of number and weighted-average grant date fair value for nonvested performance shares.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Subparagraph (c)
-Paragraph 2
-SubTopic 10
-Topic 718
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_ShareBasedCompensationPerformanceSharesAwardUnvestedActivityTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration