Share-Based Payments

9 Months Ended

Sep. 30, 2024

Share-Based Payment Arrangement [Abstract]

Equity Incentive Plan

On June 14, 2024, the Company's shareholders approved, and the Company has adopted, the Amended and Restated 2021 Equity Incentive Plan (the Amended 2021 Plan) to increase the number of shares of the Company's common stock available for issuance under the 2021 Plan by 4,000,000.

Share-based compensation expense is as follows (dollars in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2024		2023		2024		2023
	(unaudited)				(unaudited)
Research and development	$	1,350	$	1,254	$	3,946	$	3,458
Selling, general and administrative	6,324		6,666		16,177		16,856
Total	$	7,674	$	7,920	$	20,123	$	20,314

Stock Option

The following table summarizes stock option activities:


	Number of Options	Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)
Outstanding, December 31, 2023	6,583,822	$	29.20	5.90
Granted	1,171,612	$	28.05
Exercised	(336,868)	$	20.23
Forfeited	(251,657)	$	31.71
Outstanding, September 30, 2024 (unaudited)	7,166,909	$	29.34	5.87

As of September 30, 2024 (unaudited):
Vested and expected to vest	7,166,909	$	29.34	5.87
Exercisable	4,560,609	$	27.95	4.33

As of December 31, 2023:
Vested and expected to vest	6,583,822	$	29.20	5.90
Exercisable	4,110,537	$	26.58	4.43

Restricted Stock Units

The following table summarizes restricted stock unit (RSU) activities:


	Number of RSUs	Weighted Average Grant Date Fair Value per Share
Nonvested, December 31, 2023	300,141	$	36.90
Granted	198,414	$	28.06
Vested	(100,891)	$	36.51
Forfeited	(19,124)	$	34.64
Nonvested, September 30, 2024 (unaudited)	378,540	$	32.48

Performance Share Units

The following table summarizes performance share unit (PSU) activities:


	Performance-Based Units			Market-Based Units			Total PSUs
	Number of PSUs	Weighted Average Grant Date Fair Value per Share		Number of PSUs	Weighted Average Grant Date Fair Value per Share		Number of PSUs	Weighted Average Grant Date Fair Value per Share
Nonvested, December 31, 2023	251,630	$	32.22	20,000	$	28.63	271,630	$	31.96
Granted	252,700	$	26.91	—	$	—	252,700	$	26.91
Vested	(62,980)	$	33.67	—	$	—	(62,980)	$	33.67
Forfeited	(58,050)	$	29.37	—	$	—	(58,050)	$	29.37
Nonvested, September 30, 2024 (unaudited)	383,300	$	28.91	20,000	$	28.63	403,300	$	28.90