Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2023

Share-Based Compensation

Schedule of total number of shares available for future issuance under the plans

2013 EIP	5,339,942
2013 ESPP	2,453,502
2014 NEEIP	346,281
Total	8,139,725

Schedule of share-based compensation expense included in the consolidated statements of operations

	Year Ended December 31,
(In thousands)	2023		2022
Research and development	$	8,048	$	12,888
Selling, general and administrative		16,966		19,848
Restructuring and related expenses		357		6,998
Total share-based compensation expense	$	25,371	$	39,734

Schedule of share-based compensation expense by award type included in the consolidated statements of operations

	Year Ended December 31,
(In thousands)	2023		2022
Options	$	2,294	$	2,998
RSUs		21,817		35,726
Performance RSUs		1,087		237
ESPP		173		773
Total share-based compensation expense	$	25,371	$	39,734

Schedule of unrecognized compensation cost, net of expected forfeitures, and the estimated weighted-average amortization period, using the straight-line attribution method

	Unrecognized		Weighted‑Average
	Compensation		Amortization Period
(In thousands, except amortization period)	Cost		(Years)
Options	$	2,600	1.88
RSUs		30,404	2.36
Performance RSUs (1)		849	1.26
ESPP		504	1.05
Total	$	34,357

(1) Represents unrecognized share-based compensation cost associated with the Company’s market-based and performance-contingent awards described above that are probable of vesting.

Summary of option activity under the 2013 EIP and 2014 NEEIP

			Weighted-Average
	Number of Shares	Weighted-Average	Exercise Price of			Aggregate
	Subject to	Remaining Contractual	Outstanding Options			Intrinsic Value
	Outstanding Options	Term (Years)	(in dollars)			(in thousands)
Outstanding at December 31, 2022	2,411,893		$	19.53
Granted	262,386			10.84
Exercised	—			-
Forfeited	(368,403)			18.85
Outstanding at December 31, 2023	2,305,876	5.32		18.65	$	859
Exercisable at December 31, 2023		4.48				487
Vested and expected to vest at December 31, 2023		5.32				859

	2023		2022
Weighted average fair value of options (in dollars)	$	5.74	$	5.33
Total intrinsic value of options exercised (in thousands)	$	—	$	—

Schedule of RSU and RSA activity (including performance RSUs and RSAs)

	Number of Shares	Number of Shares
	Subject to	Outstanding Subject to
	Outstanding RSUs	Performance Conditions (RSAs)
Outstanding at December 31, 2022	4,109,847	—
Granted	2,228,184	—
Released	(1,651,141)	—
Forfeited	(691,140)	—
Outstanding at December 31, 2023	3,995,750	—

Schedule of range of assumptions used to estimate the fair value of share options granted and rights granted

	Year Ended December 31,
	2023		2022
Options
Risk-free interest rate		3.46% - 4.18%		1.5% - 3.8%
Expected term (in years)		5.3 - 6.5		5.3 - 6.1
Volatility		53% - 55%		55% - 70%
Dividend yield		—		—
Weighted-average estimated fair value	$	5.74	$	5.33
2013 ESPP
Risk-free interest rate		4.06% - 5.39%		1.5% - 4.57%
Expected term (in years)		0.5 - 2.0		0.5 - 2.0
Volatility		32% - 58%		41% - 72%
Dividend yield		—		—
Weighted-average estimated fair value	$	3.46	$	3.86