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Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2024

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation Expense

The following stock-based compensation expense was recognized for the periods indicated (in thousands):

			Three Months Ended September 30,												Nine Months Ended September 30,
			2024						2023						2024						2023
Research and development			$	2,940					$	2,335					$	9,033					$	6,996
Selling, general and administrative			3,030						2,455						9,141						7,018
Total stock-based compensation expense			$	5,970					$	4,790					$	18,174					$	14,014

Valuation Assumptions Using the Black-Scholes Option-Pricing Model

The fair value of each option award is estimated on the date of grant using the Black-Scholes option-pricing model using the assumptions in the following table for options issued during the period indicated:

			Nine Months Ended September 30,
			2024						2023
Expected dividend yield			0%						0%
Expected volatility			94.9% -115.7%						76.1% - 94.9%
Risk-free interest rate			3.5% - 4.7%						3.5% - 4.4%
Expected term			6.06 years						5.88 years

Schedule of Stock Options Roll Forward

The following table summarizes stock option activity during the nine months ended September 30, 2024:

			Shares						Weighted- Average Exercise Price						Weighted-Average Remaining Contractual Term (Years)						Aggregate Intrinsic Value  (in thousands)
Outstanding, December 31, 2023			12,223,637						$	15.11					6.7
Granted			1,950,032						16.18
Exercised			(331,916)						9.41
Forfeited			(141,409)						11.64
Expired			(259,817)						22.09
Outstanding, September 30, 2024			13,440,527						$	15.30					6.4						$	18
As of September 30, 2024:
Exercisable			8,970,940						$	17.66					5.4						$	10
Vested and expected to vest			12,435,275						$	15.70					6.3						$	16

Schedule of RSU Activity

The following table summarizes RSU activity during the nine months ended September 30, 2024:

			Shares						Weighted-Average Grant Date Fair Value
Outstanding, December 31, 2023			905,614						$	5.97
Granted			649,715						17.04
Vested			(477,681)						6.90
Forfeited			(27,904)						13.07
Outstanding, September 30, 2024			1,049,744						$	12.21

Stock Option Additional Information [Table]

The following table summarizes additional information on stock options (in thousands, except per share amounts):

									Nine Months Ended September 30,
															2024						2023
Weighted-average fair value per share of stock options granted															$	12.79					$	3.78
Total intrinsic value of stock options exercised															$	2,616					$	61
Total cash received for stock options exercised															$	3,122					$	87
Total grant date fair value of stock options vested															$	13,533					$	13,611

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Tabular disclosure of allocation of amount expensed and capitalized for award under share-based payment arrangement to statement of income or comprehensive income and statement of financial position. Includes, but is not limited to, corresponding line item in financial statement.

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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.

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Tabular disclosure of the change in stock options.

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