v3.26.1
Share-Based Payments
 6 Months Ended
Jun. 30, 2026
Share-Based Payment Arrangement [Abstract]  
Share-Based Payments Share-Based Payments
2023 Stock Incentive Plan and Inducement Grants
In June 2023, our stockholders approved the 2023 Stock Incentive Plan, or the 2023 Plan. The 2023 Plan provides for the grant of incentive stock options, nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock units, or RSUs, performance-based stock units, or PSUs, and other stock-based awards to employees, advisors, consultants and non-employee directors.
Following the adoption of the 2023 Plan, we ceased granting equity awards under the 2013 Stock Incentive Plan, or the 2013 Plan. Any outstanding equity awards that were previously granted under the 2013 Plan continue to be governed by their terms. Following adoption of the 2013 Plan, we ceased granting equity awards under the 2007 Stock Incentive Plan, or the 2007 Plan. There are no outstanding equity awards under the 2007 Plan.
In connection with the start of employment of our Chief Executive Officer and Chief Financial Officer in 2022, our Chief Commercial Officer in 2023, and our Chief Corporate Development and Strategy Officer in March 2025, our Board of Directors granted each of them equity awards in the form of stock options, RSUs and PSUs, which awards were made outside our equity incentive plans as inducements material to their respective entry into employment with us in accordance with Nasdaq Listing Rule 5635(c)(4).
As of June 30, 2026, the maximum number of shares reserved under the 2013 Plan, the 2023 Plan and the inducement grants described above was 13,242,570, and we had 4,014,743 shares available for future issuance under the 2023 Plan.
Stock options
The following table presents stock option activity for the six months ended June 30, 2026:
Number of
Stock Options
Weighted-Average
Exercise Price
Outstanding at December 31, 20256,113,063 $39.62 
Granted851,777 29.98 
Exercised(115,910)28.77 
Cancelled/Forfeited(168,230)46.41 
Expired(128,627)42.25 
Outstanding at June 30, 20266,552,073 $38.33 
Exercisable at June 30, 20264,629,494 $41.19 
Vested and expected to vest at June 30, 20266,552,073 $38.33 
At June 30, 2026, there was approximately $32.2 million of total unrecognized compensation expense related to unvested stock option awards, which we expect to recognize over a weighted-average period of approximately 2.60 years.
Restricted stock units
The following table presents RSU activity for the six months ended June 30, 2026:
Number of
Stock Units
Weighted-Average
Grant Date Fair 
Value
Unvested shares at December 31, 20252,007,463 $32.03 
Granted1,258,034 29.16 
Vested(871,391)29.87 
Forfeited(207,202)32.19 
Unvested shares at June 30, 20262,186,904 $31.22 
As of June 30, 2026, there was approximately $54.1 million of total unrecognized compensation expense related to RSUs, which we expect to recognize over a weighted-average period of approximately 2.04 years.
Performance-based stock units
The following table presents PSU activity for the six months ended June 30, 2026:
Number of
Stock Units
Weighted-Average
Grant Date Fair 
Value
Unvested shares at December 31, 2025376,978 $32.55 
Granted83,500 29.20 
Vested(103,128)31.69 
Unvested shares at June 30, 2026357,350 $32.02 
Stock-based compensation expense associated with PSUs is recognized if the underlying performance condition is considered probable of achievement using our management’s best estimates. For PSUs that also have a service period requirement, stock-based compensation expense is recognized over the service period once the underlying performance condition is considered probable of achievement using our management's best estimates.
Included in unvested shares were 61,812 shares with performance conditions that were considered probable of achievement at June 30, 2026, but which also have a service period requirement until December 31, 2027. As of June 30, 2026, there was approximately $1.1 million of total unrecognized compensation expense related to these PSUs.
As of June 30, 2026, there was $9.4 million of total unrecognized compensation expense related to PSUs with performance-based vesting criteria that are considered not probable of achievement.
Market-based stock units
We have issued certain equity awards that contain market-based vesting conditions, in which shares of stock are earned at vesting based on total shareholder return compared to an industry stock index. The fair value of market-based stock units, or MSUs, is estimated using a Monte Carlo simulation model. Assumptions and estimates utilized in the model include the risk-free interest rate, dividend yield, expected stock volatility and the service period.
The following table presents MSU activity for the six months ended June 30, 2026:
Number of
Stock Units
Weighted-Average
Grant Date Fair 
Value
Unvested shares at December 31, 2025— $— 
Granted131,500 49.34 
Unvested shares at June 30, 2026131,500 $49.34 
As of June 30, 2026, there was $5.7 million of unrecognized compensation expense related to MSUs with market-based vesting criteria, which we expect to recognize over a weighted-average period of approximately 2.50 years.
Amended and Restated 2013 Employee Stock Purchase Plan
In June 2013, our Board of Directors adopted, and in July 2013 our stockholders approved, the 2013 Employee Stock Purchase Plan, or 2013 ESPP, which was further amended and restated by our Board of Directors in December 2024. We issued and sold 65,809 and 52,092 shares of common stock during the six months ended June 30, 2026 and 2025, respectively, under the 2013
ESPP. The 2013 ESPP provides participating employees with the opportunity to purchase up to an aggregate of 2,363,636 shares of our common stock. As of June 30, 2026, we had 1,384,142 shares of common stock available for future issuance under the 2013 ESPP.
Stock-based compensation expense
Stock-based compensation expense by award type included within the condensed consolidated statements of operations is as follows:
Three Months Ended
June 30,		Six Months Ended
June 30,
(In thousands)2026202520262025
Stock options$5,951 $4,622 $10,452 $9,022 
Restricted stock units7,947 7,507 15,145 14,191 
Performance-based stock units964 2,188 4,232 2,188 
Market-based stock units570 — 764 — 
Employee stock purchase plan509 375 889 650 
Total stock-based compensation expense$15,941 $14,692 $31,482 $26,051 

Expenses related to stock options and stock-based awards were allocated as follows in the condensed consolidated statements of operations:
Three Months Ended June 30,Six Months Ended June 30,
(In thousands)2026202520262025
Research and development expense$6,815 $5,336 $12,510 $9,940 
Selling, general and administrative expense9,126 9,356 18,972 16,111 
Total stock-based compensation expense$15,941 $14,692 $31,482 $26,051