v3.26.1
Stock-based compensation (Tables)
6 Months Ended
Jun. 30, 2026
Stock-based compensation  
Schedule of reserved shares of common stock

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Shares

Options and RSUs issued and outstanding

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18,507,464

Shares available for future stock option and RSU grants

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3,717,710

Shares available for employee stock purchase plan

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579,499

Total

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22,804,673

Schedule of common stock available under 2021 Incentive Plan

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Shares

Balance December 31, 2025

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4,175,446

Shares reserved for issuance

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4,375,955

Options granted

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(3,649,811)

RSUs granted

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(2,229,578)

Options and RSUs forfeited / cancelled

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1,045,698

Balance June 30, 2026

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3,717,710

Schedule of stock option activity

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Weighted Average 

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Remaining

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Aggregate

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Contractual

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Intrinsic

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Term

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Value

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  ​ ​ ​

Shares

  ​ ​ ​

Exercise Price

  ​ ​ ​

(years)

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(in thousands)

Outstanding January 1, 2026

 

9,105,976

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$

4.30

 

5.75

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$

649

Granted

 

3,649,811

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​

1.94

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—

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​

1,891

Exercised

 

(350,078)

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​

1.49

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—

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​

336

Forfeited

 

(145,137)

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2.32

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—

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​

109

Cancelled

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(804,120)

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​

8.48

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—

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​

7

Outstanding, June 30, 2026

 

11,456,452

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$

5.19

​

7.09

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$

5,979

Exercisable at June 30, 2026

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5,982,722

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$

5.77

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5.19

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$

1,948

Schedule of weighted-average assumptions

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June 30, 2026

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December 31, 2025

 

Expected dividend rate

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—

 

—

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Expected option term (years)

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6.07

 

6.03

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Expected volatility

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82.81

%  

79.28

%

Risk-free interest rate

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3.79

%  

3.96

%

Schedule of Stock-based compensation expense recorded under ASC 718

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Three Months Ended

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Six Months Ended

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June 30, 

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June 30, 

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June 30, 

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June 30, 

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2026

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2025

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2026

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2025

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Research and development

$

822

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$

1,494

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$

1,660

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$

3,074

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General and administrative

​

1,128

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728

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​

1,735

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​

1,574

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Total stock-based compensation

$

1,950

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$

2,222

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$

3,395

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$

4,648

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Schedule of stock-based compensation expense and by award type

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Three Months Ended

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Six Months Ended

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June 30, 

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June 30, 

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June 30, 

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June 30, 

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2026

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2025

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2026

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2025

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Stock options

$

1,176

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​

1,682

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​

1,897

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$

3,540

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Restricted stock units

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762

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​

506

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1,474

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​

999

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Restricted stock awards

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—

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—

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—

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40

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Employee stock purchase plan

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12

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34

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24

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69

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Total stock-based compensation

$

1,950

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​

2,222

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3,395

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$

4,648

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Restricted stock units  
Stock-based compensation  
Schedule of restricted stock activity

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Weighted Average

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Shares

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Grant Date Fair Value

Total Unvested December 31, 2025

 

5,645,957

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$

0.85

Granted

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2,229,578

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​

1.88

Forfeited

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(96,441)

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1.57

Vested

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(728,082)

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​

1.49

Total Unvested June 30, 2026

 

7,051,012

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$

1.10