v3.26.1
Stock-Based Compensation (Tables)
12 Months Ended
Dec. 31, 2025
Stock-Based Compensation  
Schedule of stock option activity under the Equity Plans

Weighted

  ​ ​ ​

  ​ ​ ​

Average

  ​ ​ ​

Weighted

  ​ ​ ​

Aggregate

 

Exercise Price

 

Average Remaining

 

Intrinsic

Options

 

Per Share

Life in Years

Value

Outstanding at December 31, 2023

3,384,366

$

13.97

8.40

Granted

 

3,460,000

$

2.57

 

  ​

  ​

Exercised

 

(34,698)

$

2.68

 

Forfeited

(392,924)

$

4.98

Outstanding at December 31, 2024

 

6,416,744

$

8.43

 

8.43

Granted

 

1,000,000

$

1.18

 

  ​

  ​

Exercised

 

(6,667)

$

2.40

 

Forfeited

(3,652,839)

$

7.45

Outstanding at December 31, 2025

3,757,238

$

7.46

7.28

$

Options exercisable at December 31, 2025

 

2,417,888

$

10.76

 

6.01

Options vested and expected to vest at December 31, 2025

 

3,757,238

$

7.46

 

7.28

$

Schedule of assumptions used to determine grant-date fair value of stock options

Year Ended December 31, 

  ​ ​ ​

2025

  ​ ​ ​

2024

Expected volatility

 

103.46

%

93.92

%

Weighted average risk-free interest rate

 

3.90

%

3.82

%

Expected dividend yield

0.00

%

0.00

%

Expected term (in years)

7.00

6.46

Schedule of RSU activity under the 2016 Plan

 

Weighted

  ​ ​ ​

Number of

  ​ ​ ​

Average Grant

 

Shares

 

Date Fair Value

Outstanding at December 31, 2023

 

262,500

$

19.97

Vested

(27,500)

$

25.70

Cancelled

(15,000)

$

17.80

Outstanding at December 31, 2024

220,000

$

19.40

Vested

(303,000)

$

14.21

Granted

20,799,921

$

0.98

Cancelled

(2,411,700)

$

0.44

Outstanding at December 31, 2025

 

18,305,221

$

1.05

Schedule of recognized stock-based compensation expense related to the issuance of stock option awards and RSUs to employees and non-employees in the condensed consolidated statements of operations

Year Ended

December 31, 

  ​ ​ ​

2025

  ​ ​ ​

2024

Research and development

 

$

1,031

$

2,855

General and administrative

 

3,868

 

2,649

Total

$

4,899

$

5,504