v3.23.1
Stock-based Compensation (Tables)
9 Months Ended 12 Months Ended
Jan. 31, 2023
Apr. 30, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]    
Summary of Stock-Based Compensation Expense  
The following is a summary of stock-based compensation expense:
 
    
For the years ended April 30
 
    
2022
    
2021
 
Research and Development
   $ 4,232      $ 15,229  
Selling, General and Administrative
     64,163        9,446  
  
 
 
    
 
 
 
     $68,396      $24,675  
  
 
 
    
 
 
 
Service-based Stock Option    
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]    
Summary of Stock Option Activity
The following is a summary of service-based stock option activity during the nine months ended January 31, 2023:
 
    
Number of
Options
Outstanding
    
Weighted
Average
Exercise
Price
    
Average
Remaining
Contractual
Life
(in years)
 
Outstanding—April 30, 2022
     254,215      $ 11.79        4.6  
Options forfeited
     (2,273 )       1.16        —    
  
 
 
       
Outstanding— January 31, 2023
     251,942      $ 11.89        3.9  
  
 
 
       
Non-vested
at January 31, 2023
     3,851      $ 3.31        8.9  
Vested at January 31, 2023
     248,091      $ 12.02        3.8  
The following table summarizes the Company’s service-based stock options:
 
    
Number of
Options
Outstanding
    
Weighted
Average
Exercise
Price
    
Average
Remaining
Contractual
Life
(in years)
 
Outstanding - April 30, 2020
     248,837      $ 12.44        6.5  
Options granted
     3,030      $ 1.16        9.5  
  
 
 
       
Outstanding - April 30, 2021
     251,867      $ 12.30        5.5  
Options granted
     9,848      $ 2.93        9.8  
Options forfeited
     (7,500 )     $ 15.18        —    
  
 
 
       
Outstanding - April 30, 2022
     254,215      $ 11.79        4.6  
  
 
 
       
Non-vested
at April 30, 2022
     10,126      $ 2.89        9.5  
Vested at April 30, 2022
     244,089      $ 12.16        4.4  
Summary of Stock Option Using The Black-Scholes Option-Pricing Model On Grant Date  
The Company estimates fair values of service-based stock options using the Black-Scholes option-pricing model on grant date. The principal assumptions used in applying this model were as follows:
 
    
April 30,
2022
   
April 30,
2021
 
Risk free interest rate
     1.72 %      1.08 % 
Volatility
     55.0 %      53.0 % -66.2% 
Dividend yield
     —         —    
Weighted average expected term (in years)
     4.6       9.5  
Performance-based Stock Option    
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]    
Summary of Stock Option Activity
The following is a summary of performance-based stock option activity during the nine months ended January 31, 2023:
 
    
Number of
Options
Outstanding
    
Weighted
Average
Exercise
Price
    
Average
Remaining
Contractual
Life
(in years)
 
Outstanding—April 30, 2022
     581,768      $ 5.16        7.8  
Options forfeited
     (1,515 )       3.47        —    
  
 
 
       
Outstanding— January 31, 2023
     580,253      $ 5.16        7.1  
  
 
 
       
Non-vested
at January 31, 2023
     432,665      $ 5.57        7.1  
Vested at January 31, 2023
     147,588      $ 3.97        7.1  
The following summarizes the Company’s performance-based stock options:
 
    
Number of
Options
Outstanding
    
Weighted
Average
Exercise
Price
    
Average
Remaining
Contractual
Life
(in years)
 
Outstanding - April 30, 2020
     285,101      $ 8.20        8.2  
Options granted
     145,758      $ 1.16        9.5  
Options forfeited
     (3,788 )     $ 6.25        —    
  
 
 
       
Outstanding - April 30, 2021
     427,071      $ 5.81        8.1  
Options granted
     159,621      $ 3.47        —    
Options forfeited
     (4,924 )     $ 6.63        9.8  
  
 
 
       
Outstanding - April 30, 2022
     581,768      $ 5.16        7.8  
  
 
 
       
Non-vested
at April 30, 2022
     497,626      $ 5.30        8.1  
Vested at April 30, 2022
     84,142      $ 4.34        6.6  
Summary of Stock Option Using The Black-Scholes Option-Pricing Model On Grant Date  
The Company estimates fair values of performance-based stock options using the Black-Scholes option-pricing model on grant date. The principal assumptions used in applying this model were as follows
 
    
April 30,
2022
   
April 30,
2021
 
Risk free interest rate
     1.72 %      1.08 % 
Volatility
     55.0 %      53.0 % -66.2% 
Dividend yield
     —         —    
Weighted average expected term (in years)
     7.8       8.1