- 
        Signature
      
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        /s/ Timothy C. Dec, as attorney-in-fact
      
      
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        Stock symbol
      
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        SUPN
      
      
- 
        Transactions as of
      
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        Sep 8, 2025
      
      
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        Transactions value $
      
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        -$88,373
      
      
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        Form type
      
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        4
      
      
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        Date filed
      
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        9/9/2025, 04:21 PM
      
 
     
   
 
  
    Reporting Owners (1)
  
  
    
      
        
          | Name | Relationship | Address | Signature | Signature date | CIK | 
      
      
          
            | Khattar Jack A. | President, CEO, Director | C/O SUPERNUS PHARMACEUTICALS INC., 9715 KEY WEST AVENUE, ROCKVILLE | /s/ Timothy C. Dec, as attorney-in-fact | 2025-09-09 | 0001539937 | 
      
    
   
  
    Transactions Table
  
  
    
      
        
          | Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes | 
      
      
          
            | transaction | SUPN | Common Stock | Options Exercise | $204K | +8.07K | +0.73% | $25.30 | 1.12M | Sep 8, 2025 | Direct | F1 | 
          
            | transaction | SUPN | Common Stock | Sale | -$293K | -6.32K | -0.57% | $46.29 | 1.11M | Sep 8, 2025 | Direct | F2 | 
      
    
   
  
    Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)
  
  
    
      
        
          | Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Underlying Class | Amount | Exercise Price | Ownership | Footnotes | 
      
      
          
            | transaction | SUPN | Employee Stock Option (Right to Buy) | Options Exercise | $0 | -8.07K | -4.73% | $0.00 | 163K | Sep 8, 2025 | Common Stock | 8.07K | $25.30 | Direct | F3 | 
      
    
   
  
    * An asterisk sign (*) next to the price indicates that the price is likely invalid.
  
  Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.
  Transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c).
  
    Explanation of Responses: