v3.26.1
Merger with AlloVir - Additional Information (Details)
$ / shares in Units, $ in Thousands
1 Months Ended 3 Months Ended 6 Months Ended
Mar. 18, 2025
USD ($)
$ / shares
shares
Jan. 31, 2025
USD ($)
$ / shares
shares
Jun. 30, 2026
USD ($)
Jun. 30, 2025
USD ($)
Jun. 30, 2026
USD ($)
$ / shares
Jun. 30, 2025
USD ($)
Jan. 31, 2024
$ / shares
shares
Business Acquisition [Line Items]              
Exercise price per share, cancelled | $ / shares         $ 5.05    
Stock-based compensation expense     $ 644 $ 591 $ 1,224 $ 965  
General and Administrative              
Business Acquisition [Line Items]              
Stock-based compensation expense     $ 366 $ 378 $ 778 $ 658  
AlloVir              
Business Acquisition [Line Items]              
Merger agreement date Mar. 18, 2025            
Interest rate   8.00%          
Equity own percentage 25.53%            
Cash and cash equivalents $ 102,100            
Prepaid expenses and other current assets 1,700            
Accounts payable and accrued expenses 2,600            
Director's and officer's insurance recognized 1,500            
Transaction costs $ 5,400            
AlloVir | Common Stock              
Business Acquisition [Line Items]              
Common stock shares issued | shares 13,634,744            
AlloVir | Stock Options | General and Administrative              
Business Acquisition [Line Items]              
Stock-based compensation expense $ 100            
AlloVir | Restricted Stock Units | General and Administrative              
Business Acquisition [Line Items]              
Stock-based compensation expense $ 100            
Kalaris Therapeutics, Inc.              
Business Acquisition [Line Items]              
Equity own percentage 74.47%            
Series B-2 Redeemable Convertible Preferred Stock              
Business Acquisition [Line Items]              
Redeemable convertible preferred stock, shares issued | shares             1,280,000
Price per share | $ / shares             $ 1.25
2024 Convertible Promissory Note | Kalaris Therapeutics, Inc.              
Business Acquisition [Line Items]              
Common stock price per share | $ / shares   $ 6.2          
Debt instrument, issued, principal amount   $ 3,750          
2024 Convertible Promissory Note | Redeemable Convertible Preferred Stock | AlloVir              
Business Acquisition [Line Items]              
Redeemable convertible preferred stock, shares issued | shares 0.2016            
Conversion ratios 4.9603            
2024 Convertible Promissory Note | Series B-2 Redeemable Convertible Preferred Stock | Kalaris Therapeutics, Inc.              
Business Acquisition [Line Items]              
Redeemable convertible preferred stock, shares issued | shares   794,499          
Price per share | $ / shares   $ 4.7851          
Conversion ratios   1          
Maximum | AlloVir              
Business Acquisition [Line Items]              
Exercise price per share unvested and unexercised | $ / shares $ 92            
Maximum | 2024 Convertible Promissory Note | AlloVir              
Business Acquisition [Line Items]              
Debt instrument, issued, principal amount   $ 7,500          
Minimum | AlloVir              
Business Acquisition [Line Items]              
Exercise price per share, cancelled | $ / shares $ 92