Annual report pursuant to Section 13 and 15(d)

Nature of Operations and Basis of Presentation - Additional Information (Details)

v3.24.1
Nature of Operations and Basis of Presentation - Additional Information (Details) - USD ($)
 12 Months Ended
Feb. 29, 2024
Oct. 07, 2022
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
May 31, 2023
May 03, 2023
Oct. 17, 2022
Aug. 17, 2022
Sep. 08, 2020
Jan. 21, 2020
Organization Consolidation And Presentation Of Financial Statements [Line Items]                      
Net losses     $ 38,371,000 $ 44,434,000 $ 91,564,000            
Accumulated deficit     461,298,000 422,927,000              
Cash and cash equivalents     $ 6,071,000 $ 21,092,000              
Description of reverse share split     The Company's shareholders approved a reverse share split of the Company's ordinary shares on June 15, 2022, which became effective on August 17, 2022, (the Reverse Share Split). As of 5:00 p.m. Eastern Standard Time on August 17, 2022, every fifteen ordinary shares of $0.01 each (nominal value) in the authorized and unissued and authorized and issued share capital of the Company were consolidated into one ordinary share of $0.15 each (nominal value), and the nominal value of each ordinary share was subsequently reduced from $0.15 to $0.01 nominal value per share.                
Ordinary shares, par value     $ 0.01 $ 0.01     $ 0.01   $ 0.01    
Reverse share split previous nominal value                 0.15    
Additional ordinary shares with preemptive rights           60,000,000          
Maximum                      
Organization Consolidation And Presentation Of Financial Statements [Line Items]                      
Value of shares and securities may offer and sell               $ 100,000,000      
Sales Agreement with H.C. Wainwright & Co., L.L.C                      
Organization Consolidation And Presentation Of Financial Statements [Line Items]                      
Ordinary shares, par value   $ 0.01                  
Sales Agreement with H.C. Wainwright & Co., L.L.C | Maximum                      
Organization Consolidation And Presentation Of Financial Statements [Line Items]                      
May offer and sell ordinary shares for aggregate gross sales proceeds   $ 16,000,000                  
0.01 Nominal Value                      
Organization Consolidation And Presentation Of Financial Statements [Line Items]                      
Ordinary shares, par value                 0.01    
0.15 Nominal Value                      
Organization Consolidation And Presentation Of Financial Statements [Line Items]                      
Ordinary shares, par value                 $ 0.15    
2025 Exchangeable Notes                      
Organization Consolidation And Presentation Of Financial Statements [Line Items]                      
Aggregate principal amount                     $ 9,891,000
2025 Exchangeable Notes | Private Placement and Rights Offering                      
Organization Consolidation And Presentation Of Financial Statements [Line Items]                      
Aggregate principal amount                   $ 51,800,000  
Debt instrument interest rate                     6.50%
RLNs | Private Placement and Rights Offering                      
Organization Consolidation And Presentation Of Financial Statements [Line Items]                      
Aggregate principal amount                   $ 500 $ 100,000
Subsequent Events                      
Organization Consolidation And Presentation Of Financial Statements [Line Items]                      
Issuance of ordinary shares 1,800,000