Shareholders' (Deficit) Equity - Additional Information (Details) $ / shares in Units, $ in Thousands		1 Months Ended			3 Months Ended
	Mar. 31, 2023 USD ($) $ / shares shares	Mar. 31, 2024 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares	Sep. 30, 2023 USD ($) $ / shares shares	Mar. 31, 2024 USD ($) $ / shares shares	Mar. 31, 2023 USD ($) $ / shares	Mar. 04, 2024 $ / shares	Jun. 30, 2023 $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2020 £ / shares
Class of Stock [Line Items]
Number of shares authorized | shares		45,122,321,523	45,122,321,523		45,122,321,523			35,000,000,000
Net proceeds from sale of shares					$ 1,726	$ 3,212
Nominal value of ADS (in per warrant ADS) | (per share)	$ 0.0001	$ 0.0001	$ 0.0001		$ 0.0001	$ 0.0001		$ 0.0001	$ 0.0001	£ 0.01
Capital redemption reserve		$ 52,194	$ 52,194		$ 52,194				$ 50,600
Deferred shares issued | shares									3,847,331,913
Deferred shares issued price per share | $ / shares									$ 0.01315
Aggregate nominal value cancelled per share | $ / shares									$ 0.01
Aggregate nominal value cancelled									$ 50,600
Ordinary Shares
Class of Stock [Line Items]
Nominal value of ADS (in per warrant ADS) | $ / shares							$ 0.0001
Capital redemption reserve									$ 1,600
ADS | Ordinary Shares
Class of Stock [Line Items]
Number of ordinary shares representing one ADS | shares								2,000
Private Placement | Placement agent
Class of Stock [Line Items]
Estimated fair value of the placement agent warrants				$ 100	$ 200
Private Placement | ADS
Class of Stock [Line Items]
Aggregate ADSs issued (in shares) | shares		1,320,614	947,868	551,816
Price per share | $ / shares		$ 1.48	$ 2.11	$ 3.3
Percentage of the price per ADS for exercise price		125.00%		125.00%
Warrant expiration date				Oct. 06, 2028
Net proceeds from sale of shares		$ 1,700	$ 1,800
Gross proceeds from private placement		$ 2,000	$ 2,000
Warrants issued to purchase ADS (in shares) | shares		132,061		42,550	132,061
Exercise price of warrants | $ / shares		$ 1.85		$ 4.13	$ 1.85
Private Placement | ADS | Pre-Funded Warrants
Class of Stock [Line Items]
Purchase price of share | $ / shares				$ 3.1
Aggregate gross proceeds				$ 2,000
Net proceeds from sale of shares				$ 1,700
Warrants issued to purchase ADS (in shares) | shares				48,387
Exercise price of warrants | $ / shares				$ 0.2
Registered direct offering | ADS
Class of Stock [Line Items]
Aggregate ADSs issued (in shares) | shares	1,333,333
Price per share | $ / shares	$ 3
Proceeds from issuance of shares	$ 4,000
Net proceeds from sale of shares	$ 3,500