Nature of Business (Details)							1 Months Ended	12 Months Ended
	Oct. 08, 2021 USD ($)	May 19, 2021 USD ($) shares	May 04, 2021 shares	Sep. 22, 2020 USD ($) shares	Aug. 07, 2020 shares	Aug. 28, 2019 USD ($)	May 31, 2021 USD ($)	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($) shares	Dec. 31, 2019 USD ($)	Dec. 31, 2021 £ / shares	Dec. 31, 2020 £ / shares	Sep. 22, 2020 £ / shares shares	Aug. 19, 2020 £ / shares	Aug. 18, 2020 £ / shares	Aug. 31, 2017 £ / shares
Conversion of Stock [Line Items]
Shares issued, stock splits (in shares) | shares					1,161
Stock split, conversion ratio				8.8028	0.00086133
Consideration received on transaction						$ 25,000,000.0
Ordinary share conversion ratio	1
Net loss								$ 71,742,000	$ 60,334,000	$ 19,612,000
Accumulated deficit								169,641,000	97,899,000
Cash and cash equivalents								273,243,000	$ 190,327,000	$ 24,966,000
Initial Public Offering
Conversion of Stock [Line Items]
Consideration received on transaction		$ 154,800,000		$ 132,800,000			$ 154,800,000
Accumulated deficit								$ 169,600,000
Ordinary Shares
Conversion of Stock [Line Items]
Common stock, par value (in GBP per share) | £ / shares											£ 0.008		£ 0.008	£ 0.001	£ 1.00	£ 0.008
Common stock, outstanding (in shares) | shares								42,019,874	35,930,331				27,305,331
Sale of stock, shares issued in transaction (in shares) | shares		600,000	4,000,000
Deferred Shares
Conversion of Stock [Line Items]
Common stock, par value (in GBP per share) | £ / shares												£ 21,921.504	£ 21,921.504
Common stock, outstanding (in shares) | shares								1	1
American Depositary Shares | Initial Public Offering
Conversion of Stock [Line Items]
Sale of stock, shares issued in transaction (in shares) | shares				8,625,000
Sale of stock, price per share (in dollars per share) | £ / shares													£ 17.00
Maximum amount of stock that may be sold	$ 150,000,000.0
American Depositary Shares | Over-Allotment Option
Conversion of Stock [Line Items]
Sale of stock, shares issued in transaction (in shares) | shares				1,125,000