Annual report pursuant to Section 13 and 15(d)

Shareholders' Equity / (Deficit) - Additional Information (Details)

Shareholders' Equity / (Deficit) - Additional Information (Details) $ / shares in Units, $ in Millions										1 Months Ended	12 Months Ended
	Feb. 12, 2021 $ / shares shares	Feb. 10, 2021 $ / shares shares	Feb. 08, 2021 $ / shares shares	Oct. 31, 2020 $ / shares shares	Oct. 27, 2020 $ / shares shares	Jul. 02, 2020 $ / shares shares	Jun. 10, 2020 Vote $ / shares shares	Jun. 05, 2020 $ / shares shares	Jun. 03, 2020 $ / shares shares	Jun. 30, 2020 $ / shares shares	Dec. 31, 2021 USD ($) Vote $ / shares shares	Jan. 28, 2021 $ / shares shares	Dec. 31, 2020 $ / shares shares	May 15, 2018 $ / shares	Apr. 27, 2018 $ / shares shares	Mar. 13, 2018 $ / shares shares	Mar. 12, 2018 $ / shares	May 18, 2017 $ / shares shares	Nov. 18, 2015 $ / shares shares	Oct. 14, 2015 $ / shares shares
Class Of Stock [Line Items]
Ordinary shares, shares authorized							100,000,000				300,000,000	150,000,000	150,000,000			44,557,606		7,956,715	3,659,453	413,110
Ordinary shares, shares issued											182,775,282		49,431,028			413,110				413,110
Ordinary shares, par value \| $ / shares							$ 0.01				$ 0.01	$ 0.01	$ 0.01			$ 0.001	$ 0.0001	$ 0.01	$ 0.01	$ 0.01
Share consolidation basis nominal value per share \| $ / shares														$ 0.01571
Share consolidation basis, Renominalisation value per share \| $ / shares														$ 0.01
Number of vote per common share \| Vote							1				1
Common stock rights and preferences							The holders of ordinary shares have no preemptive or other subscription rights, and there are no redemption or sinking fund provisions with respect to such shares.				The holders of ordinary shares are entitled to one vote for each share held. The holders of ordinary shares currently have no preemptive or other subscription rights, and there are no redemption or sinking fund provisions with respect to such shares.
Number of warrants to purchase preferred shares											380,000
Proceeds from registered direct offerings, net of transaction costs \| $											$ 0.5
Undesignated preferred shares, par value \| $ / shares											$ 0.01		$ 0.01
Undesignated preferred shares, authorized											100,000,000		100,000,000
Undesignated preferred shares issued											0		0
October Offering
Class Of Stock [Line Items]
Ordinary shares, par value \| $ / shares											$ 0.01		$ 0.01
Number of warrants to purchase preferred shares				1,884,615							20,890,516
Warrants to purchase preferred shares, exercise price \| $ / shares				$ 0.8125	$ 0.65
Warrants expiry date				Oct. 22, 2025	Oct. 27, 2025
Percentage of ordinary shares issued to purchase additional warrants				7.00%
Proceeds from registered direct offerings, net of transaction costs \| $											$ 13.9
February Underwritten Offering
Class Of Stock [Line Items]
Warrants to purchase preferred shares, exercise price \| $ / shares		$ 1.4375	$ 1.4375
Warrants expiry date		Feb. 03, 2026	Feb. 03, 2026
Percentage of ordinary shares issued to purchase additional warrants		7.00%	7.00%
Offering closing date		Feb. 10, 2021	Feb. 08, 2021
Additional ordinary shares that can be purchased by underwriter		5,217,391
February Registered Direct Offering
Class Of Stock [Line Items]
Warrants to purchase preferred shares, exercise price \| $ / shares	$ 2.50
Warrants expiry date	Feb. 09, 2026
Percentage of ordinary shares issued to purchase additional warrants	7.00%
Offering closing date	Feb. 12, 2021
Maximum \| October Offering
Class Of Stock [Line Items]
Number of warrants to purchase preferred shares					20,192,307
Maximum \| February Underwritten Offering
Class Of Stock [Line Items]
Number of warrants to purchase preferred shares		365,217	2,434,783
Maximum \| February Registered Direct Offering
Class Of Stock [Line Items]
Number of warrants to purchase preferred shares	1,225,000
Undesignated Preferred Shares
Class Of Stock [Line Items]
Undesignated preferred shares, par value \| $ / shares											$ 0.01
Undesignated preferred shares, authorized											100,000,000
Undesignated preferred shares issued											0		0
Ordinary Shares
Class Of Stock [Line Items]
Number of warrants to purchase preferred shares											19,890				19,890
Silicon Valley Bank and Life Sciences Fund II LLC \| Series B Convertible Preferred Shares
Class Of Stock [Line Items]
Number of warrants to purchase preferred shares											19,890				19,890
Warrants to purchase preferred shares, exercise price \| $ / shares											$ 18.85				$ 18.85
June 3 SPA \| Private Placement
Class Of Stock [Line Items]
Number of warrants to purchase preferred shares								208,023
Warrants to purchase preferred shares, exercise price \| $ / shares								$ 2.1031	$ 1.62
Warrants expiry date								Jun. 03, 2025	Dec. 05, 2025
Percentage of ordinary shares issued to purchase additional warrants								7.00%
June 3 SPA \| Maximum \| Private Placement
Class Of Stock [Line Items]
Number of warrants to purchase preferred shares									1,485,885
June 30 SPA \| Private Placement
Class Of Stock [Line Items]
Number of warrants to purchase preferred shares						236,088					1,264,757
Warrants to purchase preferred shares, exercise price \| $ / shares						$ 1.8531				$ 1.42
Warrants expiry date						Jun. 30, 2025				Jan. 02, 2026
Percentage of ordinary shares issued to purchase additional warrants						7.00%
Proceeds from registered direct offerings, net of transaction costs \| $											$ 1.8
June 30 SPA \| Maximum \| Private Placement
Class Of Stock [Line Items]
Number of warrants to purchase preferred shares										1,686,343