Condensed Consolidated Balance Sheets (Parenthetical) - £ / shares	Jun. 30, 2019	Dec. 31, 2018
Ordinary shares, nominal value	£ 0.01	£ 0.01
Ordinary shares, shares authorized	31,995,653	15,452,420
Ordinary shares, shares issued	17,900,731	898,678
Ordinary shares, shares outstanding	17,900,731	814,728
Series A Convertible Preferred Shares
Convertible preferred shares, nominal value	£ 0.01	£ 0.01
Convertible preferred shares, shares authorized	0	3,000,001
Convertible preferred shares, shares issued	0	2,800,001
Convertible preferred shares, shares outstanding	0	2,800,001
Series B1 Convertible Preferred Shares
Convertible preferred shares, nominal value	£ 0.01	£ 0.01
Convertible preferred shares, shares authorized	0	4,690,485
Convertible preferred shares, shares issued	0	3,947,198
Convertible preferred shares, shares outstanding	0	3,947,198
Series B2 Convertible Preferred Shares
Convertible preferred shares, nominal value	£ 0.01	£ 0.01
Convertible preferred shares, shares authorized	0	1,403,633
Convertible preferred shares, shares issued	0	1,323,248
Convertible preferred shares, shares outstanding	0	1,323,248

Face amount or stated value per share of common stock.

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