Warrants
 12 Months Ended
Dec. 31, 2021
Equity [Abstract]  
Warrants Shareholders’ Equity
Under the Memorandum of Association and Articles of Association, or Articles, in effect as of December 31, 2021 and 2020, the Company had authorized an unlimited number of common shares with no par value.
As of December 31, 2021 and 2020, 24,488,335 and 23,925,789 common shares, respectively, were issued and 24,080,265 and 23,517,719 common shares, respectively, were outstanding.
During the year ended December 31, 2021, the Company granted stock options to employees and contractors (see Note 10).
The Company had reserved common shares for future issuances at December 31:
20212020
Warrants to purchase common shares5,500 5,500 
Options to purchase common shares2,098,087 2,012,960 
Remaining shares available under the 2018 Equity Incentive Plan1,780,687 1,641,112 
Shares issuable on vesting of grants of restricted stock3,982 48,624 
Remaining shares available under the 2018 ESPP661,000 474,000 
Total4,549,256 4,182,196 
Warrants
In March 2017, the Company issued warrants for the purchase of 145,000 Class B ordinary shares to parties related to Rockport Ventures, with a fixed exercise price of $3.80 per share.
During the year ended December 31, 2021, no warrants were exercised. As of December 31, 2021 and 2020, 5,500 warrants to purchase the Company’s common shares were outstanding and exercisable:
Warrant HolderIssue DateIn Connection WithWarrant to
Purchase		SharesExercise
Price		Expiration Date
Rockport3/3/2017Loan agreementCommon5,500 $3.80 8/28/2022