Stockholders' deficit - Common stock reserved for issuance (Details) - shares |
Dec. 31, 2020 |
Dec. 31, 2019 |
|---|---|---|
| Equity [Abstract] | ||
| Conversion of preferred stock (in shares) | 43,507,130 | 1,760,903 |
| Exercise of options to purchase common stock (in shares) | 7,815,442 | 7,791,833 |
| Warrants to purchase common stock (in shares) | 59,501,978 | 16,981,854 |
| Notes payable (in shares) | 7,530,232 | 4,437,500 |
| Total (in shares) | 118,354,782 | 30,972,090 |
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- Definition Number of shares of convertible preferred stock issuable upon conversion. No definition available.
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- Definition Number of share options (or share units) exercised during the current period. No definition available.
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- Definition Number of shares of notes payable issuable upon conversion. No definition available.
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- Definition Warrants reserved to purchases shares of common stock. No definition available.
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- Definition Aggregate number of common shares reserved for future issuance. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- References No definition available.
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