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NanoTx License Agreement - Additional Information (Details) - USD ($) | May 07, 2020 | Sep. 30, 2020 | Dec. 31, 2019
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Common stock, shares issued (in shares) |  | 4,591,415 | 3,880,588
Common stock, $0.001 par value; 100,000,000 shares authorized; 4,591,415 and 3,880,588 shares issued and outstanding at September 30, 2020 and December 31, 2019, respectively |  | $ 5,000 | $ 4,000
NanoTx License Agreement [Member] |  |  |
License fee payment in cash | $ 400,000 |  |
Common stock, shares issued (in shares) | 230,769 |  |
Common stock, $0.001 par value; 100,000,000 shares authorized; 4,591,415 and 3,880,588 shares issued and outstanding at September 30, 2020 and December 31, 2019, respectively | $ 781,000 |  |
NanoTx License Agreement [Member] | Development and Sales Milestone [Member] |  |  |
Milestone payments | $ 136,500,000 |  |

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