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Capital Stock - Common Stock Purchase Agreement - Additional Information (Details) - Novartis [Member] $ / shares in Units, $ in Millions | Aug. 24, 2017 USD ($) $ / shares shares
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Class Of Warrant Or Right [Line Items] |
Number of common stock agreed to issue and sell | shares | 539,131
Common stock sale price | $ / shares | $ 9.2742
Aggregate purchase price of common stock agreed to issue and sell | $ 5.0
Common stock aggregate fair value | $ 4.8
Common stock closing price | $ / shares | $ 8.93
Common stock purchase agreement date | Aug. 24, 2017
Common stock premium | $ 0.2

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- Details
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