Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid SCY-078 development services	$ 605	$ 153
Prepaid insurance	537	243
Other prepaid expenses	97	71
Other receivable due from R-Pharm	251	233
Other current assets	24	41
Total prepaid expenses and other current assets	$ 1,514	$ 741