Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Jun. 30, 2017
Payables and Accruals [Abstract]
Clinical trial costs	$ 722	$ 1,984
Personnel costs	1,144	1,632
Professional fees	1,282	590
Other	67	18
Accrued expenses	$ 3,215	$ 4,224