Accrued Liabilities - Schedule of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Sep. 30, 2019
Accrued Liabilities Current [Abstract]
Accrued professional fees	$ 257	$ 434
Accrued clinical study expense	1,438	2,163
Accrued purchases	1,150	679
Acquisition of in process research and development	1,167	989
Current portion of lease liability	472
Deferred rent		130
Other	394	395
Total	$ 4,878	$ 4,790