Accounts Payable and Accrued Expenses (Detail) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Accounts Payable and Accrued Expenses
Accounts payable	$ 1,226,000	$ 151,000
Clinical trial	2,563,000	3,288,000
Professional fees	377,000	317,000
Property taxes	25,000	96,000
Other	18,000	30,000
BLA consulting services	5,000	28,000
Insurance premiums		21,000
Accrued compensation		72,000
Directors Fees		22,000
Accounts payable and accrued expenses	$ 4,214,000	$ 4,025,000