Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Accrued Expenses and Other Current Liabilities
Drugs and clinical trial expenses	$ 2,118	$ 1,215
Accrued salaries, benefits and travel related costs	663	1,570
Professional and consultant fees	277	126
Legal expenses	450	140
Other administrative accruals	92	69
Accrued expenses	3,600	$ 3,120
Operating lease liabilities current portion	192
Insurance premiums payable	$ 1,740