v3.19.3
Note 2 - Summary of Significant Accounting Policies (Details Textual) - USD ($)
1 Months Ended 6 Months Ended 12 Months Ended
Oct. 31, 2018
Jun. 30, 2019
Jun. 30, 2018
Dec. 31, 2018
Dec. 31, 2017
Jan. 01, 2019
Research and Development Expense, Total   $ 3,226,000 $ 1,269,000 $ 2,137,000 $ 8,722,000  
Impairment of Long-Lived Assets Held-for-use   0   0    
Payments of Dividends, Total   0        
Grants Receivable       5,700,000    
Grant Reimbursements   1,198,000        
Reclassification of Warrant into Equity   234,000        
Gain (Loss) on Extinguishment of Debt, Total $ 11,000          
Operating Lease, Liability, Total   840,000   239,000    
Lessee, Operating Lease, Liability, Payments, Due, Total   1,007,000        
Operating Lease, Right-of-Use Asset   779,000        
Accounting Standards Update 2016-02 [Member]            
Operating Lease, Liability, Total           $ 227,000
Lessee, Operating Lease, Liability, Payments, Due, Total           $ 239,000
Lessee, Operating Lease, Discount Rate           9.41%
Operating Lease, Right-of-Use Asset           $ 227,000
Modified March 2018 and Modified September 2018 Notes [Member]            
Gain (Loss) on Extinguishment of Debt, Total $ 11,000          
Embedded Derivative, Fair Value of Embedded Derivative Asset   0   0    
Embedded Derivative, Fair Value of Embedded Derivative Liability   0   0    
Research and Development Expense [Member]            
Collaboration Initiation Payment   75,000        
Money Market Funds [Member]            
Restricted Cash, Total   200,000        
Letter of Credit 1 [Member]            
Restricted Cash, Total   $ 55,000   $ 55,000 55,000  
Minimum [Member]            
Property, Plant and Equipment, Useful Life   3 years   3 years    
Maximum [Member]            
Property, Plant and Equipment, Useful Life   5 years   5 years    
Grants Receivable       $ 5,700,000    
Clinical Study, Premier Research International LLC and CRF Health, Inc. [Member]            
Research and Development Expense, Total       95,000 6,200,000  
Clinical Study, PRA Health, CRF Health, Inc., Premier Research International LLC, ICON Central Laboratories, and Almac Clinical Services [Member]            
Research and Development Expense, Total       $ 185,000 $ 0  
Accounts Payable 1 [Member] | Supplier Concentration Risk [Member] | Vendor 1 [Member]            
Concentration Risk, Percentage   26.00%   52.00% 56.00%  
Accounts Payable 1 [Member] | Supplier Concentration Risk [Member] | Vendor 2 [Member]            
Concentration Risk, Percentage   22.00%   26.00% 31.00%  
Accounts Payable 1 [Member] | Supplier Concentration Risk [Member] | Vendor 3 [Member]            
Concentration Risk, Percentage   17.00%   15.00%    
Accounts Payable 1 [Member] | Supplier Concentration Risk [Member] | Two of the Three Vendors Supporting Clinical Study Activities [Member]            
Concentration Risk, Percentage   44.00%   67.00%    
Accounts Payable 1 [Member] | Supplier Concentration Risk [Member] | One of the Two Vendors Supporting Manufacturing Activities [Member]            
Concentration Risk, Percentage         56.00%