Quarterly report pursuant to Section 13 or 15(d)

Note 1 - The Company and Basis of Presentation (Details Textual)

v3.20.2
Note 1 - The Company and Basis of Presentation (Details Textual) - USD ($)
1 Months Ended 3 Months Ended 6 Months Ended 11 Months Ended
Jun. 09, 2020
Jun. 08, 2020
Apr. 20, 2020
Apr. 16, 2020
Nov. 26, 2019
Nov. 12, 2019
Jun. 30, 2020
May 31, 2020
Feb. 29, 2020
Nov. 30, 2019
Jun. 30, 2020
Mar. 31, 2020
Jun. 30, 2020
Jun. 30, 2019
Nov. 30, 2019
Apr. 15, 2020
Dec. 31, 2019
Proceeds from Warrant Exercises                         $ 4,800,000      
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)             23,583,290       23,583,290   23,583,290        
Payments of Warrant Issuance Costs     $ 326,000                   $ 326,000      
Retained Earnings (Accumulated Deficit), Ending Balance             $ (211,336,000)       $ (211,336,000)   (211,336,000)       $ (197,911,000) [1]
Cash and Cash Equivalents, at Carrying Value, Ending Balance             8,500,000       8,500,000   8,500,000       $ 13,308,000 [1]
Working Capital             $ 11,704,000       $ 11,704,000   11,704,000        
Net Cash Provided by (Used in) Operating Activities, Total                         $ (10,189,000) $ (19,254,000)      
Conversion of Term Loan with CRG Into Stock and Warrants [Member]                                  
Debt Conversion, Original Debt, Amount           $ 28,981,000                      
Debt Conversion, Converted Instrument, Amount           $ 31,300,000                      
Conversion of Term Loan with CRG Into Series B Convertible Preferred Stock [Member]                                  
Debt Conversion, Converted Instrument, Shares Issued (in shares)         31,300 31,300                      
Series A Preferred Stock [Member]                                  
Preferred Stock, Shares Outstanding, Ending Balance (in shares)             0       0   0       1,852,173
Series A Convertible Preferred Stock [Member]                                  
Preferred Stock, Shares Outstanding, Ending Balance (in shares)             0       0   0        
Common Stock [Member]                                  
Stock Issued During Period, Shares, New Issues (in shares)                     525,000            
Series A and Series B Warrants [Member]                                  
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)                               $ 0.61 $ 1.55
Proceeds from Warrant Exercises       $ 3,089,000                          
Series A Warrants [Member]                                  
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)                   $ 1.55         $ 1.55    
Stock Issued During Period, Shares, Warrant Exercises (in shares)       4,820,584     27,601 4,099 1,026,240                
Proceeds from Warrant Exercises             $ 17,000 $ 2,500 $ 1,591,000                
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)             1,540,829     7,419,353 1,540,829   1,540,829   7,419,353    
Warrants and Rights Outstanding, Term (Year)                   1 year         1 year    
Series A Warrants [Member] | Common Stock [Member]                                  
Stock Issued During Period, Shares, Warrant Exercises (in shares)                     4,852,284 1,026,240          
Series B Warrants [Member]                                  
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)                   $ 1.55         $ 1.55    
Stock Issued During Period, Shares, Warrant Exercises (in shares)       242,790     50,700   45,473                
Proceeds from Warrant Exercises             $ 31,000   $ 70,000                
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)             7,080,390     7,419,353 7,080,390   7,080,390   7,419,353    
Warrants and Rights Outstanding, Term (Year)                   5 years         5 years    
Series B Warrants [Member] | Common Stock [Member]                                  
Stock Issued During Period, Shares, Warrant Exercises (in shares)                     293,490 45,473          
Series A-2 Warrants [Member]                                  
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)     4,820,584                            
Series B-2 Warrants [Member]                                  
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)     242,790                            
Series A-2 and Series B-2 Warrants [Member]                                  
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)     $ 0.6371                            
Warrants and Rights Outstanding, Term (Year)     5 years                            
Warrants Issued Upon Conversion of Term Loan with CRG [Member]                                  
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)         9,893,776 9,893,776                      
Warrants and Rights Outstanding, Term (Year)           5 years                      
Purchase Agreement with LPC [Member]                                  
Maximum Amount of Shares Issuable $ 10,000,000 $ 10,000,000                              
Stock Purchase Agreement Duration Period (Month) 2 years 180 days 2 years 180 days                              
Stock Issued During Period, Shares, New Issues (in shares) 525,000                                
Shares Issued, Price Per Share (in dollars per share) $ 0.65                                
Maximum Number of Shares Issuable on Any Business Day Selected by The Company (in shares) 250,000                                
Maximum Number of Shares Issuable on Any Business Day Selected by The Company in Certain Circumstances (in shares) 500,000                                
November 2019 Offering [Member]                                  
Proceeds from Issuance or Sale of Equity, Total                   $ 11,500,000              
Proceeds From Issuance of Common Stock, Net                   $ 9,922,000              
November 2019 Offering [Member] | Series A Preferred Stock [Member]                                  
Stock Issued During Period, Shares, New Issues (in shares)                   5,473,410              
November 2019 Offering [Member] | Common Stock [Member]                                  
Stock Issued During Period, Shares, New Issues (in shares)                   1,945,943         1,945,943    
[1] The condensed consolidated balance sheet as of December 31, 2019 has been derived from the audited consolidated financial statements as of that date.