Quarterly report pursuant to Section 13 or 15(d)

Note 5 - Stockholders' Equity (Tables)

v3.7.0.1
Note 5 - Stockholders' Equity (Tables)
6 Months Ended
Jun. 30, 2017
Notes Tables  
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]
    Three Months Ended June 30,
    2017   2016
         
Research and development expenses   $
435,969
    $
264,137
 
General and administrative expenses    
215,980
     
552,930
 
Total   $
651,949
    $
817,067
 
    Six Months Ended June 30,
    2017   2016
         
Research and development expenses   $
808,435
    $
973,553
 
General and administrative expenses    
365,953
     
1,314,400
 
Total   $
1,174,388
    $
2,287,953
 
Share-based Compensation, Stock Options, Activity [Table Text Block]
    Number of Options   Weighted-
Average
Exercise
Price
  Weighted-
Average
Remaining
Contractual
Life (in years)
  Aggregate
Intrinsic Value
                 
Outstanding at January 1, 2017    
1,691,987
    $
22.60
     
5.1
    $
-
 
Granted    
33,408
    $
4.96
     
 
     
 
 
Exercised    
-
     
 
     
 
    $
-
 
Forfeited    
(15,386
)   $
36.40
     
 
     
 
 
Outstanding at June 30, 2017    
1,710,009
    $
22.14
     
4.7
    $
287,704
 
                                 
Exercisable at June 30, 2017    
1,438,619
    $
24.68
     
4.0
    $
31,115
 
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]
Range of Exercise Prices
  Number of Options
Outstanding
  Weighted-
Average
Exercise
Price
  Weighted-
Average
Remaining
Contractual
Life (in years)
  Aggregate
Intrinsic Value
$3.50
-
$13.00
   
751,480
    $
9.51
     
6.8
    $
287,704
 
$13.01
-
$26.00
   
379,774
    $
15.30
     
4.6
     
-
 
$26.01
-
$39.00
   
155,339
    $
32.52
     
2.2
     
-
 
$39.01
-
$65.00
   
423,416
    $
46.86
     
1.9
     
-
 
 
 
 
   
1,710,009
    $
22.14
     
4.7
    $
287,704
 
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]
   
Six Months Ended June 30,
 
   
2017
   
2016
 
                         
Annual dividend    
 
-
 
     
 
-
 
 
Expected life (in years)    
 0.3
-
4.0 
     
6.0
-
7.0
 
Risk free interest rate    
 0.80%
-
1.72% 
     
1.35%
-
1.75%
 
Expected volatility    
 62.2%
-
82.3% 
     
69.0%
-
80.2%
 
Schedule of Share-based Compensation, Warrant Activity [Table Text Block]
Range of Exercise
Prices
  Number of
Warrants
Outstanding
  Range of Expiration Dates
$3.25
-
$3.90
   
811,556
   
May 2021 - July 2021
$5.80
-
$6.50
   
282,054
   
March 2018
$12.80
-
$12.90
   
39,296
   
January 2022
$13.20
-
$13.30
   
314,246
   
August 2017
$16.20
-
$16.30
   
174,544
   
March 2020
$18.60
-
$19.80
   
12,309
   
March 2018 - June 2018
$22.10
-
$27.90
   
153,755
   
March 2019 - January 2021
$34.50
-
$39.00
   
164,114
   
November 2017 - October 2019
$39.10
-
$39.20
   
230,772
   
October 2020 - October 2021
$47.30
-
$52.20
   
275,897
   
January 2019 - July 2019
 
 
 
   
2,458,543