Common Stock (Tables)
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12 Months Ended |
Dec. 31, 2019 |
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| Equity [Abstract] |
|
| Summary of Fair Value of Option Awards |
The estimated fair value of stock options granted in the respective periods was determined using the Black-Scholes option pricing model using the following weighted average assumptions:
|
|
|
2019
|
|
|
2018
|
|
|
|
Risk-free interest rates
|
|
|
2.52
|
%
|
|
|
2.93
|
%
|
|
|
Expected dividend yield
|
|
|
0
|
%
|
|
|
0
|
%
|
|
|
Expected life
|
|
5.97 years
|
|
|
5.68 years
|
|
|
|
Expected volatility
|
|
|
94.25
|
%
|
|
|
88.23
|
%
|
|
|
| Summary of Share-Based Compensation Expense |
The results for the periods set forth below included stock-based compensation expense in the following expense categories of the consolidated statements of loss (in thousands):
|
|
|
Year ended
|
|
|
|
|
December 31,
|
|
|
|
|
2019
|
|
|
2018
|
|
|
Research and development
|
|
$
|
364
|
|
|
$
|
272
|
|
|
General and administrative
|
|
|
837
|
|
|
|
582
|
|
|
Total stock-based compensation
|
|
$
|
1,201
|
|
|
$
|
854
|
|
|
| Summary of Stock Options Activity |
Stock option transactions and the number of stock options outstanding are summarized below:
|
|
|
Number of
|
|
|
Weighted
|
|
|
|
|
Optioned
|
|
|
Average
|
|
|
|
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Common
|
|
|
Exercise
|
|
|
|
|
Shares
|
|
|
Price
|
|
|
Balance, January 1, 2019
|
|
|
665,585
|
|
|
$
|
15.65
|
|
|
Granted
|
|
|
345,350
|
|
|
|
1.73
|
|
|
Forfeited
|
|
|
(352
|
)
|
|
|
2,450.80
|
|
|
Balance, December 31, 2019
|
|
|
1,010,583
|
|
|
$
|
10.05
|
|
|
| Summary of Stock Options Outstanding Regarding Number of Common Shares Issuable upon Exercise of Outstanding Options |
(1) Number of common shares issuable upon exercise of outstanding options:
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|
|
|
|
|
|
|
|
|
|
Weighted-
|
|
|
|
|
|
|
|
|
|
|
|
|
Average
|
|
|
|
|
|
|
|
|
|
|
|
|
Remaining
|
|
|
|
|
|
|
|
|
Weighted-
|
|
|
Contractual
|
|
|
|
|
|
|
|
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Average
|
|
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Life
|
|
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Exercise Prices
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Number of Options
|
|
|
Exercise Price
|
|
|
(in years)
|
|
|
$1.42 - $1.99
|
|
|
302,100
|
|
|
$
|
1.42
|
|
|
|
9.08
|
|
|
$2.00 - $2.97
|
|
|
386,650
|
|
|
|
2.56
|
|
|
|
8.72
|
|
|
$2.98 - $3.37
|
|
|
167,750
|
|
|
|
3.37
|
|
|
|
8.57
|
|
|
$3.38 - $3.70
|
|
|
8,250
|
|
|
|
3
|
|
|
|
9
|
|
|
$3.71 - $16.46
|
|
|
35,000
|
|
|
|
4
|
|
|
|
9
|
|
|
$16.47 - $69.45
|
|
|
104,910
|
|
|
|
28.90
|
|
|
|
7.58
|
|
|
$69.46 - $206.25
|
|
|
2,190
|
|
|
|
186.98
|
|
|
|
5.57
|
|
|
$206.26- $1,286.45
|
|
|
853
|
|
|
|
465.93
|
|
|
|
4.47
|
|
|
$1,286.46 - $1,348.05
|
|
|
1,530
|
|
|
|
1,304.27
|
|
|
|
3.78
|
|
|
$1,348.06 - $1,960.20
|
|
|
1,350
|
|
|
|
1,605.51
|
|
|
|
1.62
|
|
|
|
|
|
1,010,583
|
|
|
$
|
10.05
|
|
|
|
8.69
|
|
|
| Summary of Stock Options Outstanding Regarding Number of Common Shares Issuable upon Exercise of Vested Options |
(2) Number common shares issuable upon exercise of vested options:
|
|
|
|
|
|
|
|
|
|
|
Weighted-
|
|
|
|
|
|
|
|
|
|
|
|
|
Average
|
|
|
|
|
|
|
|
|
|
|
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|
Remaining
|
|
|
|
|
|
|
|
|
Weighted-
|
|
|
Contractual
|
|
|
|
|
|
|
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Average
|
|
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Life
|
|
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Exercise Prices
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|
Number of Options
|
|
|
Exercise Price
|
|
|
(in years)
|
|
|
$1.42 - $1.99
|
|
|
34,826
|
|
|
$
|
1.42
|
|
|
|
9.08
|
|
|
$2.00 - $2.97
|
|
|
162,076
|
|
|
|
2.56
|
|
|
|
8.72
|
|
|
$2.98 - $3.37
|
|
|
59,410
|
|
|
|
3.37
|
|
|
|
8.57
|
|
|
$3.38 - $3.70
|
|
|
—
|
|
|
|
—
|
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|
—
|
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|
$3.71 - $16.46
|
|
|
—
|
|
|
|
—
|
|
|
|
—
|
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$16.47 - $69.45
|
|
|
63,144
|
|
|
|
28.90
|
|
|
|
7.58
|
|
|
$69.46 - $206.25
|
|
|
2,190
|
|
|
|
186.98
|
|
|
|
5.57
|
|
|
$206.26- $1,286.45
|
|
|
853
|
|
|
|
465.93
|
|
|
|
4.47
|
|
|
$1,286.46 - $1,348.05
|
|
|
1,530
|
|
|
|
1,304.27
|
|
|
|
3.78
|
|
|
$1,348.06 - $1,960.20
|
|
|
1,350
|
|
|
|
1,605.51
|
|
|
|
1.62
|
|
|
|
|
|
325,379
|
|
|
$
|
22.93
|
|
|
|
8.43
|
|
|
| Summary of Restricted Stock Unit Award Activity |
The following table summarizes our restricted stock unit award activity during the year ended December 31, 2019:
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|
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|
|
|
|
Weighted
|
|
|
|
|
Number
|
|
|
Average
|
|
|
|
|
of
|
|
|
Grant Date
|
|
|
|
|
Shares
|
|
|
Fair Value
|
|
|
Balance, January 1, 2019
|
|
|
15,142
|
|
|
$
|
30.53
|
|
|
Released
|
|
|
(5,134
|
)
|
|
|
33.54
|
|
|
Balance, December 31, 2019
|
|
|
10,008
|
|
|
$
|
28.99
|
|
|
| Summary of Outstanding Warrants |
The following is a summary of outstanding warrants to purchase common stock at December 31, 2019:
|
|
|
Total
|
|
|
|
|
|
|
|
|
|
|
Outstanding
|
|
|
Exercise
|
|
|
|
|
|
|
and
|
|
|
price per
|
|
|
|
|
|
|
Exercisable
|
|
|
Share
|
|
|
Expiration Date
|
|
(1) Series A-1 Warrants issued in April 2015 financing
|
|
|
2,175
|
|
|
$
|
264.0000
|
|
|
October 2020
|
|
(2) Warrants issued in September 2017 financing
|
|
|
8,224
|
|
|
$
|
34.9600
|
|
|
March 2023
|
|
(3) Warrants issued in June 2018 financing
|
|
|
2,282,000
|
|
|
$
|
4.0000
|
|
|
June 2023
|
|
(4) Warrants issued in October 2018 financing
|
|
|
624,313
|
|
|
$
|
3.1445
|
|
|
October 2023
|
|
(5) Warrants issued in May 2019 financing
|
|
|
1,200,000
|
|
|
$
|
4.5000
|
|
|
May 2025
|
|
(6) Warrants issued in December 2019 financing
|
|
|
23,000,000
|
|
|
$
|
0.6000
|
|
|
Dec 2024
|
|
| Computation of Basic and Diluted Net Loss Attributable to Common Shareholders Per Share |
The following table presents the computation of basic and diluted net loss attributable to common stockholders per share (in thousands, except per share and share amounts):
|
|
|
Years ended December 31,
|
|
|
|
|
2019
|
|
|
208
|
|
|
2017
|
|
|
Numerator
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Net loss
|
|
$
|
(16,395
|
)
|
|
$
|
(12,687
|
)
|
|
$
|
(10,583
|
)
|
|
Denominator
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Weighted average number of common shares outstanding
|
|
|
8,246,400
|
|
|
|
3,510,217
|
|
|
|
479,442
|
|
|
Basic and diluted net loss per common share
|
|
$
|
(1.99
|
)
|
|
$
|
(3.61
|
)
|
|
$
|
(22.07
|
)
|
|