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Common Stock (Tables)
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12 Months Ended |
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Dec. 31, 2014
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| Equity [Abstract] |
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| Schedule of Common Stock |
Gross proceeds of $24.0 million and underwriting discounts and commissions and offering expenses of $1.6 million were allocated as follows:
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Series B
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Pre-funded
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Series A
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Series B
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Common
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Common
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Common
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Common
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Stock
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Stock
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Stock
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Stock
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Warrants
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Warrants
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Warrants
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Units Issued
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5,559,866
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1,340,538
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2,779,933
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670,269
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Gross Proceeds (in thousands)
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$
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14,084
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$
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3,387
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$
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5,261
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$
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1,268
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Underwriting discount and offering expense (in thousands)
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$
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885
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$
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213
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$
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428
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$
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103
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| 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:
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2014
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2013
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2012
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Risk-free interest rates
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1.83
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%
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1.25
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%
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0.96
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%
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Expected dividend yield
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0
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%
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0
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%
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0
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%
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Expected life
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5.9 years
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5.8 years
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5.9 years
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Expected volatility
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82
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%
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86
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%
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95
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%
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| 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):
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Years ended
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December 31,
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2014
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2013
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2012
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Research and development
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$
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1,893
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$
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1,296
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$
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899
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General and administrative
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1,967
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1,538
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1,276
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Total stock-based compensation
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$
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3,860
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$
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2,834
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$
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2,175
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| Summary of Stock Options Activity |
Stock option transactions and the number of stock options outstanding are summarized below:
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Number of
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Weighted
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Optioned
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Average
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Common
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Exercise
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Shares
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Price
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Balance, January 1, 2012
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766,828
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$
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9.82
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Granted
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172,650
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12.97
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Expired
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(12,309
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)
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9.10
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Exercised
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(117,347
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)
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3.94
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Forfeited
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(4,541
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)
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15.26
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Balance, December 31, 2012
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805,281
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$
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11.34
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Granted
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239,282
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11.32
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Expired
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(3,061
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)
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4.11
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Exercised
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(3,475
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)
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3.00
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Forfeited
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(30,536
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)
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13.87
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Balance, December 31, 2013
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1,007,491
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$
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11.39
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Granted
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382,097
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8.97
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Expired
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(12,169
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)
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18.93
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Exercised
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(10,000
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)
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3.00
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Forfeited
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(84,000
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)
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12.14
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Balance, December 31, 2014
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1,283,419
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$
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10.55
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| 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-
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Average
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Remaining
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Weighted-
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Contractual
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Average
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Life
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Exercise Prices
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Number of Options
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Exercise Price
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(in years)
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$2.11 - $2.85
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81,000
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$
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2.50
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6.05
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$2.86 - $3.09
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219,125
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3.00
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1.00
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$3.10 - $10.27
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119,879
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4.92
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8.02
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$10.28 - $11.70
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31,000
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10.90
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8.09
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$11.71 - $11.84
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226,997
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11.79
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9.20
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$11.85 - $11.99
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165,571
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11.95
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8.14
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$12.00 - $13.06
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141,175
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12.88
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7.26
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$13.07 - $15.74
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41,176
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14.28
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6.46
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$15.75 - $16.40
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119,750
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15.97
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5.95
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$16.41 - $22.28
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137,746
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20.19
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5.22
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Total
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1,283,419
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$
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10.55
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6.30
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| 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:
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Weighted-
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Average
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Remaining
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Weighted-
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Contractual
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Average
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Life
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Exercise Prices
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Number of Options
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Exercise Price
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(in years)
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$2.11 - $2.85
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35,856
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$
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2.68
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1.29
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$2.86 - $3.09
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219,125
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3.00
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1.00
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$3.10 - $10.27
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32,452
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6.83
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4.25
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$10.28 - $11.70
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29,750
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10.87
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8.15
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$11.71 - $11.84
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51,873
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11.79
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9.20
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$11.85 - $11.99
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81,266
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11.95
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8.11
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$12.00 - $13.06
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110,840
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12.84
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7.24
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$13.07 - $15.74
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33,870
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14.41
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6.20
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$15.75 - $16.40
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119,750
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15.97
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5.95
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$16.41 - $22.28
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136,830
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20.21
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5.21
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Total
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851,612
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$
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11.12
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4.95
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| Summary of Restricted Stock Unit Award Activity |
The following table summarizes our restricted stock unit award activity during the years ended December 31, 2014, 2013 and 2012:
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Weighted
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Number
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Average
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of
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Grant Date
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Shares
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Fair Value
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Balance, January 1, 2012
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—
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$
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—
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Granted
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180,085
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13.01
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Vested
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—
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—
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Forfeited or expired
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(8,000
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)
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13.00
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Balance, December 31, 2012
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172,085
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$
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13.01
|
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Granted
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255,895
|
|
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|
11.64
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Vested
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(50,773
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)
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12.95
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Forfeited or expired
|
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(20,618
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)
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12.51
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Balance, December 31, 2013
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356,589
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$
|
12.06
|
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Granted
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814,800
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6.48
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Vested
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(199,887
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)
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7.00
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Forfeited or expired
|
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(291,301
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)
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10.93
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Balance, December 31, 2014
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680,201
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|
$
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7.34
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| Summary of Outstanding Warrants |
The following is a summary of outstanding warrants to purchase common stock at December 31, 2014:
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Total
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Outstanding
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Exercise
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and
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price per
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Exercisable
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Share
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Expiration Date
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(1) Warrants issued in October 2010 financing
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1,587,301
|
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|
$
|
20.00
|
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|
October 2015
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|
(2) Series A Warrants issued in July 2014 financing
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|
2,779,933
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4.00
|
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July 2019
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(3) Series B Warrants issued in July 2014 financing
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670,269
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4.00
|
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July 2019
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(4) Pre-Funded Series B Warrants issued in July 2014 financing
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|
—
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|
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0.01
|
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July 2019
|
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| Summary of Fair Value of Warrants Issued |
The estimated fair value of warrants issued and classified as liabilities is reassessed at each reporting date using the Black-Scholes option pricing model. The Pre-Funded Series B warrants are classified as equity and are not reassessed for their fair value at the end of each reporting date. The following assumptions were used to value the warrants that are classified as liabilities on the following reporting dates:
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As of
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December 31,
|
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|
October 2010 Warrant Valuation Assumptions
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|
2014
|
|
|
2013
|
|
|
Risk-free interest rates
|
|
|
0.25
|
%
|
|
|
0.33
|
%
|
|
Expected dividend yield
|
|
|
0
|
%
|
|
|
0
|
%
|
|
Expected life
|
|
0.81 years
|
|
|
1.8 years
|
|
|
Expected volatility
|
|
|
113.49
|
%
|
|
|
39.00
|
%
|
|
|
|
As of
|
|
|
|
|
December 31,
|
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|
Series A and Series B Warrant Valuation Assumptions
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|
2014
|
|
|
2013
|
|
|
Risk-free interest rates
|
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|
1.51
|
%
|
|
|
—
|
|
|
Expected dividend yield
|
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|
0
|
%
|
|
|
—
|
|
|
Expected life
|
|
4.50 years
|
|
|
|
—
|
|
|
Expected volatility
|
|
|
62.91
|
%
|
|
|
—
|
|
|
| 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):
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Years ended December 31,
|
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|
2014
|
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2013
|
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|
2012
|
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|
Numerator
|
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|
|
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Net loss
|
|
$
|
(26,240
|
)
|
|
$
|
(31,849
|
)
|
|
$
|
(21,098
|
)
|
|
Denominator
|
|
|
|
|
|
|
|
|
|
|
|
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Weighted average number of common shares outstanding
|
|
|
18,098,799
|
|
|
|
14,683,389
|
|
|
|
13,522,723
|
|
|
Basic and diluted net loss per common share
|
|
$
|
(1.45
|
)
|
|
$
|
(2.17
|
)
|
|
$
|
(1.56
|
)
|
|