|
Significant accounting policies (Tables)
|
12 Months Ended |
|
Dec. 31, 2014
|
| Summary of significant accounting policies |
|
| Schedule of information about financial assets and liabilities measured at fair value |
The following table presents information about the Company's financial assets and liabilities that have been measured at fair value at December 31, 2014 and indicates the fair value hierarchy of the valuation inputs utilized to determine fair value (in thousands).
|
Description
|
|
Total
|
|
Quoted prices
in active
markets
(Level 1)
|
|
Significant other
observable
inputs
(Level 2)
|
|
Significant
unobservable
inputs
(Level 3)
|
|
|
Financial assets
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Cash equivalents
|
|
$
|
32,140
|
|
$
|
32,140
|
|
$
|
—
|
|
$
|
—
|
|
|
Short-term investments
|
|
|
58,774
|
|
|
—
|
|
|
58,774
|
|
|
—
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total financial assets
|
|
$
|
90,914
|
|
$
|
32,140
|
|
$
|
58,774
|
|
$
|
—
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Financial liabilities
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Liability classified stock-based compensation awards
|
|
$
|
469
|
|
$
|
469
|
|
$
|
—
|
|
$
|
—
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total financial liabilities
|
|
$
|
469
|
|
$
|
469
|
|
$
|
—
|
|
$
|
—
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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|
|
|
|
|
|
|
|
|
|
|
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|
The following table presents information about the Company's financial assets and liabilities that have been measured at fair value at December 31, 2013 and indicates the fair value hierarchy of the valuation inputs utilized to determine such fair value (in thousands).
|
Description
|
|
Total
|
|
Quoted prices
in active
markets
(Level 1)
|
|
Significant other
observable
inputs
(Level 2)
|
|
Significant
unobservable
inputs
(Level 3)
|
|
|
Financial assets
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Cash equivalents
|
|
$
|
17,000
|
|
$
|
17,000
|
|
$
|
—
|
|
$
|
—
|
|
|
Short-term investments
|
|
|
82,423
|
|
|
—
|
|
|
82,423
|
|
|
—
|
|
|
Long-term investments
|
|
|
22,344
|
|
|
—
|
|
|
22,344
|
|
|
—
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total financial assets
|
|
$
|
121,767
|
|
$
|
17,000
|
|
$
|
104,767
|
|
$
|
—
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Financial liabilities
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Liability classified stock-based compensation awards
|
|
$
|
717
|
|
$
|
717
|
|
$
|
—
|
|
$
|
—
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total financial liabilities
|
|
$
|
717
|
|
$
|
717
|
|
$
|
—
|
|
$
|
—
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
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|
| Schedule of cash, cash equivalents and investments |
As of December 31, 2014, cash, cash equivalents and investments included (in thousands):
|
|
|
Amortized
Cost
|
|
Gross
Unrealized
Gains
|
|
Gross
Unrealized
Losses
|
|
Fair
Value
|
|
|
Cash and cash equivalents:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Cash and cash equivalents
|
|
$
|
33,901
|
|
$
|
—
|
|
$
|
—
|
|
$
|
33,901
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total cash and cash equivalents
|
|
$
|
33,901
|
|
$
|
—
|
|
$
|
—
|
|
$
|
33,901
|
|
|
Investments:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Government-sponsored enterprise securities (due within 1 year)
|
|
$
|
3,700
|
|
$
|
—
|
|
$
|
—
|
|
$
|
3,700
|
|
|
Corporate bonds and commercial paper (due within 1 year)
|
|
|
55,063
|
|
|
18
|
|
|
(7
|
)
|
|
55,074
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total investments
|
|
$
|
58,763
|
|
$
|
18
|
|
$
|
(7
|
)
|
$
|
58,774
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total cash, cash equivalents, and investments
|
|
$
|
92,664
|
|
$
|
18
|
|
$
|
(7
|
)
|
$
|
92,675
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
As of December 31, 2013, cash, cash equivalents and investments included (in thousands):
|
|
|
Amortized
Cost
|
|
Gross
Unrealized
Gains
|
|
Gross
Unrealized
Losses
|
|
Fair
Value
|
|
|
Cash and cash equivalents:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Cash and cash equivalents
|
|
$
|
18,889
|
|
$
|
—
|
|
$
|
—
|
|
$
|
18,889
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total cash and cash equivalents
|
|
$
|
18,889
|
|
$
|
—
|
|
$
|
—
|
|
$
|
18,889
|
|
|
Investments:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Government-sponsored enterprise securities (due within 1 year)
|
|
$
|
30,652
|
|
$
|
12
|
|
$
|
—
|
|
$
|
30,664
|
|
|
Government-sponsored enterprise securities (due within 1 - 2 years)
|
|
|
4,001
|
|
|
2
|
|
|
—
|
|
|
4,003
|
|
|
Corporate bonds and commercial paper (due within 1 year)
|
|
|
51,735
|
|
|
30
|
|
|
(6
|
)
|
|
51,759
|
|
|
Corporate bonds (due within 1 - 2 years)
|
|
|
18,351
|
|
|
2
|
|
|
(12
|
)
|
|
18,341
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total investments
|
|
$
|
104,739
|
|
$
|
46
|
|
$
|
(18
|
)
|
$
|
104,767
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total cash, cash equivalents, and investments
|
|
$
|
123,628
|
|
$
|
46
|
|
$
|
(18
|
)
|
$
|
123,656
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Schedule of estimated useful lives of the assets |
|
Laboratory equipment
|
|
5 years
|
|
Furniture
|
|
5 years
|
|
Computer equipment
|
|
3 years
|
|
Leasehold Improvements
|
|
Lesser of useful life or life of lease
|
|
| Schedule of potentially anti-dilutive securities excluded from calculation of diluted net loss per share |
|
|
|
Years Ended December 31,
|
|
|
|
|
2012
|
|
2013
|
|
2014
|
|
|
Outstanding stock options
|
|
|
1,424,241
|
|
|
2,388,062
|
|
|
4,206,440
|
|
|
Restricted stock units
|
|
|
899,204
|
|
|
529,850
|
|
|
293,747
|
|
|
Outstanding warrants
|
|
|
—
|
|
|
—
|
|
|
142,857
|
|
|
Unvested restricted stock
|
|
|
747,000
|
|
|
329,282
|
|
|
7,995
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
3,070,445
|
|
|
3,247,194
|
|
|
4,651,039
|
|
|
|
|
|
|
|
|
|
|
|
|
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