| Schedule of major category of financial assets and liabilities measured at fair value on a recurring basis |
|
|
|
Quoted Prices in
Active Markets
for Identical
Items (Level 1)
|
|
Significant Other
Observable Inputs
(Level 2)
|
|
Significant
Unobservable Inputs
(Level 3)
|
|
Total
|
|
|
December 31, 2014
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Assets
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Money market mutual funds
|
|
$
|
29,064,011
|
|
$
|
—
|
|
$
|
—
|
|
$
|
29,064,011
|
|
|
U.S. Treasury Bonds
|
|
|
70,698,640
|
|
|
|
|
|
|
|
|
70,698,640
|
|
|
Restricted cash
|
|
|
112,410
|
|
|
—
|
|
|
—
|
|
|
112,410
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total assets
|
|
$
|
99,875,061
|
|
$
|
—
|
|
$
|
—
|
|
$
|
99,875,061
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Liabilities
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Warrants to purchase common stock
|
|
$
|
—
|
|
$
|
—
|
|
$
|
82,851
|
|
$
|
82,851
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total liabilities
|
|
$
|
—
|
|
$
|
—
|
|
$
|
82,851
|
|
$
|
82,851
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
December 31, 2013
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Assets
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
U.S. Treasury Bills
|
|
$
|
35,551,000
|
|
|
—
|
|
|
—
|
|
$
|
35,551,000
|
|
|
Restricted cash
|
|
|
112,000
|
|
|
—
|
|
|
—
|
|
|
112,000
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total assets
|
|
$
|
35,663,000
|
|
$
|
—
|
|
$
|
—
|
|
$
|
35,663,000
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Liabilities
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Warrants to purchase redeemable preferred stock
|
|
$
|
—
|
|
$
|
—
|
|
$
|
350,519
|
|
$
|
350,519
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total liabilities
|
|
$
|
—
|
|
$
|
—
|
|
$
|
350,519
|
|
$
|
350,519
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Schedule of changes in the fair value of the Company's preferred warrant liability representing a recurring measurement classified within Level 3, wherein fair value is estimated using significant unobservable inputs |
|
|
|
Warrant Liability
|
|
|
Balance as of December 31, 2012
|
|
$
|
1,393,674
|
|
|
Amounts acquired or issued
|
|
|
(801,677
|
)
|
|
Changes in estimated fair value
|
|
|
(241,478
|
)
|
|
|
|
|
|
|
|
Balance as of December 31, 2013
|
|
|
350,519
|
|
|
Amounts acquired or issued
|
|
|
—
|
|
|
Changes in estimated fair value
|
|
|
(122,412
|
)
|
|
Amounts reclassified to additional paid-in capital
|
|
|
(145,256
|
)
|
|
|
|
|
|
|
|
Balance as of December 31, 2014
|
|
$
|
82,851
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|