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Condensed Consolidated Statement of Shareholders' Equity (Unaudited) - 9 months ended Sep. 30, 2015 - USD ($) $ in Thousands | Total | Initial Public Offering | Private Placement | Common Class A | Common Stock Class Undefined | Common Stock Class Undefined Initial Public Offering | Common Stock Class Undefined Private Placement | Brink Biologics Inc Spinout | Additional Paid-in Capital | Additional Paid-in Capital Initial Public Offering | Additional Paid-in Capital Private Placement | Other Comprehensive Loss | Accumulated Deficit | Accumulated Deficit Brink Biologics Inc Spinout
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Beginning Balance at Dec. 31, 2014 | $ 58,423 |  |  | $ 3 |  |  |  |  | $ 71,161 |  |  |  | $ (12,741) |
Beginning Balance, Shares at Dec. 31, 2014 |  |  |  | 61,094,367 | 0 |  |  |  |  |  |  |  |  |
Exercise of stock options | 843 |  |  | $ 1 |  |  |  |  | 842 |  |  |  |  |
Exercise of stock options, Shares |  |  |  | 949,396 | 83,588 |  |  |  |  |  |  |  |  |
Stock-based compensation expense | 140,667 |  |  |  |  |  |  |  | 140,667 |  |  |  |  |
Vesting of restricted stock units |  |  |  |  | 485,150 |  |  |  |  |  |  |  |  |
Employee payroll taxes withheld related to vesting of restricted stock units | (2,415) |  |  |  |  |  |  |  | (2,415) |  |  |  |  |
Employee payroll taxes withheld related to vesting of restricted stock units, Shares |  |  |  |  | (96,612) |  |  |  |  |  |  |  |  |
Adjustment for 1.8515:1 stock split |  |  |  | $ 3 |  |  |  |  | (3) |  |  |  |  |
Warrants issued in conjunction with Inex Bio acquisition | 5,170 |  |  |  |  |  |  |  | 5,170 |  |  |  |  |
Exercise of warrants | 7,340 |  |  |  |  |  |  |  | 7,340 |  |  |  |  |
Exercise of warrants, Shares |  |  |  | 4,106,492 | 565,700 |  |  |  |  |  |  |  |  |
Repurchase of common stock | (4,798) |  |  |  |  |  |  |  | (4,798) |  |  |  |  |
Repurchase of common stock, Shares |  |  |  | (249,952) |  |  |  |  |  |  |  |  |  |
Reclassification of warrant liability due to exercise | 1,544 |  |  |  |  |  |  |  | 1,544 |  |  |  |  |
Conversion of Class A common stock to common stock |  |  |  | $ (7) | $ 7 |  |  |  |  |  |  |  |  |
Conversion of Class A common stock to common stock, Shares |  |  |  | (65,900,303) | 65,900,303 |  |  |  |  |  |  |  |  |
Issuance of common stock | 77,975 | $ 221,214 | $ 17,000 |  |  | $ 1 |  |  | 77,975 | $ 221,213 | $ 17,000 |  |  |
Issuance of common stock, Shares |  |  |  |  | 4,063,333 | 9,531,200 | 680,000 |  |  |  |  |  |  |
Spinout of Brink Biologics, Inc. |  |  |  |  |  |  |  | $ 73 |  |  |  |  |  | $ 73
Other comprehensive loss | (50) |  |  |  |  |  |  |  |  |  |  | $ (50) |  |
Net loss | (160,055) |  |  |  |  |  |  |  |  |  |  |  | (160,055) |
Beginning Balance at Sep. 30, 2015 | $ 362,931 |  |  |  | $ 8 |  |  |  | $ 535,696 |  |  | $ (50) | $ (172,723) |
Beginning Balance, Shares at Sep. 30, 2015 |  |  |  | 0 | 81,212,662 |  |  |  |  |  |  |  |  |

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