v3.8.0.1

Consolidated Statements of Stockholders' (Deficit) Equity - USD ($) $ in Thousands | Common Stock [Member] | Additional Paid-in Capital [Member] | Retained Earnings [Member] | AOCI Attributable to Parent [Member] | Total
--- | --- | --- | --- | --- | ---
Balance (in shares) at Dec. 31, 2014 | 43,712,363 |  |  |  |
Balance at Dec. 31, 2014 | $ 43 | $ 225,423 | $ (178,806) | $ (4) | $ 46,656
Stock-based compensation |  | 5,010 |  |  | 5,010
Issuance of common stock upon exercise of stock options (in shares) | 938,497 |  |  |  |
Issuance of common stock upon exercise of stock options | $ 1 | 2,769 |  |  | $ 2,770
Issuance of common stock upon exercise of stock warrants (in shares) | 527,101 |  |  |  | 527,101
Issuance of common stock upon exercise of stock warrants | $ 1 | 2,543 |  |  | $ 2,544
Modification of warrants |  | 100 |  |  | 100
Issuance of common stock upon ESPP purchase (in shares) | 95,811 |  |  |  |
Issuance of common stock upon ESPP purchase |  | 429 |  |  | 429
Change in unrealized gains and losses on investments |  |  |  | 3 | 3
Net loss |  |  | (24,399) |  | (24,399)
Balance (in shares) at Dec. 31, 2015 | 45,273,772 |  |  |  |
Balance at Dec. 31, 2015 | $ 45 | 236,274 | (203,205) | (1) | 33,113
Stock-based compensation |  | 4,479 |  |  | 4,479
Modification of warrants |  | 45 |  |  | 45
Issuance of common stock upon ESPP purchase (in shares) | 60,018 |  |  |  |
Issuance of common stock upon ESPP purchase |  | 179 |  |  | 179
Change in unrealized gains and losses on investments |  |  |  | 4 | 4
Net loss |  |  | (43,157) |  | (43,157)
Balance (in shares) at Dec. 31, 2016 | 45,333,790 |  |  |  |
Balance at Dec. 31, 2016 | $ 45 | 240,977 | (246,362) | 3 | (5,337)
Stock-based compensation |  | 4,294 |  |  | $ 4,294
Issuance of common stock upon exercise of stock options (in shares) | 69,372 |  |  |  | 69,372
Issuance of common stock upon exercise of stock options |  | 105 |  |  | $ 105
Issuance of common stock upon ESPP purchase (in shares) | 94,893 |  |  |  |
Issuance of common stock upon ESPP purchase |  | 246 |  |  | 246
Change in unrealized gains and losses on investments |  |  |  | (3) | (3)
Net loss |  |  | (51,508) |  | $ (51,508)
Net proceeds from issuance of common stock in connection with equity financings (in shares) | 5,401,099 |  |  |  | 5,400,000
Net proceeds from issuance of common stock in connection with equity financings | $ 6 | 15,688 |  |  | $ 15,694
Balance (in shares) at Dec. 31, 2017 | 50,899,154 |  |  |  |
Balance at Dec. 31, 2017 | $ 51 | $ 261,310 | $ (297,870) |  | $ (36,509)

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