| Dec'18 | Sep'18 | Jun'18 | Mar'18 | Dec'17 | Sep'17 | Jun'17 | Mar'17 | Dec'16 | Sep'16 | Jun'16 | Mar'16 | Dec'15 | Sep'15 | Jun'15 | Mar'15 | Dec'14 | Sep'14 | Jun'14 | Mar'14 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Operating activities | |||||||||||||||||||
Net loss | |||||||||||||||||||
-13,601 | -14,049 | -13,808 | -13,300 | -11,980 | -13,416 | -13,846 | -12,620 | -14,446 | -12,443 | -14,347 | -12,294 | -12,115 | -7,407 | -10,517 | -9,406 | -13,120 | -6,682 | -6,126 | -8,223 |
Adjustments to reconcile net loss to net cash used in operating activities: | |||||||||||||||||||
Depreciation and amortization | |||||||||||||||||||
78 | 82 | 102 | 84 | 95 | 87 | 90 | 79 | 76 | 77 | 75 | 76 | 66 | 66 | 59 | 52 | 61 | 55 | 61 | 61 |
Amortization of premium/discount on investments | |||||||||||||||||||
130 | 139 | 142 | 150 | 71 | 11 | -30 | -26 | -156 | 2 | -20 | 48 | 0 | 0 | 0 | 0 | - | - | - | - |
Stock-based compensation | |||||||||||||||||||
1,224 | 1,803 | 1,511 | 2,738 | 2,032 | 2,149 | 2,205 | 2,247 | 2,376 | 2,326 | 2,246 | 2,335 | 1,846 | 1,407 | 1,813 | 1,231 | 466 | 424 | 267 | 187 |
Revaluation of convertible preferred stock warrant liability | |||||||||||||||||||
- | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | 0 | 127 | 1,439 | 2,711 |
Changes in operating assets and liabilities: | |||||||||||||||||||
Accounts receivable | |||||||||||||||||||
-75 | 120 | 320 | -307 | 127 | 25 | -108 | 86 | -6,977 | 7,117 | 364 | -959 | -2,171 | 2,264 | -699 | -392 | 1,920 | -988 | 1,026 | -75 |
Inventory | |||||||||||||||||||
-18 | 454 | 226 | -10 | 76 | -16 | 48 | -31 | -102 | -15 | 19 | 692 | -294 | -127 | 407 | 2 | -456 | 462 | 5 | -3 |
Prepaid expenses | |||||||||||||||||||
- | 617 | -403 | 943 | - | 1,114 | -588 | -635 | - | 1,018 | 640 | 1,240 | - | - | - | - | - | - | - | - |
Restricted cash | |||||||||||||||||||
- | - | - | - | - | - | - | - | - | 0 | 0 | 0 | - | - | - | - | - | - | - | - |
Prepaid expenses | |||||||||||||||||||
- | - | - | - | - | - | - | - | - | - | - | - | - | - | -349 | 148 | -155 | -181 | 645 | 145 |
Other assets | |||||||||||||||||||
1,543 | 155 | -9 | -3,037 | 21 | 2,990 | -23 | -3,010 | 3,059 | 0 | 0 | 0 | - | - | - | - | - | - | - | - |
Accounts payable | |||||||||||||||||||
-1,341 | -337 | 526 | 296 | -218 | -1,694 | 932 | -1,245 | 208 | 823 | 1,763 | -1,309 | 395 | 663 | -407 | -4,480 | 3,833 | 1,815 | 318 | 71 |
Accrued liabilities | |||||||||||||||||||
1,603 | 1,019 | 1,024 | -2,465 | 557 | -140 | 1,558 | -772 | 239 | -2,405 | 2,973 | 169 | 38 | 313 | 1,701 | -2,571 | 1,661 | 1,676 | -34 | 121 |
Accrued litigation-related settlement | |||||||||||||||||||
0 | 0 | 0 | -6,000 | -1,250 | 0 | 0 | 0 | - | - | - | - | - | - | - | - | - | - | - | - |
Deferred rent and other noncurrent liabilities | |||||||||||||||||||
- | - | - | - | - | - | - | - | - | - | - | - | - | - | -7 | -9 | 523 | -7 | -7 | -2 |
Deferred rent and other liabilities | |||||||||||||||||||
- | 1 | 2 | 3 | - | -16 | 25 | -2,486 | - | 2,972 | -4 | -96 | - | - | - | - | - | - | - | - |
Net cash used in operating activities | |||||||||||||||||||
- | -12,966 | -10,919 | -16,383 | - | -17,179 | -8,660 | -11,181 | - | - | - | - | - | - | - | - | - | - | - | - |
Security deposits | |||||||||||||||||||
- | - | - | - | - | - | - | - | - | - | - | 0 | - | - | - | - | - | - | - | - |
Net cash used in operating activities | |||||||||||||||||||
- | - | - | - | - | - | - | - | - | - | - | -12,140 | -7,543 | -8,600 | -6,717 | -14,941 | -7,885 | -1,885 | -5,758 | -5,141 |
Investing activities | |||||||||||||||||||
Purchases of property and equipment | |||||||||||||||||||
121 | 26 | 39 | 204 | 84 | 83 | 59 | 202 | 57 | 22 | 35 | 19 | 119 | 102 | 74 | 132 | 153 | 74 | 58 | 59 |
Maturities of short-term investments | |||||||||||||||||||
27,000 | 17,000 | 21,000 | 21,000 | 15,000 | 22,000 | 19,000 | 9,000 | 17,000 | 17,000 | 6,000 | 0 | - | - | - | - | - | - | - | - |
Purchases of short-term investments | |||||||||||||||||||
- | 8,903 | 8,915 | 10,921 | - | 11,966 | 2,999 | 8,999 | - | 17,000 | 2,000 | 46,000 | 0 | 0 | 0 | 0 | - | - | - | - |
Net cash provided by investing activities | |||||||||||||||||||
- | 8,071 | 12,046 | 9,875 | - | 9,951 | 15,942 | -201 | - | - | - | - | - | - | - | - | - | - | - | - |
Net cash provided by (used in) investing activities | |||||||||||||||||||
- | - | - | - | - | - | - | - | - | - | - | -46,019 | -119 | -102 | -74 | -132 | -153 | -74 | -58 | -59 |
Financing activities | |||||||||||||||||||
Deferred offering costs | |||||||||||||||||||
- | - | - | - | - | - | - | - | - | - | - | - | - | - | - | 128 | - | - | 1,197 | 171 |
Proceeds from issuances of common stock under stock-based compensation plans | |||||||||||||||||||
-129 | 0 | 131 | 226 | 31 | 286 | 111 | 286 | 18 | 25 | 101 | 0 | 93 | 194 | 72 | 77 | - | - | - | - |
Proceeds from exercise of stock options | |||||||||||||||||||
- | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | 0 |
Net cash provided by financing activities | |||||||||||||||||||
- | - | - | - | - | - | - | - | - | - | - | 0 | 93 | 194 | 75,559 | -51 | 4 | 67,344 | -1,197 | -171 |
Net cash provided by financing activities | |||||||||||||||||||
- | 0 | 131 | 226 | - | 286 | 111 | 286 | - | - | - | - | - | - | - | - | - | - | - | - |
Net (decrease) increase in cash and cash equivalents | |||||||||||||||||||
9,406 | -4,895 | 1,258 | -6,282 | 44,085 | -6,942 | 7,393 | -11,096 | - | - | - | - | - | - | - | - | - | - | - | - |
Supplemental cash flow information | |||||||||||||||||||
Net (decrease) increase in cash and cash equivalents | |||||||||||||||||||
- | - | - | - | - | - | - | - | - | 19,903 | -4,231 | -58,159 | -7,569 | -8,508 | 68,768 | -15,124 | -8,034 | 65,385 | -7,013 | -5,371 |
Stock offering costs incurred, not yet paid | |||||||||||||||||||
- | - | - | - | - | - | - | - | - | - | - | - | - | - | - | 72 | - | - | 230 | 167 |