Statements of Cash Flows - USD ($)
$ in Thousands |
12 Months Ended |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
| Operating activities |
|
|
|
| Net loss |
$ (57,280)
|
$ (24,690)
|
$ (17,745)
|
| Adjustments to reconcile net loss to net cash used in operating activities: |
|
|
|
| Stock-based compensation expense |
2,800
|
2,514
|
1,371
|
| Depreciation & amortization |
1,465
|
839
|
783
|
| Amortization/accretion of available-for-sale marketable securities |
(218)
|
(18)
|
|
| Realized gain on sale of available-for-sale marketable securities |
(23)
|
|
|
| Deferred rent costs |
(114)
|
(289)
|
(265)
|
| Loss on write-off of fixed assets |
|
2
|
|
| Changes in operating assets and liabilities: |
|
|
|
| Income tax receivable |
(468)
|
(184)
|
(139)
|
| Other receivables |
(7)
|
(80)
|
|
| Prepaid expenses |
199
|
(1,442)
|
388
|
| Accounts payable and accrued expenses |
6,265
|
3,322
|
(12)
|
| Deferred revenue |
|
(1,452)
|
(2,023)
|
| Net cash used in operating activities |
(47,381)
|
(21,478)
|
(17,642)
|
| Investing activities |
|
|
|
| Proceeds from maturities of available-for-sale marketable securities |
80,380
|
|
|
| Proceeds from sale of available-for-sale marketable securities |
34,003
|
|
|
| Purchase of available-for-sale marketable securities |
(68,648)
|
(91,657)
|
|
| Change in restricted cash |
(769)
|
|
|
| Purchases of property and equipment |
(717)
|
(20)
|
(42)
|
| Net cash provided by (used in) investing activities |
44,249
|
(91,677)
|
(42)
|
| Financing activities |
|
|
|
| Proceeds from sale of common stock |
|
|
100
|
| Proceeds from the exercise of stock options |
123
|
362
|
128
|
| Proceeds from initial public offering, net of issuance costs |
|
|
57,762
|
| Net cash provided by financing activities |
123
|
75,593
|
57,990
|
| Net cash (decrease) increase for the period |
(3,009)
|
(37,562)
|
40,306
|
| Cash and cash equivalents at beginning of period |
15,101
|
52,663
|
12,357
|
| Cash and cash equivalents at end of period |
12,092
|
15,101
|
52,663
|
| Noncash financing activities |
|
|
|
| Conversion of convertible preferred stock to common stock |
|
|
65,586
|
| Reclassification of prepaid IPO costs paid in 2013 |
|
|
$ 1,465
|
| Tenant improvements paid by landlord |
$ 1,094
|
|
|
| Follow On Offering [Member] |
|
|
|
| Financing activities |
|
|
|
| Proceeds from follow-on offering, net of issuance costs |
|
$ 75,231
|
|