| Quarterly financial information (unaudited) |
Quarterly financial information (unaudited, in thousands, except per share data) | | | | | | | | | | | | | | | | | | | | Three Months Ended, | | | March 31, 2019 | | June 30, 2019 | | September 30, 2019 | | December 31, 2019 | Operating expenses | | $ | 9,477 |
| | 10,066 |
| | 9,584 |
| | 9,862 |
| Net income (loss) | | (15,567 | ) | | (6,495 | ) | | (7,532 | ) | | (9,356 | ) | Net loss per share - basic and diluted | | $ | (1.22 | ) | | $ | (0.42 | ) | | $ | (0.28 | ) | | $ | (0.34 | ) | Weighted-average number of common shares used in computing net loss per share - basic and diluted | | 12,713 |
| | 15,344 |
| | 26,681 |
| | 27,620 |
|
| | | | | | | | | | | | | | | | | | | | Three Months Ended, | | | March 31, 2018 | | June 30, 2018 | | September 30, 2018 | | December 31, 2018 | Operating expenses | | $ | 10,384 |
| | 9,788 |
| | 10,460 |
| | $ | 8,886 |
| Net loss | | (15,890 | ) | | (4,438 | ) | | (7,833 | ) | | 350 |
| Net loss per share - basic and diluted | | $ | (1.78 | ) | | $ | (0.42 | ) | | $ | (0.72 | ) | | $ | 0.03 |
| Weighted-average number of common shares used in computing net loss per share - basic and diluted | | 8,905 |
| | 10,693 |
| | 10,829 |
| | 10,847 |
|
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