Condensed Statements of Redeemable Convertible Preferred Stock, Convertible Preferred Stock and Stockholders' Deficit (Unaudited) - USD ($) $ in Thousands | Total | Redeemable Convertible Preferred Stock | Convertible Preferred Stock | Common Stock | Additional Paid-in Capital | Accumulated Other Comprehensive Gain (Loss) | Accumulated Deficit |
Beginning balance, shares at Dec. 31, 2017 | | 12,956,724 | 69,834,789 | | | | |
Beginning balance at Dec. 31, 2017 | | $ 50,367 | $ 122,990 | | | | |
Beginning balance, shares at Dec. 31, 2017 | | | | 8,287,983 | | | |
Beginning balance at Dec. 31, 2017 | $ (176,986) | | | | $ 4,591 | $ (6) | $ (181,571) |
Accretion of redeemable convertible preferred stock to redemption value | (1,109) | | | | (1,109) | | |
Accretion of redeemable convertible preferred stock to redemption value | | $ 1,109 | | | | | |
Issuance of common stock upon exercise of options | 39 | | | | 39 | | |
Issuance of common stock upon exercise of options, shares | | | | 18,621 | | | |
Stock-based compensation expense | 545 | | | | 545 | | |
Other comprehensive income | 6 | | | | | 6 | |
Net loss | (14,106) | | | | | | (14,106) |
Ending balance, shares at Mar. 31, 2018 | | 12,956,724 | 69,834,789 | | | | |
Ending balance at Mar. 31, 2018 | | $ 51,476 | $ 122,990 | | | | |
Ending balance, shares at Mar. 31, 2018 | | | | 8,306,604 | | | |
Ending balance at Mar. 31, 2018 | (191,611) | | | | 4,066 | | (195,677) |
Beginning balance, shares at Dec. 31, 2017 | | 12,956,724 | 69,834,789 | | | | |
Beginning balance at Dec. 31, 2017 | | $ 50,367 | $ 122,990 | | | | |
Beginning balance, shares at Dec. 31, 2017 | | | | 8,287,983 | | | |
Beginning balance at Dec. 31, 2017 | (176,986) | | | | 4,591 | (6) | (181,571) |
Net loss | (31,701) | | | | | | |
Ending balance, shares at Jun. 30, 2018 | | 31,053,601 | 71,832,498 | | | | |
Ending balance at Jun. 30, 2018 | | $ 144,910 | $ 133,192 | | | | |
Ending balance, shares at Jun. 30, 2018 | | | | 8,324,106 | | | |
Ending balance at Jun. 30, 2018 | (210,213) | | | | 3,059 | | (213,272) |
Beginning balance, shares at Mar. 31, 2018 | | 12,956,724 | 69,834,789 | | | | |
Beginning balance at Mar. 31, 2018 | | $ 51,476 | $ 122,990 | | | | |
Beginning balance, shares at Mar. 31, 2018 | | | | 8,306,604 | | | |
Beginning balance at Mar. 31, 2018 | (191,611) | | | | 4,066 | | (195,677) |
Issuance of convertible preferred stock upon conversion of notes, net of issuance costs | | $ 5,452 | $ 10,202 | | | | |
Issuance of convertible preferred stock upon conversion of notes, net of issuance costs, shares | | 1,067,550 | 1,997,709 | | | | |
Loss on extinguishment of convertible notes | (370) | | | | (370) | | |
Issuance of convertible preferred stock, net of issuance costs | | $ 86,640 | | | | | |
Issuance of convertible preferred stock, net of issuance costs, shares | | 17,029,327 | | | | | |
Accretion of redeemable convertible preferred stock to redemption value | (1,342) | | | | (1,342) | | |
Accretion of redeemable convertible preferred stock to redemption value | | $ 1,342 | | | | | |
Issuance of common stock upon exercise of options | 24 | | | | 24 | | |
Issuance of common stock upon exercise of options, shares | | | | 17,502 | | | |
Stock-based compensation expense | 681 | | | | 681 | | |
Net loss | (17,595) | | | | | | (17,595) |
Ending balance, shares at Jun. 30, 2018 | | 31,053,601 | 71,832,498 | | | | |
Ending balance at Jun. 30, 2018 | | $ 144,910 | $ 133,192 | | | | |
Ending balance, shares at Jun. 30, 2018 | | | | 8,324,106 | | | |
Ending balance at Jun. 30, 2018 | $ (210,213) | | | | 3,059 | | (213,272) |
Beginning balance, shares at Dec. 31, 2018 | 104,778,246 | 31,053,601 | 73,724,645 | | | | |
Beginning balance at Dec. 31, 2018 | $ 294,200 | $ 151,381 | $ 142,819 | | | | |
Beginning balance, shares at Dec. 31, 2018 | | | | 8,593,077 | | | |
Beginning balance at Dec. 31, 2018 | (257,690) | | | | | (25) | (257,665) |
Issuance of convertible preferred stock, net of issuance costs | | $ 43,572 | $ 26,279 | | | | |
Issuance of convertible preferred stock, net of issuance costs, shares | | 6,350,345 | 3,831,766 | | | | |
Accretion of redeemable convertible preferred stock to redemption value | 3,355 | | | | (3,260) | | (95) |
Accretion of redeemable convertible preferred stock to redemption value | | $ 3,355 | | | | | |
Compensation expense related to stock sales by current and former employees | 819 | | | | 819 | | |
Issuance of common stock upon exercise of options | 1,319 | | | | 1,319 | | |
Issuance of common stock upon exercise of options, shares | | | | 739,053 | | | |
Issuance of common stock upon exercise of warrants, shares | | | | 4,935 | | | |
Issuance of common stock upon exercise of warrants | 13 | | | | 13 | | |
Stock-based compensation expense | 1,109 | | | | 1,109 | | |
Other comprehensive income | 28 | | | | | 28 | |
Net loss | (23,222) | | | | | | (23,222) |
Ending balance, shares at Mar. 31, 2019 | | 37,403,946 | 77,556,411 | | | | |
Ending balance at Mar. 31, 2019 | | $ 198,308 | $ 169,098 | | | | |
Ending balance, shares at Mar. 31, 2019 | | | | 9,337,065 | | | |
Ending balance at Mar. 31, 2019 | $ (280,979) | | | | | 3 | (280,982) |
Beginning balance, shares at Dec. 31, 2018 | 104,778,246 | 31,053,601 | 73,724,645 | | | | |
Beginning balance at Dec. 31, 2018 | $ 294,200 | $ 151,381 | $ 142,819 | | | | |
Beginning balance, shares at Dec. 31, 2018 | | | | 8,593,077 | | | |
Beginning balance at Dec. 31, 2018 | (257,690) | | | | | (25) | (257,665) |
Net loss | $ (50,097) | | | | | | |
Ending balance, shares at Jun. 30, 2019 | 114,960,357 | 37,403,946 | 77,556,411 | | | | |
Ending balance at Jun. 30, 2019 | $ 367,330 | $ 198,228 | $ 169,102 | | | | |
Ending balance, shares at Jun. 30, 2019 | | | | 9,701,266 | | | |
Ending balance at Jun. 30, 2019 | (306,122) | | | $ 1 | 1,729 | 5 | (307,857) |
Beginning balance, shares at Mar. 31, 2019 | | 37,403,946 | 77,556,411 | | | | |
Beginning balance at Mar. 31, 2019 | | $ 198,308 | $ 169,098 | | | | |
Beginning balance, shares at Mar. 31, 2019 | | | | 9,337,065 | | | |
Beginning balance at Mar. 31, 2019 | (280,979) | | | | | 3 | (280,982) |
Stock issuance costs | | $ (80) | $ 4 | | | | |
Issuance of common stock upon exercise of options | 423 | | | $ 1 | 422 | | |
Issuance of common stock upon exercise of options, shares | | | | 358,459 | | | |
Issuance of common stock upon exercise of warrants, shares | | | | 5,742 | | | |
Issuance of common stock upon exercise of warrants | 20 | | | | 20 | | |
Stock-based compensation expense | 1,287 | | | | 1,287 | | |
Other comprehensive income | 2 | | | | | 2 | |
Net loss | $ (26,875) | | | | | | (26,875) |
Ending balance, shares at Jun. 30, 2019 | 114,960,357 | 37,403,946 | 77,556,411 | | | | |
Ending balance at Jun. 30, 2019 | $ 367,330 | $ 198,228 | $ 169,102 | | | | |
Ending balance, shares at Jun. 30, 2019 | | | | 9,701,266 | | | |
Ending balance at Jun. 30, 2019 | $ (306,122) | | | $ 1 | $ 1,729 | $ 5 | $ (307,857) |