Statement of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities
Net loss	$ (125,580,000)	$ (60,080,000)
Income (Loss) Attributable to Parent, before Tax	(126,038,000)	(60,080,000)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation and amortization	1,078,000	320,000
Amortization of investments	(686,000)	(218,000)
Amortization of debt issuance costs	948,000	560,000
Stock-based compensation	6,484,000	1,728,000
Loss on extinguishment of debt	2,324,000	0
Change in fair value of warrants	(692,000)	(196,000)
Changes in operating assets and liabilities
Trade accounts receivable	(4,693,000)	0
Other accounts receivable	1,634,000	(1,670,000)
Prepaid expenses and other current assets	(960,000)	(1,588,000)
Inventory	(2,176,000)	0
Other assets	(247,000)	62,000
Accounts payable	4,737,000	(1,110,000)
Other accrued liabilities	8,912,000	5,630,000
Accrued trade discounts and rebates	1,375,000	0
Accrued returns reserve	1,957,000	0
Other liabilities	1,239,000	283,000
Net cash used in operating activities	(104,346,000)	(56,279,000)
Cash flows from investing activities
Capital expenditures	(1,107,000)	(1,510,000)
Purchases of investments	(102,472,000)	(68,851,000)
Sales and maturities of investments	101,196,000	2,100,000
Net cash used in investing activities	(2,383,000)	(68,261,000)
Cash flows from financing activities
Proceeds from Initial Public Offering	0	98,325,000
Payments for Initial Public Offering Costs	0	(9,422,000)
Proceeds from public offerings	61,692,000	0
Payments of public offering costs	(4,465,000)	0
Proceeds from sale of Series C Preferred Stock	0	4,438,000
Payments for preferred stock issuance costs	0	(24,000)
Proceeds from issuance of debt	60,000,000	35,000,000
Repayment of debt	(35,000,000)	0
Payments of debt issuance costs	(2,381,000)	(333,000)
Proceeds from employee stock purchase plan	532,000	0
Proceeds from exercise of stock awards	152,000	227,000
Net cash provided by financing activities	80,530,000	128,211,000
Effect of exchange rate on cash and cash equivalents	2,000	0
Increase (decrease) in cash and cash equivalents	(26,197,000)	3,671,000
Cash and cash equivalents, beginning of period	45,716,000	42,045,000
Cash and cash equivalents, end of period	19,519,000	45,716,000
Supplemental schedule of cash flow information
Cash paid for interest	3,717,000	1,711,000
Supplemental schedule of non-cash investing and financing activities
Tenant improvement allowance	5,658,000	0
Accrued debt issuance costs	1,800,000	2,325,000
Allocation of debt proceeds to warrants	$ 0	$ 1,012,000