Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 45,302	$ 17,278
Short-term investments	9,285
Accounts receivable, net	2,836	1,298
Inventory	4,603	4,348
Prepaid expenses and other assets	2,308	330
Total current assets	64,334	23,254
Property and equipment, net	677	758
Intangible assets, net	2,911	3,215
Total assets	67,922	27,227
Current liabilities:
Accounts payable	3,171	3,421
Accrued expenses	3,533	5,153
Other current liabilities	9	985
Total current liabilities	6,713	9,559
Long-term debt with related party	30,243	29,733
Preferred stock warrant liability		1,640
Other long-term liabilities	4	5
Total liabilities	36,960	40,937
Redeemable convertible preferred stock		124,150
Stockholders' equity (deficit):
Preferred stock; $0.001 par value: 10,000,000 shares authorized; no shares issued and outstanding
Common stock; $0.001 par value: 200,000,000 shares authorized; 11,406,976 and 296,624 shares issued and 11,406,221 and 295,712 shares outstanding at December 31, 2019 and 2018, respectively	11
Additional paid‑in capital	198,829
Accumulated other comprehensive loss	(19)
Accumulated deficit	(167,859)	(137,860)
Total stockholders' equity (deficit)	30,962	(137,860)
Total liabilities, redeemable convertible preferred stock and stockholders' equity (deficit)	$ 67,922	27,227
Series A Redeemable convertible preferred stock
Current liabilities:
Redeemable convertible preferred stock		33,112
Series B Redeemable convertible preferred stock
Current liabilities:
Redeemable convertible preferred stock		$ 91,038