Annual report pursuant to Section 13 and 15(d)

CONSOLIDATED STATEMENTS OF CASH FLOWS

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities
Net loss	$ (75,438)	$ (62,279)	$ (54,010)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	2,521	1,604	1,527
Amortization of financing right-of-use asset	201
Gain on disposal of fixed assets and modification of lease	(181)
Stock-based compensation expense	9,839	6,610	4,419
Net amortization of premiums and discounts on marketable securities	(949)	(642)	(102)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(783)	(500)	131
Accounts receivable	(20,158)		867
Other long-term assets		(34)	(365)
Accounts payable	1,493	888	141
Accrued expenses	(3,576)	4,191	3,533
Deferred revenue	18,176	10,202	(550)
Proceeds for tenant improvement incentive from landlord	7,237
Operating lease asset and liabilities	1,365
Deferred rent and lease incentive		(355)	(320)
Net cash used in operating activities	(60,253)	(40,315)	(44,729)
Investing activities
Purchases of property and equipment	(12,638)	(1,384)	(821)
Proceeds from the disposition of property and equipment	110	9
Purchases of marketable securities	(108,206)	(96,768)	(41,770)
Maturities of marketable securities	109,000	87,500	27,000
Net cash used in investing activities	(11,734)	(10,643)	(15,591)
Financing activities
Payments on financing and capital lease obligations	(205)	(50)	(168)
Proceeds from issuance of common stock through employee benefit plans	211	626	1,799
Proceeds from issuance of common stock through exercise of warrants	2
Proceeds from the issuance of common stock through employee stock purchase plan	161
Proceeds from issuance of common stock through at-the-market sales agreement, net of issuance costs	824	16,538
Proceeds from issuance of common stock and accompanying warrants in public offerings and private placements, net of issuance costs	60,359	51,970	32,306
Proceeds from issuance of convertible preferred stock and accompanying warrants in public offering, net of issuance costs	4,638
Net cash provided by financing activities	65,990	69,084	33,937
(Decrease) increase in cash, cash equivalents and restricted cash	(5,997)	18,126	(26,383)
Cash and cash equivalents, Beginning of period	50,814	32,688	59,071
Cash and cash equivalents, End of period	44,817	50,814	32,688
Supplemental disclosure of cash flow information:
Cash paid for interest	72	2	9
Cash paid for tax	29	7
Non-cash investing and financing activities:
Property and equipment received but unpaid as of period end	1,565	268	143
Asset acquired under operating lease	16,240
Assets acquired under financing lease	1,059	$ 28
Deferred financing costs incurred but unpaid as of period end	58
Offering costs incurred but unpaid as of period end	$ 23		$ 13