Note 4 - Balance Sheet Components (Tables)

6 Months Ended

Jun. 30, 2019

Notes Tables

Schedule of Cash and Cash Equivalents [Table Text Block]

	June 30, 2019		December 31, 2018
	(in thousands)
Cash at banks	$	16,243	$	11,441
Restricted cash		—		50
Money market funds		15		15
Total cash and cash equivalents	$	16,258	$	11,506

Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]

	June 30, 2019		December 31, 2018
	(in thousands)
Royalties receivable	$	15	$	1,776
Government contract - billed		20		20
Accounts receivable	$	35	$	1,796

Property, Plant and Equipment [Table Text Block]

	June 30, 2019			December 31, 2018
	(in thousands)
Laboratory equipment	$	2,775		$	2,076
Office and computer equipment		227			227
Leasehold improvements		340			333
Total property and equipment		3,342			2,636
Less: accumulated depreciation		(1,825	)		(1,570	)
Property and equipment, net	$	1,517		$	1,066

Lessee, Operating Lease, Right-of-Use Assets [Table Text Block]

	June 30, 2019
	(in thousands)
Facilities	$	557
Office equipment		8
Right-of-use assets, net	$	565

Schedule of Finite-Lived Intangible Assets [Table Text Block]

	June 30, 2019			December 31, 2018
	(in thousands)
Purchased technology	$	22,100		$	22,100
Intellectual property		80			80
Total cost		22,180			22,180
Less: accumulated amortization		(4,221	)		(2,767	)
Intangible assets, net	$	17,959		$	19,413

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]

Year Ending December 31,	Amount
2019 (six months remaining)	$	866
2020		1,732
2021		1,732
2022		1,732
2023		1,731
Thereafter		10,166
Total	$	17,959

Schedule of Accrued Liabilities [Table Text Block]

	June 30, 2019		December 31, 2018
	(in thousands)
Accrued compensation	$	773	$	632
Accrued clinical and manufacturing expenses		18		75
Accrued professional and consulting services		48		166
Reserve for return of royalties		339		339
Deferred rent and lease loss accrual, current portion		—		111
Other liabilities, current portion		307		195
Total	$	1,485	$	1,518