Note 4 - Trade Receivables (Tables)

12 Months Ended

Dec. 31, 2022

Receivables [Abstract]

Summary of Receivables

Receivables from collaborations were as follows (in thousands):

	December 31, 2022
	Billed		Unbilled		Total
U.S. Department of Health and Human Services, net	$	7,218	$	284	$	7,502
Royalty receivables from partners	741		—		741
Other collaborations	—		25		25
Total receivables from collaborators	$	7,959	$	309	$	8,268

	December 31, 2021
	Billed		Unbilled		Total
U.S. Department of Health and Human Services, net	$	5	$	1,670	$	1,675
Royalty receivables from partners	305		—		305
Total receivables from collaborators	$	310	$	1,670	$	1,980