Revenue (Tables)

6 Months Ended

Jun. 30, 2020

Revenue

Summary of revenue by type

	Three Months Ended				Six Months Ended
	June 30,				June 30,
(in thousands)	2019		2020		2019		2020
Product revenue, net	$	—	$	(48)	$	—	$	108
Collaboration revenues		—		7		1,000		152
Research premium		351		301		744		591
Government grants		174		227		484		425
Total	$	525	$	487	$	2,228	$	1,276

Summary of gross-to-net ("GTN") adjustments

	Three Months Ended		Six Months Ended
(in thousands)	June 30, 2020		June 30, 2020
Product revenue, gross	$	149	$	398
GTN accruals
Chargebacks and cash discounts		5		13
Medicaid and Medicare rebates		18		46
Other returns, rebates, discounts and adjustments		35		92
Total GTN accruals		58		151
Product revenue		91		247
Adjustments to prior period accruals
Returns reserve (1)		(349)		(349)
GTN accrual adjustments		210		210
Product revenue, net	$	(48)	$	108