Net Product Revenue

6 Months Ended

Jun. 30, 2020

Revenue From Contract With Customer [Abstract]

Net Product Revenue

3. Net Product Revenue

Net product revenue consists of sales of TEGSEDI and WAYLIVRA. TEGSEDI is sold in the U.S. and the European Union, or E.U. On May 7, 2019, we obtained regulatory approval of WAYLIVRA in Europe, following which we began to commercialize WAYLIVRA in the E.U.

During the three and six months ended June 30, 2020 we recorded product revenue, net, of $16.4 million and $31.5 million, respectively. We recorded product revenue, net, of $9.9 million and $16.6 million for the same periods in 2019. The following table summarizes balances and activity in each of our product revenue allowance and reserve categories (in thousands):

	Chargebacks, discounts and fees			Government and other rebates			Returns		Total
Balance at December 31, 2019	$	270		$	1,353		$	197	$	1,820
Provision related to current period sales		1,044			4,830			58		5,932
Adjustment related to prior period sales		(66	)		83			—		17
Credits or payments made during the period		(1,093	)		(1,790	)		—		(2,883	)
Balance at June 30, 2020	$	155		$	4,476		$	255	$	4,886
Balance at December 31, 2018	$	50		$	293		$	5	$	348
Provision related to current period sales		438			774			138		1,350
Adjustment related to prior period sales		(4	)		(25	)		—		(29	)
Credits or payments made during the period		(311	)		(210	)		—		(521	)
Balance at June 30, 2019	$	173		$	832		$	143	$	1,148

The following table presents the balance of our receivables and contract liabilities related to net product revenue (in thousands):

	June 30, 2020		December 31, 2019
Receivables included in "Accounts receivable"	$	13,536	$	6,946
Contract liabilities included in "Accrued liabilities"		4,632		1,550