Product Sales

3 Months Ended

Mar. 31, 2021

Revenues [Abstract]

Product Sales

Product Sales

Net product sales consist of the following:

(In millions)	Three Months Ended March 31,
Net Product Sales in the United States	2021		2020
EYLEA®	$	1,347.0	$	1,172.0
Libtayo®	69.1		61.7
Praluent®	43.3		*
REGEN-COV™ (casirivimab with imdevimab)	262.2		—
Evkeeza™	0.5		—
ARCALYST®	2.2		3.0
	$	1,724.3	$	1,236.7
* Effective April 1, 2020, the Company became solely responsible for the development and commercialization of Praluent in the United States and records net product sales of Praluent in the United States. See Note 3 for further details.

The Company had product sales to certain customers that accounted for more than 10% of total gross product revenue for the three months ended March 31, 2021 and 2020. Sales to each of these customers as a percentage of the Company's total gross product revenue are as follows:

	Three Months Ended March 31,
	2021		2020
Besse Medical, a subsidiary of AmerisourceBergen Corporation	46	%	54	%
McKesson Corporation	29	%	36	%
U.S. Government (see Note 3)	13	%	—

As of March 31, 2021 and December 31, 2020, the Company had $3.173 billion and $3.112 billion, respectively, of trade accounts receivable that were recorded within Accounts receivable, net.