Collaboration Revenue (Notes)

3 Months Ended

Mar. 31, 2013

Collaboration Revenue Disclosure [Abstract]

Collaborative Arrangement Disclosure

Collaboration Revenue

Sanofi Collaboration Revenue

The collaboration revenue the Company earned from Sanofi, as detailed below, consisted primarily of reimbursement for research and development expenses that the Company incurred, recognition of the Company's share of losses in connection with Sanofi's commercialization of ZALTRAP^®, and recognition of revenue related to non-refundable up-front payments.

	Three months ended March 31,
Sanofi Collaboration Revenue:	2013			2012
ZALTRAP:
Regeneron's share of losses in connection with commercialization of ZALTRAP	$	(7,789	)	$	(3,705	)
Reimbursement of Regeneron research and development and other expenses	2,563			2,820
Recognition of deferred revenue related to up-front payments	1,384			2,483
Total ZALTRAP	(3,842		)	1,598
Antibody:
Reimbursement of Regeneron research and development expenses	100,554			80,855
Recognition of deferred revenue related to up-front and other payments	2,162			2,153
Recognition of revenue related to VelociGene agreement	399			399
Total Antibody	103,115			83,407
Total Sanofi collaboration revenue	$	99,273		$	85,005

Sanofi commenced sales of ZALTRAP(ziv-aflibercept) Injection for Intravenous Infusion, in combination with 5-fluorouracil, leucovorin, irinotecan ("FOLFIRI"), for patients with metastatic colorectal cancer (“mCRC”) that is resistant to or has progressed following an oxaliplatin-containing regimen, in the United States in the third quarter of 2012 and in certain countries in Europe in the first quarter of 2013. The Company and Sanofi globally collaborate on the development and commercialization of ZALTRAP. Under the terms of the companies' September 2003 collaboration agreement, as amended, Regeneron and Sanofi share co-promotion rights and profits and losses on sales of ZALTRAP outside of Japan. In Japan, the Company is entitled to a royalty on sales of ZALTRAP.

Bayer HealthCare Collaboration Revenue

Bayer HealthCare commenced sales of EYLEA for the treatment of wet AMD in the fourth quarter of 2012 following receipt of regulatory approvals in the European Union and other regions. The Company and Bayer HealthCare globally collaborate on the development and commercialization of EYLEA outside of the United States.

The collaboration revenue the Company earned from Bayer HealthCare is detailed below:

	Three months ended March 31,
Bayer HealthCare Collaboration Revenue	2013		2012
Regeneron's net profit in connection with commercialization of EYLEA outside the United States	$	6,362
Cost-sharing of Regeneron EYLEA development expenses	5,971		$	10,506
Reimbursement of other Regeneron EYLEA expenses	597
Recognition of deferred revenue related to up-front and other milestone payments	1,977		1,977
	$	14,907	$	12,483