The Company is party to a global, strategic collaboration with Sanofi to research, develop, and commercialize fully human monoclonal antibodies, which currently consists of Dupixent® (dupilumab), Kevzara® (sarilumab), and itepekimab.

Sanofi is generally responsible for funding 80% to 100% of agreed-upon development expenses as incurred. The Company is obligated to reimburse Sanofi for 30% to 50% of development expenses that were funded by Sanofi (i.e., "development balance") based on the Company's share of collaboration profits. The Company is required to apply 20% of its share of profits from the collaboration each calendar quarter to reimburse Sanofi for these development expenses. The Company's contingent reimbursement obligation to Sanofi in connection with the development balance was approximately $278 million as of March 31, 2026.

Sanofi leads commercialization activities for products under the collaboration, subject to the Company's right to co-commercialize such products. The Company co-commercializes Dupixent in the United States and in certain countries outside the United States. The Company supplies certain commercial bulk product to Sanofi. The parties equally share profits from sales within the United States. The parties share profits outside the United States on a sliding scale based on sales starting at 65% (Sanofi)/35% (Regeneron) and ending at 55% (Sanofi)/45% (Regeneron).


	Statement of Operations Classification	Three Months Ended March 31,
(In millions)		2026		2025
Regeneron's share of profits	Collaboration revenue	$	1,450.8	$	1,018.2
Reimbursement for manufacturing of commercial supplies	Collaboration revenue	$	154.3	$	165.0
Regeneron's obligation for its share of Sanofi R&D expenses, net of reimbursement of R&D expenses	(R&D expense)	$	(16.7)	$	(15.5)
Reimbursement of commercialization-related expenses	Reduction of SG&A expense	$	184.1	$	159.2


	March 31,		December 31,
(In millions)	2026		2025
Accounts receivable, net	$	1,713.2	$	1,610.6
Deferred revenue	$	545.4	$	442.3

The Company is party to a license and collaboration agreement with Bayer for the global development and commercialization of EYLEA 8 mg (aflibercept 8 mg) and EYLEA (aflibercept) outside the United States. Agreed-upon development expenses incurred by the Company and Bayer are generally shared equally. The Company is also obligated to use commercially reasonable efforts to supply clinical and commercial bulk product to Bayer.

Bayer is responsible for commercialization activities outside the United States, and the companies share equally in profits from such sales. Within the United States, the Company is responsible for commercialization and retains profits from such sales.


	Statement of Operations Classification	Three Months Ended March 31,
(In millions)		2026		2025
Regeneron's share of profits	Collaboration revenue	$	240.0	$	317.3
Reimbursement for manufacturing of commercial supplies	Collaboration revenue	$	47.3	$	26.6
Reimbursement of R&D expenses, net of Regeneron's obligation for its share of Bayer R&D expenses	Reduction of R&D expense/(R&D expense)	$	1.0	$	(9.4)

In addition to the collaboration and license agreements discussed above, the Company has collaboration and license agreements that are not individually significant to its operating results or financial condition at this time. Pursuant to the terms of those agreements, the Company may (i) incur, and/or get reimbursed for, research and development expenses, and/or (ii) be required to pay, and/or may receive, additional amounts contingent upon the occurrence of various future events (e.g., upon the achievement of development and commercial milestones), which in the aggregate could be significant.

Acquired IPR&D expenses for the three months ended March 31, 2026 primarily related to the premium on equity securities purchased, as well as development milestone and up-front payments, in connection with collaboration and licensing agreements.