Revenues

Product Revenues

Revenues by product are summarized as follows:



	For the Three Months Ended March 31,
(In millions)	2019						2018
	United States		Rest of World		Total		United States		Rest of World		Total
Multiple Sclerosis (MS):
TECFIDERA	$	717.7	$	281.1	$	998.8	$	728.9	$	258.0	$	986.9
Interferon*	327.3		173.6		500.9		371.4		178.9		550.3
TYSABRI	245.0		215.4		460.4		249.7		212.4		462.1
FAMPYRA	—		22.9		22.9		—		24.4		24.4
ZINBRYTA	—		—		—		—		1.4		1.4
Subtotal: MS product revenues	1,290.0		693.0		1,983.0		1,350.0		675.1		2,025.1

Spinal Muscular Atrophy:
SPINRAZA	223.3		295.2		518.5		188.0		175.9		363.9

Biosimilars:
BENEPALI	—		124.0		124.0		—		120.9		120.9
FLIXABI	—		14.7		14.7		—		6.6		6.6
IMRALDI	—		35.7		35.7		—		—		—
Subtotal: Biosimilar product revenues	—		174.4		174.4		—		127.5		127.5

Other:
FUMADERM	—		4.1		4.1		—		7.0		7.0
Total product revenues	$	1,513.3	$	1,166.7	$	2,680.0	$	1,538.0	$	985.5	$	2,523.5

*Interferon includes AVONEX and PLEGRIDY.

We recognized revenues from two wholesalers accounting for 31.3% and 14.2% of gross product revenues for the three months ended March 31, 2019, and 34.0% and 15.9% of gross product revenues for the three months ended March 31, 2018.

An analysis of the change in reserves for discounts and allowances is summarized as follows:



(In millions)	Discounts			Contractual Adjustments			Returns			Total
Balance, as of December 31, 2018	$	127.8		$	888.8		$	34.7		$	1,051.3
Current provisions relating to sales in current year	141.2			680.3			4.7			826.2
Adjustments relating to prior years	0.3			(25.1		)	0.3			(24.5		)
Payments/credits relating to sales in current year	(60.8		)	(233.9		)	(0.1		)	(294.8		)
Payments/credits relating to sales in prior years	(92.1		)	(378.1		)	(4.6		)	(474.8		)
Balance, as of March 31, 2019	$	116.4		$	932.0		$	35.0		$	1,083.4

The total reserves above, which are included in our condensed consolidated balance sheets, are summarized as follows:



(In millions)	As of March 31, 2019		As of December 31, 2018
Reduction of accounts receivable, net	$	175.8	$	176.6
Component of accrued expenses and other	907.6		874.7
Total revenue-related reserves	$	1,083.4	$	1,051.3

Revenues from Anti-CD20 Therapeutic Programs

Revenues from anti-CD20 therapeutic programs are summarized as follows:



	For the Three Months Ended March 31,
(In millions)	2019		2018
Biogen’s share of pre-tax profits in the U.S. for RITUXAN, RITUXAN HYCELA and GAZYVA	$	390.8	$	349.6
Other revenues from anti-CD20 therapeutic programs	126.6		93.6
Total revenues from anti-CD20 therapeutic programs	$	517.4	$	443.2

For additional information on our collaboration arrangements with Genentech, please read Note 19, Collaborative and Other Relationships, to our consolidated financial statements included in our 2018 Form 10-K.

Other Revenues

Other revenues are summarized as follows:



	For the Three Months Ended March 31,
(In millions)	2019			2018
Revenues from collaborative and other relationships:
(Loss) profit earned under our 50% share of the co-promotion losses on ZINBRYTA in the U.S. with AbbVie	$	(0.4	)	$	(4.7	)
Revenues earned under our technical development agreement, manufacturing services agreements and royalty revenues on biosimilar products with Samsung Bioepis	24.8			17.9
Other royalty and corporate revenues:
Royalty	3.9			10.6
Other corporate	264.1			140.6
Total other revenues	$	292.4		$	164.4

Other corporate revenues primarily reflect amounts earned under contract manufacturing agreements with our strategic partners, including Bioverativ Inc. (Bioverativ). During the three months ended March 31, 2019 and 2018, we recognized $206.8 million and $47.0 million, respectively, in revenues under the manufacturing and supply agreement with Bioverativ entered into in connection with the spin-off of our hemophilia business.

For additional information on our collaboration arrangement with Samsung Bioepis, please read Note 17, Collaborative and Other Relationships, to these condensed consolidated financial statements. For additional information on our collaboration arrangement with AbbVie Inc. (AbbVie), please read Note 19, Collaborative and Other Relationships, to our consolidated financial statements included in our 2018 Form 10-K. For additional information on our contract manufacturing agreements with Bioverativ, please read Note 3, Hemophilia Spin-Off, to our consolidated financial statements included in our 2018 Form 10-K.