Inventory

12 Months Ended

Dec. 31, 2021

Inventory Disclosure [Abstract]

Inventory

INVENTORY

The components of inventory are summarized as follows:

	As of December 31,
(In millions)	2021		2020
Raw materials	$	349.6	$	314.9
Work in process	814.0		544.5
Finished goods	187.9		209.2
Total inventory	$	1,351.5	$	1,068.6

Inventory amounts written down as a result of excess, obsolescence or unmarketability are charged to cost of sales, and totaled $167.6 million, $26.6 million and $52.2 million for the years ended December 31, 2021, 2020 and 2019, respectively.

Upon review of the ADUHELM inventory it was determined that a portion of the inventory will not be consumed prior to product expiration based on our latest estimates of forecasted demand. During the fourth quarter of 2021

we wrote-off approximately $120.0 million of inventory in excess of forecasted demand related to ADUHELM, which was recognized in cost of sales within our consolidated statements of income. As of December 31, 2021, we had approximately $223.0 million of inventory related to ADUHELM. For additional information please read Note 18, Collaborative and Other Relationships, to these consolidated financial statements.