Intangible Assets

12 Months Ended

Dec. 31, 2022

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible assets consist of the following:


		As of December 31,
		2022						2021
(In millions)	Estimated Useful Life	Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount		Gross carrying Amount		Accumulated Amortization		Net Carrying Amount
Acquired product rights - Libtayo	13 years	$	946.3	$	(35.7)	$	910.6	$	—	$	—	$	—
Other intangibles	5–8 years	10.0		(5.1)		4.9		29.3		(22.6)		6.7
Intangible assets, net		$	956.3	$	(40.8)	$	915.5	$	29.3	$	(22.6)	$	6.7

As described in Note 3, the Company recorded an intangible asset in connection with obtaining the exclusive right to develop, commercialize, and manufacture Libtayo worldwide. The intangible asset recognized upon the effective date of the A&R IO LCA primarily consisted of the $900.0 million up-front payment, offset by the remaining IO Collaboration Other liabilities balance of $241.0 million. During the year ended December 31, 2022, the Company recorded additions to the Libtayo intangible asset primarily related to contingent consideration (including regulatory and sales-based milestones, as described in Note 3) and other amounts due to Sanofi in connection with obtaining the worldwide rights to Libtayo.

Amortization expense on intangible assets was $37.6 million for the year ended December 31, 2022. Amortization expense for the years ended December 31, 2021 and 2020 was not material.

As of December 31, 2022, assuming no changes in the gross carrying amount of intangible assets, amortization expense is estimated to be approximately $72 million for each of the years ending December 31, 2023 through December 31, 2027.