Goodwill and intangible assets acquired are recognized at fair value as of the acquisition date. The carrying amount of goodwill as of March 31, 2023 was $27.9 million. We have not recognized any impairment losses related to goodwill during the periods presented.

Intangible assets with definite lives are amortized over their estimated useful lives. The carrying basis and accumulated amortization of recognized intangible assets as of March 31, 2023 and December 31, 2022 were as follows:


	March 31, 2023
	Useful Life	Gross		Accumulated			Net Carrying
(In thousands)	(Years)	Amount		Amortization			Amount
Marketed products	8-10	$	151,000	$	(9,386	)	$	141,614
In-process research and development			71,300		—		$	71,300
Collaboration agreement			35,400		—		$	35,400
Total		$	257,700	$	(9,386	)	$	248,314


	December 31, 2022
	Useful Life	Gross		Accumulated			Net Carrying
(In thousands)	(Years)	Amount		Amortization			Amount
Marketed products	8-10	$	151,000	$	(5,581	)	$	145,419
In-process research and development			72,100		—		$	72,100
Collaboration agreement			35,400		—		$	35,400
Total		$	258,500	$	(5,581	)	$	252,919

Intangible assets recognized as a result of the acquisition of Entasis amounted to $106.7 million, which consist of Entasis’ in-process research and development related to its antibacterial therapeutic product candidates and a collaboration agreement amounting to $71.3 million and $35.4 million, respectively. The useful lives of these intangible assets will be determined upon commercialization of the underlying product candidates; thus, no amortization expense of determinable assets was recognized for the three months ended March 31, 2023.

Intangible assets recognized as a result of the acquisition of La Jolla amounting to $151.0 million pertain to product rights and developed technologies on La Jolla’s currently marketed products. These are intangible assets with determinable lives and are amortized over their estimated useful lives. We recognized amortization expense of $3.8 million for the period through March 31, 2023. Future amortization expense is expected to be $11.6 million for the remainder of 2023, $15.4 million for each of the years from 2024 to 2027 and $68.4 million thereafter.