Goodwill and intangible assets acquired are recognized at fair value as of the acquisition date. We recognized goodwill of $11.5 million and $6.4 million from our acquisitions of Entasis and La Jolla, respectively, in 2022. The carrying amount of goodwill

as of March 31, 2024 and December 31, 2023 was $17.9 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, 2024 and December 31, 2023 were as follows:


	March 31, 2024
	Useful Life	Gross		Accumulated			Net Carrying
(In thousands)	(Years)	Amount		Amortization			Amount
Marketed products	8-10	$	219,700	$	(30,763	)	$	188,937
In-process research and development			2,600		—		$	2,600
Collaboration agreement	10		35,400		(3,042	)	$	32,358
Total		$	257,700	$	(33,805	)	$	223,895


	December 31, 2023
	Useful Life	Gross		Accumulated			Net Carrying
(In thousands)	(Years)	Amount		Amortization			Amount
Marketed products	8-10	$	219,700	$	(25,204	)	$	194,496
In-process research and development			2,600		—			2,600
Collaboration agreement	10		35,400		(2,161	)		33,239
Total		$	257,700	$	(27,365	)	$	230,335

Intangible assets recognized as a result of the acquisition of Entasis amounted to $106.7 million, which consisted 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. Following the FDA approval of XACDURO® in May 2023, we started amortizing $68.7 million of the then in-process research and development as a marketed product, as well as the collaboration agreement, over their estimated useful lives. The useful life of the remaining in-process research and development of $2.6 million will be determined upon commercialization of the underlying product candidate; thus, no amortization expense for this intangible asset was recognized for the periods presented.

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 $6.4 million and $3.8 million for the three months ended March 31, 2024 and 2023, respectively. Future amortization expense is expected to be $19.4 million for the remainder of 2024, $25.8 million for each of the years from 2025 to 2028 and $98.7 million thereafter.