Intangible assets

12 Months Ended

Dec. 31, 2022

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible assets, net of accumulated amortization, are summarized as follows (in thousands):


	As of December 31,						As of December 31,
	2022						2021
	Cost		Accumulated amortization		Net		Cost		Accumulated amortization		Net
Developed technology	$	30,100	$	(30,100)	$	—	$	30,100	$	(28,218)	$	1,882
In-licensed rights	8,500		(1,198)		7,302		8,500		(490)		8,010
Total	$	38,600	$	(31,298)	$	7,302	$	38,600	$	(28,708)	$	9,892

Amortization expense for intangible assets was $2.6 million, $4.3 million, and $3.8 million for the years ended December 31, 2022, 2021 and 2020, respectively.

Developed technology

The Company's developed technology was obtained through the acquisition in 2014 of Pregenen, a privately-held biotechnology company includes gene editing and cell signaling technology with a broad range of potential

therapeutic applications. The gene editing platform intangible asset was amortized on a straight-line basis over its expected useful life until it was fully amortized in the second quarter of 2022.

In-licensed rights

In-licensed rights consist of capitalized milestone payments made to third parties upon receiving regulatory approval of Abecma in the U.S. The in-licensed rights are being amortized on a straight-line basis over the remaining life of the related patents of approximately twelve years, as the life of the related patents reflects the expected time period that the Company will benefit from the in-licensed rights.

The following table summarizes the estimated future amortization for intangible assets for the next five years and thereafter (in thousands):


	As of December 31, 2022
2023	$	708
2024	708
2025	708
2026	708
2027	708
2028 and thereafter	3,762
Total	$	7,302