The following table summarizes our recognized intangible assets as a result of the arrangements described in the following sections:


	March 31, 2023				December 31, 2022
	Weighted-average Estimated Useful Lives	Amount			Weighted-average Estimated Useful Lives	Amount
		(in thousands)				(in thousands)
Gross amount	11.7 years	$	32,500		12.0 years	$	32,500
Less: accumulated amortization			(4,387	)			(3,788	)
Total		$	28,113			$	28,712

Amortization expense recorded as part of cost of license revenue and products sold for the three months ended March 31, 2023 and March 31, 2022 was $0.6 million and $0.9 million, respectively. Future amortization expense is $1.8 million for the remainder of 2023, $2.4 million for each of the years from 2024 to 2027 and $16.7 million thereafter.

In January 2018, QED entered into a License Agreement with Novartis International Pharmaceutical, Inc. or Novartis, pursuant to which QED acquired certain intellectual property rights, including patents and know-how, related to infigratinib for the treatment of patients with FGFR-driven diseases. QED accounted for the transaction as an asset acquisition as substantially all of the estimated fair value of the gross assets acquired was concentrated in a single identified asset, in-process research and development, or IPR&D, thus satisfying the requirements of the screen test in ASU 2017-01, Business Combinations (Topic 805), Clarifying the Definition of a Business. The assets acquired and liabilities assumed in the transaction were measured based on their fair values. The fair value of the IPR&D acquired was charged to research and development expense as it had no alternative future use at the time of the acquisition.

If certain substantial milestones are met, QED could be required to pay up to $60.0 million in regulatory milestone payments, $35.0 million in sales-based milestone payments, and pay royalties of up to low double-digit percentages on net sales. Following the U.S. Food and Drug Administration ("FDA") approval of TRUSELTIQTM in May 2021, we paid a one-time regulatory milestone payment to Novartis of $20.0 million. We capitalized such payment as a finite-lived intangible asset and amortize the amount over its estimated useful life on a straight-line basis.

In June 2018, our subsidiary Origin Biosciences, Inc., or Origin, entered into an Asset Purchase Agreement with Alexion Pharma Holding Unlimited Company, or Alexion, to acquire intellectual property rights, including patent rights, know-how, and contracts, related to the ALXN1101 molecule. Origin accounted for the transaction as an asset acquisition as substantially all of the estimated fair value of the gross assets acquired was concentrated in a single identified asset, or IPR&D, thus satisfying the requirements of the screen test in ASU 2017-01. The assets acquired and liabilities assumed in the transaction were measured based on their fair values. The fair value of the IPR&D acquired was charged to research and development expense as it had no alternative future use at the time of the acquisition.

Pursuant to the Asset Purchase Agreement, Origin was required to pay $15.0 million upon the satisfaction of a certain condition, which was met in 2021. We capitalized the amount as a finite-lived intangible asset and amortize it over its estimated useful life on a straight-line basis. In addition, under the Asset Purchase Agreement, Origin could be required to pay up to $17.0 million in sales-based milestone payments and royalties of up to low double-digit percentages on net sales.

In connection with the Asset Purchase Agreement entered between Origin and Sentynl Therapeutics, Inc., or Sentynl, in March 2022, or the Origin-Sentynl APA, (see Note 11), Sentynl assumed the obligation to pay sales-based milestone payments and royalties to Alexion that occur subsequent to the closing of the Origin-Sentynl APA when they become due. Origin will continue to be responsible for a regulatory-based milestone payment upon first pricing approval in a European Medicines Agency, or EMA, country of up to $1.0 million when it becomes due. As a result of the Origin-Sentynl APA, we also derecognized the associated intangible asset with a net book value of $13.5 million as this was part of the assets that were transferred to Sentynl.

In November 2018, QED and Foundation Medicine, Inc., or FMI, entered into a companion diagnostics agreement relating to QED’s drug discovery and development initiatives. Pursuant to the agreement, QED could be required to pay $12.5 million in regulatory approval milestones over a period of four years subsequent to the FDA approval of a companion diagnostic for TRUSELTIQTM in patients with cholangiocarcinoma. The FDA approved the companion diagnostic for TRUSELTIQTM in May 2021, which resulted in the capitalization of $12.5 million as a finite-lived intangible asset to be amortized over its estimated useful life on a straight-line basis. As of March 31, 2023 and December 31, 2022, the amount due to FMI is presented in our condensed consolidated balance sheet as $2.5 million in "Other accrued liabilities" and $8.5 million in "Other long-term liabilities", respectively.