Note 10.

Intangible Assets, Net and Other non-current assets

The following table provides the components of identifiable intangible assets, all of which are finite lived and other non-current assets:

	December 31,
	2020			2019
Purchase technology-based intangible	$	2,358		$	2,358
Purchased patent		509			509
		2,867			2,867
Less: accumulated amortization		(2,765	)		(2,714	)
Intangible assets, net		102			153

Royalty receivable		7,000			—
Other		836			286
Total other non-current assets	$	7,836		$	286

Amortization expense was $51 and $50 for each of the years ended December 31, 2020 and 2019, respectively. During the remaining life of the purchased patent, estimated annual amortization expense is $51 for each of the years from 2021 to 2022.

During the second quarter of 2020, under the Sunovion License Agreement, the Company recognized $8,000 of royalty revenue and corresponding royalty receivable, related to the $1,000 annual minimum guaranteed royalty that is due in each of the next eight years. In connection with the Monetization Agreement, the Company performed an assessment under ASC 860 Transfer and Servicing to determine whether the existing receivable was to transferred to Marathon and concluded it was not transferred. Royalty receivable consists of seven annual minimum payments due from Sunovion, the last of which is due in March 2028. The current portion of the royalty receivable is included in Trade and other receivables, net. The Company will account for the future royalties from Sunovion as revenue that exceed the annual minimum royalty of $1,000. The first $1,000 of royalties will reduce the existing annual minimum royalty of $1,000.