In conjunction with the Merger, the Company recorded a long-lived contract intangible asset related to Aerpio’s license agreement with Gossamer Bio. Inc., which was assumed in the Merger. In accordance with GAAP, for asset acquisitions, the excess purchase price over the fair value of the acquired assets and liabilities was ascribed to the acquired contract intangible asset. Due to the significant excess purchase price being allocated over the fair value of the acquired contract intangible asset, the Company determined that an indicator of impairment was present. The contract intangible asset was assessed for recoverability using an undiscounted cash flow model, which resulted in undiscounted cash flows below the carrying amount. The Company therefore recognized an impairment of $74.2 million to bring the carrying amount of the contract intangible asset down to its estimated fair value of $3.9 million. The fair value estimate of the intangible asset relates to contingent cash flows expected from Aerpio’s out-licensing arrangement, of which 90% of any future net cash proceeds will be remitted to CVR Holders and paid through the CVRs. The fair value determination of the intangible asset was based upon a discounted cash flow valuation of the milestone payments and Monte Carlo valuation for the sales royalties. The estimated useful life of the intangible asset is approximately 14.3 years. Amortization expense was $26,000 for the three and nine months ended September 30, 2021. No intangible asset or amortization expense was recorded in 2020.

The estimated amortization expense related to this finite lived intangible asset for the five succeeding years is as follows (amounts in thousands):

	September 30,
	2021
Intangible asset	$	3,906
Less amortization		(26	)
Intangible asset, net	$	3,880


2021 (remaining)	$	68
2022		273
2023		273
2024		273
2025		273
Amounts thereafter		2,720
	$	3,880

As of September 30, 2021, all development milestones, sales-based milestones and royalty payments within the license agreement are constrained. There can be no assurance that any proceeds will be received under the license agreement.