12.        Intangible assets and goodwill

Definite-lived intangibles

On April 20, 2017, the Company completed its previously announced acquisition of all rights to Emflaza pursuant to the Asset Purchase Agreement, dated March 15, 2017, and amended on April 20, 2017, by and between the Company and Marathon. The assets acquired by the Company in the transaction include intellectual property rights related to Emflaza, inventories of Emflaza, and certain contractual rights related to Emflaza. In accordance with ASU 2017-01, the Company determined that substantially all of the fair value is concentrated in the Emflaza rights intangible asset and as such accounted for the transaction as an asset acquisition under ASC 805-50 and recorded an intangible asset of $148.4 million, which is being amortized to cost of product sales over its expected useful life of approximately seven years on a straight line basis.

Marathon is entitled to receive contingent payments from the Company based on annual net sales of Emflaza beginning in 2018, up to a specified aggregate maximum amount over the expected commercial life of the asset. In accordance with the guidance for an asset acquisition, the Company records the milestone payment when it becomes payable to Marathon and increases the cost basis for the Emflaza rights intangible asset. Marathon received a $50.0 million sales-based milestone during the nine months ended September 30, 2022. For the three months ended September 30, 2022 and 2021, total milestone payments of $21.3 million and $16.8 million were recorded, respectively. For the nine months ended September 30, 2022 and 2021, total milestone payments of $105.1 million and $42.8 million were recorded, respectively. These payments are being amortized over the remaining useful life of the Emflaza rights asset on a straight line basis. As

of September 30, 2022, a milestone payable to Marathon of $27.4 million was recorded on the balance sheet within accounts payable and accrued expenses.

Pursuant to the Tegsedi-Waylivra Agreement, in May 2019 the Company made a $6.0 million milestone payment to Akcea upon regulatory approval of Waylivra from the EMA. In December 2019, the Company made a $4.0 million milestone payment to Akcea upon regulatory approval of Tegsedi from ANVISA. Both payments were recorded as intangible assets and are being amortized to cost of product sales over their expected useful life of approximately ten years on a straight line basis. Additionally, in August 2021, the Company made a $4.0 million milestone payment to Akcea upon regulatory approval of Waylivra from ANVISA. In accordance with the guidance for an asset acquisition, the Company recorded the milestone payment when it became payable to Akcea, and it increased the cost basis for the Waylivra intangible asset. This payment is being amortized to cost of product sales over the expected remaining useful life of the Waylivra asset on a straight line basis.

Akcea is also entitled to receive royalty payments subject to certain terms set forth in the Tegsedi-Waylivra Agreement related to sales of Waylivra and Tegsedi. In accordance with the guidance for an asset acquisition, the Company will record royalty payments when they become payable to Akcea and increase the cost basis for the Waylivra and Tegsedi intangible assets, respectively. For the three and nine months ended September 30, 2022, a royalty payment of $0.5 million and $2.5 million was recorded for Tegsedi, respectively. No royalty payment was recorded for the three and nine months ended September 30, 2021. As of September 30, 2022, a royalty payable of $0.5 million was recorded on the balance sheet within accounts payable and accrued expenses.

In connection with the acquisition of the Company’s gene therapy platform from Agilis, the Company acquired rights to Upstaza, for the treatment of AADC deficiency. In accordance with the acquisition method of accounting, the Company allocated the acquisition cost for the Agilis Merger to the underlying assets acquired and liabilities assumed, based upon the estimated fair values of those assets and liabilities at the date of acquisition. The Company classified the fair value of the acquired IPR&D as indefinite lived intangible assets until the successful completion or abandonment of the associated research and development efforts. The value allocated to the indefinite lived intangible assets was $576.5 million.

In July 2022, the European Commission approved Upstaza for the treatment of AADC deficiency for patients 18 months and older within the EEA. With this approval, $89.5 million was reclassified from indefinite lived intangible assets to definite lived intangible assets. The Company will amortize this allocated balance of $89.5 million over its expected useful life of 12 years on a straight-line basis.

For the three months ended September 30, 2022 and 2021, the Company recognized amortization expense of $31.0 million and $14.4 million, respectively, related to the Emflaza rights, Upstaza, Waylivra, and Tegsedi intangible assets. For the nine months ended September 30, 2022 and 2021, the Company recognized amortization expense of $80.8 million and $38.4 million, respectively, related to the Emflaza rights, Upstaza, Waylivra, and Tegsedi intangible assets. The estimated future amortization of the Emflaza rights, Upstaza, Waylivra, and Tegsedi intangible assets is expected to be as follows:

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The weighted average remaining amortization period of the definite-lived intangibles as of September 30, 2022 is 5.1 years.

Indefinite-lived intangibles

The gene therapy platform that the Company acquired from Agilis includes Upstaza, for the treatment of AADC deficiency. AADC deficiency is a rare CNS disorder arising from reductions in the enzyme AADC that result from

mutations in the dopa decarboxylase gene. This gene therapy platform also includes an asset targeting Friedreich ataxia, a rare and life-shortening neurodegenerative disease caused by a single defect in the FXN gene which causes reduced production of the frataxin protein. Additionally, the gene therapy platform includes two other programs targeting CNS disorders, including Angelman syndrome, a rare, genetic, neurological disorder characterized by severe developmental delays.

The ratification of Upstaza by the European Commission in July 2022 makes Upstaza the first approved disease-modifying treatment for aromatic L-amino acid decarboxylase (AADC) deficiency for patients 18 months and older, and the first marketed gene therapy directly infused into the brain. At the time of the Agilis acquisition, the value allocated to the indefinite lived intangible assets was $576.5 million. With the Upstaza approval in the EU, a balance of $487.0 million remains on the balance sheet within intangible assets.

Goodwill

As a result of the Agilis Merger on August 23, 2018, the Company recorded $82.3 million of goodwill. As of September 30, 2022, there have been no changes to the balance of goodwill since the date of the Agilis Merger. Accordingly, the goodwill balance as of September 30, 2022 is $82.3 million.