Future lease payments for non-cancellable operating leases as of December 31, 2020 were as follows: Right-of-use assets obtained in exchange for new operating lease obligations were $326 million in 2020 which includes $82 million of right-of-use assets acquired in the MyoKardia acquisition. Cash paid for amounts included in the measurement of operating lease liabilities was $164 million in 2020 and $79 million in 2019. Cash paid in 2019 was net of a $33 million lease incentive received. Undiscounted lease obligations for operating leases not yet commenced were approximately $750 million as of December 31, 2020. The obligation primarily relates to a research and development facility that is being constructed by the lessor and which is expected to be ready for use in 2022. A right-of-use asset impairment charge of $31 million was incurred during 2020 due to a site vacancy and partial sublease. The fair value of the right- of-use asset was determined using an income approach incorporating potential future cash flows associated with the sublease of the building. Supplemental balance sheet information related to leases was as follows: (a) Includes measurement period adjustments. Refer to “—Note 4. Acquisitions, Divestitures, Licensing and Other Arrangements” for more information. In 2020, $13.1 billion of IPRD was reclassified to acquired marketed product rights upon approval in the U.S. for  Reblozyl  for the treatment of anemia in adults with lower-risk MDS,  Zeposia  and  Onureg . Amortization expense of other intangible assets was $9.9 billion in 2020, $1.3 billion in 2019 and $198 million in 2018. Future annual amortization expense of other intangible assets is expected to be approximately $10.2 billion in 2021, $10.1 billion in 2022, $9.5 billion in 2023 $8.5 billion in 2024 and $1.2 billion in 2025. Other intangible asset impairment charges were $1.1 billion in 2020, $66 million in 2019 and $84 million in 2018, respectively. December 31, 2020 2019 Weighted average remaining lease term 9.0 years 9.0 years Weighted average discount rate 3  % 4  % Estimated Useful Lives December 31, Dollars in Millions 2020 2019 Goodwill $ 20,547  $ 22,488  Other intangible assets: Licenses 5 – 15 years 328  482  Acquired marketed product rights 3 – 15 years 59,076  46,827  Capitalized software 3 – 10 years 1,325  1,297  IPRD 6,130  19,500  Gross other intangible assets 66,859  68,106  Less accumulated amortization (13,616) (4,137) Other intangible assets $ 53,243  $ 63,969  (a) (a) Note 14. GOODWILL AND OTHER INTANGIBLE ASSETS 103 Dollars in Millions 2021 $ 195  2022 169  2023 142  2024 106  2025 84  Thereafter 468  Total future lease payments 1,164  Less imputed interest (167) Total lease liability $ 997 