Contingencies and commitments	3 Months Ended
Contingencies and commitments	Mar. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Contingencies and commitments	Contingencies and commitments Contingencies In the ordinary course of business, we are involved in various legal proceedings, government investigations and other matters that are complex in nature and have outcomes that are difficult to predict. See our Annual Report on Form 10-K for the year ended December 31, 2021, Part I, Item 1A. Risk Factors—Our business may be affected by litigation and government investigations. We describe our legal proceedings and other matters that are significant or that we believe could become significant in this footnote; and in Note 19, Contingencies and commitments, to the consolidated financial statements in our Annual Report on Form 10-K for the year ended December 31, 2021. We record accruals for loss contingencies to the extent that we conclude it is probable that a liability has been incurred and the amount of the related loss can be reasonably estimated. We evaluate, on a quarterly basis, developments in legal proceedings and other matters that could cause an increase or decrease in the amount of the liability that has been accrued previously. Our legal proceedings involve various aspects of our business and a variety of claims, some of which present novel factual allegations and/or unique legal theories. In each of the matters described in this filing; and in Note 19, Contingencies and commitments, to the consolidated financial statements in our Annual Report on Form 10-K for the year ended December 31, 2021, in which we could incur a liability, our opponents seek an award of a not-yet-quantified amount of damages or an amount that is not material. In addition, a number of the matters pending against us are at very early stages of the legal process, which in complex proceedings of the sort we face often extend for several years. As a result, none of the matters described in this filing; and in Note 19, Contingencies and commitments, to the consolidated financial statements in our Annual Report on Form 10-K for the year ended December 31, 2021, in which we could incur a liability, have progressed sufficiently through discovery and/or the development of important factual information and legal issues to enable us to estimate a range of possible loss, if any, or such amounts are not material. While it is not possible to accurately predict or determine the eventual outcomes of these matters, an adverse determination in one or more of these matters currently pending could have a material adverse effect on our consolidated results of operations, financial position or cash flows. Certain recent developments concerning our legal proceedings and other matters are discussed below: Repatha Patent Litigation Amgen Inc., et al. v. Sanofi, et al. On March 28, 2022, Amgen filed a reply brief in support of its petition for certiorari to the U.S. Supreme Court. On April 18, 2022, the Supreme Court requested that the Office of the Solicitor General of the United States submit a brief providing the government’s view on the issues raised by Amgen’s petition. Patent Disputes in the International Region On March 23, 2022, Amgen filed counterclaims alleging that PRALUENT® infringes Amgen’s European Patent 2,641,917 (the ‘917 Patent). A European Patent Office (EPO) opposition to the ‘917 Patent, filed by Sanofi on February 5, 2021, is pending, and the hearing before the EPO’s Opposition Division is scheduled for February 21, 2023. NEUPOGEN (filgrastim)/Neulasta Patent Litigation Amgen Inc., et al. v. Hospira Inc. et al. On March 18, 2022, the parties filed a stipulation of dismissal, and the U.S. District Court for the District of Delaware (the Delaware District Court) dismissed the case on March 21, 2022. Patent Trial and Appeal Board (PTAB) Challenge Apotex PTAB Challenge On April 4, 2022, Amgen’s appeal of the PTAB’s decision, holding all claims of Amgen’s U.S. Patent No. 8,952,138 (the ‘138 Patent) unpatentable, was submitted to the U.S. Court of Appeals for the Federal Circuit (the Federal Circuit Court) for determination on the briefs without oral argument. On April 14, 2022, the Federal Circuit Court held that the PTAB misconstrued the patent claims and reversed the PTAB’s decision because Apotex failed to prove the invention of the ‘138 Patent unpatentable. Pfizer PTAB Challenge On March 18, 2022, the parties filed a joint motion to terminate the inter partes review proceeding at the U.S. Patent and Trademark Office of U.S. Patent No. 8,273,707. On April 20, 2022, the PTAB granted the motion and terminated the proceeding. Antitrust Class Action Sensipar Antitrust Class Actions On March 11, 2022, the Delaware District Court granted defendants’ (including Amgen’s) motion to dismiss except as to the reverse payment claim and various state law claims from ten of the states in which plaintiffs reside. U.S. Tax Litigation Amgen Inc. & Subsidiaries v. Commissioner of Internal Revenue See Note 4, Income taxes, for discussion of the IRS tax dispute and the Company’s petition in the U.S. Tax Court.