Summary of Significant Accounting Policies	6 Months Ended
Summary of Significant Accounting Policies	Jun. 30, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Nature of Operations. Avadel Pharmaceuticals plc (Nasdaq: AVDL) (“Avadel,” the “Company,” “we,” “our,” or “us”) is a biopharmaceutical company. The Company is registered as an Irish public limited company. The Company’s headquarters are in Dublin, Ireland with operations in Dublin, Ireland and St. Louis, Missouri, United States (“U.S.”). LUMRYZ is an extended-release formulation of sodium oxybate indicated to be taken once at bedtime for the treatment of cataplexy or excessive daytime sleepiness (“EDS”) in adults with narcolepsy. LUMRYZ was approved by the U.S. Food and Drug Administration (“FDA”) on May 1, 2023. The FDA also granted Orphan Drug Exclusivity (“ODE”) to LUMRYZ for a period of seven years until May 1, 2030. In June 2023, the Company commercially launched LUMRYZ in the U.S. In approving LUMRYZ, the FDA approved a risk evaluation and mitigation strategy (“REMS”) for LUMRYZ to help ensure that the benefits of the drug in the treatment of cataplexy and EDS in narcolepsy outweigh the risks of serious adverse outcomes resulting from inappropriate prescribing, misuse, abuse, and diversion of the drug. Under this REMS, healthcare providers who prescribe the drug must be specially certified; pharmacies that dispense the drug must be specially certified; and the drug must be dispensed only to patients who have enrolled in the LUMRYZ REMS and completed all REMS requirements, including documentation of safe use conditions. As of the date of this Quarterly Report, the Company’s only commercialized product is LUMRYZ. The Company continues to evaluate opportunities to expand its product portfolio. Liquidity. The accompanying unaudited condensed consolidated financial statements are prepared in accordance with accounting principles generally accepted in the U.S. (“U.S. GAAP”) applicable to a going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. The adequacy of the Company’s cash resources depends on the outcome of certain business conditions including the cost of the Company’s ongoing LUMRYZ commercialization activities, the Company’s cost structure, and other factors set forth in “Risk Factors” within Part I, Item 1A of the Company’s Annual Report on Form 10-K filed with the U.S. Securities and Exchange Commission (“SEC”) on February 29, 2024 (the “Annual Report on Form 10-K”). Ordinary Shares Effective April 15, 2024, the Company’s ordinary shares, nominal value $0.01 per share (“ordinary shares”), became directly listed on the Nasdaq Stock Market. The Company caused a mandatory exchange of its American Depositary Shares (“ADSs”) for the underlying ordinary shares on a one-for-one basis. Accordingly, the Bank of New York Mellon (“BNY Mellon”), as Depositary for the ADSs, issued a notice of termination of its American Depository Receipt program (“ADR Program”) of ADSs to the registered holders of ADSs according to the requirements under the deposit agreement dated January 3, 2017 (the “Deposit Agreement”) among the Company, BNY Mellon and holders of ADSs. The Deposit Agreement terminated on July 15, 2024. At-the-Market Offering Program On May 8, 2024, the Company entered into an Open Market Sale AgreementSM (the “Sales Agreement”) with Jefferies LLC (“Jefferies”) pursuant to which the Company may offer and sell its ordinary shares, from time to time, with respect to an at-the-market offering program (“ATM Program”) under which Jefferies will act as sales agent. The Sales Agreement provides that Jefferies will be entitled to aggregate compensation for its services an amount up to 3.0% of the gross proceeds of any ordinary shares sold through Jefferies under the Sales Agreement. The Sales Agreement replaces the Company’s previous Open Market Sale AgreementSM with Jefferies, dated February 4, 2020 (the “ADS Sales Agreement”), which provided for the sale of ADSs by the Company. The Company terminated the ADS Sales Agreement upon effectiveness of the Sales Agreement following the mandatory exchange of the ADSs and the direct listing of the ordinary shares on the Nasdaq Stock Market on April 15, 2024. The ordinary shares will be offered and sold pursuant to the Company’s shelf registration statement on Form S-3 (File No. 333-267198), filed with the SEC on August 31, 2022, as amended, and declared effective by the Commission on September 12, 2022, as supplemented by the prospectus supplement dated May 8, 2024 (the “Prospectus Supplement”). The Company may offer and sell ordinary shares having an aggregate offering price of up to $100,000 under the Prospectus Supplement. Prior to termination, the Company issued and sold 640 ordinary shares pursuant to the ADS Sales Agreement during the three months ended March 31, 2024, resulting in net proceeds to the Company of approximately $9,250. The Company did not issue or sell ordinary shares during the three months ended June 30, 2024 under the Sales Agreement. Preferred Shares In March 2024, 5,194 Series A Non-Voting Convertible Preferred Shares and Series B Non-Voting Convertible Preferred Shares (“Series B Preferred Shares”) were converted to 5,194 ordinary shares at the option of the holders. Accordingly, there were no preferred shares issued and outstanding at June 30, 2024. Basis of Presentation. The unaudited condensed consolidated balance sheet as of June 30, 2024 and the interim unaudited condensed consolidated financial statements presented herein, have been prepared in accordance with U.S. GAAP, the requirements of Form 10-Q and Article 10 of Regulation S-X and, consequently, do not include all information or footnotes required by U.S. GAAP for complete financial statements or all the disclosures normally made in an Annual Report on Form 10-K. Accordingly, the unaudited condensed consolidated financial statements included herein should be read in conjunction with the audited consolidated financial statements and footnotes included in the Annual Report on Form 10-K. Certain prior year amounts have been reclassified within the notes to the unaudited condensed consolidated financial statements to condense line items of the same nature to conform with the current year presentation. The unaudited condensed consolidated financial statements include the accounts of the Company and subsidiaries and reflect all adjustments (consisting only of normal recurring adjustments) that are, in the opinion of management, necessary for a fair presentation of the Company’s financial position, results of operations and cash flows for the dates and periods presented. All intercompany accounts and transactions have been eliminated. Results for interim periods are not necessarily indicative of the results to be expected during the remainder of the current year or for any future period. Newly Issued Climate-Related Disclosure Rule. In March 2024, the SEC issued a final rule requiring public companies to disclose climate-related information in their registration statements and annual reports. For large accelerated filers, the initial disclosure rules are effective for annual periods for the year ending December 31, 2025. In April 2024, the SEC voluntarily stayed the final rule pending the completion of judicial review by the Court of Appeals for the Eighth Circuit. The Company is monitoring the development of litigation related to the SEC’s rule, and is currently evaluating the effects of the final rule on its disclosures, processes and procedures.