THIS ANNOUNCEMENT CONTAINS INSIDE INFORMATION FOR THE PURPOSES OF ARTICLE 7 OF THE MARKET ABUSE REGULATION (EU) 596/2014 NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION IN WHOLE OR IN PART IN, INTO OR FROM ANY JURISDICTION

THIS ANNOUNCEMENT CONTAINS INSIDE INFORMATION FOR THE PURPOSES OF

ARTICLE 7 OF THE MARKET ABUSE REGULATION (EU) 596/2014

NOT FOR RELEASE, PUBLICATION

OR DISTRIBUTION IN WHOLE OR IN PART IN, INTO OR FROM ANY JURISDICTION WHERE TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT

LAWS OR REGULATIONS OF THAT JURISDICTION.

THIS IS AN ANNOUNCEMENT FALLING UNDER RULE 2.4

OF THE IRISH TAKEOVER PANEL ACT, 1997, TAKEOVER RULES, 2022 (THE "IRISH TAKEOVER RULES") AND IS NOT AN ANNOUNCEMENT OF A FIRM

INTENTION TO MAKE AN OFFER UNDER RULE 2.7 OF THE IRISH TAKEOVER RULES AND THERE CAN BE NO CERTAINTY THAT AN OFFER WILL BE MADE, NOR AS

TO THE TERMS ON WHICH ANY OFFER MIGHT BE MADE.

FOR IMMEDIATE RELEASE.

Avadel Receives Unsolicited Proposal from Lundbeck

Avadel Board of Directors Determines Proposal

From Lundbeck Reasonably Expected to Result in a "Company Superior Proposal"

DUBLIN, November 14, 2025 - Avadel

Pharmaceuticals plc (Nasdaq: AVDL) ("Avadel") announced today that it has received an unsolicited proposal from H. Lundbeck

A/S ("Lundbeck") to acquire Avadel for up to $23.00 per ordinary share, comprised of (i) $21.00 per ordinary share in

cash at closing and (ii) a non-transferable contingent value right (CVR) entitling holders to potential additional cash payments

of (a) $1.00 per ordinary share, contingent upon LUMRYZ and valiloxybate collectively reaching total annual net sales for

end-use in the United States of at least $450 million in any calendar year by December 31, 2027 and (b) $1.00 per ordinary share,

contingent upon LUMRYZ and valiloxybate collectively reaching total annual net sales for end-use in the United States of at least

$700 million in any calendar year by December 31, 2030 (the "Lundbeck Proposal"). The Lundbeck Proposal is subject to,

among other things, various closing conditions, including Avadel shareholder approval and regulatory approvals. Avadel's Board of

Directors has determined in good faith, after consultation with its financial and legal advisors, that the Lundbeck Proposal would reasonably

be expected to result in a "Company Superior Proposal" as defined in Avadel's existing transaction agreement with Alkermes

plc (Nasdaq: ALKS) ("Alkermes").

As previously announced, on October 22, 2025,

Avadel entered into a definitive transaction agreement with Alkermes, a global biopharmaceutical company that seeks to develop innovative

medicines in the field of neuroscience, under which Alkermes will acquire all outstanding ordinary shares of Avadel (the "acquisition").

Under the terms of the transaction agreement, Avadel shareholders will receive a total purchase price of up to $20.00 per ordinary share,

consisting of $18.50 per ordinary share payable in cash at closing and a CVR of $1.50 per ordinary share, contingent upon final FDA approval

of LUMRYZ for the treatment of idiopathic hypersomnia in adults by the end of 2028.

Under the transaction agreement with Alkermes,

the Avadel Board's determination that the unsolicited Lundbeck Proposal would reasonably be expected to result in a Company Superior

Proposal at this time allows Avadel to provide information to and conduct discussions and negotiations with Lundbeck, but does not allow

Avadel to terminate its agreement with Alkermes or enter into any other agreement with Lundbeck. Avadel's Board has not determined

that the Lundbeck Proposal in fact constitutes a Company Superior Proposal under the existing transaction agreement with Alkermes and

has not changed its recommendation in support of the Alkermes acquisition at this time.

There can be no assurance that the discussions

with Lundbeck will result in a determination by Avadel's Board that the Lundbeck Proposal is a Company Superior Proposal.

Avadel will have no further comment on the Lundbeck

Proposal until the Board has completed discussions and/or negotiations with Lundbeck.

In accordance with Rule 2.6(d) of the

Irish Takeover Rules (as amended by section 3 of Appendix 4 thereto), unless the Irish Takeover Panel consents otherwise, Lundbeck

must, by no later than 5:00 p.m. (U.S. Eastern Time) on the seventh day prior to the date of the general meeting of Avadel shareholders

convened to consider and approve the proposed scheme of arrangement (under Chapter 1 of Part 9 of the Companies Act 2014 of Ireland)

to effect the proposed acquisition by Alkermes, either (i) announce a firm intention to make an offer for Avadel in accordance with

Rule 2.7 of the Irish Takeover Rules; or (ii) announce that it does not intend to make such an offer for Avadel, in which case

the announcement will be treated as a statement to which Rule 2.8 of the Irish Takeover Rules applies.

Morgan Stanley and Goldman Sachs are serving as

financial advisors to Avadel, and Goodwin Procter LLP and Arthur Cox LLP are serving as legal counsel.

This announcement has been made without the consent

of Lundbeck. The Lundbeck Proposal is deemed unsolicited since the issuance of the Rule 2.7 Announcement (as defined herein). There

can be no certainty that an offer for Avadel will be made by Lundbeck, nor as to the terms on which any such offer may be made, if forthcoming.

No action by Avadel shareholders is required at

Avadel Pharmaceuticals plc (Nasdaq:

AVDL) is a biopharmaceutical company focused on transforming medicines to transform lives. Avadel's approach includes applying

innovative solutions to the development of medications that address the challenges patients face with current treatment options. Avadel's

commercial product, LUMRYZ , was approved by the U.S. Food & Drug Administration (FDA) as the first and only

once-at-bedtime oxybate for extended-release oral suspension for the treatment of cataplexy or excessive daytime sleepiness (EDS) in

patients 7 years and older with narcolepsy. For more information, please visit Avadel's website at www.avadel.com.

Avadel Investor Relations:

NO OFFER OR SOLICITATION

This communication is for information purposes

only and is not intended to and does not constitute, or form part of, an offer, invitation or the solicitation of an offer or invitation

to purchase, otherwise acquire, subscribe for, sell or otherwise dispose of any securities, or the solicitation of any vote or approval

in any jurisdiction, pursuant to the acquisition or otherwise, nor shall there be any sale, issuance or transfer of securities in any

jurisdiction in contravention of applicable law.

The acquisition will be implemented by means of

an Irish High Court-sanctioned scheme of arrangement on the terms provided for in the scheme document (or, if the acquisition is implemented

by way of a takeover offer, the applicable takeover offer document), which will contain the full terms and conditions of the acquisition,

including details of how Avadel shareholders may vote in respect of the acquisition. Any decision in respect of, or other response to,

the acquisition, should be made only on the basis of the information contained in the scheme document (or if the acquisition is implemented

by way of a takeover offer, the applicable takeover offer document).

Additional Information and Where To Find It

In connection with the acquisition, Avadel filed

a preliminary proxy statement (which includes a draft of the scheme document) with the Securities and Exchange Commission (the "SEC")

on November 13, 2025 and intends to file a definitive proxy statement (which will include the scheme document). The definitive proxy

statement will be sent to Avadel's shareholders as of the record date to be established for voting at Avadel shareholder meetings

to approve the acquisition. This communication is not a substitute for the proxy statement or any other document that Avadel may file

with the SEC or send to its shareholders in connection with the acquisition. BEFORE MAKING ANY VOTING DECISION, AVADEL'S SHAREHOLDERS

ARE URGED TO READ THE DEFINITIVE PROXY STATEMENT (INCLUDING THE SCHEME DOCUMENT), ANY AMENDMENTS OR SUPPLEMENTS THERETO AND OTHER RELEVANT

DOCUMENTS FILED OR TO BE FILED WITH THE SEC IN CONNECTION WITH THE ACQUISITION, INCLUDING ANY DOCUMENTS INCORPORATED BY REFERENCE

THEREIN, CAREFULLY AND IN THEIR ENTIRETY WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT THE ACQUISITION,

THE PARTIES TO THE SCHEME AND RELATED MATTERS.

Any vote in respect of the resolutions to be proposed

at the Avadel shareholder meeting to approve the acquisition, the scheme or related matters, or other responses in relation to the acquisition,

should be made only on the basis of the information contained in the definitive proxy statement (including the scheme document).

The preliminary and definitive proxy statements,

if and when filed, as well as Avadel's other public filings with the SEC, may be obtained without charge at the SEC's website

at www.sec.gov and at Avadel's website at https://investors.avadel.com/sec-filings. Avadel shareholders and investors will also

be able to obtain, without charge, a copy of the preliminary and definitive proxy statements (including the scheme document) and other

relevant documents (when available) by directing a written request to Avadel Pharmaceuticals plc, Attn: Investor Relations, 16640 Chesterfield

Grove Road #200, Chesterfield, MO 63005, United States, or by contacting Investor Relations via email at investors@avadel.com.

PARTICIPANTS IN THE SOLICITATION

Avadel and certain of its directors, executive

officers and employees may be deemed to be participants in the solicitation of proxies from Avadel shareholders in connection with the

acquisition and any other matters to be voted on at Avadel shareholder meetings to approve the acquisition. Information about the directors

and executive officers of Avadel, including a description of their direct or indirect interests, by security holdings or otherwise, is