SC TO-C

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE TO

TENDER OFFER STATEMENT UNDER SECTION 14(D)(1) OR 13(E)(1)

OF THE SECURITIES EXCHANGE ACT OF 1934

ZOGENIX, INC.

(Name of Subject Company — Issuer)

ZINC MERGER SUB, INC.

a wholly owned subsidiary of

UCB S.A.

(Names of Filing Persons — Offerors)

Common Stock, par value $0.001 per share

(Title of Class of Securities)

98978L204

(CUSIP Number of Class of Securities)

Bill Silbey

Executive Vice President and General Counsel

UCB S.A.

Allée de la Recherche, 60

1070 Brussels

Tel: 32 2 559 99 99

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications on Behalf of Filing Persons)

Copies to:

J. D. Weinberg, Esq.

Kyle Rabe, Esq.

Covington & Burling LLP

The New York Times Building

620 Eighth Avenue

New York, NY 10018-1405

+1 (212) 841 1000

CALCULATION OF FILING FEE

Transaction Valuation*	Amount of Filing Fee*
Not applicable*	Not applicable*

* A filing fee is not required in connection with this filing as it relates solely to preliminary communications made before the commencement of a tender offer.

☐  Check the box if any part of the fee is offset as provided by Rule 0-11(a)(2) and identify the filing with which the offsetting fee was previously paid. Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.

Amount Previously Paid: Not applicable.	Filing Party: Not applicable.
Form of Registration No.: Not applicable.	Date Filed: Not applicable.

☒  Check the box if the filing relates solely to preliminary communications made before the commencement of a tender offer.

Check the appropriate boxes to designate any transactions to which this statement relates:

☒  third party tender offer subject to Rule 14d-l

☐  issuer tender offer subject to Rule 13e-4

☐  going-private transaction subject to Rule 13e-3

☐  amendment to Schedule 13D under Rule 13d-2

Check the following box if the filing is a final amendment reporting the results of the tender offer.  ☐

If applicable, check the appropriate box(es) below to designate the appropriate rule provision(s) relied upon:

☐  Rule 13e-4(i) (Cross-Border Issuer Tender Offer)

☐  Rule 14d-1(d) (Cross-Border Third-Party Tender Offer)

This filing relates solely to preliminary communications made before the commencement of a tender offer for the outstanding common stock of Zogenix, Inc. (“Zogenix”) by Zinc Merger Sub, Inc. (the “Purchaser”), an indirect wholly owned subsidiary of UCB S.A. (“UCB”), to be commenced pursuant to the Agreement and Plan of Merger dated as of January 18, 2022, among Zogenix, Purchaser and UCB.

Important Information About the Tender Offer

The tender offer described in this document has not yet commenced. This document is for informational purposes only and is neither an offer to purchase nor a solicitation of an offer to sell any shares of the common stock of Zogenix or any other securities, nor is it a substitute for the tender offer materials described herein. At the time the planned tender offer is commenced, a tender offer statement on Schedule TO, including an offer to purchase, a letter of transmittal and related documents, will be filed by UCB and the Purchaser with the Securities and Exchange Commission (the “SEC”), and a solicitation/recommendation statement on Schedule 14D-9 will be filed by Zogenix with the SEC.

INVESTORS AND SECURITY HOLDERS ARE URGED TO READ BOTH THE TENDER OFFER MATERIALS CAREFULLY (INCLUDING AN OFFER TO PURCHASE, A RELATED LETTER OF TRANSMITTAL AND CERTAIN OTHER TENDER OFFER DOCUMENTS) AND THE SOLICITATION/RECOMMENDATION STATEMENT ON SCHEDULE 14D-9 REGARDING THE OFFER, AS THEY MAY BE AMENDED FROM TIME TO TIME, WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION THAT INVESTORS AND SECURITY HOLDERS SHOULD CONSIDER BEFORE MAKING ANY DECISION REGARDING TENDERING THEIR SECURITIES.

Investors and security holders may obtain a free copy of the Offer to Purchase, the related Letter of Transmittal, certain other tender offer documents and the Solicitation/Recommendation Statement (when available) and other documents filed with the SEC at the website maintained by the SEC at www.sec.gov or by directing such requests to the Information Agent for the tender offer, which will be named in the tender offer statement. In addition, Zogenix files annual, quarterly and current reports and other information with the SEC, which is available to the public from commercial document-retrieval services and at the SEC’s website at www.sec.gov. Copies of the documents filed with the SEC by UCB in connection with the tender offer may be obtained at no charge on UCB’s internet website at www.ucb.com or by contacting UCB at Allée de la Recherche, 60, 1070 Brussels, or via phone +32 2 559 99 99.

Copies of the documents filed with the SEC by Zogenix may be obtained at no charge on Zogenix’s internet website at www.Zogenix.com or by contacting Zogenix at 5959 Horton Street, Suite 500, Emeryville, California 94608 or (510) 550-8300.

Forward-Looking Statement of UCB S.A.

This document includes statements that are not statements of historical fact, or “forward-looking statements,” including with respect to UCB’s proposed acquisition of Zogenix. Such forward-looking statements include, but are not limited to, the ability of UCB and Zogenix to complete the transactions contemplated by the merger agreement, including the parties’ ability to satisfy the conditions to the consummation of the offer contemplated thereby and the other conditions set forth in the merger agreement, statements about the expected timetable for completing the transaction, UCB’s and Zogenix’s beliefs and expectations and statements about the benefits sought to be achieved in the proposed acquisition of Zogenix, the potential effects of the acquisition on both UCB and Zogenix, the possibility of any termination of the merger agreement, as well as the expected benefits and success of Zogenix’s product candidates. These statements are based upon the current beliefs and expectations of UCB’s management and are subject to significant risks and uncertainties. There can be no guarantees that the conditions to the closing of the proposed transaction will be satisfied on the expected timetable or at all, with respect to pipeline products, that the products will receive the necessary regulatory approvals or that they will prove to be commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements.

Risks and uncertainties include but are not limited to, uncertainties as to the timing of the offer and the subsequent merger; uncertainties as to how many of Zogenix’s stockholders will tender their shares in the offer; the risk that competing offers or acquisition proposals will be made; the possibility that various conditions to the consummation of the merger and the offer contemplated thereby may not be satisfied or waived; the effects of disruption from the transactions contemplated by the merger agreement and the impact of the announcement and pendency of the transactions on Zogenix’s business; the risk that stockholder litigation in connection with the offer or the merger may result in significant costs of defense, indemnification and liability; the risks related to non-achievement of the CVR milestones and that holders of the CVRs will not receive payments in respect of the CVRs; the global spread and impact of COVID-19, changes in general economic, business and competitive conditions, the inability to obtain necessary regulatory approvals or to obtain them on acceptable terms or within expected timing, costs associated with research and development, changes in the prospects for products in the pipeline or under development by UCB, effects of future judicial decisions or governmental investigations, safety, quality, data integrity or manufacturing issues; potential or actual data security and data privacy breaches, or disruptions of our information technology systems, product liability claims, challenges to patent protection for products or product candidates, competition from other products including biosimilars, changes in laws or regulations, exchange rate fluctuations, changes or uncertainties in tax laws or the administration of such laws and hiring and retention of its employees.

UCB expressly disclaims any obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise, except to the extent required by law.

Exhibit Index

Exhibit No	Description
99.1	Joint Press Release dated January 19, 2022
99.2	Employee Newsflash and News Plaza Article dated January 19, 2022
99.3	U.S. Employee Newsflash dated January 19, 2022
99.4	Employee Town Hall Presentation dated January 19, 2022
99.5	Email to Employees dated January 19, 2022
99.6	Investor Presentation dated January 19, 2022
99.7	Social Media Posts of UCB and its representatives dated January 19, 2022
99.8	Transcript of Jean-Christophe Tellier’s video message to Zogenix employees dated January 19, 2022

EX-99.1

Exhibit 99.1

UCB to acquire Zogenix

• Transaction broadens and builds upon UCB’s role as a leader in, and our continued commitment to, addressing unmet needs of people living with epilepsy, complementing existing medicines and expanding clinical development pipeline of epilepsy and rare disease therapies

• Adds treatment option for specific, vulnerable patient populations with FINTEPLA^® (fenfluramine) C-IV oral solution—approved for seizures associated with Dravet syndrome, with potential in other significant seizure disorders including Lennox-Gastaut syndrome

• Total transaction^* value of up to approximately US$ 1.9 billion / € 1.7 billion. This consists of US$ 26.00 in cash per Zogenix share plus a milestone-based contingent value right for a potential cash payment of US$ 2.00 per share

Brussels (Belgium) and Emeryville, CA (USA), 19 January 2022—Regulated information—Inside information – UCB (Euronext: UCB) and Zogenix (NASDAQ: ZGNX) announced today that the companies have entered into a definitive agreement under which UCB would acquire Zogenix, Inc., a global biopharmaceutical company commercializing and developing therapies for rare diseases. Under the terms of the agreement, UCB will commence a tender offer to purchase all outstanding shares of Zogenix for a purchase price per share of US$ 26.00 in cash at closing, plus a contingent value right (CVR) for a potential cash payment of US$ 2.00 upon EU approval by December 31, 2023, of FINTEPLA^® as an orphan medicine for treatment of Lennox-Gastaut syndrome (LGS). The upfront consideration represents a 72% premium to Zogenix shares based on the 30-day volume weighted average closing stock price of Zogenix prior to signing. The total transaction is valued at up to approximately US$ 1.9 billion / € 1.7 billion.

The board of directors of both companies have unanimously approved the transaction, the closing of which remains subject to the tender of shares representing at least a majority of the total number of Zogenix’s outstanding shares, receipt of required antitrust clearances, and other customary conditions.

The transaction will broaden and build upon UCB’s role as a leader in, and our continued commitment to, addressing unmet needs of people living with specific or rare forms of epilepsy, in particular, adding FINTEPLA^® to UCB’s existing product line. FINTEPLA^® has been approved by the U.S. Food and Drug Administration (FDA)¹ and the European Medicines Agency (EMA)² and is under regulatory review in Japan³, for the treatment of seizures associated with Dravet syndrome in patients two years of age and older. Zogenix is also pursuing indications for the use of FINTEPLA^® in the treatment of seizures associated with additional rare epilepsies, Lennox-Gastaut syndrome (LGS) and CDKL5 Deficiency Disorder (CDD)⁴. Zogenix has submitted a Type II Variation Application to the EMA⁵, and the U.S. FDA recently accepted for filing Zogenix’s supplemental New Drug Application (sNDA)⁶, granting Priority Review, for LGS. Beginning in childhood, Dravet syndrome and Lennox-Gastaut syndrome are two of the most devastating and life-long forms of epilepsy ^7,8,9,10.

“The proposed acquisition of Zogenix reinforces UCB’s sustainable patient value strategy and continued commitment to addressing unmet needs of people living with epilepsy with an increasing focus on those living with specific or rare forms of epilepsy, where few options exist. Complementing UCB’s existing therapeutic offerings, the Zogenix acquisition provides UCB with an approved medicine for a life-threatening, rare infant- and childhood-onset epilepsy marked by frequent and severe treatment-resistant seizures, that are particularly challenging to treat,” said Charl van Zyl, Executive Vice President, Neurology & Head of Europe/International Markets, UCB. “Utilizing our deep expertise, experience and global capabilities, we plan to accelerate access for patients to the treatment. We look forward to welcoming the Zogenix team to UCB, benefiting from their insights and working together to maximize the reach and impact of their medicines for the benefit of as many people as possible.”

“We are delighted to announce UCB’s proposed acquisition of Zogenix, recognizing the value of our lead medicine, both for the important role it has already begun to play for Dravet patients and their caregivers, and for its potential to help many others in the future,” said Stephen J. Farr, PhD, President and Chief Executive Officer of Zogenix. “We are excited for the potential opportunities ahead of us, working together to accelerate our mission and progress to improve the care of patients in need of new therapies. We believe this transaction is in the best interests of both patients and our shareholders.”

Strategic Benefits

• Builds on UCB’s continued epilepsy ambitions: Acquisition provides medicine that complements UCB’s existing symptomatic treatments, bringing significant and differentiated value to patients suffering from Dravet syndrome and, if approved, from seizures associated with Lennox-Gastaut syndrome and potentially other rare epilepsies.

• Expands benefits for patients globally: UCB brings an established global footprint, together with deep research and development, commercial, medical, and regulatory expertise in epilepsy, which will be utilized to rapidly advance and optimize the availability of these new treatments and reach additional patients.

• Enhances future epilepsy pipeline and strategic priorities in rare/orphan diseases: Zogenix’s pipeline will add to UCB’s short-term and long-term epilepsy pipeline, as well as provide critical learnings in rare/orphan disease health ecosystems.

• Enhances UCB’s top-line growth: FINTEPLA^® was launched in the U.S. and Europe in 2020 and has significant potential for usage in other seizure types. It is expected that the proposed acquisition, if completed, will contribute to UCB’s revenue growth upon closing and will be accretive to UCB’s earnings in 2023.

Transaction Terms, Approvals and Time to Closing

Under the terms of the acquisition agreement, UCB, through a wholly-owned subsidiary, Zinc Merger Sub, Inc., will initiate a tender offer to acquire all outstanding shares of Zogenix for a purchase price of US$ 26.00 per share in cash, plus one non-tradeable CVR. The CVR will entitle holders to an additional cash payment of US$ 2.00 per share if a regulatory milestone related to approval of FINTEPLA^® for treatment of seizures associated with Lennox-Gastaut syndrome (LGS) is achieved by or before December 31, 2023. The closing of the tender offer will be subject to certain conditions, including the tender of shares representing at least a majority of the total number of Zogenix’s outstanding shares, receipt of required antitrust clearances, and other customary conditions. Upon the successful completion of the tender offer, UCB’s acquisition subsidiary will be merged into Zogenix, and any remaining shares of common stock of Zogenix will be cancelled and converted into the right to receive the same consideration per share offered in the tender offer. The transaction is expected to close by the end of the second quarter of 2022. There can be no assurance any payments will be made with respect to the CVR.

Financing and Guidance

The acquisition of Zogenix will be financed by a combination of available cash resources and a new term loan. The transaction is not subject to any financing condition. In addition to contributing to UCB’s revenue growth after closing, the acquisition of Zogenix is expected to be accretive to UCB’s earnings from 2023 onwards.

Advisors

Lazard and Barclays are acting as financial advisors to UCB in relation to the transaction. Covington & Burling LLP is acting as legal advisor to UCB on this transaction.

BofA Securities and SVB Leerink are acting as financial advisors to Zogenix on this transaction. Latham & Watkins LLP is acting as legal advisor to Zogenix on this transaction.

UCB Conference call

UCB hosts a Capital Markets Call 19^th January 2022, at 08:30am EST / 13:30 GMT / 14:30 CET. Please register via the UCB Investor Relations website: www.ucb.com/investors

About Dravet Syndrome

Dravet syndrome is a rare, devastating and life-long form of epilepsy that generally begins in infancy and is marked by frequent, treatment-resistant seizures, significant developmental, motor, and behavioral impairments, and an increased risk of sudden unexpected death in epilepsy (SUDEP). Affecting one in 15,700 live births in the U.S. and approximately one in 20,000 to 40,000 live births in Europe, most patients follow a course of developmental delay with cognitive, motor and behavioral deficits that persist into adulthood. Dravet syndrome severely impacts quality of life for patients, families, and caregivers due to the high physical, emotional, caregiving, and financial burden associated with the disease^7,8,9.

About FINTEPLA^® (fenfluramine) C-IV

FINTEPLA^® (fenfluramine) oral solution is a prescription medication used to treat seizures associated with Dravet syndrome in patients two years of age and older ^{11, 12}. FINTEPLA possesses dual activities to inhibit seizures: as a serotonergic agent, acting as a potent 5-HT releaser with agonist activity at 5-HT1D, 2A, and 2C receptors, and as a positive modulator of Sigma1R. FINTEPLA is approved in the U.S. and Europe, and under regulatory review in Japan, for the treatment of seizures associated with Dravet syndrome. The U.S. Food and Drug Administration (FDA) has accepted for filing the company’s supplemental New Drug Application (sNDA) and granted Priority Review for the use of FINTEPLA for the treatment of seizures associated with Lennox-Gastaut syndrome (LGS).

In the United States, FINTEPLA is available only through a restricted distribution program called the FINTEPLA REMS program. FINTEPLA is available in Europe under a controlled access program requested by the European Medicines Agency to prevent off-label use for weight management and to confirm that prescribing physicians have been informed of the need for periodic cardiac monitoring in patients taking FINTEPLA. Further information is available at www.FinteplaREMS.com or by telephone at +1 877 964 3649.

Please see full Prescribing Information, including Boxed Warning, for additional important information on FINTEPLA.

About Lennox-Gastaut Syndrome

Lennox-Gastaut syndrome (LGS) is a rare and devastating lifelong childhood-onset epilepsy that can arise from multiple different causes. LGS is characterized by many different seizure types, including many that result in frequent falls and injuries. The intellectual and behavioral problems associated with LGS, as well as around-the-clock care requirements, add to the complexity of life with this disease¹⁰.

About Zogenix

Zogenix is a global biopharmaceutical company committed to developing and commercializing therapies with the potential to transform the lives of patients and their families living with rare diseases. The company’s first rare disease therapy, FINTEPLA^® (fenfluramine) oral solution, has been approved by the U.S. Food and Drug Administration (FDA) and the European Medicines Agency and is under regulatory review in Japan for the treatment of seizures associated with Dravet syndrome, a rare, severe lifelong epilepsy. The U.S. FDA recently accepted for filing Zogenix’s supplemental New Drug Application (sNDA) and granted Priority Review for the use of FINTEPLA for the treatment of seizures associated with an additional rare epilepsy, Lennox-Gastaut syndrome (LGS). Zogenix is also initiating a study of FINTEPLA in a genetic epilepsy called CDKL5 Deficiency Disorder (CDD) and is collaborating with Tevard Biosciences to identify and develop potential next-generation gene therapies for Dravet syndrome and other genetic epilepsies. The company has an additional late-stage development program, MT-1621, in a mitochondrial disease called TK2 deficiency¹³.

About UCB

UCB, Brussels, Belgium (www.ucb.com) is a global biopharmaceutical company focused on the discovery and development of innovative medicines and solutions to transform the lives of people living with severe diseases of the immune system or of the central nervous system. With more than 8,000 people in approximately 40 countries, the company generated revenue of €5.3 billion in 2020. UCB is listed on Euronext Brussels (symbol: UCB). Follow us on Twitter: @UCB_news.

For further information –

UCB

Investor Relations

Antje Witte

T +32 2 559 94 14 | antje.witte@ucb.com

Media/Corporate Communications

Laurent Schots

T +32 2 559 9264 | laurent.schots@ucb.com

Nick Francis

T +44 7769 307745 | nick.francis@ucb.com

Erica Puntel (U.S. Media)

T +404 938 5359 | erica.puntel@ucb.com

Zogenix

corpcomms@zogenix.com

Investors

Brian Ritchie

Managing Director, LifeSci Advisors LLC

T +1 (212) 915-2578 | britchie@lifesciadvisors.com

Media

Trish McCall, Porter Novelli

T +1 (805) 390 3279 | trish.mccall@porternovelli.com

Important Information About the Tender Offer

The tender offer described in this press release has not yet commenced. This press release is for informational purposes only and is neither an offer to purchase nor a solicitation of an offer to sell any shares of the common stock of Zogenix, Inc. (“Zogenix”) or any other securities, nor is it a substitute for the tender offer materials described herein. At the time the planned tender offer is commenced, a tender offer statement on Schedule (TO), including an offer to purchase, a letter of transmittal and related documents, will be filed by UCB S.A. (“UCB”) and Zinc Merger Sub, Inc., a wholly-owned subsidiary of UCB, with the Securities and Exchange Commission (the “SEC”), and a solicitation/recommendation statement on Schedule 14D-9 will be filed by Zogenix with the SEC.

INVESTORS AND SECURITY HOLDERS ARE URGED TO READ BOTH THE TENDER OFFER MATERIALS CAREFULLY (INCLUDING AN OFFER TO PURCHASE, A RELATED LETTER OF TRANSMITTAL AND CERTAIN OTHER TENDER OFFER DOCUMENTS) AND THE SOLICITATION/RECOMMENDATION STATEMENT ON SCHEDULE 14D-9 REGARDING THE OFFER, AS THEY MAY BE AMENDED FROM TIME TO TIME, WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION THAT INVESTORS AND SECURITY HOLDERS SHOULD CONSIDER BEFORE MAKING ANY DECISION REGARDING TENDERING THEIR SECURITIES.

Investors and security holders may obtain a free copy of the Offer to Purchase, the related Letter of Transmittal, certain other tender offer documents and the Solicitation/Recommendation Statement (when available) and other documents filed with the SEC at the website maintained by the SEC at www.sec.gov or by directing such requests to the Information Agent for the Offer, which will be named in the tender offer statement. In addition, Zogenix files annual, quarterly and current reports and other information with the SEC, which is available to the public from commercial document-retrieval services and at the SEC’s website at www.sec.gov. Copies of the documents filed with the SEC by UCB in connection with the Offer may be obtained at no charge on UCB’s internet website at www.ucb.com or by contacting UCB at Allée de la Recherche, 60 1070 Brussels, Belgium, or Tel: +32 2 559 99 99. Copies of the documents filed with the SEC by Zogenix may be obtained at no charge on Zogenix’s internet website at www.zogenix.com or by contacting Zogenix at 5959 Horton St Fl 5, Emeryville, California, 94608, USA, or Tel: +1 (510) 550 8300.

Forward-Looking Statement of UCB, S.A.

This news release of UCB, S.A., Brussels, Belgium (the “company”) includes statements that are not statements of historical fact, or “forward-looking statements,” including with respect to the company’s proposed acquisition of Zogenix. Such forward-looking statements include, but are not limited to, the ability of the company and Zogenix to complete the transactions contemplated by the merger agreement, including the parties’ ability to satisfy the conditions to the consummation of the offer contemplated thereby and the other conditions set forth in the merger agreement, statements about the expected timetable for completing the transaction, the company’s and Zogenix’s beliefs and expectations and statements about the benefits sought to be achieved in the company’s proposed acquisition of Zogenix, the potential effects of the acquisition on both the company and Zogenix, the possibility of any termination of the merger agreement, as well as the expected benefits and success of Zogenix’s product candidates. These statements are based upon the current beliefs and expectations of the company’s management and are subject to significant risks and uncertainties. There can be no guarantees that the conditions to the closing of the proposed transaction will be satisfied on the expected timetable or at all or that pipeline products will receive the necessary regulatory approvals or that they will prove to be commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements.

Risks and uncertainties include but are not limited to, uncertainties as to the timing of the offer and the subsequent merger; uncertainties as to how many of Zogenix’s shares will be tendered in the offer by Zogenix’s stockholders; the risk that competing offers or acquisition proposals will be made; the possibility that various conditions to the consummation of the offer and the merger may not be satisfied or waived; the effects of disruption from the transactions contemplated by the merger agreement and the impact of the announcement and pendency of the transactions on Zogenix’s business; the risk that stockholder litigation in connection with the offer or the merger may result in significant costs of defense, indemnification and liability; the risks related to non-achievement of the CVR milestones and that holders of the CVRs will not receive payments in respect of the CVRs; the global spread and impact of COVID-19, changes in general economic, business and competitive conditions, the inability to obtain necessary regulatory approvals or to obtain them on acceptable terms or within expected timing, costs associated with research and development, changes in the prospects for products in the

pipeline or under development by UCB, effects of future judicial decisions or governmental investigations, safety, quality, data integrity or manufacturing issues; potential or actual data security and data privacy breaches, or disruptions of our information technology systems, product liability claims, challenges to patent protection for products or product candidates, competition from other products including biosimilars, changes in laws or regulations, exchange rate fluctuations, changes or uncertainties in tax laws or the administration of such laws, and hiring and retention of its employees.

UCB expressly disclaims any obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise, except to the extent required by law.

Forward-Looking Statement of Zogenix, Inc.

Zogenix cautions you that statements included in this press release that are not a description of historical facts are forward-looking statements. Words such as “believes,” “anticipates,” “plans,” “expects,” “indicates,” “will,” “intends,” “potential,” “suggests,” “assuming,” “designed,” and similar expressions are intended to identify forward-looking statements. These statements include: the ability of Zogenix and UCB to complete the transactions contemplated by the merger agreement, including the parties’ ability to satisfy the conditions to the consummation of the offer contemplated thereby and the other conditions set forth in the merger agreement, statements about the expected timetable for completing the transaction, Zogenix’s and UCB’s beliefs and expectations and statements about the benefits sought to be achieved in the transaction, the potential effects of the acquisition on both Zogenix and UCB, the possibility of any termination of the merger agreement, as well as the expected benefits and success of Zogenix’s product candidates. These statements are based on Zogenix’s current beliefs and expectations. The inclusion of forward-looking statements should not be regarded as a representation by Zogenix that any of its plans will be achieved. Actual results may differ from those set forth in this release due to uncertainties as to the timing of the offer and the subsequent merger; uncertainties as to how many of Zogenix’s shares will be tendered in the offer by Zogenix’s stockholders; the possibility that various conditions to the consummation of the offer and the merger may not be satisfied or waived; the effects of disruption from the transactions contemplated by the merger agreement and the impact of the announcement and pendency of the transactions on Zogenix’s business; the risk that stockholder litigation in connection with the offer or the merger may result in significant costs of defense, indemnification and liability; the risks related to non-achievement of the CVR milestones and that holders of the CVRs will not receive payments in respect of the CVRs; the global spread and impact of COVID-19; changes in general economic, business and competitive conditions; and the potential inability to obtain necessary regulatory approvals or to obtain them on acceptable terms or within expected timing. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof, and Zogenix undertakes no obligation to revise or update this press release to reflect events or circumstances after the date hereof. All forward-looking statements are qualified in their entirety by this cautionary statement. This caution is made under the safe harbor provisions of Section 21E of the Private Securities Litigation Reform Act of 1995.

Footnote:

[*Total transaction value fully diluted].

References:

1. FDA News Release. FDA Approves New Therapy for Dravet Syndrome. June 25, 2020.

2. Meeting highlights from the Committee for Medicinal Products for Human Use (CHMP) 12-15 October 2020.

3. Zogenix Press Release. Zogenix Submits New Drug Application for FINTEPLA^® (Fenfluramine) in Japan for the Treatment of Epileptic Seizures Associated with Dravet Syndrome. 21^st December 2021.

4. Zogenix Pipeline Presentation. November 2021.

5. Zogenix Press Release. Zogenix Submits Type II Variation Application to the European Medicines Agency (EMA) to Expand the Use of FINTEPLA^® (Fenfluramine) for the Treatment of Seizures Associated with Lennox-Gastaut Syndrome. 20^th December 2021.

6. Zogenix Press Release. Zogenix Announces U.S. FDA Acceptance for Priority Review of Supplemental New Drug Application for FINTEPLA^® (Fenfluramine) for the Treatment of Seizures Associated with Lennox-Gastaut Syndrome (LGS). 1^st December 2021.

7. Dravet C. The Core Dravet Syndrome Phenotype. Epilepsia. 2011 Apr;52 Suppl 2:3-9. 2.

8. Dravet C. Dravet syndrome history. Dev Med Child Neurol. 2011 Apr;53 Suppl 2:1-6.

9. Wu YW, Sullivan J, McDaniel SS, et al. Incidence of Dravet Syndrome in the US Population. Pediatrics. 2015 Nov;136(5):e1310-1315.

10. National Institute of Neurological Disorders and Stroke. Lennox-Gastaut Syndrome Information Page. Last Accessed January 2022.

11. Fintepla Summary of Product Characteristics. January 2022.

12. Fintepla U.S. Prescribing Information. January 2022.

13. Zogenix Presentation. MT-1621 Virtual Investor Event. November 2021.

EX-99.2

Exhibit 99.2

UCB to acquire Zogenix

UCB has entered into an important agreement to acquire Zogenix, Inc., a global biopharmaceutical company developing therapies for specific or rare forms of epilepsy. When finalized, this acquisition will be a tremendous strategic addition for UCB, broadening and building upon our role as a leader and reinforcing our continued commitment to addressing unmet needs of people living with epilepsy.

Zogenix’s main product is Fintepla^® (fenfluramine) C-IV oral solution, which is approved in the U.S. and in Europe (and under regulatory review in Japan) for the treatment of seizures associated with Dravet syndrome. Dravet syndrome is a rare, severe and life-long form of epilepsy that generally begins in infancy and is marked by frequent, treatment-resistant seizures, significant developmental, motor, and behavioural impairments, and an increased risk of sudden unexpected death in epilepsy (SUDEP). Affecting one in 15,700 live births in the U.S. and approximately one in 20,000 to 40,000 live births in Europe, Dravet syndrome severely impacts quality of life for patients, families, and caregivers due to the high physical, emotional, caregiving, and financial burden associated with the disease.

“I am delighted to announce this proposed acquisition. At UCB it is our purpose to create value for patients, now and into the future, and delivering value in epilepsy remains a priority. A key part of our unified epilepsy strategy is an increased focus on addressing unmet needs of people living with specific or rare forms of epilepsy, where few options exist. The proposed acquisition accelerates this focus, providing an approved medicine for a life-threatening, rare infant- and childhood-onset epilepsy, that is particularly challenging to treat. Upon closing of the transaction, we will utilize our experience and expertise to work with the talented Zogenix team to accelerate access to Fintepla and further its potential to treat other types of rare epilepsies,” said Charl van Zyl.

An additional approval for Fintepla is also being pursued for the treatment of seizures associated with Lennox-Gastaut syndrome; a rare and devastating lifelong childhood-onset epilepsy that can arise from multiple different causes. Lennox-Gastaut syndrome is characterized by many different seizure types, including many that result in frequent falls and injuries.

Zogenix is also initiating a phase 3 study of Fintepla in CDKL5 Deficiency Disorder (CDD) - a rare developmental epileptic encephalopathy caused by mutations in the CDKL5 gene - and has a research collaboration with Tevard Biosciences to identify and develop potential next-generation gene therapies for Dravet syndrome and other genetic epilepsies.

UCB will commence a tender offer to purchase all outstanding shares of Zogenix for a purchase price per share of US$ 26.00 in cash at closing, plus a contingent value right (CVR) for a potential cash payment of US$ 2.00 upon EU approval by December 31, 2023, of Fintepla as an orphan medicine for treatment of Lennox-Gastaut syndrome (LGS). The transaction is valued at up to approximately $1.9 billion / € 1.7 billion.

Under the terms of the definitive merger agreement, the completion of the tender offer is conditioned upon satisfaction or waiver of customary terms and conditions, including a minimum tender condition requiring that the securities tendered in the tender offer represent a majority of the outstanding shares of Zogenix common stock and obtaining required antitrust clearances.

Join the global call today

To hear more about the strategy behind the proposed acquisition and what it brings to UCB, please join us at 3:45PM CET today for a global employee townhall.

Important Information About the Tender Offer

The tender offer described in this communication has not yet commenced. This communication is for informational purposes only and is neither an offer to purchase nor a solicitation of an offer to sell any shares of the common stock of Zogenix, Inc. (“Zogenix”) or any other securities, nor is it a substitute for the tender offer materials described herein. At the time the planned tender offer is commenced, a tender offer statement on Schedule (TO), including an offer to purchase, a letter of transmittal and related documents, will be filed by UCB S.A. (“UCB”) and Zinc Merger Sub, Inc., an indirect wholly-owned subsidiary of UCB, with the Securities and Exchange Commission (the “SEC”), and a solicitation/recommendation statement on Schedule 14D-9 will be filed by Zogenix with the SEC.

INVESTORS AND SECURITY HOLDERS ARE URGED TO READ BOTH THE TENDER OFFER MATERIALS CAREFULLY (INCLUDING AN OFFER TO PURCHASE, A RELATED LETTER OF TRANSMITTAL AND CERTAIN OTHER TENDER OFFER DOCUMENTS) AND THE SOLICITATION/RECOMMENDATION STATEMENT ON SCHEDULE 14D-9 REGARDING THE OFFER, AS THEY MAY BE AMENDED FROM TIME TO TIME, WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION THAT INVESTORS AND SECURITY HOLDERS SHOULD CONSIDER BEFORE MAKING ANY DECISION REGARDING TENDERING THEIR SECURITIES.

Investors and security holders may obtain a free copy of the Offer to Purchase, the related Letter of Transmittal, certain other tender offer documents and the Solicitation/Recommendation Statement (when available) and other documents filed with the SEC at the website maintained by the SEC at www.sec.gov or by directing such requests to the Information Agent for the Offer, which will be named in the tender offer statement. In addition, Zogenix files annual, quarterly and current reports and other information with the SEC, which is available to the public from commercial document-retrieval services and at the SEC’s website at www.sec.gov. Copies of the documents filed with the SEC by UCB in connection with the Offer may be obtained at no charge on UCB’s internet website at

www.ucb.com or by contacting UCB at UCB S.A. Allée de la Recherche, 60. 1070 Brussels or call Belgium Tel +32 2 559 99 99. Copies of the documents filed with the SEC by Zogenix may be obtained at no charge on Zogenix’s internet website at www.Zogenix.com or by contacting Zogenix at 5959 Horton St Fl 5, Emeryville, CA 94608 or call +1 510 550 8300.

Forward-Looking Statement of UCB, S.A.

This communication includes statements that are not statements of historical fact, or “forward-looking statements,” including with respect to UCB’s proposed acquisition of Zogenix. Such forward-looking statements include, but are not limited to, the ability of UCB and Zogenix to complete the transactions contemplated by the merger agreement, including the parties’ ability to satisfy the conditions to the consummation of the offer contemplated thereby and the other conditions set forth in the merger agreement, statements about the expected timetable for completing the transaction, UCB’s and Zogenix’s beliefs and expectations and statements about the benefits sought to be achieved in UCB’s proposed acquisition of Zogenix, the potential effects of the acquisition on both UCB and Zogenix, the possibility of any termination of the merger agreement, as well as the expected benefits and success of Zogenix’s product candidates. These statements are based upon the current beliefs and expectations of UCB’s management and are subject to significant risks and uncertainties. There can be no guarantees that the conditions to the closing of the proposed transaction will be satisfied on the expected timetable or at all, with respect to pipeline products that the products will receive the necessary regulatory approvals or that they will prove to be commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements.

Risks and uncertainties include but are not limited to, uncertainties as to the timing of the offer and the subsequent merger; uncertainties as to how many of Zogenix’s stockholders will tender their shares in the offer; the risk that competing offers or acquisition proposals will be made; the possibility that various conditions to the consummation of the merger and the offer contemplated thereby may not be satisfied or waived; the effects of disruption from the transactions contemplated by the merger agreement and the impact of the announcement and pendency of the transactions on Zogenix’s business; the risk that stockholder litigation in connection with the offer or the merger may result in significant costs of defense, indemnification and liability; the risks related to non-achievement of the CVR milestones and that holders of the CVRs will not receive payments in respect of the CVRs; the global spread and impact of COVID-19, changes in general economic, business and competitive conditions, the inability to obtain necessary regulatory approvals or to obtain them on acceptable terms or within expected timing, costs associated with research and development, changes in the prospects for products in the pipeline or under development by UCB, effects of future judicial decisions or governmental investigations, safety, quality, data integrity or manufacturing issues; potential or actual data security and data privacy breaches, or disruptions of our information technology systems, product liability claims, challenges to patent protection for products or product candidates, competition from other products including biosimilars, changes in laws or regulations, exchange rate fluctuations, changes or uncertainties in tax laws or the administration of such laws, and hiring and retention of its employees.

UCB expressly disclaims any obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise, except to the extent required by law.

EX-99.3

Exhibit 99.3

Subject: UCB to Acquire Zogenix

Dear colleagues,

As you may have seen this morning, we’re pleased to share that UCB has entered into a definitive agreement to acquire Zogenix, Inc., a U.S.-based global biopharmaceutical company commercializing and developing medicines to treat specific or rare forms of epilepsy, including Dravet and Lennox-Gastaut syndromes.

In line with our Breakthrough and Lead strategy, the transaction will broaden and build upon our role as a leader in, and our continued commitment to, addressing unmet needs of people living with epilepsy, where few options exist. The transaction will add to our short-term and long-term epilepsy pipeline, as well as provide critical learnings in orphan disease health ecosystems.

The Zogenix acquisition accelerates this focus, providing UCB with an approved medicine, Fintepla (fenfluramine) oral solution, to treat Dravet syndrome - a severe epilepsy syndrome that has high pediatric mortality rates. Given Priority Review by the FDA, Fintepla is also being pursued to treat Lennox-Gastaut, another epilepsy syndrome that affects children and causes severe cognitive and behavioral impairments - in addition to devastating seizures.

Please join the all company call today at 9:45 am ET (invite sent from Global Communications) to hear more from Jean-Christophe Tellier and Charl van Zyl.

The transaction holds promise as a means for expanding our pipeline in epilepsy and rare disease. Zogenix has built a robust development program, with plans to initiate a Phase 3 study of Fintepla in CDKL5 Deficiency Disorder (CDD) - a rare developmental epileptic encephalopathy caused by mutations in the CDKL5 gene. Zogenix has another early stage therapy, MT1621, that is being explored for Thymidine-Kinase-2 deficiency (TK2d), a mitochondrial depletion syndrome, and is collaborating with Tevard Biosciences to identify and develop potential next-generation gene therapies for Dravet syndrome and other genetic epilepsies.

UCB’s ambition goes beyond symptomatic treatment. We hope to be able to develop solutions that may be able to impact the underlying causes of certain epilepsies and potentially lead to a cure in the future.

As always, we will keep you updated on next steps and developments as we turn to planning and preparations for closing of the acquisition. The transaction remains subject to the receipt of required antitrust clearances and other customary closing conditions, but we are optimistic about the value this transaction will bring to people living with these devastating and complex epilepsy syndromes.

All the best,

Charl van Zyl

Executive Vice President, Neurology Solutions & Head of EU/International

Emmanuel Caeymaex

Executive Vice President, Immunology Solutions & Head of U.S.

Mike Davis

Head of U.S. Neurology

Important Information About the Tender Offer

The tender offer described in this communication has not yet commenced. This communication is for informational purposes only and is neither an offer to purchase nor a solicitation of an offer to sell any shares of the common stock of Zogenix, Inc. (“Zogenix”) or any other securities, nor is it a substitute for the tender offer materials described herein. At the time the planned tender offer is commenced, a tender offer statement on Schedule (TO), including an offer to purchase, a letter of transmittal and related documents, will be filed by UCB S.A. (“UCB”) and Zinc Merger Sub, Inc., an indirect wholly-owned subsidiary of UCB, with the Securities and Exchange Commission (the “SEC”), and a solicitation/recommendation statement on Schedule 14D-9 will be filed by Zogenix with the SEC.

INVESTORS AND SECURITY HOLDERS ARE URGED TO READ BOTH THE TENDER OFFER MATERIALS CAREFULLY (INCLUDING AN OFFER TO PURCHASE, A RELATED LETTER OF TRANSMITTAL AND CERTAIN OTHER TENDER OFFER DOCUMENTS) AND THE SOLICITATION/RECOMMENDATION STATEMENT ON SCHEDULE 14D-9 REGARDING THE OFFER, AS THEY MAY BE AMENDED FROM TIME TO TIME, WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION THAT INVESTORS AND SECURITY HOLDERS SHOULD CONSIDER BEFORE MAKING ANY DECISION REGARDING TENDERING THEIR SECURITIES.

Investors and security holders may obtain a free copy of the Offer to Purchase, the related Letter of Transmittal, certain other tender offer documents and the Solicitation/Recommendation Statement (when available) and other documents filed with the SEC at the website maintained by the SEC at www.sec.gov or by directing such requests to the Information Agent for the Offer, which will be named in the tender offer statement. In addition, Zogenix files annual, quarterly and current reports and other information with the SEC, which is available to the public from commercial document-retrieval services and at the SEC’s website at www.sec.gov. Copies of the documents filed with the SEC by UCB in connection with the Offer may be obtained at no charge on UCB’s internet website at www.ucb.com or by contacting UCB at UCB S.A. Allée de la Recherche 60, 1070 Brussels or call Belgium Tel: +32 2 559 99 99. Copies of the documents filed with the SEC by Zogenix may be obtained at no charge on Zogenix’s internet website at www.Zogenix.com or by contacting Zogenix at 5959 Horton St Fl 5, Emeryville, CA 94608 or call +1 210 550 8300.

Forward-Looking Statement of UCB, S.A.

This communication includes statements that are not statements of historical fact, or “forward-looking statements,” including with respect to UCB’s proposed acquisition of Zogenix. Such forward-looking statements include, but are not limited to, the ability of UCB and Zogenix to complete the transactions contemplated by the merger agreement, including the parties’ ability to satisfy the conditions to the consummation of the offer contemplated thereby and the other conditions set forth in the merger

agreement, statements about the expected timetable for completing the transaction, UCB’s and Zogenix’s beliefs and expectations and statements about the benefits sought to be achieved in UCB’s proposed acquisition of Zogenix, the potential effects of the acquisition on both UCB and Zogenix, the possibility of any termination of the merger agreement, as well as the expected benefits and success of Zogenix’s product candidates. These statements are based upon the current beliefs and expectations of UCB’s management and are subject to significant risks and uncertainties. There can be no guarantees that the conditions to the closing of the proposed transaction will be satisfied on the expected timetable or at all, with respect to pipeline products that the products will receive the necessary regulatory approvals or that they will prove to be commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements.

Risks and uncertainties include but are not limited to, uncertainties as to the timing of the offer and the subsequent merger; uncertainties as to how many of Zogenix’s stockholders will tender their shares in the offer; the risk that competing offers or acquisition proposals will be made; the possibility that various conditions to the consummation of the merger and the offer contemplated thereby may not be satisfied or waived; the effects of disruption from the transactions contemplated by the merger agreement and the impact of the announcement and pendency of the transactions on Zogenix’s business; the risk that stockholder litigation in connection with the offer or the merger may result in significant costs of defense, indemnification and liability; the risks related to non-achievement of the CVR milestones and that holders of the CVRs will not receive payments in respect of the CVRs; the global spread and impact of COVID-19, changes in general economic, business and competitive conditions, the inability to obtain necessary regulatory approvals or to obtain them on acceptable terms or within expected timing, costs associated with research and development, changes in the prospects for products in the pipeline or under development by UCB, effects of future judicial decisions or governmental investigations, safety, quality, data integrity or manufacturing issues; potential or actual data security and data privacy breaches, or disruptions of our information technology systems, product liability claims, challenges to patent protection for products or product candidates, competition from other products including biosimilars, changes in laws or regulations, exchange rate fluctuations, changes or uncertainties in tax laws or the administration of such laws, and hiring and retention of its employees.

UCB expressly disclaims any obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise, except to the extent required by law.

EX-99.4

UCB to acquire Zogenix, Inc. Global Employee Townhall Update Broadening and building on our role as a leader and continued commitment to addressing unmet needs of people living with epilepsy Exhibit 99.4

Important Information About the Tender Offer The tender offer described in this document (the “Offer”) has not yet commenced. This document is for informational purposes only and is neither an offer to purchase nor a solicitation of an offer to sell any shares of the common stock of Zogenix, Inc. (“Zogenix”) or any other securities. At the time the planned tender offer is commenced, a tender offer statement on Schedule TO, including an offer to purchase, a letter of transmittal and related documents, will be filed by UCB (“UCB”) and Zinc Merger Sub, Inc., a wholly owned subsidiary of UCB, with the Securities and Exchange Commission (the “SEC”), and a solicitation/recommendation statement on Schedule 14D-9 will be filed by Zogenix with the SEC. The offer to purchase shares of Zogenix common stock will only be made pursuant to the offer to purchase, the letter of transmittal and related documents filed as a part of the Schedule TO. INVESTORS AND SECURITY HOLDERS ARE URGED TO READ BOTH THE TENDER OFFER STATEMENT AND THE SOLICITATION/ RECOMMENDATION STATEMENT REGARDING THE OFFER, AS THEY MAY BE AMENDED FROM TIME TO TIME, WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION. Investors and security holders may obtain a free copy of these statements (when available) and other documents filed with the SEC at the website maintained by the SEC at www.sec.gov or by directing such requests to the Information Agent for the Offer, which will be named in the tender offer statement. Additional copies of the tender offer materials may be obtained at no charge by contacting UCB. In addition, UCB posts its annual reports in English at ucb.com. Zogenix files annual, quarterly and current reports and other information with the SEC, which is also available to the public at the SEC’s website at www.sec.gov.

Disclaimer Forward-looking statements This presentation contains forward-looking statements, including, without limitation, statements containing the words “believes”, “anticipates”, “expects”, “intends”, “plans”, “seeks”, “estimates”, “may”, “will”, and “continue” and similar expressions, the ability of UCB and Zogenix to complete the transactions contemplated by the merger agreement, including the parties’ ability to satisfy the conditions to the consummation of the offer contemplated thereby and the other conditions set forth in the merger agreement, statements about the expected timetable for completing the transaction, UCB’s and Zogenix’s beliefs and expectations and statements about the benefits sought to be achieved in UCB’s proposed acquisition of Zogenix, the potential effects of the acquisition on both UCB and Zogenix, the possibility of any termination of the merger agreement, as well as the expected benefits and success of Zogenix’s products and product candidates. These statements are based upon the current beliefs and expectations of UCB’s management and are subject to significant risks and uncertainties. There can be no guarantees that the conditions to the closing of the proposed transaction will be satisfied on the expected timetable or at all, or with respect to pipeline products that the products will receive the necessary regulatory approvals or that they will prove to be commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements. Risks and uncertainties include but are not limited to, uncertainties as to the timing of the offer and the subsequent merger; uncertainties as to how many of Zogenix’s stockholders will tender their shares in the offer; the risk that competing offers or acquisition proposals will be made; the possibility that various conditions to the consummation of the merger and the offer contemplated thereby may not be satisfied or waived; the effects of disruption from the transactions contemplated by the merger agreement and the impact of the announcement and pendency of the transactions on Zogenix’s business; the risk that stockholder litigation in connection with the offer or the merger may result in significant costs of defense, indemnification and liability; the risks related to non-achievement of the CVR milestones and that holders of the CVRs will not receive payments in respect of the CVRs; the global spread and impact of COVID-19, changes in general economic, business and competitive conditions, the inability to obtain necessary regulatory approvals or to obtain them on acceptable terms or within expected timing, costs associated with research and development, changes in the prospects for products in the pipeline or under development by UCB, effects of future judicial decisions or governmental investigations, safety, quality, data integrity or manufacturing issues; potential or actual data security and data privacy breaches, or disruptions of our information technology systems, product liability claims, challenges to patent protection for products or product candidates, competition from other products including biosimilars, changes in laws or regulations, exchange rate fluctuations, changes or uncertainties in tax laws or the administration of such laws, and hiring and retention of its employees. UCB expressly disclaims any obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise, except to the extent required by law. In the event of any differences between this Presentation and the Annual or Half Year Report, the information included in the Report shall prevail.

Creating value for patients Breaking News: UCB to acquire Zogenix, Inc. Up to approx 1.9 Billion (Transaction Value) 26.00 in cash per Zogenix share at closing - plus $2.00 CVR tied to a Fintepla regulatory approval milestone in the EU Broadening our role as a leader in epilepsy and the delivery of medicines to patients

Our purpose is to create value for patients now and into the future

Acquiring “possible best in class” treatment option Broadens UCB’s epilepsy offering, adding new patient populations Excellent strategic fit with UCB Creating value for patients Complements epilepsy treatments, enhances pipeline & augments our learnings in rare diseases Contributes to sustainable, long-term company growth Builds on our role as a leader in epilepsy providing patient value for unmet needs

Broadening our our epilepsy ambitions Charl van Zyl, EVP, Neurology Solutions & Head Europe/International Markets

Our Unified Epilepsy Strategy Our ambition is to redefine the future of epilepsy medicine, aspiring to bring even greater value to people living with seizures. Proposed acquisition is consistent with UCB’s sustainable patient value strategy and continued commitment to people living with epilepsy Increasing focus on addressing unmet needs of people living with specific or rare forms of epilepsy, where few options exist. Maximising - existing and future treatments Innovate Science - new areas of science with a focus on specific unmet needs Sustainable Value - driving access in a sustainable way; improve outcomes Digital Health - investments to provide a more holistic level of treatment Four key drivers fuel our unified epilepsy strategy

Our Long Term Vision One day, it is our hope that we can develop solutions that could impact the underlying causes of certain epilepsies and potentially lead to a cure

About Zogenix, Inc. HQ: San Francisco Bay Area, CA (additional operations in Europe; partnership in Japan Employees: 300 + Founded in 2006 Stock listed – NASDAQ: ZGNX) A global pharmaceutical company focused on serious rare diseases (particularly epilepsy)

FINTEPLA® Fenfluramine Oral Solution Under priority regulatory review by U.S. FDA (PDUFA date March 2022) and regulatory review by EMA for the EU Positive global Phase 3 trial results Top-line results announced Q1 2020; long-term efficacy data Q3 2021 Dravet Syndrome Lennox-Gastaut Syndrome 1Risk Evaluation and Mitigation Strategy Approved in U.S. and EU- in 2020 for the treatment of seizures associated with Dravet Syndrome in patients 2 years of age and older (reg review in Japan) Three positive global Phase 3 trials completed (US, EU, JPN) Data published in the Lancet December 2019 Ongoing open label extension has shown robust efficacy results up to three years REMS1 provides additional patient safety through regular screening Launched in U.S. and Germany (cATU authorization in France)

Dravet Syndrome Early Onset About 200-250 infants/year, ~20k patients in both the U.S> and EU5 Highly treatment resistant >70% of patients take three or more antiepileptic drugs >80% of patients are inadequately controlled on traditional AEDs Significant impact Prolonged and frequent generalized convulsive seizures Often fatal (15-20% mortality rate); High seizure frequency; significant developmental and motor impairments 6x higher risk of death, most commonly due to SUDEP (sudden unexpected death in epilepsy) and Status Epilepticus A rare and frequently catastrophic epilepsy Wu YW et al. Pediatrics 20015; Berg AT et al. Epilepsia 2010; Bayat A et al. Epilepsia 2015; Brunklaus A et al. Brain 2012; Dravet C et al. Eurotext 2011; Villas N et al. Epilepsy & Behavior 2017 and Company analysis Picture courtesy of Zogenix

Lennox-Gastaut Syndrome Early onset 60,000-100,000 living with LGS in the U.S. and Europe1 Childhood onset, usually between 2-7 years of age (accounts for ~1-4 % of all cases of childhood epilepsy) 2 Varied causes Significant impact Higher risk of status epilepticus and sudden death; mortality rate 13.9-fold higher than in other children Intellectual, behavioral, and motor disabilities Most patients’ seizures remain uncontrolled on current antiepileptic treatment regimens Rare, highly refractory, and notoriously difficult to treat 1. Zogenix company estimates 2. NORD website https://rarediseases.org/rare-diseases/lennox-gastaut-syndrome/ Accessed Jan 2022 Picture courtesy of Zogenix

Project & Indication Preclinical Phase 1 Phase 2 Phase 3 Regulatory Commercialization 2 Rare, Treatment-Resistant Epilepsies Mitochondrial Depletion Syndromes (MDS) : (fenfluramine) oral solution: Dravet Syndrome Lennox-Gastaut Syndrome (LGS) CDKL5 Deficiency Disorder (CDD) Rare Epilepsies Investigator Initiated Trials Thymidine Kinase 2 Deficiency (TK2d) MT1621 Substrate enhancement therapy sNDA and MAA Type2 Variation submitted FDA & MAA Approved,  Filed in Japan Positive Efficacy Trial Other Rare Epilepsies Phase 3 Trial Other Substrate Enhancement Therapies tRNA based therapies MDS Zogenix Focused Product Pipeline

Thank you A big thank you to all the people that worked tirelessly to get us here today We look forward to working with the team at Zogenix to close the transaction and together deliver on these transformational treatments Reminder: Closing remains subject to obtaining required anti-trust clearances and other customary closing conditions

Thank you for your attention

Agenda TOPIC SPEAKERS Our Purpose Jean-Christophe Tellier, Chief Executive Officer The acquisition of Zorro Charl van Zyl, Neurology Solutions and Head of Europe/International Markets.

EX-99.5

Exhibit 99.5

Dear colleagues,

I hope you had chance to join the global employee town hall today to hear more about the exciting proposed UCB acquisition of Zogenix, Inc. I know you will have many questions, but there is only so much we can share at this stage. However, I wanted to reinforce why this makes sense for us.

In epilepsy, leading from the front remains a priority and core to our patient value strategy. For over 30 years, UCB has focused on providing solutions that have helped to transform the epilepsy treatment landscape, creating leading treatments that have improved the lives of millions of people. We see many more opportunities to deliver patient value in epilepsy, and a significant unmet need remains, especially for those living with specific or rare forms of epilepsy.

We have both short-, and long-term ambitions. In the near term we are focused on maximizing our existing medicines, progressing our digital support solutions in seizure prediction, detection and management, as well as focusing on completing a successful phase 3 program for staccato alprazolam. Longer term, our ongoing early research programs are focused on developing solutions that address unmet needs of people living with specific or rare forms of epilepsy, where few options exist. One day, it is our hope that we can discover, develop and deliver solutions that could even impact the underlying causes of the disease, utilizing for example the promise of gene therapy.

The acquisition of Zogenix would immediately provide an approved medicine for a rare, severe epilepsy – Dravet syndrome - that is particularly challenging to treat. Utilizing our experience and expertise we will work to accelerate and broaden access to this treatment and further develop its potential to treat other rare epilepsies. In addition, Zogenix has already been granted a Priority Review by the FDA for Fintepla’s use in Lennox-Gastaut syndrome, and they have also submitted for approval in Europe. They also have a research and development program looking at other rare epilepsies.

This is why we are excited by this proposed acquisition. The agreement aligns perfectly with our strategy of broadening our role as one of the leaders in treating epilepsy, complementing our existing therapeutic medicines and continued commitment to addressing unmet needs of people living with epilepsy. We can also benefit from Zogenix’s experience in rare diseases, this area being a strategic priority for UCB as we prepare for potential launches in generalized Myasthenia Gravis.

Over the coming weeks we will explain more about our plans for integrating Zogenix into UCB. You will also be hearing more from your regional and local leaders in due course, so you have time to ask questions and find out more.

I’d like to thank all those involved in the transaction for their massive efforts in getting us to this point.

As a reminder, the deal remains subject to obtaining antitrust clearances and other customary closing conditions.

Best wishes

Charl

Executive Vice President, Neurology Solutions & Head of EU/International

Important Information About the Tender Offer

The tender offer described in this communication has not yet commenced. This communication is for informational purposes only and is neither an offer to purchase nor a solicitation of an offer to sell any shares of the common stock of Zogenix, Inc. (“Zogenix”) or any other securities, nor is it a substitute for the tender offer materials described herein. At the time the planned tender offer is commenced, a tender offer statement on Schedule (TO), including an offer to purchase, a letter of transmittal and related documents, will be filed by UCB S.A. (“UCB”) and Zinc Merger Sub, Inc., an indirect wholly-owned subsidiary of UCB, with the Securities and Exchange Commission (the “SEC”), and a solicitation/recommendation statement on Schedule 14D-9 will be filed by Zogenix with the SEC.

INVESTORS AND SECURITY HOLDERS ARE URGED TO READ BOTH THE TENDER OFFER MATERIALS CAREFULLY (INCLUDING AN OFFER TO PURCHASE, A RELATED LETTER OF TRANSMITTAL AND CERTAIN OTHER TENDER OFFER DOCUMENTS) AND THE SOLICITATION/RECOMMENDATION STATEMENT ON SCHEDULE 14D-9 REGARDING THE OFFER, AS THEY MAY BE AMENDED FROM TIME TO TIME, WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION THAT INVESTORS AND SECURITY HOLDERS SHOULD CONSIDER BEFORE MAKING ANY DECISION REGARDING TENDERING THEIR SECURITIES.

Investors and security holders may obtain a free copy of the Offer to Purchase, the related Letter of Transmittal, certain other tender offer documents and the Solicitation/Recommendation Statement (when available) and other documents filed with the SEC at the website maintained by the SEC at www.sec.gov or by directing such requests to the Information Agent for the Offer, which will be named in the tender offer statement. In addition, Zogenix files annual, quarterly and current reports and other information with the SEC, which is available to the public from commercial document-retrieval services and at the SEC’s website at www.sec.gov. Copies of the documents filed with the SEC by UCB in connection with the Offer may be obtained at no charge on UCB’s internet website at www.ucb.com or by contacting UCB at UCB S.A. Allée de la Recherche, 60. 1070 Brussels or call Belgium tel: +32 2 559 99 99. Copies of the documents filed with the SEC by Zogenix may be obtained at no charge on Zogenix’s internet website at www.Zogenix.com or by contacting Zogenix at 5959 Horton St Fl 5, Emeryville, CA 94608 or call +1 510 550 8300.

Forward-Looking Statement of UCB, S.A.

This communication includes statements that are not statements of historical fact, or “forward-looking statements,” including with respect to UCB’s proposed acquisition of Zogenix. Such forward-looking statements include, but are not limited to, the ability of UCB and Zogenix to complete the transactions contemplated by the merger agreement, including the parties’ ability to satisfy the conditions to the consummation of the offer contemplated thereby and the other conditions set forth in the merger agreement, statements about the expected timetable for completing the transaction, UCB’s and Zogenix’s beliefs and expectations and statements about the benefits sought to be achieved in UCB’s proposed acquisition of Zogenix, the potential effects of the acquisition on both UCB and Zogenix, the possibility of any termination of the merger agreement, as well as the expected benefits and success of Zogenix’s product candidates. These statements are based upon the current beliefs and expectations of UCB’s management and are subject to significant risks and uncertainties. There can be no guarantees that the conditions to the closing of the proposed transaction will be satisfied on the expected timetable or at all, with respect to pipeline products that the products will receive the necessary regulatory approvals or that they will prove to be commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements.

Risks and uncertainties include but are not limited to, uncertainties as to the timing of the offer and the subsequent merger; uncertainties as to how many of Zogenix’s stockholders will tender their shares in the offer; the risk that competing offers or acquisition proposals will be made; the possibility that various conditions to the consummation of the merger and the offer contemplated thereby may not be satisfied or waived; the effects of disruption from the transactions contemplated by the merger agreement and the impact of the announcement and pendency of the transactions on Zogenix’s business; the risk that stockholder litigation in connection with the offer or the merger may result in significant costs of defense, indemnification and liability; the risks related to non-achievement of the CVR milestones and that holders of the CVRs will not receive payments in respect of the CVRs; the global spread and impact of COVID-19, changes in general economic, business and competitive conditions, the inability to obtain necessary regulatory approvals or to obtain them on acceptable terms or within expected timing, costs associated with research and development, changes in the prospects for products in the pipeline or under development by UCB, effects of future judicial decisions or governmental investigations, safety, quality, data integrity or manufacturing issues; potential or actual data security and data privacy breaches, or disruptions of our information technology systems, product liability claims, challenges to patent protection for products or product candidates, competition from other products including biosimilars, changes in laws or regulations, exchange rate fluctuations, changes or uncertainties in tax laws or the administration of such laws, and hiring and retention of its employees.

UCB expressly disclaims any obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise, except to the extent required by law.

EX-99.6

UCB to Acquire Zogenix Capital Markets Conference Call 19 January 2022 Committed to Improving Lives of People Living with Epilepsy Exhibit 99.6

Important Information About the Tender Offer The tender offer described in this document (the “Offer”) has not yet commenced. This document is for informational purposes only and is neither an offer to purchase nor a solicitation of an offer to sell any shares of the common stock of Zogenix, Inc. (“Zogenix”) or any other securities. At the time the planned tender offer is commenced, a tender offer statement on Schedule TO, including an offer to purchase, a letter of transmittal and related documents, will be filed by UCB S.A. (“UCB”) and Zinc Merger Sub, Inc., a wholly owned subsidiary of UCB, with the Securities and Exchange Commission (the “SEC”), and a solicitation/recommendation statement on Schedule 14D-9 will be filed by Zogenix with the SEC. The offer to purchase shares of Zogenix common stock will only be made pursuant to the offer to purchase, the letter of transmittal and related documents filed as a part of the Schedule TO. INVESTORS AND SECURITY HOLDERS ARE URGED TO READ BOTH THE TENDER OFFER STATEMENT AND THE SOLICITATION/ RECOMMENDATION STATEMENT REGARDING THE OFFER, AS THEY MAY BE AMENDED FROM TIME TO TIME, WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION. Investors and security holders may obtain a free copy of these statements (when available) and other documents filed with the SEC at the website maintained by the SEC at www.sec.gov or by directing such requests to the Information Agent for the Offer, which will be named in the tender offer statement. Additional copies of the tender offer materials may be obtained at no charge by contacting UCB at Allée de la Recherche 60, 1070 Brussels, Belgium, or Tel: +32 2 559 99 99. In addition, UCB posts its annual reports in English at ucb.com. Zogenix files annual, quarterly and current reports and other information with the SEC, which is also available to the public at the SEC’s website at www.sec.gov.

Disclaimer Forward-Looking Statements This presentation contains forward-looking statements, including, without limitation, statements containing the words “believes”, “anticipates”, “expects”, “intends”, “plans”, “seeks”, “estimates”, “may”, “will”, and “continue” and similar expressions, the ability of UCB and Zogenix to complete the transactions contemplated by the merger agreement, including the parties’ ability to satisfy the conditions to the consummation of the offer contemplated thereby and the other conditions set forth in the merger agreement, statements about the expected timetable for completing the transaction, UCB’s and Zogenix’s beliefs and expectations and statements about the benefits sought to be achieved in UCB’s proposed acquisition of Zogenix, the potential effects of the acquisition on both UCB and Zogenix, the possibility of any termination of the merger agreement, as well as the expected benefits and success of Zogenix’s products and product candidates. These statements are based upon the current beliefs and expectations of UCB’s management and are subject to significant risks and uncertainties. There can be no guarantees that the conditions to the closing of the proposed transaction will be satisfied on the expected timetable or at all, or with respect to pipeline products that the products will receive the necessary regulatory approvals or that they will prove to be commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements. Risks and uncertainties include but are not limited to, uncertainties as to the timing of the offer and the subsequent merger; uncertainties as to how many of Zogenix’ stockholders will tender their shares in the offer; the risk that competing offers or acquisition proposals will be made; the possibility that various conditions to the consummation of the merger and the offer contemplated thereby may not be satisfied or waived; the effects of disruption from the transactions contemplated by the merger agreement and the impact of the announcement and pendency of the transactions on Zogenix’s business; the risk that stockholder litigation in connection with the offer or the merger may result in significant costs of defense, indemnification and liability; the risks related to non-achievement of the CVR milestones and that holders of the CVRs will not receive payments in respect of the CVRs; the global spread and impact of COVID-19, changes in general economic, business and competitive conditions, the inability to obtain necessary regulatory approvals or to obtain them on acceptable terms or within expected timing, costs associated with research and development, changes in the prospects for products in the pipeline or under development by UCB, effects of future judicial decisions or governmental investigations, safety, quality, data integrity or manufacturing issues; potential or actual data security and data privacy breaches, or disruptions of our information technology systems, product liability claims, challenges to patent protection for products or product candidates, competition from other products including biosimilars, changes in laws or regulations, exchange rate fluctuations, changes or uncertainties in tax laws or the administration of such laws, and hiring and retention of its employees. UCB expressly disclaims any obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise, except to the extent required by law. In the event of any differences between this Presentation and the Annual or Half Year Report, the information included in the Report shall prevail.

UCB is Progressing on its Strategic Growth Path Jean-Christophe Tellier, CEO UCB and Zogenix Serving People Living with Epilepsy Charl van Zyl, EVP Head of Neurology Epilepsy – Dravet Syndrome and Lennox-Gastaut Syndrome Iris Loew-Friedrich, CMO Transaction Terms, Funding & Timing Sandrine Dufour, CFO Q&A Information Flow

UCB is Progressing on its Strategic Growth Path Jean-Christophe Tellier, CEO

UCB Is Progressing On Its Strategic Growth Path Identify & Act On Potential New Opportunities Builds upon UCB’s role as a leader and continued commitment to addressing the unmet needs of people living with epilepsy Strategic Missions Zogenix Acquisition Sustainable company growth Provide sustainable patient value, lead in specific patient populations Option for new specific, vulnerable patient populations with Fintepla® (fenfluramine) oral solution Addressing rare/orphan diseases After closing: Enhances UCB’s revenue growth Accretive to UCB’s earnings from 2023 onwards

2019 HY report - *fully diluted UCB Recognized as a leader in epilepsy with core competencies, key strategic focus and differentiated portfolio UCB’s commitment To bring tailored treatments to specific populations, incl. rare epilepsies and genetic epilepsies Strong Strategic Fit FINTEPLA®: Fenfluramine oral solution in Dravet Syndrome (approved) and Lennox-Gastaut Syndrome - LGS (filed) Consideration US$ 26.00 per share at closing Plus a CVR for a potential cash payment of US$ 2.00 per share based on EU LGS approval for FINTEPLA® designated as an orphan medicine, by 31 Dec. 2023 Total* = up to US$ 1.9bn equity value / € 1.7bn Funding US$ 800m new term loan and available cash sources Timing Approved by boards of directors of both companies Closing expected by end of Q2 2022 Subject to completion of tender offer for acquisition of majority of shares, antitrust clearance, incl. HSR, and other customary closing conditions Financial Impact Enhances UCB’s revenue growth (after closing) Accretive to UCB’s earnings from 2023 onwards CVR: contingent value rights; HSR: Hart-Scott-Rodino Antitrust Improvements Act

UCB and Zogenix Serving People Living with Epilepsy Charl van Zyl, EVP Head of Neurology Jerome, living with epilepsy

UCB: Over 20 Years of R&D Expertise and Commercial Success Enrolled >25 000 patients in >250 clinical studies for more than 10 epilepsy conditions Current phase 3 program: Staccato alprazolam in active epileptic seizures New indications by innovative clinical development-extrapolation 2021: > 3 million patients used Keppra®, Vimpat®, Briviact® or Nayzilam® 2021: Briviact® approved in the U.S. for the treatment of partial-onset seizures in children as young as one month of age, first IV formulation of an anti-seizure medication available for this age group since Keppra® in 2014 UCB stand alone countries UCB/Partner countries Over 40 countries Source: UCB database – like Nile, Stanford HealthCare, Microsoft,… Strong commitment to people living with epilepsy underlined by strong partnerships*

UCB’s Epilepsy Strategy Delivering Value for Patients Our ambition is to redefine the future of epilepsy medicine, aspiring to bring even greater value to people living with seizures Utilizing our experience and expertise to develop new differentiated medicines and technology support solutions that address specific unmet patient needs Increasing focus on certain specialized or rare types of epilepsy Maximising our existing and future treatments Pioneering new areas of science with a focus on unmet needs Creating sustainable value in care Four key drivers fuel our long-term ambition Investing in digital health technology to provide a more holistic level of treatment

Zogenix, Inc.: Committed to Innovative Therapies Helping Those Most in Need: Children Living with Dravet Syndrome and Other Rare Neurologic Indications HQ: San Francisco Bay Area, CA/USA Employees: 200+¹ Founded in 2006 Stock listed since 2011 – ticker: ZGNX Lead product FINTEPLA® fenfluramine oral solution Orphan drug designation in US/EU/JPN for Dravet Syndrome Approved in the U.S. and Europe for the treatment of Dravet Syndrome* Launched in U.S. and Germany (cATU authorization in France) Under regulatory review in Japan Under U.S. priority review & EU review for the treatment of seizures associated with Lennox-Gastaut Syndrome Under development for the treatment of seizures associated with other rare, difficult-to-treat epilepsies Source: Zogenix 1) as of May 2021*as an add-on therapy to other anti-epileptic medicines for patients two years of age and older

Excellent Strategic Fit with UCB Augments UCB’s Offering by Adding New Patient Populations Contributes to sustainable, long-term company growth Creating value for patients Enhances epilepsy offering & rare diseases priorities Builds on UCB’s focus on epilepsy and ambitions to bring even greater value to people living with seizures Acquires "possible best in class" treatment option

Jerome, living with epilepsy Epilepsy – Dravet Syndrome and Lennox-Gastaut Syndrome Iris Loew-Friedrich, CMO

Evolving from broad to specific populations according to patient needs and disease biology Paradigm Shift From Suppression of Seizures to Disease Modification Sources: Semah et al; Is the underlying cause of epilepsy a major prognostic factor for recurrence, Neurology (51) 1256-1262, 1998 Brenner et al; Prevalence of neurologic autoantibodies in cohorts of patients with new and established epilepsy, Epilepsia, 54(6),1028–1035, 2013 www.orpha.net (data on syndromes) www.epilepsydiagnosis.org (ILAE data on classification of seizures) Combined focal and generalized JME Absence Unknown etiology (Normal MRI) Hippocampal Sclerosis Acute Seizure Therapy / Prodromes Vascular malformations Tumoral Post-traumatic Focal cortical Dyplasia Cerebro-vascular disease / post-stroke Autoimmune epilepsy Infantile Spasms TSC Generalized/ Combined Focal Syndromes Mixed Lennox-Gastaut Syndrome Dravet Medically Controllable 70% Drug Resistant 30% Paradigm shift for disease treatment in epilepsy Suppression of seizures Targeting molecular disease mechanisms towards disease modification Suppression of seizures in Broad Epilepsy Population (~65 Million) TODAY Focus on mortality reduction in High Need Specific Populations of Epilepsy FUTURE Not to scale or Exhaustive, multiple sources. Drug resistant (DR) is not achieving seizure freedom ≥1 year PRN, pro re nata; JME, juvenile myoclonic epilepsy; TSC, tuberous sclerosis DEE – Developmental and Epileptic Encephalopathy Epilepsy Other DEE Genetic or developmental or metabolic etiology and childhood onset

Dravet Syndrome A Rare and Often Fatal Epilepsy with Early Onset Early onset About 200-250 infants/year; ~20k patients in both the U.S. and EU5 Most cases are due to severe SCN1A gene mutations (90% de novo) Onset in the 1st year of life in an otherwise healthy infant Highly treatment resistant Rare, drug-resistant epilepsy, >80% remain refractory >70% of patients take three or more antiepileptic drugs Significant impact on people living with Dravet Syndrome Prolonged and frequent generalized convulsive seizures Often fatal, lifelong form of epilepsy with 15-20% mortality rate; 6x higher risk of death, most commonly due to sudden unexpected death in epilepsy Symptoms include cognitive & motor impairment, language and speech issues Multidisciplinary team and early developmental assessment needed to address the many ways Dravet syndrome can affect a child and their family Wu YW et al. Pediatrics 20015; Berg AT et al. Epilepsia 2010; Bayat A et al. Epilepsia 2015; Brunklaus A et al. Brain 2012; Dravet C et al. Eurotext 2011; Villas N et al. Epilepsy & Behavior 2017; and information according to Zogenix analyses

FINTEPLA® Fenfluramine Oral Solution Positive global Phase 3 trial results Top-line results announced Q1 2020; long-term efficacy data Q3 2021 Under priority regulatory review by U.S. FDA (PDUFA date March 2022) and regulatory review by EMA for the EU Dravet Syndrome Lennox-Gastaut Syndrome 1Risk Evaluation and Mitigation Strategy Approved in U.S. and EU in 2020 for the treatment of seizures associated with Dravet Syndrome in patients 2 years of age and older Three positive global Phase 3 trials completed (US, EU, JPN) Data published in the Lancet December 2019 Ongoing open label extension has shown robust efficacy results up to three years REMS1 provides additional patient safety through regular screening

Lennox-Gastaut Syndrome (LGS) A Rare Syndrome in Epilepsy with Childhood-Onset* Early onset 60,000-100,000 living with LGS in the U.S. and Europe Caused by injuries, brain malformations, infections, genetic factors; unknown cause in 25% of cases Childhood onset, accounts for ~1- 4% of all cases of childhood epilepsy Highly treatment resistant Most (>80%) patients’ seizures remain uncontrolled on current antiepileptic treatment regimens Significant impact on people living with LGS Higher risk of status epilepticus and sudden death; mortality rate 13.9-fold higher than in other children Intellectual, behavioural, and motor disabilities; >50% suffer from LGS Associated Disorders (LAD) including communication, balance or behavioural issues, sleep disturbances, rage attacks, aggression, autistic features, and other issues A multidisciplinary team and early developmental assessment are needed to address the many ways LGS can affect a child and their family *All data derived from Zogenix or patient organizations.

Transaction Terms, Funding & Timing Sandrine Dufour, CFO

Terms Upon Closure of the Transaction Compelling Value Proposition for all Stakeholders Consideration Zogenix’ shareholders to receive US$ 26 per share in cash at closing Plus a CVR for a potential cash payment of US$ 2.00 per share based on EU LGS approval for FINTEPLA® designated as an orphan medicine, by 31 Dec. 2023 Total1 transaction value (incl. CVR) of up to ~US$ 1.9bn / ~€ 1.7bn Timing Transaction approved by Boards of both companies Transaction subject to completion of tender offer (with tender by holders of majority of Zogenix shares), antitrust clearances2 and other customary closing conditions Closing expected by end of Q2 2022 Funding Financing out of US$ 800m new term loan and available cash sources UCB maintains strategic balance sheet flexibility Financial Impact Enhances UCB’s top line growth (after closing) Accretive to UCB’s earnings from 2023 onwards CVR: contingent value rights; LGS: Lennox-Gastaut Syndrome 1 fully diluted; 2 including Hart-Scott-Rodino Antitrust Improvements Act clearance

Excellent Strategic Fit with UCB Combining Forces to Better Serve People Living with Epilepsy Maximizes impact of UCB’s and Zogenix’s teams and infrastructure, expertise and experience Strengthens epilepsy offering and rare diseases at UCB Maximizes addressable patient population Integration* under preparation Enhances UCB’s top line growth* Accretive to UCB’s earnings from 2023 onwards* UCB maintains strategic balance sheet flexibility Creating value for patients *after closing

Q&A Antje Witte, Head of Investor Relations

EX-99.7

Exhibit 99.7

UCB US Twitter post:For Media: UCB has entered into a definitive agreement to acquire @Zogenix. This broadens and builds upon UCBs role as a leader in, and our continued commitment to, addressing the unmet needs of people living with #epilepsy. #DravetSyndrome #Dravet https://www.ucb-usa.com/stories-media/UCB-U-S-News/detail/article/ucb-acquire-zogenixUCB US@UCBUSAFor Media: UCB has entered into a definitive agreement to acquire @Zogenix. This broadens and builds upon UCBs role as a leader in, and our continued commitment to, addressing the unmet needs of people living with #epilepsy. #DravetSyndrome #DravetUcb Inspired by patients.Driven by science.Ucb-usa.comRead more7:00 AM Jan 19, 2022 Twitter for Advertisers

UCB News Twitter post:For media. Today we announced our entry into a definitive agreement to acquire Zogenix, a global biopharmaceutical company commercializing and developing rare epilepsy therapies. Learn more:https://https://t.co/2quQR787KWUCB News@ucb_newsFor media. Today we announced our entry into a definitive agreement to acquire Zogenix, a global biopharmaceutical company commercializing and developing rare epilepsy therapies. Learn more:ucb.com/stories-media/&Ucb Inspired by patients.Driven by science.1:16 Am Jan 19, 2022 Twitter Web App

EX-99.8

Exhibit 99.8

Dear all,

Many thanks for giving me the opportunity to say hello to all of you on what is an important day for both companies. Unfortunately, I’m not able to join you live during your meeting, but I’m sure we will have occasions in the future to do so.

I’m excited that UCB and Zogenix have agreed to enter into an agreement for UCB to acquire Zogenix because I believe we share your passions to drive, discover and develop differentiated solutions to help patients suffering from very severe forms of epilepsy.

So, this is today an important milestone for UCB and I’m looking forward to working with you to create even more value for these patients.

Like you, we saw the potential in Fintepla^® and I’m convinced that in working with UCB we can deliver even more for Fintepla^® and create even more value for patients in need.

I know that this is a very important change for you and I expect that you are leaving today feeling a lot of mixed emotions. But we will get to know each other and I hope that through the dialogue you will be able to know more about us, you will be able to get more confidence, and we will be able to answer your questions along the road.

Now a few words about UCB. We are a purpose-driven company. Everything we do is with the aim to create value for patients and their families now and in the future. Our purpose is really embedded into our strategy. Patients and individual experiences are at the heart of everything we do and I understand that we have this in common.

We believe very strongly that a successful future must deliver value for all: people living with severe diseases, their family, colleagues, community, planet, stakeholders and shareholders. Because at the end, it doesn’t make sense to create value for patients if this is at the expense of others. So, yes, sustainability is an integrate part of our strategy. We have a highly collaborative environment, we want everyone to thrive at UCB, to contribute to our journey, to be part of our communities. So, yes, we are looking forward to welcoming you in our organisation after the closing. So, once again, welcome and looking forward to seeing you in the near future at Emeryville. Thank you.