Zogenix Receives Positive CHMP Opinion for FINTEPLA® (Fenfluramine) Oral Solution for the Treatment of Seizures in Patients with Dravet Syndrome

Zogenix Receives Positive CHMP Opinion for FINTEPLA®

(Fenfluramine) Oral Solution for the Treatment of Seizures in

Patients with Dravet Syndrome

• Dravet syndrome is a rare, life-long, infant- and childhood-onset epilepsy associated

with severe, treatment-resistant seizures

• CHMP positive opinion based on Phase 3 study data that demonstrated FINTEPLA®

significantly reduced convulsive seizure frequency in patients whose seizures were

not adequately controlled on other medications, including stiripentol

• Final decision on Marketing Authorization Application expected by year-end 2020

EMERYVILLE, Calif., Oct. 16, 2020 – Zogenix (NASDAQ: ZGNX), a global

biopharmaceutical company developing rare disease therapies, today announced that the

Committee for Medicinal Products for Human Use (CHMP), a part of the European

Medicines Agency (EMA), has adopted a positive opinion recommending the marketing

authorization of FINTEPLA® (fenfluramine) oral solution for the treatment of seizures

associated with Dravet syndrome, a rare and devastating infant- and childhood onset

epilepsy, as an add-on therapy to other antiepileptic medicines for patients two years of age

and older. The European Commission (EC) is expected to make a final decision on the

company’s Marketing Authorization Application (MAA) by the end of the year.

“We are pleased that the CHMP’s regulatory review of FINTEPLA for quality, safety, and

efficacy has resulted in their positive opinion,” said Stephen J. Farr, Ph.D., President and

CEO of Zogenix. “We began our rigorous global development program for FINTEPLA nearly

six years ago after researchers in Belgium recognized the potential of fenfluramine, a drug

with distinct pharmacology from all other anticonvulsant agents, to treat intractable seizures

in Dravet syndrome. Many Dravet syndrome patients continue to experience frequent severe

seizures even while taking one or more currently available anti-seizure medications. For this

reason, we are excited to be another step closer to potentially introducing FINTEPLA as an

important new treatment option for these patients and their families in Europe.”

“Reducing seizure frequency is the first and most important step in treating all Dravet

syndrome children, regardless of age,” said Lieven Lagae, M.D, Ph.D., Full Professor and

Head of Pediatric Neurology Department at the University Hospitals of Leuven in Belgium. “I

am thrilled that all Phase 3 studies with fenfluramine demonstrated a clinically meaningful,

highly statistically significant decrease of seizure frequency in Dravet syndrome patients.”

The MAA for FINTEPLA included positive results from two randomized, controlled Phase 3

trials (Study 1 and Study 2), together with an interim analysis of an ongoing long-term, openlabel

extension study involving a total of 330 Dravet syndrome patients. These studies

demonstrated that adjunctive fenfluramine treatment provided a highly statistically significant

and clinically meaningful reduction in convulsive seizure frequency compared to placebo and

was generally well-tolerated. In one of the trials, Study 2, all subjects were treated with a

background regimen that included stiripentol, with significant improvement observed for

FINTEPLA over placebo. The long-term, open-label extension study demonstrated durable efficacy, with patients in that study treated for up to three years with FINTEPLA. The most

commonly reported adverse events experienced during these studies were decreased

appetite, diarrhea, pyrexia, fatigue, upper respiratory tract infection, lethargy, somnolence

and bronchitis.1,2,3 No patient developed any cardiovascular adverse events, including

valvular heart disease or pulmonary arterial hypertension.

If authorized by the EC, FINTEPLA will be approved for use by patients with Dravet

syndrome aged two years and older in all European Union member states, as well as the

United Kingdom, Iceland, Liechtenstein and Norway. The product is expected to be made

available under a controlled access program to ensure regular cardiac monitoring and to

mitigate potential off-label use for weight management.

Earlier this year, FINTEPLA was approved by the U.S. Food & Drug Administration (FDA) for

the treatment of seizures associated with Dravet syndrome in patients aged two years and

older. A third positive Phase 3 clinical trial (Study 3) was recently reported to support

registration of FINTEPLA in Japan.

About Dravet Syndrome

Dravet syndrome is a rare, devastating and life-long form of epilepsy that 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.

Affecting one in 15,700 individuals in the U.S. and approximately one in 20,000 to 40,000 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, and financial

burden associated with the disease.4,5,6,7

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. FDA and has received a positive

CHMP opinion in Europe for the treatment of seizures associated with Dravet syndrome, a

rare, severe childhood onset epilepsy in patients aged two and older. The company has two

additional late-stage development programs underway: one for FINTEPLA for the treatment

of seizures associated with Lennox-Gastaut syndrome, a different rare childhood-onset

epilepsy and another for MT1621, an investigational novel substrate enhancement therapy

for the treatment of TK2 deficiency, a rare genetic disorder. MT1621 is being developed

through Modis Therapeutics, a Zogenix company.

Forward-Looking Statement

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 potential that FINTEPLA, if approved by the EC, will be an

important new treatment option for Dravet syndrome patients; and the timing and results of

any decision regarding the MAA for FINTEPLA for the treatment of seizures associated with

Dravet syndrome. 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 the risks and uncertainties inherent in Zogenix’s

business, including, without limitation: the EC may not agree with the Company’s

interpretation of the clinical data submitted in the MAA; the EC may not affirm the CHMP

opinion and grant a centralized marketing authorization; additional data from Zogenix’s

ongoing studies may contradict or undermine the data submitted in the Dravet syndrome

MAA for FINTEPLA or reported for LGS; unexpected adverse side effects or inadequate

therapeutic efficacy of FINTEPLA that could limit approval and/or commercialization, or that

could result in recalls or product liability claims; and other risks described in Zogenix’s prior

press releases as well as in public periodic filings with the U.S. Securities & Exchange

Commission. 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.

CONTACTS:

Zogenix

Melinda Baker

Senior Director, Corporate Communications

+1 (510) 788-8732 | corpcomms@zogenix.com

Investors

Brian Ritchie

Managing Director, LifeSci Advisors LLC

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

Media

In Europe: Kerry Lloyd-Jones, Account Director, Porter Novelli

+44 (0) 7949 794 290 | kerry.lloyd-jones@porternovelli.co.uk

In the US: Stefanie Tuck, Vice President, Porter Novelli

+1 (978) 390-1394 | stefanie.tuck@porternovelli.com

¹ Lagae L, Sullivan J, Knupp K, et al. Fenfluramine hydrochloride for the treatment of seizures in Dravet

syndrome: a randomised, double-blind, placebo-controlled trial. Lancet. 2020;394:2243-2254.

² Nabbout R, Mistry A, Zuberi S, et al. Fenfluramine for treatment-resistant seizures in patients with Dravet

syndrome receiving stiripentol-inclusive regimens. JAMA Neurol. 2020;77:300-308.

³ Sullivan J, Auvin S, Pringsheim M, et al. Long-term (2-year) safety and efficacy of adjunctive ZX008

(fenfluramine hydrochloride oral solution) for Dravet syndrome: Interim results of an ongoing open-label

extension study. Originally scheduled for presentation at the cancelled American Academy of Neurology 2020

Annual Meeting. Program number S31.007.

4 Aras LM, Isla J, Mingorance-Le Meur A. The European patient with Dravet syndrome: results from a parentreported

survey on antiepileptic drug use in the European population with Dravet syndrome. Epilepsy Behav.

2015;44:104-9.

5 Lagae L, Brambilla I, Mingorance A, et al. Quality of life and comorbidities associated with Dravet syndrome

severity: a multinational cohort survey. Dev Med Child Neurol. 2018;60:63-72.

6 Sullivan J, Knupp K, Wirrel E. Rare disease database: Dravet syndrome. National Organization of Rare

Diseases. Available at: https://rarediseases.org/rare-diseases/dravet-syndrome-spectrum/. Last updated: 2018.

Last accessed: September 2020.

7 Villas N, Meskis MA, Goodliffe S. Dravet syndrome: characteristics, comorbidities, and caregiver concerns.

Epilepsy Behav. 2017;74:81-86.