A Study to Investigate the Efficacy and Safety of ZX008 in Subjects With CDKL5 Deficiency Disorder

  • End date
    May 29, 2024
  • participants needed
  • sponsor
    Zogenix, Inc.
Updated on 29 May 2022


This is a multicenter, double-blind, parallel-group, placebo controlled, 2-part study to evaluate the efficacy and safety of ZX008 when used as adjunctive therapy for the treatment of uncontrolled seizures in children and adults with cyclin-dependent kinase like-5 (CDKL5) deficiency disorder (CDD).


This is a 2-part multicenter trial. Part 1 is a 20-week randomized, double-blind, placebo-controlled, fixed-dose, parallel-group study to examine the efficacy and safety of ZX008 as an adjunctive therapy (to existing concomitant treatment with antiepileptic treatments [AETs]) in children and adults with a CDD diagnosis and uncontrolled seizures.

Part 1 of the study is 20 weeks in duration and will consist of the following stages: Baseline Period (ie, Baseline [BL]; 4 weeks including the Screening Visit and baseline observation), Titration Period (ie, Titration; 2 weeks), Maintenance Period (ie, Maintenance; 12 weeks), and a 2-week Transition Period (ie, Transition; 2 weeks) to the open-label starting dose.

Part 2 is a 54-week, open-label, flexible-dose, long-term extension for subjects who complete Part 1. Part 2 includes an Open-Label Extension (OLE) Treatment Period (52 weeks) with a Taper Period (ie, Taper; 2 weeks).

The primary study analysis to evaluate the efficacy and safety of ZX008 in children and adults with CDD will be based on Part 1 data in all randomized subjects.

Condition CDKL5 Deficiency Disorder, Generalized Tonic Clonic Seizure, Epileptic Spasm, Refractory Seizures
Treatment ZX008 (Fenfluramine Hydrochloride), Matching ZX008 Placebo
Clinical Study IdentifierNCT05064878
SponsorZogenix, Inc.
Last Modified on29 May 2022


Yes No Not Sure

Inclusion Criteria

Subject has a confirmed pathogenic or likely pathogenic mutation in the CDKL5 gene and a clinical diagnosis of CDD with epilepsy onset in the first year of life, plus motor and developmental delays
Subject is male or female, aged 1 to 35 years, inclusive, as of the day of the Screening Visit
Subject must have failed to achieve seizure control despite previous or current use of 2 or more AETs
Subject is currently receiving at least 1 concomitant antiseizure treatment: antiseizure medication (ASM), vagus nerve stimulation (VNS), responsive neurostimulation (RNS), or ketogenic diet (KD)
All medications or interventions for epilepsy (including VNS, RNS, and KD) must be stable prior to screening and are expected to remain stable throughout the study
At the Screening Visit, parent/caregiver reports that subject has ≥ 4 countable motor seizures(CMS) per week

Exclusion Criteria

Subject has a known hypersensitivity to fenfluramine or any of the excipients in the study drug
Subject has a diagnosis of pulmonary arterial hypertension
Subject has a clinically significant medical condition, including chronic obstructive pulmonary disease, interstitial lung disease, or portal hypertension, or has had clinically relevant symptoms or a clinically significant illness currently or in the 4 weeks prior to the Screening Visit, other than epilepsy, that would negatively impact study participation, collection of study data, or pose a risk to the subject
Subject has current or past history of cardiovascular or cerebrovascular disease, such as cardiac valvulopathy, myocardial infarction or stroke, severe ventricular arrhythmias, or clinically significant structural cardiac abnormality, including but not limited to mitral valve prolapse, atrial or ventricular septal defects, patent ductus arteriosus, and patent foramen ovale with reversal of shunt. (Note: Patent foramen ovale or a bicuspid aortic valve are not considered exclusionary)
Subject has moderate to severe hepatic impairment
Subject has current eating disorder that suggests anorexia nervosa or bulimia
Subject has a current or past history of glaucoma
Subject is taking > 4 concomitant ASMs. Rescue medications are not included in the count
Subject is receiving concomitant treatment with cannabidiol (CBD) other than Epidiolex/Epidyolex or is being actively treated with tetrahydrocannabinol (THC) or any marijuana product for any condition
Subject has participated in another interventional clinical trial within 30 days of the Screening Visit or is currently receiving an investigational product
Subject has previously been treated with Fintepla® (fenfluramine) prior to the Screening Visit
Clear my responses

How to participate?

Step 1 Connect with a study center
What happens next?
  • You can expect the study team to contact you via email or phone in the next few days.
  • Sign up as volunteer to help accelerate the development of new treatments and to get notified about similar trials.

You are contacting

Investigator Avatar

Primary Contact



Additional screening procedures may be conducted by the study team before you can be confirmed eligible to participate.

Learn more

If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.

Learn more

Complete your scheduled study participation activities and then you are done. You may receive summary of study results if provided by the sponsor.

Learn more

Similar trials to consider


Not finding what you're looking for?

Every year hundreds of thousands of volunteers step forward to participate in research. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.

Sign up as volunteer

user name

Added by • 



Reply by • Private

Lorem ipsum dolor sit amet consectetur, adipisicing elit. Ipsa vel nobis alias. Quae eveniet velit voluptate quo doloribus maxime et dicta in sequi, corporis quod. Ea, dolor eius? Dolore, vel!

  The passcode will expire in None.

No annotations made yet

Add a private note
  • abc Select a piece of text from the left.
  • Add notes visible only to you.
  • Send it to people through a passcode protected link.
Add a private note