A Study to Investigate the Effectiveness and Safety of ZX008 in Subjects with CDKL5 Deficiency Disorder


About this study

The primary purpose of this study is to evaluate the effectiveness and safety of ZX008 in subjects with CDD.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

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

- 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.

Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Eligibility last updated 2/1/23. Questions regarding updates should be directed to the study team contact.

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Elaine Wirrell, M.D.

Closed-enrolling by invitation

What is this? (?)
Not open to everyone who meets the eligibility criteria, but only those invited to participate by the study team.

Contact information:

Bridget Neja C.N.A.

(507) 266-9150


More information


Publications are currently not available

Mayo Clinic Footer