The pivotal trial included 101 children and young
adults with CDD1,2

Patients in the randomized, placebo-controlled pivotal trial ranged in age from 2 to 19 years. Approximately 79% of these patients were female, 92% were white, and the mean age was 7.3 years.1,3 The minimum and maximum weight of patients enrolled in this study were 8.7 kg and 46.5 kg, respectively.3

Baseline characteristics

Patients had tried and discontinued a median
of 7 ASMs (range: 1 to 16)3

Patients were taking an average of
concomitant ASMs3*

Patients had a median of 50 major motor
seizures per 28 days3

* 96% of patients were taking at least 1 ASM. The most frequently used (≥20% of patients) concomitant ASMs were valproate, levetiracetam, clobazam, and vigabatrin.1

Patients taking ZTALMY experienced a significant reduction in seizure frequency1

ZTALMY reduced the frequency of monthly major motor seizures by a median of 31%, compared with 7% for placebo, over 17 weeks (P=0.0036).1

Reduction in monthly major motor seizure frequency over 17 weeks (primary endpoint)1

Chart showing seizure reduction of ZTALMY versus placebo Chart showing seizure reduction of ZTALMY versus placebo

ZTALMY provided


the reduction in seizure

frequency vs placebo1

*Change from baseline. Baseline frequency of major motor seizures per 28 days was a median of 54 for the ZTALMY group (n=49) and a median of 49 for the placebo group (n=51).1

Multiple major motor seizure types associated with CDD were measured1

  • Bilateral tonic
  • Generalized tonic-clonic
  • Atonic
  • Bilateral clonic
  • Focal to bilateral tonic-clonic

Seizure frequency was reduced by at least half for some patients1,2

More patients in the ZTALMY group (24.5%) experienced a ≥50% reduction from baseline in monthly major motor seizure frequency over 17 weeks compared with placebo (9.8%).3

Responder analysis over 17 weeks3

ZTALMY (n=49) Placebo (n=51)
Proportion of patients seeing a reduction in 28-day major motor seizure frequency ZTALMY versus placebo Proportion of patients seeing a reduction in 28-day major motor seizure frequency ZTALMY versus placebo

21 patients taking ZTALMY had a <25% response, compared with 39 placebo-treated patients.3

*A key secondary endpoint; not statistically significant.3

Pivotal trial design: The Marigold study1-4

The efficacy and safety of ZTALMY to treat seizures associated with CDD in patients 2 years of age and older were established in a single, double-blind, randomized, placebo-controlled study.1

Patients enrolled in the study were required to have1:

  • Molecular confirmation of a pathogenic or likely pathogenic cyclin-dependent kinase-like 5 (CDKL5) variant
  • Seizures inadequately controlled by at least 2 previous ASM regimens
  • A minimum of 16 major motor seizures per 28 days during the
    2 months prior to screening
Study design for the Marigold study

The 17-week double-blind phase of the Marigold study was followed by a long-term open-label phase in which all patients received ZTALMY. The primary objective of the open-label phase was to collect additional safety and tolerability data; additional efficacy assessments were also performed.2,4

*Total daily dosage divided 3 times a day.

Results from an open-label extension study of patients taking ZTALMY

Following the pivotal trial, 88 out of 101 patients entered an open-label extension study to evaluate the ongoing safety and efficacy of ZTALMY.3

The primary objective of the OLE was to collect additional safety and tolerability data. Safety findings were consistent with the double-blind phase; no new safety findings had emerged at the time of analysis.3,4

Additional efficacy assessments were also performed. Open-label design and small sample size preclude conclusions about efficacy.

Percent reduction in median major motor seizure frequency through 2 years of the OLE3*

Median percent reduction in 28-day major motor seizure frequency, open-label ZTALMY versus placebo
Median percent reduction in 28-day major motor seizure frequency, open-label ZTALMY versus placebo

Patients who remained in this study at 2 years experienced sustained reduction in MMSF3

All patients were in the OLE for 2 years. 37 (42.0%) patients discontinued from the OLE due to lack of efficacy (n=13), withdrawal by caregiver (n=12), adverse event (n=10), physician decision (n=1), and death (n=1).3

MMSF=major motor seizure frequency.

*Date of analysis: June 30, 2022.

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Learn about the
safety data




  • Somnolence and Sedation: ZTALMY can cause somnolence and sedation. In a clinical study somnolence and sedation appeared early during treatment and were generally dose related. Other CNS depressants, including opioids, antidepressants, and alcohol, could potentiate these effects. Monitor patients for these effects and advise them not to drive or operate machinery until they have gained sufficient experience on ZTALMY to gauge whether it adversely affects their ability to drive or operate machinery.



ZTALMY is indicated for the treatment of seizures associated with cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder (CDD) in patients 2 years of age and older.




The most common adverse reactions (incidence of at least 5% and at least twice the rate of placebo) were somnolence (38%), pyrexia (18%), salivary hypersecretion (6%), and seasonal allergy (6%).


Cytochrome P450 inducers will decrease ganaxolone exposure. Avoid concomitant use with strong or moderate CYP3A4 inducers; if unavoidable, consider a dosage increase of ZTALMY, but do not exceed the maximum recommended dosage.



ZTALMY contains ganaxolone, a Schedule V controlled substance (CV). Advise patients of the potential for abuse and dependence. It is recommended that ZTALMY be tapered according to the dosage recommendations unless symptoms warrant immediate discontinuation.

Please see full Prescribing Information.


  1. ZTALMY [package insert]. Radnor, PA: Marinus Pharmaceuticals, Inc.; 2023.
  2. Knight EMP, Amin S, Bahi-Buisson N, et al. Lancet Neurol. 2022;21(5):417-427.
  3. Data on file. Marinus Pharmaceuticals, Inc.
  4. Specchio N, Amin S, Hulihan J, et al. Extended duration safety and efficacy of ganaxolone for the treatment of CDKL5 deficiency disorder: preliminary open-label extension analysis (Marigold Study). American Epilepsy Society. Dec 4-8, 2020. Virtual conference.