Ztalmy Drug Information

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. ZTALMY is a neuroactive steroid gamma-aminobutyric acid (GABA) A receptor positive modulator 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.

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In controlled and uncontrolled trials in patients with seizures associated with CDD, 102 patients were treated with ZTALMY, including 83 patients treated for more than 6 months, and 50 patients treated for more than 1 year. In Study 1, 50 patients received ZTALMY . The duration of treatment in this trial was up to 17 weeks.

Approximately 78% of these patients were female, 92% were White, and the mean age was 6.8 years (range 2 to 19 years). All patients receiving ZTALMY, except 1, were taking other AEDs. Adverse reactions in these patients are presented below. The most common adverse reactions (an incidence of at least 5% and at least twice the rate of placebo) were somnolence, pyrexia, salivary hypersecretion, and seasonal allergy (Table 6). The adverse reactions leading to treatment discontinuation in ZTALMY-treated patients were somnolence and seizure (1 patient) and seizure (1 patient). Twenty-two percent of ZTALMY-treated patients had dosing interrupted or reduced because of any adverse reaction, compared to 16% of placebo-treated patients.

The most frequent adverse reactions leading to a dose interruption or reduction in ZTALMY-treated patients were somnolence (10%) and sedation (2%). Table 6 presents the adverse reactions that occurred in ZTALMY-treated patients with seizures associated with CDD at a rate of at least 3% and at a rate greater than in placebo-treated patients during the double-blind phase. Table 6 Adverse Reactions that Occurred in ZTALMY-Treated Patients with Seizures Associated with CDD at a Rate of At Least 3% and Greater Than in Placebo (Study 1) Adverse Reactions ZTALMY (N=50) Placebo (N=51) % % Somnolence somnolence includes the terms lethargy and hypersomnia adverse reactions that occurred with a 21-day titration; somnolence and sedation are expected to be reduced with the recommended 28-day titration 38 20 Pyrexia 18 8 Upper respiratory tract infection 10 6 Sedation 6 4 Salivary Hypersecretion 6 2 Seasonal allergy 6 0 Bronchitis 4 0 Influenza 4 2 Gait disturbance 4 2 Nasal congestion 4 2

Effect of

UGT Inhibitors on ZTALMY Concomitant use of ZTALMY and UGT inhibitors (e.g., valproic acid) may increase the exposure of ganaxolone, which may increase the risk of ZTALMY associated adverse reactions in patients who have titrated to a stable ZTALMY dosage. Consider a reduction of ZTALMY maintenance dosage when initiating a UGT inhibitor.

Effect of Strong or Moderate Cytochrome P450 Inducers on

ZTALMY Coadministration of ZTALMY with CYP450 inducers, such as strong or moderate CYP3A4 inducers, will decrease ganaxolone exposure, which can lower the efficacy of ZTALMY . It is recommended to avoid concomitant use of strong or moderate CYP3A4 inducers with ZTALMY. When concomitant use of strong or moderate CYP3A4 inducers is unavoidable, consider an increase in the dosage of ZTALMY; however, do not exceed the maximum daily dosage of ZTALMY . In patients on a stable ZTALMY dosage who are initiating or increasing the dosages of enzyme-inducing antiepileptic drugs (e.g., carbamazepine, phenytoin, phenobarbital, and primidone), the ZTALMY dosage may need to be increased; however, do not exceed the maximum daily dosage of ZTALMY .

Concomitant Use of

ZTALMY with CNS Depressants and Alcohol Concomitant use of ZTALMY with CNS depressants, including alcohol, may increase the risk of somnolence and sedation .

Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to antiepileptic drugs (AEDs), such as ZTALMY, during pregnancy. Encourage women who are taking ZTALMY during pregnancy to enroll in the North American Antiepileptic Drug (NAAED) Pregnancy Registry by calling the toll-free number 1-888-233-2334 or visiting http://www.aedpregnancyregistry.org/. Risk Summary There are no available data on ZTALMY use in pregnant women to inform a drug-associated risk of adverse developmental outcomes. In animal studies, adverse effects on development were observed in mice (fetal malformations) and rats (neurobehavioral and growth impairment) following exposure during organogenesis (mouse) or throughout gestation and lactation (rat) at maternal exposures lower than that in human adults at the maximum recommended human dose (MRHD) of 1800 mg.

In addition, neuronal death was observed in rats exposed to ganaxolone during a period of brain development that begins during the third trimester of pregnancy in humans and continues during the first few years after birth. In the US general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. The background risks of major birth defects and miscarriage for the indicated populations are unknown.

Clinical Considerations Disease-associated Maternal and/or Embryofetal Risk Epilepsy, with or without exposure to antiepileptic drugs, has been associated with several adverse outcomes during pregnancy, including preeclampsia, preterm labor, antepartum and postpartum hemorrhage, placental abruption, poor fetal growth, prematurity, fetal death, and maternal mortality. The risk of maternal or fetal injury may be greatest for patients with untreated or poorly controlled convulsive seizures. Women with epilepsy who become pregnant should not abruptly discontinue antiepileptic drugs, including ZTALMY, due to the risk of status epilepticus or severe seizures, which may be life-threatening.

Data Animal Data In an embryofetal development study in mice, oral administration of ganaxolone (0, 50, 175, or 300 mg/kg/day) throughout the period of organogenesis resulted in increased incidences of fetal malformations (external and/or visceral) at all doses in the absence of maternal toxicity. Maternal plasma drug exposures (AUC) at the low-effect dose (50 mg/kg/day) for embryofetal developmental toxicity in the mouse were approximately 10-fold lower than that in humans at the MRHD. In a combined embryofetal development and pre- and postnatal development study in rats, ganaxolone (0, 10, 20, or 40 mg/kg/day) was administered orally to females throughout gestation and lactation. There were no effects on embryofetal growth, survival, or morphology; however, adverse effects on offspring growth (delayed reflex development, decreased body weight gain) were observed during the postnatal period (prior to and after weaning) at the high dose, and neurobehavioral impairment (decreased locomotor activity) was observed in the offspring at the two highest doses.

The no-effect dose (10 mg/kg/day) for pre- and postnatal developmental toxicity in rats was associated with maternal drug exposures less than that in humans at the MRHD. Oral administration of ganaxolone (0, 20, 45, or 90 mg/kg/day) to rats on postnatal day (PND) 7 resulted in widespread apoptotic neurodegeneration in the brain (cortex, thalamus, and hippocampus) at all doses; a no-effect dose was not identified. Brain development on PND 7 in rat corresponds to that beginning in humans during the third trimester of pregnancy and continuing for the first several months to years after birth .

Pediatric Use The safety and effectiveness of ZTALMY for the treatment of seizures associated with CDD have been established in pediatric patients 2 years of age and older. The use of ZTALMY for the treatment of seizures associated with CDD in patients 2 years of age and older is supported by a randomized, double-blind, placebo-controlled trial that included 99 pediatric patients 2 to less than 18 years of age . Safety and effectiveness of ZTALMY in pediatric patients below 2 years of age have not been established. Juvenile Animal Data Oral administration of ganaxolone (0, 20, 45, 90/150/250/500 mg/kg/day) to juvenile rats from postnatal day (PND) 7 through PND 91 resulted in deaths associated with sedation and decreased male reproductive organ weights at the mid and high doses, and delayed female sexual maturation and decreased brain weights at all doses.

There were no adverse effects on neurobehavioral (locomotor activity, auditory startle response, learning and memory) or reproductive function. A no-effect dose was not established. The lowest dose producing developmental toxicity in juvenile rats (20 mg/kg/day) was associated with plasma drug exposures (AUC) less than that in pediatric patients at the maximum recommended human dose (MRHD) of 1800 mg.

Oral administration of ganaxolone (0, 10, 45, or 90 mg/kg/day) to rats on postnatal day (PND) 7 resulted in widespread neuronal death in multiple brain regions, including cortex, thalamus, and hippocampus, at all doses. The pattern and extent of neuronal death was similar to that produced by intraperitoneal injection of the positive control, the NMDA receptor antagonist MK-801 (1 mg/kg). The hippocampus, in particular, is recognized to have an important role in learning and memory. Effects of ganaxolone and MK-801 on neurobehavioral function were not assessed in this study.

Brain development on PND 7 in rat corresponds to that beginning in humans during the third trimester of pregnancy and continuing for the first several months to years after birth. At the lowest-effect dose for neuronal death, plasma drug exposure in the neonatal rat was less than that in pediatric patients at the MRHD. Oral administration of M2 (0, 15, 30, or 60 mg/kg/day), a human-specific metabolite of ganaxolone, to juvenile rats from PNDs 7 to 70 resulted in adverse effects on reproductive system development in both sexes at all doses. Effects in females included decreased corpora lutea and follicular cysts in the ovary at the high dose and signs of precocious puberty and estrous cycle disruption at all doses.

Female reproductive tract changes indicative of estrous cycle disruption persisted after a 5-week recovery period at the high dose. In males, effects consisted of delayed sexual maturation and decreased epididymis and prostate weights at the high dose, seminal vesicle atrophy at mid and high doses, and decreased seminal vesicle weights at all doses. Plasma exposures (AUC) of M2 at the highest dose were 2 times those in humans at the ganaxalone MRHD of 1,800 mg, while exposures at the mid and low doses were below those in humans at the ganaxolone MRHD.

There is limited clinical trial experience regarding overdose with ZTALMY. Unintentional overdose has been reported in 1 pediatric patient. This patient received ten times the prescribed dose. The patient was hospitalized for evaluation, including an electrocardiogram (ECG) and blood tests, and recovered.

Patients who overdose should be closely monitored and receive standard supportive care. No specific information is available regarding treatment of overdose. In the event of overdose, a certified poison control center should be contacted for updated information on the management of overdose with ZTALMY.