CDKL5 Deficiency Disorder

Our mission: Fight for children with CDKL5 Deficiency Disorder and their families.

At Marinus, we ally with our healthcare partners and advocacy groups because we care about our patients’ lives, stories, and voices.

What is CDKL5 Deficiency Disorder?

CDKL5 deficiency disorder (CDD) is a serious and rare genetic disorder that is caused by a mutation of the cyclin-dependent kinase-like 5 (CDKL5) gene, which is located on the X chromosome and encodes proteins essential for normal brain function. CDD predominantly affects females and is characterized by early-onset, difficult-to-control seizures and severe neuro-developmental impairment. Many children diagnosed with CDD also experience scoliosis, visual impairment, sensory problems, gastrointestinal difficulties, and sleeping disorders.


CDKL5 deficiency disorder treatment options

While genetic testing is available to determine if a patient has a mutation in the CDKL5 gene, there are currently no approved therapies for CDD. Marinus has completed the Marigold Study which is a Phase 3, global pivotal clinical study evaluating the use of oral ganaxolone in children and young adults with CDD.

The science behind treating CDKL5 deficiency disorder

The mechanism of disease in CDD, particularly the epilepsy phenotype, is not fully understood. However, it has been reported that other neurosteroids, particularly pregnenolone, are capable of rescuing morphological defects in neurons without the CDKL5 protein. One of pregnenolone’s metabolites is allopregnanolone, which is structurally and mechanistically similar to ganaxolone. There is also a broad GABAergic dysfunction reported in patients with CDD establishing the rationale for ganaxolone in this indication.


It is estimated that there are at least two children diagnosed with CDD each week.

The Clinical Development of Ganaxolone in CDKL5 Deficiency Disorder

Top-line data from the Phase 3 Marigold Study

In the trial, patients given ganaxolone showed a significant 32.2 percent median reduction in 28-day major motor seizure frequency, compared to a 4.0 percent reduction for those receiving the placebo, achieving the primary endpoint (p=0.002). The trial’s primary efficacy endpoint was the percentage change in 28-day frequency of major motor seizures during the double-blind phase relative to the 6-week prospective baseline period. Ganaxolone was generally well tolerated with a safety profile consistent with previous clinical studies. The most frequent adverse event was somnolence.

The global, double-blind, placebo-controlled, Phase 3 trial enrolled 101 patients. Children and young adults ages 2 to 21 with a confirmed, disease-related CDKL5 gene variant were eligible to enroll. Following a 6-week baseline period, trial participants were randomized to receive either oral ganaxolone (up to 1,800 mg/day) or placebo for 17 weeks, in addition to their existing anti-seizure treatment. Following the double-blind phase, patients were eligible to continue receiving ganaxolone in an open-label extension.

Rare Pediatric Disease Designation

The FDA grants Rare Pediatric Disease Designation (RPD) for diseases that affect fewer than 200,000 people in the U.S. in which the serious or life-threatening manifestations are primarily in individuals 18 years of age and younger. If a new drug application (NDA) for ganaxolone in CDD is approved, Marinus may be eligible to receive a priority review voucher from the FDA, which can be redeemed for priority review in a subsequent marketing application. The program is intended to encourage development of new drugs and biologics for the prevention and treatment of rare pediatric diseases.

Young Girl Teddy Heart Physician

Learn more about CDKL5 deficiency disorder

Additional educational and support resources:

International Foundation for CDKL5 Research

CDKL5 Alliance

CDKL5 Research Collaborative

Loulou Foundation

Hope4Harper

Links to third party sites are provided for convenience purposes only. The information contained on these sites is not information provided, controlled or monitored by Marinus Pharmaceuticals in any way. Marinus Pharmaceuticals is not responsible in any way for the accuracy, completeness, or fitness for any particular purpose of any content appearing on such sites.

Partridge Family Cdlk5 1

Patient Story:

CDKL5 Deficiency Disorder: Partridge Family