Cannabidiol Gel Achieves Top Line Results in Treatment of Fragile X Syndrome

Data from a phase 2 trial demonstrates positive results on improving the disabling symptoms of a rare form of autism.

The investigational cannabidiol (CBD) gel ZYN002 achieved positive top line results in a phase 2 study for the treatment of Fragile X syndrome.

ZYN002 is a permeation-enhanced gel designed to provide controlled drug delivery transdermally once or twice per day, according to a press release.

Included in the open label exploratory phase 2 FAB-C clinical trial were 20 patients aged 6 to 17 years with confirmed Fragile X. According to the release, ZYN002 was added on to other medications being administered.

The first 6 weeks of the study were designed to titrate dosing in participants. Dosing was initiated at 50 mg per day and could be increased to 250 mg daily. Week 7 through 12 was a maintenance period, in which patients were treated with the dose established at 6 weeks.

Once the study was completed, patients had the option to enter an open label extension study for up to 12 months.

The primary endpoint was change in the total score of the Anxiety, Depression, and Mood Scales (ADAMS) from baseline to week 12. Secondary endpoints included the Aberrant Behavior Checklist-FXS Specific (ABC-FXS), a Clinical Global Impression of Improvement (CGI-I), the Pediatric Anxiety Rating Scale (PARS-R), visual scales for anxiety, hyperactivity and tantrum/mood lability, the Vineland Adaptive Behavior III, a quality of sleep measurement, and the Pediatric Quality of Life (PedsQL).

The results of the study showed ZYN002 achieved a 46% improvement in the total score of ADAMS at week 12 compare with baseline. The CBD gel also achieved clinically meaningful improvements in all measures of the ABC-FXS.

ZYN002 was found to be well tolerated and the safety profile was consistent with previous data. Treatment was discontinued in 2 patients due to worsening of pre-existing eczema. Adverse events (AEs) occurred in 4 patients, and no severe AEs were observed.

“The data from the FAB-C trial are very exciting and demonstrate that ZYN002 may have a profound effect on improving many of the most disabling symptoms of Fragile X, such as anxiety and difficult behaviors,” Steven Siegel, MD, PhD, Professor and Chair of Psychiatry and Behavior sciences at Keck School of Medicine, USC, said in the release. “Fragile X is a challenging genetic autism spectrum disorder, with complex symptomatology that significantly impacts patients and their families. Many children with Fragile X and their families struggle with the lack of approved drugs to safely treat their symptoms. This study suggests that ZYN002 is ready for the next phase of development, and I believe that this drug holds great promise as a potential treatment for these very difficult-to-treat symptoms.”

Fragile X syndrome affects 1 of every 4000 males and 1 of every 8000 females. It is an autism spectrum disorder, and is the most common inherited intellectual disability in males and a significant cause in females, according to the release. It is caused by a mutation in the Fragile X Mental Retardation gene, resulting in the dysregulation of the endocannabinoid pathway and a reduction in 2-AG and anandamide, according to the release.

“The symptoms of Fragile X can be overwhelming to a patient and caregiver, so I’m very enthusiastic about the response to ZYN002 that we saw during this study,” lead investigator Honey Heussler, FRACP, said in the release. “These data are extremely promising, particularly the improvements in anxiety, social avoidance, and irritability as measured by scales including ADAMS, ABC-FXS, and PARS-R. Tolerability is essential in these patients, so I’m very pleased to see that ZYN002 was well tolerated in Fragile X patients.”

ZYN002 manufacturer Zynerba Pharmaceuticals anticipates it will meet with the FDA in the first half of 2018. They hope to move quickly into a pivotal phase 2/3 program in pediatric and adolescent patients with Factor X syndrome in 2018. The FDA granted Orphan Drug designation for the use of CBD to treat patients with Factor X syndrome, according to the release.

“We are thrilled with the positive results of ZYN002 in the FAB-C trial; it is a major step forward for the hundreds of thousands of patients worldwide with Fragile X who currently have no approved therapeutic options to treat their symptoms,” Armando Anido, chairman and CEO of Zynerba, said in the release. “The clinically meaningful improvements in Fragile X symptoms and the excellent tolerability seen in the FAB-C trial are compelling. These data will allow us to discuss the pathway to approval in a meeting with the FDA, which we expect to take place during the first half of 2018. I want to thank the patients, families, physicians, and study coordinators, and the Zynerba team for their support of this important study.”

ZYN002 is the first and only pharmaceutically produced CBD formulated as a patent-protected permeation-enhanced gel that is under examination to treat children with Fragile X Syndrome, osteoarthritis, and adult patients with epilepsy with focal seizures.