There are currently no approved therapies available for Fragile X Syndrome (FXS), with prescribed treatments consisting exclusively of off-label drugs that target individual symptoms of the disease. However, as these therapies do not target the pathogenesis underlying FXS, they have only a modest effect on a subset of patients. This has led to a call for the need for an FXS-specific pharmacological treatment that targets the underlying brain deficits of FXS, which could be addressed by Zynerba Pharmaceuticals’ Zygel, says GlobalData, a leading data and analytics company.

According to GlobalData’s report, ‘Fragile X Syndrome – Market Size and Trend Report Competitor Assessment, Unmet Needs, Clinical Trial Strategies and Forecast, 2021-2030’, Zygel is anticipated to launch in the US in Q3 2025 and is forecast to generate US sales of $17.9 million by 2030.

Christie Wong, Pharma Analyst at GlobalData comments: “Zygel is a transdermal cannabidiol gel that is suggested to modulate the endocannabinoid system. Key opinion leaders (KOLs) previous interviewed by GlobalData agreed that products that target the pathogenesis of FXS could have superior efficacy and safety profile over currently off-label symptomatic treatments.”

The proposed mechanisms of action of Zygel are supported by the results from the Phase III CONNECT-FX trial in patients with FXS with greater than or equal to 90% methylation of the fragile X mental retardation 1 (FMR1) gene, with the Zygel treatment group demonstrating improvements in social interactions, irritability, and behavior.

Wong notes: “As the severity of symptoms is correlated with the amount of FMRP protein produced and the degree of methylation in the FMR1 gene, Zygel could be beneficial to the most severely impacted patients with FXS. However, KOLs noted that the use of cannabinoid treatments is yet to be widely accepted. Furthermore, when the annual cost of therapy of Zygel was compared with Epidiolex, the first marketed cannabidiol treatment, they were concerned that Zygel would also be associated with a high cost of treatment that could be a barrier for its uptake.”

Current FXS symptomatic treatments include selective serotonin reuptake inhibitors, stimulants like methylphenidate, antipsychotics, and anticonvulsant agents for seizures. These classes of drugs are highly genericized. As a result, payers and physicians may prefer to offer cheaper alternatives when possible.

Wong concludes: “Zygel will need to demonstrate significant improvements in daily function, quality of life, and drug safety profile to displace the widely available generic therapies used in the treatment of FXS.”