Real-world efficacy and safety of cannabidiol in developmental and epileptic encephalopathies.

OBJECTIVE

Highly purified cannabidiol (CBD) is approved as adjunctive therapy for seizures associated with Dravet syndrome (DS), Lennox-Gastaut syndrome (LGS), and tuberous sclerosis complex (TSC), although its role in other developmental and epileptic encephalopathies (DEEs) remains unexplored. The aim of this study was to assess the real-world use, efficacy, and safety of CBD across a broad cohort of patients with DEEs, including off-label indications.

METHODS

In this retrospective study, we evaluated 107 patients with DEEs treated with CBD for ≥3 months between 2020 and 2024. Data on seizure frequency, tolerability, retention, and non-seizure outcomes were collected. Efficacy was defined as ≥50% or ≥75% seizure reduction. Statistical analyses explored predictors of response.

RESULTS

Patients had LGS (55.1%), DS (16.8%), TSC (8.4%), or other DEEs (19.6%), with a genetic etiology in 56.1%. At a median follow-up of 20 months, 69% achieved ≥50% seizure reduction, and 21% achieved ≥75% reduction. Patients with LGS, TSC, and other DEEs showed higher efficacy and retention rates compared to DS. Genetic or unknown etiology was associated with better outcomes (p = 0.011). Combination with valproate was associated with reduced efficacy (p = 0.006), while combination with clobazam had no significant effect on efficacy nor safety. Non-seizure improvements included increased alertness (56%), improved sleep quality (25%), and enhanced motor performance (14%). Adverse events occurred in 33.6%, mostly mild and transient; 9% discontinued due to side effects.

SIGNIFICANCES: This study confirms the effectiveness and good tolerability of CBD in a real-world DEE population, including off-label use. These findings support expanding CBD indications and underscore the need for prospective studies targeting both seizure and developmental outcomes.

PLAIN LANGUAGE SUMMARY: This study looked at the use of cannabidiol (CBD), a cannabis-based medicine, in 107 people with severe forms of epilepsy called developmental and epileptic encephalopathies (DEEs). With CBD add-on, about two-thirds of patients had fewer seizures, and some caregivers noticed improvements in alertness, sleep, or movement. Most patients tolerated the treatment well, but some experienced side effects, and a few had to stop taking it. While the results are promising, more research is needed to confirm how effective and safe CBD is for different types of DEEs, especially those not currently approved for treatment with CBD.