CBD reduced seizures by 50% or more in 40% of highly treatment-resistant epilepsy patients
Among 82 patients with severe Dravet or Lennox-Gastaut syndrome who had failed a median of 8 prior medications, 40.2% achieved at least 50% seizure reduction with purified CBD within 3 months.
Quick Facts
What This Study Found
At 3 months, 40.2% of patients achieved 50% or greater seizure reduction, with 1.2% becoming seizure-free. Retention rates were similar for Dravet and Lennox-Gastaut syndromes but higher in adults than pediatric patients. Of 93 enrolled patients, 31.2% dropped out (17.2% for lack of efficacy, 12.9% for adverse events). Most common side effects were somnolence (22.6%) and diarrhea (11.9%).
Key Numbers
93 enrolled, 82 analyzed. Median 8 failed prior medications. 50% seizure reduction: 40.2%. Seizure-free: 1.2%. Dropout: 31.2%. Somnolence: 22.6%. Diarrhea: 11.9%. Transaminase elevation noted. CBD coadministered with valproic acid (62.2%) and clobazam (41.5%).
How They Did This
Open-label prospective expanded access program across 30 Italian centers (December 2018 to December 2019). Purified CBD up to 25 mg/kg/day added to existing medications. 93 patients enrolled for safety analysis, 82 with at least 3 months follow-up for effectiveness. Median 8 previously failed antiseizure medications.
Why This Research Matters
These patients represent the most treatment-resistant cases, having failed a median of 8 medications. Achieving 50% seizure reduction in 40% of this population is clinically meaningful, and the real-world expanded access design provides pragmatic evidence beyond controlled trials.
The Bigger Picture
This Italian EAP adds to the global evidence supporting CBD for treatment-resistant epilepsy. The finding that effectiveness was independent of clobazam use is important, as some have questioned whether CBD benefits in epilepsy are partly mediated through clobazam interactions.
What This Study Doesn't Tell Us
Open-label design with no placebo group. Potential placebo effect. Only 3 months of effectiveness data. Concurrent medication changes possible. Dropout rate of 31% may bias results.
Questions This Raises
- ?Do seizure reduction rates improve or decline beyond 3 months?
- ?Which patients are most likely to respond?
- ?Is the benefit maintained when adjusting concurrent medications?
Trust & Context
- Key Stat:
- 40.2% achieved ≥50% seizure reduction after failing median 8 prior drugs
- Evidence Grade:
- Multicenter prospective design in a real-world setting, but open-label with no placebo control.
- Study Age:
- 2021 interim results from Italian expanded access program (2018-2019).
- Original Title:
- Results From an Italian Expanded Access Program on Cannabidiol Treatment in Highly Refractory Dravet Syndrome and Lennox-Gastaut Syndrome.
- Published In:
- Frontiers in neurology, 12, 673135 (2021)
- Authors:
- Iannone, Luigi Francesco, Arena, Gabriele, Battaglia, Domenica(2), Bisulli, Francesca, Bonanni, Paolo, Boni, Antonella, Canevini, Maria Paola, Cantalupo, Gaetano, Cesaroni, Elisabetta, Contin, Manuela, Coppola, Antonietta, Cordelli, Duccio Maria, Cricchiuti, Giovanni, De Giorgis, Valentina, De Leva, Maria Fulvia, De Rinaldis, Marta, d'Orsi, Giuseppe, Elia, Maurizio, Galimberti, Carlo Andrea, Morano, Alessandra, Granata, Tiziana, Guerrini, Renzo, Lodi, Monica A M, La Neve, Angela, Marchese, Francesca, Masnada, Silvia, Michelucci, Roberto, Nosadini, Margherita, Pilolli, Nicola, Pruna, Dario, Ragona, Francesca, Rosati, Anna, Santucci, Margherita, Spalice, Alberto, Pietrafusa, Nicola, Striano, Pasquale, Tartara, Elena, Tassi, Laura, Papa, Amanda, Zucca, Claudio, Russo, Emilio, Mecarelli, Oriano
- Database ID:
- RTHC-03215
Evidence Hierarchy
Enrolls participants and follows them forward in time.
What do these levels mean? →Frequently Asked Questions
Did CBD work independently of clobazam?
Yes. The study found CBD effectiveness was independent of clobazam coadministration, though CBD was most commonly combined with valproic acid (62.2%) and clobazam (41.5%).
What were the main side effects?
The most common were somnolence (22.6%) and diarrhea (11.9%), followed by transaminase elevation and loss of appetite. Side effects led to dropout in 12.9% of patients.
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Cite This Study
https://rethinkthc.com/research/RTHC-03215APA
Iannone, Luigi Francesco; Arena, Gabriele; Battaglia, Domenica; Bisulli, Francesca; Bonanni, Paolo; Boni, Antonella; Canevini, Maria Paola; Cantalupo, Gaetano; Cesaroni, Elisabetta; Contin, Manuela; Coppola, Antonietta; Cordelli, Duccio Maria; Cricchiuti, Giovanni; De Giorgis, Valentina; De Leva, Maria Fulvia; De Rinaldis, Marta; d'Orsi, Giuseppe; Elia, Maurizio; Galimberti, Carlo Andrea; Morano, Alessandra; Granata, Tiziana; Guerrini, Renzo; Lodi, Monica A M; La Neve, Angela; Marchese, Francesca; Masnada, Silvia; Michelucci, Roberto; Nosadini, Margherita; Pilolli, Nicola; Pruna, Dario; Ragona, Francesca; Rosati, Anna; Santucci, Margherita; Spalice, Alberto; Pietrafusa, Nicola; Striano, Pasquale; Tartara, Elena; Tassi, Laura; Papa, Amanda; Zucca, Claudio; Russo, Emilio; Mecarelli, Oriano. (2021). Results From an Italian Expanded Access Program on Cannabidiol Treatment in Highly Refractory Dravet Syndrome and Lennox-Gastaut Syndrome.. Frontiers in neurology, 12, 673135. https://doi.org/10.3389/fneur.2021.673135
MLA
Iannone, Luigi Francesco, et al. "Results From an Italian Expanded Access Program on Cannabidiol Treatment in Highly Refractory Dravet Syndrome and Lennox-Gastaut Syndrome.." Frontiers in neurology, 2021. https://doi.org/10.3389/fneur.2021.673135
RethinkTHC
RethinkTHC Research Database. "Results From an Italian Expanded Access Program on Cannabidi..." RTHC-03215. Retrieved from https://rethinkthc.com/research/iannone-2021-results-from-an-italian
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.