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– Interim results of long-term, open-label extension trials of add-on prescription cannabidiol in patients with Dravet syndrome or Lennox-Gastaut syndrome show sustained, clinically meaningful seizure reductions with no new safety concerns, Anup D. Patel, MD, reported at the International Epilepsy Congress.

Dr. Anup D. Patel, chief of child neurology at Nationwide Children's Hospital in Columbus, Ohio
Dr. Anup D. Patel

“Overall, this is a very promising and sustainable result that we were happy to see,” said Dr. Patel, chief of child neurology at Nationwide Children’s Hospital in Columbus, Ohio.

Epidiolex is the brand name for the plant-derived, highly purified cannabidiol (CBD) in an oil-based oral solution at 100 mg/mL. Dr. Patel has been involved in the medication’s development program since the earliest open-label compassionate use study, which was followed by rigorous phase 3, double-blind, placebo-controlled randomized trials, eventually leading to Food and Drug Administration marketing approval for the treatment of Dravet syndrome and Lennox-Gastaut syndrome in patients 2 years of age or older.

“On June 25th, 2018, history was made: for the first time in United States history, a plant-based derivative of marijuana was approved for use as a medication, and it was also the first FDA-approved treatment for Dravet syndrome,” Dr. Patel noted at the congress sponsored by the International League Against Epilepsy.

A total of 96% of the 289 children with Dravet syndrome who completed the 14-week, double-blind, controlled randomized trials enrolled in the open-label, long-term extension study, during which they were on a median of three concurrent antiepileptic drugs along with a mean modal dose of CBD at 22 mg/kg/day. Although the target maintenance dose of CBD was 20 mg/kg/day, as advised in the product labeling, physicians could reduce or increase the dose up to 30 mg/kg/day.

“In the initial compassionate-use study, our site could go up to 50 mg/kg/day,” according to Dr. Patel. “We have plenty of data showing efficacy and continued safety beyond the FDA-recommended dose.”

In the open-label extension study, the median reduction from baseline in monthly seizure frequency assessed in 12-week intervals up to a maximum of week 72 was 44%-57% for convulsive seizures and 49%-67% for total seizures. More than 80% of patients and/or caregivers reported improvement in the patient’s overall condition as assessed on the Subject/Caregiver Global Impression of Change scale.

The pattern of adverse events associated with CBD has been consistent across all of the studies. The most common side effects are diarrhea in about one-third of patients, sleepiness in one-quarter, and decreased appetite in about one-quarter. Seven percent of patients discontinued the long-term extension trial because of adverse events.

Seventy percent of patients remained in the long-term extension study at 1 year.

Twenty-six patients developed liver transaminase levels greater than three times the upper limit of normal, and of note, 23 of the 26 were on concomitant valproic acid. None met criteria for severe drug-induced liver injury, and all recovered either spontaneously or after a reduction in the dose of CBD or valproic acid. But this association between CBD, valproic acid, and increased risk of mild liver injury has been a consistent finding across the clinical trials program.

“This is a very important clinical pearl to take away,” commented Dr. Patel, who is also a pediatric neurologist at Ohio State University.

The interim results of the long-term, open-label extension study of add-on CBD in patients with Lennox-Gastaut syndrome are similar to the Dravet syndrome study. Overall, 99% of the 368 patients with Lennox-Gastaut syndrome who completed the 14-week, double-blind, randomized trials signed up for the open-label extension. During a median follow-up of 61 weeks, the median percent reduction in seizure frequency as assessed in serial 12-week windows was 48%-70% for drop seizures and 48%-63% for total seizures. Twenty-four percent of patients withdrew from the study. Eighty-eight percent of patients or caregivers reported an improvement in overall condition when assessed at weeks 24 and 48. Forty-seven patients developed elevated transaminase levels – typically within the first 2 months on CBD – and 35 of them were on concomitant valproic acid.
 

 

 

More on drug-drug interactions

Elsewhere at IEC 2019, Gilmour Morrison of GW Pharmaceuticals, the Cambridge, England, company that markets Epidiolex, presented the findings of a series of drug-drug interaction studies involving coadministration of their CBD with clobazam (Sympazan and Onfi), valproate, stiripentol (Diacomit), or midazolam (Versed) in adult epilepsy patients and healthy volunteers. The researchers reported a bidirectional drug-drug interaction between Epidiolex and clobazam resulting in increased levels of the active metabolites of both drugs. The mechanism is believed to involve inhibition of cytochrome P450 2C19. However, there were no interactions with midazolam or valproate, and the slight bump in stiripentol levels when given with CBD didn’t reach the level of a clinically meaningful drug-drug interaction, according to the investigators.

On the horizon, Canadian researchers are investigating the possibility that since both the tetrahydrocannabinol (THC) and CBD components of marijuana have been shown to have anticonvulsant effects, adding a bit of THC to CBD will result in even better seizure control than with pure CBD in patients with Dravet syndrome. Investigators at Toronto’s Hospital for Sick Children have conducted a prospective, open-label study of a product containing CBD and THC in a 50:1 ratio as add-on therapy in 20 children with Dravet syndrome. The dose was 2-16 mg/kg/day of CBD and 0.04-0.32 mg/kg/day of THC. The cannabis plant extract used in the study was produced by Tilray, a Canadian pharmaceutical company.

Nineteen of the 20 patients completed the 20-week study. The sole noncompleter died of SUDEP (sudden unexpected death in epilepsy) deemed treatment unrelated. Patients experienced a median 71% reduction in motor seizures, compared with baseline. Sixty-three percent of patients had at least a 50% reduction in seizure frequency. Elevated liver transaminases occurred in patients on concomitant valproic acid, as did platelet abnormalities, which have not been seen in the Epidiolex studies, noted Dr. Patel, who was not involved in the Canadian study (Ann Clin Transl Neurol. 2018 Aug 1;5[9]:1077-88).

Dr. Patel reported serving as a consultant to Greenwich Biosciences, a U.S. offshoot of GW Pharmaceuticals. He receives research grants from that company as well as from the National Institutes of Health and the Pediatric Epilepsy Research Foundation.

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– Interim results of long-term, open-label extension trials of add-on prescription cannabidiol in patients with Dravet syndrome or Lennox-Gastaut syndrome show sustained, clinically meaningful seizure reductions with no new safety concerns, Anup D. Patel, MD, reported at the International Epilepsy Congress.

Dr. Anup D. Patel, chief of child neurology at Nationwide Children's Hospital in Columbus, Ohio
Dr. Anup D. Patel

“Overall, this is a very promising and sustainable result that we were happy to see,” said Dr. Patel, chief of child neurology at Nationwide Children’s Hospital in Columbus, Ohio.

Epidiolex is the brand name for the plant-derived, highly purified cannabidiol (CBD) in an oil-based oral solution at 100 mg/mL. Dr. Patel has been involved in the medication’s development program since the earliest open-label compassionate use study, which was followed by rigorous phase 3, double-blind, placebo-controlled randomized trials, eventually leading to Food and Drug Administration marketing approval for the treatment of Dravet syndrome and Lennox-Gastaut syndrome in patients 2 years of age or older.

“On June 25th, 2018, history was made: for the first time in United States history, a plant-based derivative of marijuana was approved for use as a medication, and it was also the first FDA-approved treatment for Dravet syndrome,” Dr. Patel noted at the congress sponsored by the International League Against Epilepsy.

A total of 96% of the 289 children with Dravet syndrome who completed the 14-week, double-blind, controlled randomized trials enrolled in the open-label, long-term extension study, during which they were on a median of three concurrent antiepileptic drugs along with a mean modal dose of CBD at 22 mg/kg/day. Although the target maintenance dose of CBD was 20 mg/kg/day, as advised in the product labeling, physicians could reduce or increase the dose up to 30 mg/kg/day.

“In the initial compassionate-use study, our site could go up to 50 mg/kg/day,” according to Dr. Patel. “We have plenty of data showing efficacy and continued safety beyond the FDA-recommended dose.”

In the open-label extension study, the median reduction from baseline in monthly seizure frequency assessed in 12-week intervals up to a maximum of week 72 was 44%-57% for convulsive seizures and 49%-67% for total seizures. More than 80% of patients and/or caregivers reported improvement in the patient’s overall condition as assessed on the Subject/Caregiver Global Impression of Change scale.

The pattern of adverse events associated with CBD has been consistent across all of the studies. The most common side effects are diarrhea in about one-third of patients, sleepiness in one-quarter, and decreased appetite in about one-quarter. Seven percent of patients discontinued the long-term extension trial because of adverse events.

Seventy percent of patients remained in the long-term extension study at 1 year.

Twenty-six patients developed liver transaminase levels greater than three times the upper limit of normal, and of note, 23 of the 26 were on concomitant valproic acid. None met criteria for severe drug-induced liver injury, and all recovered either spontaneously or after a reduction in the dose of CBD or valproic acid. But this association between CBD, valproic acid, and increased risk of mild liver injury has been a consistent finding across the clinical trials program.

“This is a very important clinical pearl to take away,” commented Dr. Patel, who is also a pediatric neurologist at Ohio State University.

The interim results of the long-term, open-label extension study of add-on CBD in patients with Lennox-Gastaut syndrome are similar to the Dravet syndrome study. Overall, 99% of the 368 patients with Lennox-Gastaut syndrome who completed the 14-week, double-blind, randomized trials signed up for the open-label extension. During a median follow-up of 61 weeks, the median percent reduction in seizure frequency as assessed in serial 12-week windows was 48%-70% for drop seizures and 48%-63% for total seizures. Twenty-four percent of patients withdrew from the study. Eighty-eight percent of patients or caregivers reported an improvement in overall condition when assessed at weeks 24 and 48. Forty-seven patients developed elevated transaminase levels – typically within the first 2 months on CBD – and 35 of them were on concomitant valproic acid.
 

 

 

More on drug-drug interactions

Elsewhere at IEC 2019, Gilmour Morrison of GW Pharmaceuticals, the Cambridge, England, company that markets Epidiolex, presented the findings of a series of drug-drug interaction studies involving coadministration of their CBD with clobazam (Sympazan and Onfi), valproate, stiripentol (Diacomit), or midazolam (Versed) in adult epilepsy patients and healthy volunteers. The researchers reported a bidirectional drug-drug interaction between Epidiolex and clobazam resulting in increased levels of the active metabolites of both drugs. The mechanism is believed to involve inhibition of cytochrome P450 2C19. However, there were no interactions with midazolam or valproate, and the slight bump in stiripentol levels when given with CBD didn’t reach the level of a clinically meaningful drug-drug interaction, according to the investigators.

On the horizon, Canadian researchers are investigating the possibility that since both the tetrahydrocannabinol (THC) and CBD components of marijuana have been shown to have anticonvulsant effects, adding a bit of THC to CBD will result in even better seizure control than with pure CBD in patients with Dravet syndrome. Investigators at Toronto’s Hospital for Sick Children have conducted a prospective, open-label study of a product containing CBD and THC in a 50:1 ratio as add-on therapy in 20 children with Dravet syndrome. The dose was 2-16 mg/kg/day of CBD and 0.04-0.32 mg/kg/day of THC. The cannabis plant extract used in the study was produced by Tilray, a Canadian pharmaceutical company.

Nineteen of the 20 patients completed the 20-week study. The sole noncompleter died of SUDEP (sudden unexpected death in epilepsy) deemed treatment unrelated. Patients experienced a median 71% reduction in motor seizures, compared with baseline. Sixty-three percent of patients had at least a 50% reduction in seizure frequency. Elevated liver transaminases occurred in patients on concomitant valproic acid, as did platelet abnormalities, which have not been seen in the Epidiolex studies, noted Dr. Patel, who was not involved in the Canadian study (Ann Clin Transl Neurol. 2018 Aug 1;5[9]:1077-88).

Dr. Patel reported serving as a consultant to Greenwich Biosciences, a U.S. offshoot of GW Pharmaceuticals. He receives research grants from that company as well as from the National Institutes of Health and the Pediatric Epilepsy Research Foundation.

 

– Interim results of long-term, open-label extension trials of add-on prescription cannabidiol in patients with Dravet syndrome or Lennox-Gastaut syndrome show sustained, clinically meaningful seizure reductions with no new safety concerns, Anup D. Patel, MD, reported at the International Epilepsy Congress.

Dr. Anup D. Patel, chief of child neurology at Nationwide Children's Hospital in Columbus, Ohio
Dr. Anup D. Patel

“Overall, this is a very promising and sustainable result that we were happy to see,” said Dr. Patel, chief of child neurology at Nationwide Children’s Hospital in Columbus, Ohio.

Epidiolex is the brand name for the plant-derived, highly purified cannabidiol (CBD) in an oil-based oral solution at 100 mg/mL. Dr. Patel has been involved in the medication’s development program since the earliest open-label compassionate use study, which was followed by rigorous phase 3, double-blind, placebo-controlled randomized trials, eventually leading to Food and Drug Administration marketing approval for the treatment of Dravet syndrome and Lennox-Gastaut syndrome in patients 2 years of age or older.

“On June 25th, 2018, history was made: for the first time in United States history, a plant-based derivative of marijuana was approved for use as a medication, and it was also the first FDA-approved treatment for Dravet syndrome,” Dr. Patel noted at the congress sponsored by the International League Against Epilepsy.

A total of 96% of the 289 children with Dravet syndrome who completed the 14-week, double-blind, controlled randomized trials enrolled in the open-label, long-term extension study, during which they were on a median of three concurrent antiepileptic drugs along with a mean modal dose of CBD at 22 mg/kg/day. Although the target maintenance dose of CBD was 20 mg/kg/day, as advised in the product labeling, physicians could reduce or increase the dose up to 30 mg/kg/day.

“In the initial compassionate-use study, our site could go up to 50 mg/kg/day,” according to Dr. Patel. “We have plenty of data showing efficacy and continued safety beyond the FDA-recommended dose.”

In the open-label extension study, the median reduction from baseline in monthly seizure frequency assessed in 12-week intervals up to a maximum of week 72 was 44%-57% for convulsive seizures and 49%-67% for total seizures. More than 80% of patients and/or caregivers reported improvement in the patient’s overall condition as assessed on the Subject/Caregiver Global Impression of Change scale.

The pattern of adverse events associated with CBD has been consistent across all of the studies. The most common side effects are diarrhea in about one-third of patients, sleepiness in one-quarter, and decreased appetite in about one-quarter. Seven percent of patients discontinued the long-term extension trial because of adverse events.

Seventy percent of patients remained in the long-term extension study at 1 year.

Twenty-six patients developed liver transaminase levels greater than three times the upper limit of normal, and of note, 23 of the 26 were on concomitant valproic acid. None met criteria for severe drug-induced liver injury, and all recovered either spontaneously or after a reduction in the dose of CBD or valproic acid. But this association between CBD, valproic acid, and increased risk of mild liver injury has been a consistent finding across the clinical trials program.

“This is a very important clinical pearl to take away,” commented Dr. Patel, who is also a pediatric neurologist at Ohio State University.

The interim results of the long-term, open-label extension study of add-on CBD in patients with Lennox-Gastaut syndrome are similar to the Dravet syndrome study. Overall, 99% of the 368 patients with Lennox-Gastaut syndrome who completed the 14-week, double-blind, randomized trials signed up for the open-label extension. During a median follow-up of 61 weeks, the median percent reduction in seizure frequency as assessed in serial 12-week windows was 48%-70% for drop seizures and 48%-63% for total seizures. Twenty-four percent of patients withdrew from the study. Eighty-eight percent of patients or caregivers reported an improvement in overall condition when assessed at weeks 24 and 48. Forty-seven patients developed elevated transaminase levels – typically within the first 2 months on CBD – and 35 of them were on concomitant valproic acid.
 

 

 

More on drug-drug interactions

Elsewhere at IEC 2019, Gilmour Morrison of GW Pharmaceuticals, the Cambridge, England, company that markets Epidiolex, presented the findings of a series of drug-drug interaction studies involving coadministration of their CBD with clobazam (Sympazan and Onfi), valproate, stiripentol (Diacomit), or midazolam (Versed) in adult epilepsy patients and healthy volunteers. The researchers reported a bidirectional drug-drug interaction between Epidiolex and clobazam resulting in increased levels of the active metabolites of both drugs. The mechanism is believed to involve inhibition of cytochrome P450 2C19. However, there were no interactions with midazolam or valproate, and the slight bump in stiripentol levels when given with CBD didn’t reach the level of a clinically meaningful drug-drug interaction, according to the investigators.

On the horizon, Canadian researchers are investigating the possibility that since both the tetrahydrocannabinol (THC) and CBD components of marijuana have been shown to have anticonvulsant effects, adding a bit of THC to CBD will result in even better seizure control than with pure CBD in patients with Dravet syndrome. Investigators at Toronto’s Hospital for Sick Children have conducted a prospective, open-label study of a product containing CBD and THC in a 50:1 ratio as add-on therapy in 20 children with Dravet syndrome. The dose was 2-16 mg/kg/day of CBD and 0.04-0.32 mg/kg/day of THC. The cannabis plant extract used in the study was produced by Tilray, a Canadian pharmaceutical company.

Nineteen of the 20 patients completed the 20-week study. The sole noncompleter died of SUDEP (sudden unexpected death in epilepsy) deemed treatment unrelated. Patients experienced a median 71% reduction in motor seizures, compared with baseline. Sixty-three percent of patients had at least a 50% reduction in seizure frequency. Elevated liver transaminases occurred in patients on concomitant valproic acid, as did platelet abnormalities, which have not been seen in the Epidiolex studies, noted Dr. Patel, who was not involved in the Canadian study (Ann Clin Transl Neurol. 2018 Aug 1;5[9]:1077-88).

Dr. Patel reported serving as a consultant to Greenwich Biosciences, a U.S. offshoot of GW Pharmaceuticals. He receives research grants from that company as well as from the National Institutes of Health and the Pediatric Epilepsy Research Foundation.

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