Common side effects associated with Epidiolex included somnolence, diarrhea, vomiting, decreased appetite/weight loss, and elevated hepatic transaminases (high levels of liver enzymes that might indicate liver damage).
It is carbohydrate neutral and compatible with ketogenic diets — a diet high in fats and low in carbs that has been shown to reduce the frequency of seizures and improve cognitive function in children with Dravet syndrome.
“The frequency and severity of seizures have profound impacts on quality of life, risk for injury (eg, convulsive seizures in [Dravet syndrome], drop seizures in [Lennox-Gastaut syndrome]), health care use, and increased risk for mortality,” the researchers wrote.
Relevant studies focused on assessing the efficacy and safety of Epidiolex in patients were identified through the EMBASE and Ovid MEDLINE databases. Studies on the pharmacokinetics — essentially how the body affects a medicine — in humans, animal models, and lab-cultured cells were also included in the review. Information on clinical trials was also extracted from clinicaltrials.gov.
Previous clinical trials have found that Epidiolex effectively reduces the frequency of epileptic seizures when used in combination with other anti-epileptic medications.
According to the researchers, the EAP trial was the first to present preliminary evidence suggesting “CBD’s positive effect in reducing seizure frequency and tolerable safety profile.”
Further chemical analysis also revealed that when used together with another anti-epileptic medication, such as Onfi (clobazam) or Depacon (valproate sodium), Epidiolex may increase the risk of side effects and should, therefore, be administered with caution.
“Our expectation was and continues to be that physicians will prescribe to gain experience with an initial set of patients and observe those patients over a four- to six-month period as to therapeutic effect, before determining how to utilize Epidiolex in a broader set of patients,” Gangolli said, adding that it has now entered that evaluation period.
Since its launch last November, more 7,600 patients have received an Epidiolex prescription, and more than 1,900 doctors have prescribed the med, Julian Gangolli, who just retired as GW’s commercial chief, said on the company’s first-quarter earnings call, calling it “an unusually high rate of new-patient acquisition.”
The company is also seeing a higher percentage of adult patients than it had expected, which Gangolli attributed to payer deals that feature less restrictive prior authorization requirements, or no prior authorization at all. Because Epidiolex’s dosage level is weight-based, more adult patients could also translate into bigger sales.
But Epidiolex could boast an official new indication soon. Results from a phase 3 trial of Epidiolex in the rare childhood-onset condition tuberous sclerosis complex (TSC) showed the drug could significantly cut the number of seizures by 48.6% on the 25 mg/kg/day dose or 47.5% on double that dosage level over 16 weeks. Patients on placebo only saw a 26.5% reduction, GW reported Monday. The most common side effects lined up with those seen in the drug’s four pivotal studies.
Given the “huge influx of patients,” Gangolli cautioned about looking at quarter-on-quarter growth when Q2 results come around. Some unusual factors played into the Q1 beat that neither execs nor analysts seem to have expected.
GW itself helped turn up the valve by increasing the number of specialty pharmacies in its network and cutting the time to fill the initial prescriptions from over a month at launch to an average of two weeks in Q1. And more than 75% of some 900-plus clinical trial patients have transitioned to the commercial product, a faster-than-expected conversion that contributed to the initial surge in scripts, Gangolli said.
GW Pharmaceuticals’ cannabis-based seizure drug Epidiolex is off to an exceptionally good start—so good that executives tried hard to dampen investor enthusiasm for the rest of the year by pointing to some “unusual launch dynamics.”
Clinical Effect Data – All Patients
At the end of 12 weeks, 13% of Dravet syndrome patients were seizure-free.
At the request of the study authors, the data disclosed in this press release is limited to the data presented at the AES meeting.
Clinical Effect Data – Dravet syndrome patients only
, M.D., of New York University Langone Medical Center’s Comprehensive Epilepsy Center. “These data reinforce and support the safety and efficacy we have shared in previous studies. Most importantly it is providing hope to the children and their families who have been living with debilitating seizures.” However, Devinsky cautions that “these results are from an uncontrolled study. Further study is needed before results can be confirmed. Randomized controlled studies are now underway to help us better understand the effectiveness of the drug. We very much look forward to the results from these studies during 2016.”