"These patients deserve and will soon have access to a cannabinoid medicine that has been thoroughly studied in clinical trials, manufactured to assure quality and consistency, and available by prescription under a physician's care," Gover said.
Epidiolex will become available in the fall, Gover told CNN. He would not give any information on cost, saying only that it will be discussed with insurance companies and announced later.
With Epidiolex meeting FDA standards, the drug will "finally be made available to the thousands that may benefit from it," he said.
It's an option for those patients who have not responded to other treatments to control seizures.
According to the Epilepsy Foundation, up to one-third
of Americans who have epilepsy have found no therapies that will control their seizures.
Shauna Garris, a pharmacist, pharmacy clinical specialist and adjunct assistant professor at the University of North Carolina's Eshelman School of Pharmacy, said the drug is effective and works somewhere between "fairly" and "very well." She has not used Epidiolex in her own clinical practice and was not involved in the development of the drug but said she's not sure it will live up to "all of the hype" that has surrounded it.
There are side effects, the most common being sleepiness, Gover said. But Garris highlighted that many of the side effects occur when it is taken with other medications, which she said is a concern because most patients are on other medications.
There are likely to be drug interactions, she said, but "that's not uncommon for antiepileptic medications," and she noted that this could affect the effectiveness of the medication.
The European Medical Society is also considering approval of Epidiolex and is expected to announce a decision in the first quarter of next year, according to Gover.
A phase three clinical trial is underway for a third seizure-related condition called tuberous sclerosis complex, which begins in infancy and causes a sudden stiffening of the body, arms and legs, with the head bent forward. Glover said that if the results are positive, his company will apply for supplemental approval for this condition.
In the meantime, it is possible that once on the market, Epidiolex could be prescribed for conditions other than the ones it's approved for. This is called off-label use and is a common practice with many medications.
As part of the FDA's review of the medication, the potential for abuse was assessed and found to be low to negative, according to Gover.
Still, this approval comes as the White House is said to be reconsidering federal prohibition of marijuana and as more and more states approve it for recreational and medicinal use.
Gover said the approval signals "validation of the science of cannabinoid medication."