At 3 months old, Marissa Parsons began having frequent seizures, some lasting a half-hour. For almost two decades, her desperate parents tried drug after drug to treat her rare type of childhood epilepsy, but the medications mostly produced side effects — pancreatitis, hives and extreme drowsiness — and she was frequently hospitalized. Family outings became almost impossible. Eventually, her mother said, Marissa stopped smiling.
Three years ago, Marissa was enrolled in a clinical trial at Nationwide Children's Hospital in Columbus, Ohio, testing a liquid anti-seizure drug made from a component of marijuana. Marissa, who cannot speak and uses a wheelchair, quickly went from eight seizures a day to half that number; these days, the 21-year-old has some weeks in which she doesn't have any seizures. She routinely goes to her sisters' baseball games and band concerts. In 2016, she and her family visited Mount Rushmore and the Grand Canyon. Plus, she's smiling again.
“We can function like a typical family,” said her mother, Ronda Parsons. “That, and her smile, mean the world to me.”
The drug that helped Marissa, called Epidiolex, is on the verge of becoming the first drug approved by the FDA that is derived from marijuana. In April, an advisory committee unanimously recommended approval of the drug for two of the most severe types of childhood epilepsy, and the agency is expected to render its decision by the end of June. The medication is an oral solution containing highly purified cannabidiol, or CBD, which is one of scores of chemicals in the cannabis plant. It contains only trace amounts of the psychoactive element THC, and does not induce euphoria.
For those who have long argued that cannabis offers medical benefits, an FDA approval would be a milestone, “a recognition that the plant is a rich source of compounds which have potential therapeutic activity,” said Justin Gover, chief executive of GW Pharmaceuticals, the London-based company that developed the drug. “We are just scratching the surface of what could be a range of cannabis-based medications.”
The FDA previously has cleared medications containing synthetic versions of THC for nausea for patients getting chemotherapy and for other uses, but it has not approved any drug derived from the plant itself. Marijuana and its components, including CBD, are Schedule 1 controlled substances — meaning they are banned because they are thought to have a high abuse potential, no medical value and serious safety implications. If approved by the FDA, cannabidiol would probably be reclassified by the Drug Enforcement Administration within 90 days.
The company is seeking approval to use the drug to treat Lennox-Gastaut and Dravet syndromes, which cause uncontrolled daily seizures and put patients at high risk for other physical and intellectual disabilities, injury and early death. The disorders afflict fewer than 45,000 people in the United States, but experts expect Epidiolex to be prescribed for other types of epilepsy, as well.
The medication, which would continue to be manufactured in Britain, would be marketed by Greenwich Biosciences, the U.S. subsidiary of GW Pharmaceuticals. The drugmaker is testing other CBD treatments for glioblastoma and schizophrenia.
Shlomo Shinnar, president of the American Epilepsy Society and a neurologist at Montefiore Medical Center in New York, said the drug would be “a very valuable addition” to the limited options for treating severe childhood-onset epilepsy. Shinnar said he would welcome approval of a medicine that had undergone stringent FDA review for safety and effectiveness.
Many parents already are giving children unregulated CBD formulations that are available in medical marijuana dispensaries in the many states where such operations are legal.
Heather Jackson, who lives in Colorado Springs, began giving her son Zaki a compound called Charlotte's Web, an unregulated type of CBD, six years ago. Her son, who was 12 at the time, had been having uncontrollable seizures since he was 6 months old. Not long after he started CBD, she said, the seizures stopped and did not return for four years. Now, he has occasional, minor seizures, Jackson said. She co-founded Realm of Caring Foundation to provide support services for people using CBD therapy and does not plan on switching her son to Epidiolex.
Igor Grant, a psychiatrist at the University of California at San Diego and director of the Center for Medicinal Cannabis Research, said an FDA approval for Epidiolex might spur companies to investigate CBD for other purposes. There are “clues” it might be helpful for treating anxiety, post-traumatic stress disorder and inflammatory diseases such as Crohn's, but “it's all speculation at this point,” he said. Early next year, his center is planning to launch a four-year study looking at CBD and autism.
In many ways, the story of Epidiolex began with Sam Vogelstein, a Berkeley, Calif., youngster who once was having as many as 100 seizures a day. In late 2012, Sam, who was 11 at the time, flew with his mother to London to try the GW Pharmaceuticals' compound; he was the first person from the United States to take the drug. His seizures declined sharply, and his remarkable response, along with pleas from other patients and doctors, prompted the company to begin making the unapproved medicine available in the United States under the FDA's “expanded access” program. The company then launched clinical trials at several medical centers. Those trials showed major reductions in seizures.
In April, Sam Vogelstein testified at the FDA advisory committee meeting in support of the drug. The audience applauded. Now 17, he takes Epidiolex and an older medication and has not had any seizures for two and a half years. This fall, he will be a junior in high school.
“He wants be a neurologist,” said his father, Fred Vogelstein, a contributing editor at Wired magazine. “He wants to help other people.”