Nearly 30 states have some sort of approval of medical marijuana or cannabis, and nine states (including the District of Columbia) have taken the step of legalizing recreational marijuana use. This week, the U.K.-owned GW Pharmaceuticals won unanimous approval from an expert panel at the FDA to market its cannabidiol (CBD) drug, Epidiolex, in the U.S. They are seeking to market Epidiolex to treat Lennox-Gastaut and Dravet syndromes, two rare epilepsy conditions that occur in very young children. These diseases are rarely responsive to other drugs.

If Epidiolex receives full FDA approval (an announcement will be forthcoming in June of this year), it will likely be the beginning of a domino effect that will lead to the declassification or reclassification of how the cannabis plant and its derivatives are classified in the Controlled Substances Act. Currently, cannabis is listed as Schedule I, which means that it has no medical value and pharmaceutical companies aren’t allowed to make it.

In order for Epidiolex to win complete approval and be marketed, it must receive a positive decision by the U.S. Drug Enforcement Administration (DEA) and the FDA’s parent agency, the U.S. Department of Health and Human Services. Despite years of anecdotal evidence and the many states approving cannabis for medical or recreational use, to date, the DEA has been recalcitrant to re- or de-classifying cannabis from Schedule 1 because CBD exists in cannabis along with tetrahydrocannabinol (THC), which is known to produce the intoxicating or euphoric effects of cannabis. Interestingly, the Federal government itself owns a U.S. patent (US 6,630,507) relating to the use of cannabinoids in treating certain diseases. Although, CBD itself is not intoxicating, because CBD coexists with THC in cannabis plants, the DEA has maintained that CBD is considered an illegal substance—just like other marijuana products. Currently, in states that have legalized medical and recreational marijuana products, even products sold as “CBD-only,” typically contain other compounds—or cannabinoids—including THC, even in minute amounts.

Even CBD derived from industrial hemp plants (cannabis plants which do not contain THC but from which other cannabinoids, such as CBD, can be extracted) is considered to be Schedule 1. Although the DEA has broad discretion in how it interprets and enforces the Controlled Substances Act, courts have been equivocal on the issue of substances derived from the cannabis plant versus those derived from hemp plants. One argument is that substances derived from the cannabis plant fall under the Controlled Substances Act and are scheduled as Schedule 1, while products derived from the mature stalks (i.e. hemp) should not be controlled. Thus, if a company could extract pure CBD with no detectable amount of THC from a hemp plant, a plain reading of the Controlled Substances Act could provide cover for its legality.

Currently, strict rules emerging from a 2014 Farm Bill about the manner in which hemp can be grown in the U.S. make it illegal to grow for commercial purposes. However, Kentucky Republican Sen. Mitch McConnell recently introduced a bill in the U.S. Senate, which would take hemp out of the Controlled Substances Act and make it a mainstream crop after decades of prohibition. Hemp plants would be treated like any other crop and regulated by the U.S. Department of Agriculture, rather than the Department of Justice and its DEA. According to the bill, hemp would be defined as a Cannabis sativa plant at or below 0.3% THC. CBD derived from hemp thus would not likely be covered as a marijuana-derived product under the Controlled Substance Act and not be Schedule 1.

If Epidiolex is approved by the FDA in June, the DEA will then have to reschedule CBD since it will have been demonstrated to have a medical value. The FDA has previously approved other synthetic medications (i.e. Marinol® and Cesamet®) that resemble or are identical to THC to treat nausea from chemotherapy and other conditions. These are listed at Schedule III and Schedule II, respectively.

GW Pharmaceuticals does not indicate whether Epidiolex is derived from hemp or marijuana but instead comes from a proprietary strain of cannabis grown by GW Pharmaceuticals.

Full FDA approval of Epidiolex would be a blessing for parents of children with the debilitating and often fatal forms of epilepsy that this drug would treat. Parents often watch in horror of their children’s violent seizures, which can break bones. Worse, parents and families often are forced to move to states where CBD (typically as an oil) or marijuana is legal either recreationally or medically to obtain CBD oil for their children’s epilepsy. Alternatively, many parents resort to importing CBD oil illegally into their state through so called “underground railroads.” Having an approved and regulated medication available in a standard dose will allow these children to be treated anywhere, legally.

The potential approval of Epidiolex could very well open the door to controlled clinical trials for other uses of CBD and THC. The beginning of this domino effect may conceivably lead to the removal of cannabis and marijuana from Schedule 1 of the Controlled Substance Act, and hence the legalization of cannabis on the Federal level in all 50 states.