The U.S. Food and Drug Administration has denied approval for a treatment for post-traumatic stress disorder that uses MDMA, a drug known as ecstasy, according to a statement released Thursday by the company that develops it, Lykos Therapeutics.
The FDA said it could not validate the treatment "based on the data submitted to date" and asked the company to "conduct an additional phase 3 trial" to obtain data on the "safety and efficacy" of the treatment, according to the statement.
MDMA is an illicit substance in the United States, so its approval for medical treatment would represent a major change.
The treatment containing ecstasy, known for its illegal use for recreational purposes, was subject to several tests and its intake was accompanied by psychotherapy sessions.
In June, an advisory committee of American experts, convened by the FDA, which often follows its advice, voted against the treatment, based in particular on one of the tests.
Just under 200 people took part in two similar clinical trials: half of the participants received MDMA (or midomafetamine) and the other half a placebo, during three sessions of eight hours each, spaced several weeks apart and conducted in the presence of a therapist.
Participants given MDMA "appeared to experience rapid, clinically meaningful and sustained improvement in their post-traumatic stress symptoms," according to the FDA, but the agency criticized an "incomplete" assessment of possible side effects.
She also pointed out that, given the powerful mood- and sensation-altering effects of ecstasy, patients were largely able to guess whether they had received the treatment or a placebo, which may have influenced the results.
Post-traumatic stress disorder occurs after a traumatic event and affects approximately 51% of the American population.
Those affected are at increased risk of suicidal behaviour and drug addiction, among other things.
There are currently only two approved treatments in the United States, and they are not always effective.
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