Medical company Lykos Therapeutics on Friday said the US Food and Drug Administration (FDA) had rejected its bid for approval to use the psychedelic substance MDMA to treat post-traumatic stress disorder (PTSD). 

Lykos said it had received a formal "complete response letter" to its application refusing it, at least for the time being. 

"The FDA communicated that it had completed its review of the [new drug application] and determined that it could not be approved based on data submitted to date," Lykos said in a statement.  

"The FDA has requested that Lykos conduct an additional Phase 3 trial to further study the safety and efficacy of midomafetamine," it said, using another name for the substance more commonly known as the active ingredient in ecstasy.

'Deeply disappointing' decision: CEO

Phase 3 trials can take years, cost millions to conduct and are particularly difficult for smaller organizations.

"The FDA request for another study is deeply disappointing," Lykos CEO Amy Emerson said Friday in a statement. "Our heart breaks for the millions of military veterans, first responders, victims of sexual and domestic abuse and countless others suffering from PTSD who may now face more years without access to new treatment options."

The FDA said on Friday that the MDMA application had "significant limitations" that "prevent the agency from concluding that the drug is safe and effective for the proposed indication." It said it would continue encouraging "innovation for psychedelic treatments and therapies to address these medical needs."  

Company plans to appeal decision

Lykos said it had requested a meeting to appeal the decision and also said it had lodged complaints about the evaluation process so far. 

The reasons given for the refusal, Lykos said, "echo those raised during the FDA Advisory Committee meeting on June 4, 2024."

Observers had expected the FDA to refuse the application given a meeting in June when a panel of government advisors voted overwhelmingly against the drug's use.

But Lykos said the company and other stakeholders had "expressed concerns around the structure and conduct of the Advisory Committee meeting." These included "the limited number of subject matter experts on the panel and the nature of the discussion, which at times veered beyond the scientific content in the briefing documents," it said. 

The bid would have made MDMA the first illegal psychedelic to become a federally approved medicine in the US. Australia took a similar step last year. 

MDMA, otherwise known as active ingredient of 'ecstasy'

MDMA was first synthesized by a German chemist at the company Merck, Anton Köllisch, in 1912. 

Its experimental use as a treatment in psychotherapy dates back to the 1970s. 

It was popularized as a party drug in the 1980s and is the core ingredient of "ecstasy." 

The substance can have relatively mild psychedelic effects and a stronger impact on empathic or emotional experiences.

Proponents of its use in medicine argue that in smaller doses it can complement psychotherapy for people with conditions like PTSD, social anxiety, or autism.

Lykos, which says on its company homepage that it was founded in 2014 "to create an organization that could bring novel psychedelic-assisted therapies to market and integrate them into the healthcare system," is among these. 

msh/sms (AP, AFP)