A psychedelic drug that gives trips lasting half an hour improves the symptoms of moderate to severe depression for up to six months, early trial results suggest.
Biotechnology company Small Pharma announced the results of its phase 2a clinical trials of the effects of a pharmaceutical-grade formulation of Dimethyltryptamine (SPL026) on major depressive disorder, simply referred to as depression.
The drug is a powerful hallucinogenic found in several plants and is the psychoactive compound found in ayahuasca, a compound used in shamanic rituals in South America.
The individual sessions lasted less than two-and-a-half hours, and included a preparation session with a therapist, a psychedelic experience after administering the drug (where the therapist was present) lasting less than 30 minutes, and a therapy session to help patients process their trip.
According to data from the trial, among the patients who had achieved remission within three months of taking the drug, 64% sustained remission to six months.
Robin Carhart-Harris, director of the psychedelics division at the Weill Institute for Neurosciences at the University of California San Francisco, who is also the Ralph Metzner distinguished professor of neurology, psychiatry and behavioural sciences, said: “These data indicate that SPL026 can elicit a fast-acting antidepressant response that appears to be enduring in several cases.
“Recent neuroimaging and preclinical findings imply a regenerative action with DMT and other related serotonergic agonists.”
The trial investigated the effectiveness and safety of 21.5mg of SPL026 given intravenously with supportive therapy in 34 patients with moderate or severe depression.
The study was carried out in two stages – the first aimed to assess the efficacy of a single dose of SPL026 with supportive therapy, compared to placebo.
And in the second patients received SPL026 treatment, and were followed up for a further three months in study.
They continued to be followed up out of study to six months after the second stage, enabling further assessment of the durability of the antidepressant effect.
A total of 25 patients from both treatment groups completed the six-month patient follow-up.
According to the results announced on Tuesday, which have not been peer-reviewed, of these patients, 14 had initially achieved remission (considered to be no depression, or very mild depression) within the three-month in-study period.
Nine of these people sustained remission at six months.
Dr Carol Routledge, chief medical and scientific officer, said: “With our ongoing analyses of the Phase IIa trial data, we are increasingly encouraged by the treatment potential of SPL026.
“A single dose in conjunction with therapy demonstrated a rapid and robust antidepressant effect after one week.
“As we finalise the design of the Phase IIb study, this data helps to inform our understanding of treatment durability and our approach to patient retreatment within the trial.”
George Tziras, chief executive of Small Pharma, said: “We are pleased to see that participants in our study experienced durable relief from their depression for an extended period of time.
“Given these clinical outcomes from one or two treatments, this could further offer potential value to healthcare systems that face challenges with patients who struggle to adhere to their daily antidepressant use.”
Dr James Rucker, consultant psychiatrist and senior clinical lecturer at the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London, said: “Phase 2a trials generally cannot tell us whether a treatment is effective, but they can pave the way for further trials that may. This is the case here.
“On the face of it, this data is encouraging. However, this part of the study does not include a comparator group so it is not possible to gauge whether participants may have improved for reasons unrelated to the drug and therapy provided.
“It is important to note that, when all participants who took part in this part of the trial were considered, the majority were not in remission.
“This is not unusual in trials in major depression, and underpins the observation that major depression is a multifactorial problem that responds to psychological and social treatments, as well as biological.
“This work is a good foundation for further, more rigorous trials using DMT given alongside psychotherapy for people suffering with major depression.”