Six patients who had lived with binge eating disorder for as long as two decades sat down for two infusions of an experimental psychedelic drug. Three months later, all of them were still doing better. Half of them had not binged once.
Those are the twelve-week results Entropy Neurodynamics released from Cohort 1 of its Phase 2 trial of TRP-8803, an intravenously infused form of psilocin, the active metabolite of the psychedelic compound psilocybin. The trial, run in treatment-resistant binge eating disorder patients, is being conducted in collaboration with Swinburne University of Technology.
The trial patients' binge eating disorder had lasted between two and twenty years, with a median duration of fifteen years. Each had already tried and failed at least one previous treatment. Before the study began, they were averaging 2.3 binge eating episodes a week, a disease burden equivalent to 28 episodes over a twelve-week period.
After just two TRP-8803 infusions, all six patients, one hundred per cent of the cohort, maintained a clinically meaningful improvement in their symptoms across the full twelve weeks of follow-up. Three of the six experienced no binge eating episodes at all during the entire 84-day follow-up period, a result the company describes as full clinical remission. Across the whole cohort, weekly binge eating episodes remained 73 per cent below the pretreatment baseline at twelve weeks, essentially holding the 74 per cent reduction reported at the four-week mark in an earlier announcement.
Patients maintained a 50 per cent reduction in anxiety, a 42 per cent reduction in depression and a 61 per cent improvement in quality of life. Clinician-rated Clinical Global Impression scores actually improved further between the two assessment points, rising from a 33 per cent improvement at four weeks to a 44 per cent improvement at twelve weeks.
Entropy's chief executive Jason Carroll said the durability of the response was the point of the exercise. "These 12-week results are particularly encouraging. These were patients who had lived with Binge Eating Disorder for as long as 20 years and who had previously failed treatment. Before entering the study, patients averaged 2.3 binge-eating episodes every week. Following completion of just two TRP-8803 treatments, 50% of patients did not experience a single binge-eating episode during the entire 84-day follow-up period."
"Equally important is what happened across the whole cohort. Every patient maintained a clinically meaningful improvement at 12 weeks and weekly binge-eating episodes remained 73% below baseline. For us, durability is critical. We are not seeking to develop another medicine that patients need to take every day. We are investigating whether a limited number of precision-controlled psychedelic treatments can produce a clinically meaningful benefit that persists long after dosing has finished," he said.
Carroll also pointed to the timing of the release against the backdrop of a newly finalised regulatory framework in the United States. "What is particularly interesting is that the FDA's recently finalised guidance for psychedelic drug development specifically identifies 12 weeks as an important efficacy assessment period for chronic psychiatric conditions. Our BED program has independently generated 12-week follow-up data showing that the clinical response after two TRP-8803 infusions was substantially maintained. These are early data from a small study, but the regulatory direction and the clinical evidence we are generating are increasingly aligned."
The treatment sessions themselves produced what the company calls a powerful and reproducible psychedelic state, with nine of the twelve infusions across the cohort reaching a maximum reported intensity of 10 out of 10 and a mean peak intensity of 9.4 out of 10. Preliminary independent EEG analysis identified large and reproducible changes in brain dynamics following the infusions, including increased EEG complexity and substantial reductions in alpha activity.
Carroll summed up the cumulative picture from Cohort 1 this way. "Cohort 1 has now demonstrated a powerful and reproducible psychedelic experience, reproducible changes in brain dynamics, substantial clinical improvement and encouraging durability. We believe these results provide increasing clinical validation of our precision-controlled approach and materially strengthen the clinical rationale for continued development of TRP-8803."
Attention now turns to Cohort 2, which will trial a shorter infusion regimen of two 60-minute sessions rather than the two 140-minute sessions used in Cohort 1, aiming to make the treatment more efficient and easier to scale in a clinical setting. Topline results are expected in the fourth quarter of calendar year 2026.
