Psychedelic · ELE-101

ELE-101 (intravenous psilocin benzoate)

Phase 1/2Beckley Psytech Limited (ATAI)

Patent-protected intravenous benzoate-salt formulation of psilocin (4-hydroxy-N,N-dimethyltryptamine), the active metabolite of psilocybin and a non-selective serotonergic 5-HT2A agonist. Delivered as a short (~10-minute) IV infusion to produce a high-intensity but short-duration psychedelic experience (~2 hour treatment window) with more consistent, controllable exposure than oral psilocybin. Lead indication major depressive disorder. Chemical identifiers below refer to the active moiety psilocin; ELE-101 is its benzoate salt.

Also known as: ELE-101, psilocin, 4-hydroxy-N,N-dimethyltryptamine, 520-53-6, psilocin benzoate

Modality
Psychedelic
Chemical class
tryptamine, indole
DEA schedule
Schedule I
Chemistry
Achiral
Mechanism
5-HT2A agonist
Highest phase
Phase 1/2
Developer
Beckley Psytech Limited (ATAI)
Trials
1 tracked · 2 sites

Mechanism of action

ELE-101 delivers psilocin, the active metabolite of psilocybin, directly by IV infusion. Psilocin is a non-selective serotonergic agonist whose 5-HT2A receptor agonism mediates the classic psychedelic experience thought to underlie rapid, durable antidepressant effects; it also engages other serotonin receptors (5-HT1A, 5-HT2C). IV delivery bypasses oral psilocybin's variable first-pass conversion, giving more consistent, controllable exposure and a shorter ~2 hour experience.

TargetActionAffinity
5-HT2AprimaryHTR2AAgonistpEC50 7.6
5-HT1AHTR1AAgonist
5-HT2CHTR2CAgonist

Formulations

FormulationRouteRegimenPharmacokinetics
ELE-101 (IV psilocin benzoate)psilocin benzoate salt; ~10-minute IV infusion
Single intravenous infusion administered over approximately 10 minutes; acute effects short-lived (patients typically ready for discharge within ~2 hours of dosing)
IntravenousSingle dose

Development timeline

Phase 1/2Jun 2024 – Dec 2024
  1. metPositive Phase 2a topline: single IV dose of ELE-101 produced mean >20-point MADRS reduction sustained to 3 months in MDD (n=6); 4/4 evaluable subjects in remission at Day 90
  2. Initial Phase 1 results reported (well tolerated, dose-proportional PK, high-intensity short-duration psychedelic experiences) and first patients dosed in the open-label Phase 2a (MDD) portion.
Phase 1Oct 2022
  1. Phase 1/2a trial NCT05434156 initiated (study start date); Part 1 single-ascending-dose study in healthy adults.

ELE-101 (intravenous psilocin benzoate) for Major depressive disorder

Phase 1/2ActiveMajor depressive disorder indication →

ELE-101 (intravenous psilocin benzoate) for major depressive disorder. A single combined Phase 1/2a trial (NCT05434156): Part 1 was a randomized, double-blind, placebo-controlled single-ascending-dose study in healthy adults; Part 2 an open-label Phase 2a study in MDD patients. Phase 1 (June 2024) showed ELE-101 was well tolerated with a dose-proportional PK profile and induced high-intensity, short-duration psychedelic experiences (~2 hour treatment window). Positive Phase 2a topline (announced 16 Dec 2024, n=6 MDD): a single ~10-minute IV infusion produced a mean >20-point reduction in MADRS at all time points through 3 months; all 4 subjects evaluable at Day 90 met remission criteria; well tolerated with mostly mild, transient adverse events and no serious or severe AEs; patients ready for discharge in a mean ~2 hours. Trial Active, not recruiting; estimated primary completion December 2025.

Readouts

  • 2024-12-16ReportedTopline datametNCT05434156

    Positive Phase 2a topline: single IV dose of ELE-101 produced mean >20-point MADRS reduction sustained to 3 months in MDD (n=6); 4/4 evaluable subjects in remission at Day 90

Clinical trials

NCT05434156Phase 1/2Activen=84

A Phase I, Randomised, Double-Blind, Placebo-Controlled Study to Assess Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of Single Ascending Intravenous Doses of ELE-101 in Healthy Adult Participants (Part 1) and Part 2, Open-Label Study to Evaluate a Range of Pharmacodynamic Effects of a Single Intravenous Dose of ELE-101 in Patients With Major Depressive Disorder

Started Oct 2022· Primary completion Dec 2025· 📍 2 sites across 1 country (United Kingdom)

metsecondaryMADRS change from baseline (Phase 2a open-label, through Day 90) — mean >20-point MADRS reduction at all time points through 3 months; 4/4 evaluable subjects in remission at Day 90

Open-label Phase 2a (Part 2), n=6 MDD. A single ~10-minute IV infusion of ELE-101 induced rapid, robust antidepressant effects with a mean reduction of more than 20 points on MADRS observed at all time points through 3 months; all 4 subjects evaluable at Day 90 met remission criteria. Well tolerated (mostly mild, transient AEs; no serious/severe AEs); mean ~2 hours to readiness for discharge. Note: open-label, n=6, no placebo/comparator arm in Part 2.

Identifiers

Sources

  1. atai Life Sciences Announces Update on Beckley Psytech's Phase 1/2a Trial of ELE-101 (IV Psilocin) for MDD, with Initial Phase 1 Results and First Patients Dosed in Phase 2a — atai Life Sciences
  2. Beckley Psytech announces initial Phase I results and first Phase IIa patients dosed - ELE-101 (IV psilocin benzoate) for MDD — Beckley Psytech (atai/Beckley)
  3. Beckley Psytech announces positive topline results from Phase IIa study of ELE-101 (IV psilocin benzoate) for Major Depressive Disorder — Beckley Psytech / AtaiBeckley
  4. ELE-101 Safety & Tolerability Study in Healthy Participants and Patients With Depression (NCT05434156) — ClinicalTrials.gov
  5. psilocin — IUPHAR/BPS Guide to Pharmacology (Ligand 11291) — IUPHAR/BPS
  6. Psilocin (ligand 11291) — biological activity (5-HT2A pEC50 7.6, agonist) — IUPHAR/BPS Guide to PHARMACOLOGY