SPL026 (DMT Fumarate) in Healthy Subjects and MDD Patients

2-part study. Part A in psychedelic-naïve healthy volunteers. Part B in patients with MDD who score moderate-severe on Ham-D.

Healthy volunteers will receive a single dose of SPL026 in a dose-escalation parallel group study.

Patients will receive up to 2 single doses of SPL026, 2 weeks apart. Dose 1 will be randomised double-blind with placebo. Dose 2 will be open label, active SPL026.

SPL026 will be administered by IV injection. Safety and tolerability, PK, PD and efficacy will be measured.

Inclusion criteria

Normotensive male or female, deemed healthy on the basis of a clinical history, physical examination, ECG, vital signs, laboratory tests of blood and urine, Mini-International Neuropsychiatric Interview (MINI) and Beck Scale for Suicidal Ideation (BSS); willing to follow the contraception requirements of the trial; willing to refrain from psychedelic drug use (excluding the study drug) during the trial and ≥ 3 months afterwards; willing to be contacted by email and video call, and have online access; able to give fully informed written consent. Part A only: psychedelic-naïve, ie have never taken a serotonergic psychedelic drug, in any form. Must be 25 years or older. Part B only: MDD diagnosis (as per DSM-V); not on antidepressant medication or willing to discontinue antidepressant medication (eg selective serotonin reuptake inhibitor [SSRI] treatment) for a sufficient time before and during the study; no psychedelic drug use in the 6 months before dosing.

Exclusion criteria

Pre-menopausal females who are pregnant or lactating, or who are sexually active and not using a reliable method of contraception; clinically relevant abnormal findings at the screening assessment; acute or chronic illness (other than MDD [Part B only]) or infection; clinically relevant abnormal medical history or concurrent medical condition (other than MDD [Part B only]); positive tests for hepatitis B & C, or HIV; severe adverse reaction to any drug; use of over-the-counter or prescribed medication (excluding oral contraceptives) within previous 28 days (paracetamol [acetaminophen] permitted up to 7 days, and antidepressant medication must have ceased for at least 14 days; 28 days for MOAIs) before first dose of trial medication; drug or alcohol abuse; use of cannabis in the 24 h before each study visit; heavy smokers (> 10 [Part A] or > 20 cigarettes [Part B] daily); supine blood pressure, heart rate, or QTcF outside the acceptable ranges; participation in other clinical trials of unlicensed medicines, or loss of more than 400 mL blood, within the previous 3 months; phobia of needles or blood; possibility that volunteer will not cooperate with the study.