Small Pharma has announced results from its Phase 2a trial of its intravenous formulation of DMT – SPL026 – demonstrating improvement in depression and anxiety.
The study is the first placebo-controlled study of a short-duration psychedelic for the treatment of Major Depressive Disorder (MDD).
The trial investigated the efficacy and safety of a 21.5mg dose of SPL026 with supportive therapy in 34 patients with moderate to severe MDD.
Analyses of additional secondary and exploratory endpoints, including effects on self-reported depression, anxiety and wellbeing, demonstrated that patients receiving at least a single dose of IV SPL026 with supportive therapy experienced clinically relevant improvements in function and mood.
The company states that this supports previously announced topline efficacy results.
Chief Medical and Scientific Officer, Dr Carol Routledge, commented: “We are encouraged by the data from our additional analyses, which further strengthens our previously reported topline efficacy results.
“We are pleased that patient reported outcomes on depression symptoms and broader measures on wellbeing are reflective of the rapid and durable antidepressant effects demonstrated by independent rater assessment using MADRS [Montgomery-Asberg Depression Rating Scale].
“Importantly, the data suggests that SPL026 has the potential to offer symptom relief from elevated anxiety, providing an encouraging basis from which to further explore its potential as a treatment for anxiety-related disorders.
“This data will help inform our future clinical strategy as we think about the expansion of the SPL026 clinical programme and broader pipeline.”
The study
In January 2023, Small Pharma reported that the Phase 2a trial met its primary endpoint with a statistically significant and clinically relevant reduction in depression symptoms at two-weeks post-dose, compared to placebo.
SPL026 with supportive therapy also demonstrated a rapid onset and durable antidepressant effect, as assessed by the Montgomery-Asberg Depression Rating Scale (MADRS).
Small Pharma has said that the analysis of patient-reported depression scores corroborate the MADRS assessments conducted by independent clinical raters.
Improvements in depression scores from baseline were observed across all study timepoints in patients receiving at least a single dose of SPL026, as measured by the Beck Depression Inventory (BDI), including a statistically significant improvement in depression symptoms compared to placebo at two-weeks post-dose.
The efficacy outcomes on the BDI were consistent with MADRS, providing additional support for the rapid and sustained therapeutic profile of SPL026 for the treatment of MDD.
Measures assessing patients’ anxiety and wellbeing were also analysed across the study.
Following both one and two doses of IV SPL026 with supportive therapy, patients demonstrated a rapid and sustained improvement in anxiety symptoms as measured by the State-Trait Anxiety Inventory-Trait (STAI-T) scale.
A statistically significant improvement in anxiety symptoms was observed compared to placebo at two-weeks post-dose.
At 12-weeks following the open-label dose, a -14.2 mean change from baseline (CFB) was demonstrated in the patient group receiving the single dose regimen.
Further, a rapid and sustained improvement in wellbeing was observed following at least a single treatment of IV SPL026 with supportive therapy, as measured by the Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS).
The results at two-weeks following the blinded dose of SPL026 or placebo showed a 10.1 mean CFB in the SPL026 group compared to 0.9 in the placebo group.
Statistical analysis was conducted on the MADRS open-label data. A statistically significant difference in mean total MADRS score was observed for both the one and two dose regimen groups across all open-label study timepoints.
Further analysis was conducted to assess the difference in total MADRS scores between the one and two dose regimen groups using a mixed model of repeated measures for all subjects across all timepoints.
No statistical difference was demonstrated between these dose regimens across all time points to 12 weeks. This analysis provides further support that a single dose of SPL026 is sufficient to elicit a rapid and durable antidepressant effect.
Further analysis of the Phase 2a dataset is ongoing and full trial results will be submitted for publication in a peer-reviewed journal.
CEO, George Tziras, said: “Alongside our recent release of positive topline efficacy results from the Phase IIa study, this additional analysis demonstrates that a single treatment of SPL026 with therapy has the potential to lead not only to rapid and long-lasting relief from depression but provide improvements in anxiety symptoms and offer a broader benefit to patients’ wellbeing.
“With an estimated cost of USD$1 trillion in lost global economic productivity due to depression, the potential for a treatment to offer a more holistic improvement in patients’ mental health has the potential to reduce negative societal and economic impacts of MDD.”
