Delix Therapeutics has raised $100 million in a series C round to advance zalsupindole, a phase 2-ready non-hallucinatory psychedelic therapy for major depressive disorder. The Boston company said it expects to start a placebo-controlled phase 2b study in the first half of 2027.
The financing was led by Johnson & Johnson’s venture capital arm JJDC, with participation from SV Health Investors’ Dementia Discovery Fund, RA Capital, UC Investments, Artis Ventures and Adage Capital Management, among others. Delix said it will also use the funds to develop other neuroplastogens for neurological and neurodegenerative diseases including substance use disorders, bipolar disorder, schizophrenia and Alzheimer's disease.
The Program
Zalsupindole is an oral neuroplastogen designed to promote structural and functional neuroplasticity without hallucinatory or psychedelic effects. Delix is positioning that distinction as the core of its value proposition in a field more commonly associated with ketamine, psilocybin and second-generation drugs such as Johnson & Johnson’s Spravato.
The drug is based on mebufotenin, which the source describes as a naturally occurring fast-acting psychedelic found in plants and secreted by a species of toad. Delix’s broader thesis is that major depressive disorder damages an interconnected network of brain regions involved in mood regulation, emotion processing, memory and cognitive control through loss of critical synapses, and that neuroplasticity-focused medicines could help repair that network.
In late 2024, the company reported positive phase 1b data for zalsupindole in major depressive disorder. In 106 healthy volunteers enrolled, Delix reported no serious adverse events and no hallucinatory or dissociative effects at any dose level.
Why The Financing Matters
The round gives Delix a larger balance-sheet base as psychedelic development regains momentum, but the investment case here is more specific than a general sector revival. Investors are backing a program that aims to preserve the perceived therapeutic mechanism of psychedelics while removing the hallucinatory effects that can complicate clinical use, care delivery and scaling.
That matters commercially because a non-hallucinatory oral drug could fit more easily into standard depression treatment pathways than therapies that require the infrastructure and monitoring associated with psychedelic experiences. JJDC’s lead role and participation from crossover and specialist investors also suggest there is still demand for differentiated central nervous system programs when the mechanism and development plan are clear enough to support a later-stage clinical push.
Delix was founded in 2019 out of the University of California lab of co-founder and chief innovation officer David Olson, Ph.D. The company previously raised a $70 million series A in 2021. With the series C now in place, the next real test shifts from platform story to mid-stage efficacy in patients with major depressive disorder.
