Definium Therapeutics has reported positive Phase III results for its LSD-based medicine DT120 in generalised anxiety disorder, giving the company a second late-stage clinical success for the same drug this year.
The result puts Definium in an increasingly strong position as it attempts to develop lysergide into a conventional pharmaceutical treatment for psychiatric disorders.
The company, formerly known as Mind Medicine or MindMed, said on 12 August that its Phase III Voyage study met its primary endpoint, with patients receiving a single 100-microgram dose of DT120 recording a significantly greater reduction in anxiety symptoms than those receiving placebo.
DT120 Reduced Anxiety After a Single Dose
Voyage enrolled 214 adults with generalised anxiety disorder, a condition characterised by persistent and excessive anxiety that can interfere with everyday life.
Patients receiving DT120 recorded an 11.6-point reduction from baseline on the Hamilton Anxiety Rating Scale after 12 weeks, compared with a 6.2-point reduction among patients receiving placebo.
The resulting placebo-adjusted difference was 5.4 points, with a Cohen’s d effect size of 0.81 and a p-value below 0.0001.
The effect appeared quickly. Definium said differences from placebo were visible as early as two days after dosing and remained through the 12-week study period.
The company also reported a 43% response rate in the DT120 group at Week 12, compared with 16% for placebo, while 14% of patients receiving DT120 met the study’s remission threshold compared with 4% of those receiving placebo.
The safety results were broadly consistent with previous clinical studies. Most treatment-emergent adverse events were mild to moderate, transient and concentrated around the dosing session, with no new safety signals or increase in suicidal thoughts reported.
The average time for patients receiving DT120 to meet the study’s end-of-session criteria was 6.4 hours, with 92% meeting those criteria within eight hours.
A Second Phase III Success
The Voyage result is particularly significant because it is the second positive Phase III result for DT120.
In June, Definium reported positive results from Emerge, its first Phase III study of DT120 in major depressive disorder.
The two trials are testing the same medicine in different psychiatric conditions.
That makes the latest result more significant than a standalone positive trial. It provides additional evidence that DT120 may have applications across multiple psychiatric disorders.
Definium is now running a second Phase III study in GAD, known as Panorama.
The company expects topline results from Panorama in September. The trial includes both a 100-microgram DT120 dose and a 50-microgram dose alongside placebo.
If Panorama also produces positive results, Definium could have two successful Phase III GAD studies as well as the positive MDD result from Emerge.
That could support potential regulatory filings covering both anxiety and depression.
Developing LSD as a Pharmaceutical
DT120 is not simply LSD supplied in a clinical setting.
It is Definium’s proprietary formulation of lysergide tartrate, developed as an orally disintegrating tablet using Catalent’s Zydis fast-dissolve technology.
The company is developing the medicine around a single-dose treatment model rather than daily administration.
That is one of the most unusual aspects of the programme.
Most commonly prescribed treatments for anxiety and depression are taken regularly, often every day. DT120 is instead designed to be administered as a single dose during a monitored clinical session, with patients observed for several hours following treatment.
Definium’s Phase III programme consists of four pivotal studies: two in GAD and two in MDD.
The company is also planning a Phase III programme in post-traumatic stress disorder, with the Haven study expected to begin in 2027.
The broader objective is to develop lysergide as a regulated pharmaceutical rather than as a traditional psychedelic treatment.
That means the company is not only testing whether the drug works, but also establishing a dosing protocol, treatment duration, safety profile and clinical delivery model that could potentially be used within mainstream healthcare.
From MindMed to Definium
The company has also undergone a significant transformation over the past year.
Formerly known as Mind Medicine, or MindMed, it changed its name to Definium Therapeutics in January 2026 and began trading on Nasdaq under the ticker DFTX.
The rebrand reflected the company’s move towards a broader pharmaceutical identity.
Its lead programme remains DT120, but Definium is also developing DT402, a programme based on R(-)-MDMA for autism spectrum disorder.
DT402 is currently in Phase 2a development, with initial data expected during 2026.
For now, however, DT120 accounts for the majority of the company’s clinical development activity.
Definium Has the Capital to Keep Going
The company is also in a considerably stronger financial position than many of the smaller psychedelic companies operating in the sector.
Definium reported approximately US$1.1 billion in cash, cash equivalents and investments as of 30 June 2026.
It also recently completed a large public offering that generated approximately US$805 million in gross proceeds and US$757.9 million after offering expenses.
The company says its current resources are sufficient to fund operations into 2030.
That gives Definium the financial capacity to continue its Phase III programme and prepare for potential commercialisation without relying on immediate additional financing.
What Happens Next
The immediate focus is Panorama.
The second Phase III GAD study is expected to report topline results in September.
A positive result would strengthen the case for DT120 in GAD by showing that the Voyage findings can be replicated in another pivotal trial.
It could also put Definium in a position to pursue regulatory submissions for both GAD and MDD, assuming the company’s broader development and regulatory requirements are met.
There are still significant steps between positive Phase III data and an approved medicine.
Definium will need to complete its clinical programme, submit its data to regulators and establish how DT120 can be delivered safely and practically outside a clinical trial.
The treatment model will also need to work commercially.
Unlike a conventional tablet that patients take at home, DT120 requires a monitored dosing session lasting several hours. How that model fits into existing healthcare systems, reimbursement structures and clinical capacity will become increasingly important if the drug advances towards approval.
For now, however, Definium has achieved something that remains unusual in psychedelic medicine.
It has produced positive Phase III results for an LSD-based medicine in two different psychiatric disorders.
The next question is whether Panorama can provide the confirmation needed to take DT120 from a promising late-stage programme towards potential regulatory approval.
