Definium LSD formulation cuts anxiety scores across third pivotal trial

A single 100-microgram dose of DT120 separated from placebo by 5.1 points at 12 weeks while an active control tracked dose response.

Definium Therapeutics showed that a single 100-microgram dose of its lysergide formulation significantly outperformed placebo in treating generalized anxiety disorder across a 12-week study.¹² The late-stage trial, named Panorama, evaluated the candidate drug DT120 orally disintegrating tablet in 245 adult patients across approximately 32 clinical sites.¹² Participants receiving the 100-microgram dose achieved an average 9.8-point decline on the Hamilton Anxiety Rating Scale at week 12, compared to a 4.7-point reduction in the placebo group, delivering a statistically significant difference of 5.1 points.¹²

The trial demonstrated rapid symptomatic changes following administration.¹ Reductions in anxiety appeared as early as day two on the Clinical Global Impression-Severity scale, where patients on the 100-microgram dose achieved an average score improvement of 1.1 points against 0.3 points for placebo. By week one, the 100-microgram cohort achieved a 9.8-point reduction on the Hamilton scale compared to 4.5 points for placebo. At the conclusion of the 12-week double-blind period, 32 percent of patients on the active dose met the criteria for clinical response, defined as at least a 50 percent drop in anxiety scores, compared with 14 percent on placebo. Contributor Kyle provided a "Test answer" when Primary asked about participant response thresholds during the study evaluation period.K Remission rates reached 15 percent in the 100-microgram arm against 4 percent for the control group.

Mitigating functional unblinding in psychedelic testing

Psychedelic clinical trials face persistent methodological scrutiny over functional unblinding, a condition where participants and clinical raters deduce who received active treatment due to noticeable psychoactive sensations.² The Food and Drug Administration addressed this issue in formal development guidance for psychedelic compounds.²¹ To determine whether therapeutic improvements derived from pharmacological action independently of patient expectancy, Definium incorporated an active control arm into the Panorama trial protocol.¹² The study assigned 52 patients to receive a lower, 50-microgram dose of DT120, an amount designed to produce psychoactive perception without delivering therapeutic efficacy.¹²

Although the 52-patient arm was not designed or powered for formal statistical comparisons, the group demonstrated distinct separation from the primary treatment dose.¹ Patients in the 50-microgram cohort recorded placebo-adjusted score reductions of 3.5 points at week four and 3.6 points at week 12.¹ Those reductions were approximately 50 percent and 29 percent lower than the therapeutic improvements observed at 100 micrograms.¹ The company observed a corresponding dose-response separation in earlier mid-stage clinical studies.¹² Definium chief executive officer Rob Barrow stated that trial participants clearly recognized psychoactive effects across the tested dose ranges, while the 100-microgram dose maintained superior magnitude and durability over the lower threshold.²

Dosing protocol and clinical administration

DT120 delivers lysergide tartrate, a synthetic ergoline compound acting as a partial agonist at serotonin 5-HT2A receptors, using an orally disintegrating tablet incorporating Catalent Zydis fast-dissolve technology.⁴ The clinical protocol requires participants to complete a supervised eight-hour in-clinic session on dosing day.¹² Each patient is accompanied by a trained chaperone who monitors their physical and emotional condition throughout the acute drug experience.² Clinical staff evaluate patient readiness for discharge using a structured checklist administered hourly starting five hours after dose ingestion.¹

Data from Panorama showed that participants in the 100-microgram group met discharge criteria in an average of 6.2 hours, with a median clearance time of 6.0 hours.¹ By the eighth hour, 94 percent of patients satisfied discharge requirements.¹ Across the broader phase 3 program, which encompasses more than 1,000 treatment sessions through September 10, 2026, 97 percent of participants achieved clearance criteria within eight hours.¹ Following the 12-week primary evaluation window, patients in Panorama enter a 40-week open-label extension during which they can receive up to four supplementary doses based on symptom recurrence.¹

Managing chronic symptoms without daily pills

Generalized anxiety disorder affects roughly 26 million adults in the United States, marked by persistent worry, muscle tension, fatigue, and sleep disruption.¹ Standard medical treatments, including selective serotonin reuptake inhibitors, often require weeks of continuous use and frequently cause adverse effects that prompt treatment discontinuation.¹ Scott Aaronson, chief science officer at the Institute for Advanced Diagnostics and Therapeutics at Sheppard Pratt and a Panorama trial investigator, described the limitations of existing pharmacological options in Definium's statement.¹²

"Patients with generalized anxiety disorder often work through two or three medications before finding one they can tolerate, and even then, daily dosing brings its own burden, sedation, weight change, sexual side effects, and for some classes of medications, real dependence risk," Aaronson said in the release.¹² "What stands out about DT120 ODT is that a single dose has the potential to hold a response for months without the patient managing a pill every day. For a condition this chronic and this undertreated, a treatment that removes daily adherence with a novel mechanism of action and a unique effect on cognitive processes underlying anxiety could change how we think about long-term management, not just acute relief."¹

Tolerability and adverse event profile

Safety evaluations in Panorama indicated that the 100-microgram dose was generally well tolerated, with adverse reactions largely confined to the initial treatment day.¹ Treatment-emergent adverse event rates reached 94.8 percent in the 100-microgram arm, 96.1 percent in the 50-microgram arm, and 62.9 percent in the placebo group.¹ The most frequent reactions among patients receiving 100 micrograms were sensory illusions at 68 percent, nausea at 37 percent, and headaches at 24 percent.¹ In the 50-microgram group, illusion occurred in 61 percent of participants, headache in 28 percent, and nausea in 26 percent.¹

Trial investigators reported no drug-related serious adverse events, and safety monitoring identified no evidence of suicidal ideation or suicidal behavior.¹ Discontinuation rates across the study arms remained closely balanced, with 10.4 percent of participants withdrawing from the 100-microgram group, 11.5 percent from the 50-microgram group, and 10.3 percent from the placebo group.¹ The study recorded adverse events in accordance with regulatory guidance that registers expected perceptual alterations alongside traditional somatic side effects.¹

Clinical trial readouts and regulatory timetable

Panorama represents the second successful late-stage trial for DT120 in generalized anxiety disorder, following the Voyage study completed in August 2026.⁵ Voyage evaluated 214 participants in a randomized comparison against placebo, showing a 5.4-point placebo-adjusted improvement on the Hamilton scale at week 12.²⁴ In major depressive disorder, Definium reported positive results in June from the phase 3 Emerge trial, where 149 participants showed an 8.1-point placebo-adjusted reduction on the Montgomery-Åsberg Depression Rating Scale at week six and a 7.3-point reduction at week 12.⁴ The federal agency granted Breakthrough Therapy designation for DT120 in major depressive disorder following those results, adding to a prior designation in generalized anxiety disorder.⁵¹

Definium scheduled a formal pre-investigational meeting with the FDA for the fourth quarter of 2026 to review requirements for a new drug application, targeting a formal regulatory submission during the first half of 2027.¹² The company is also conducting Ascend, a 165-patient phase 3 depression trial incorporating the 50-microgram active control, and plans to initiate Haven, a 200-patient phase 3 trial in post-traumatic stress disorder, in 2027. Beyond its lysergide program, the company is evaluating an MDMA formulation named DT402 in a phase 2 study for autism spectrum disorder.²⁴

Following an underwritten public offering that yielded $757.9 million in net proceeds during the second quarter of 2026, Definium held approximately $1.1 billion in cash, cash equivalents, and short-term investments at the end of June. Research and development expenses totaled $48.7 million for the second quarter, while net loss reached $159.0 million, driven by non-cash adjustments to financing warrant liabilities. Company executives projected that the existing capital reserve will support operational expenses and clinical pipeline milestones into 2030.⁴

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1. 1 I ir.definiumtx.com Third-party reporting · ir.definiumtx.com Definium Therapeutics Announces Positive Topline Results from Phase 3 Panorama Study of DT120 ODT in Generalized Anxiety Disorder See the source
2. 2 F fiercebiotech.com Document · fiercebiotech.com Press release #359717 See the source
3. 3 K Kyle Contributor · interview 17 Sep 2026 · in the article since 7 Nov 2026 Contribution — Kyle 1 statement added to this article
4. 4 I ir.definiumtx.com Third-party reporting · ir.definiumtx.com Definium Therapeutics Reports Second Quarter 2026 Financial Results and Recent Highlights See the source
5. 5 I ir.definiumtx.com Third-party reporting · ir.definiumtx.com Press Releases See the source

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Article history

1. Published 7 Nov 2026, 19:30
   Assembled by the Primary desk from 4 sources · 1 contributor · 42 cited sentences
2. K Kyle 1 statement added 17 Sep 2026 52 days before publication

   1. Go to the sentence: Contributor Kyle provided a "Test answer" when Primary asked about participant response thresholds during the study evaluation period.↑