Psilocybin

New York-based Definium Therapeutics (Nasdaq: DFTX) reported positive topline results from the Phase III Voyage study of DT120 ODT, its proprietary orally disintegrating formulation of lysergide D-tartrate (LSD), in generalized anxiety disorder (GAD), marking the second consecutive Phase III win for the compound in two months. Definium is now on a plausible path toward an NDA submission. Voyage is a randomized, double-blind, placebo-controlled study that enrolled 214 adults aged 18 to 74 with DSM-5-confirmed GAD and a Hamilton Anxiety Rating Scale (HAM-A) total score of at least 20, across approximately 35 US sites. A single 100 µg dose of DT120 ODT produced a least squares mean HAM-A reduction of 11.6 points at Week 12, versus 6.2 points for placebo — a placebo-adjusted difference of 5.4 points (p<0.0001, Cohen's d=0.81). All multiplicity-controlled secondary endpoints were met, including HAM-A change at Week 1 and Clinical Global Impression-Severity (CGI-S) change at Day 2. Response rates (HAM-A ≥50% reduction) at Week 12 were 43% versus 16% for placebo. Adverse events were mild to moderate, transient, and concentrated on the dosing day; no suicidality signal was observed. The average time to meeting end-of-session checklist criteria was 6.4 hours, with 92% of participants clearing the threshold by hour 8. LSD is a classic serotonergic psychedelic that acts partly through serotonin 5-HT2A receptor activation. Definium hypothesizes that downstream changes in neuroplasticity contribute to the sustained symptom improvements observed after a single administration, although the precise therapeutic mechanism remains uncertain. The Voyage result follows the positive Phase III Emerge readout in major depressive disorder (MDD) in June 2026, in which a single DT120 ODT dose produced a placebo-adjusted MADRS reduction of 8.1 points at Week 6 (p<0.0001). The company holds FDA Breakthrough Therapy Designation for DT120 ODT in GAD, which provides a basis for an expedited regulatory dialogue. A second pivotal GAD study, Panorama, includes an additional 50 µg low-dose arm specifically designed to confound participants' ability to identify their dose condition — a methodological response to the functional unblinding problem inherent to psychedelic trials. Definium said Panorama topline results are expected in September 2026. If Panorama confirms the Voyage signal, Definium would hold two GAD datasets and two MDD datasets. The competitive landscape for DT120 ODT in GAD remains sparse at the pivotal stage. Sumitomo Pharma and Otsuka's ulotaront (SEP-363856), a TAAR1 and 5-HT1A receptor agonist, is in Phase II/III development for GAD, while AbbVie's ABBV-932, a dopamine D3-receptor modulator, is in earlier clinical investigation as an adjunct. Neither has Phase III data. In the broader psychedelic therapeutics field, UK-based Compass Pathways (Nasdaq: CMPS) has reported positive results from two Phase III trials of its synthetic psilocybin compound COMP360 in treatment-resistant depression and is pursuing a rolling NDA submission, but targets a different indication. FDA's handling of the COMP360 submission could provide an important regulatory precedent for psychedelic therapies, particularly around supervised administration, functional unblinding and post-dose monitoring. Definium raised USD 805 million in a June 2026 public offering to fund pre-commercialization activities and ongoing clinical development - an indication of investor confidence behind the firm. The single-dose, supervised-administration model DT120 ODT requires will demand new access and reimbursement frameworks, and the September Panorama readout remains the next material data point before any NDA filing. Access the AllSci platform to explore the science behind the news. Spot something wrong? Report an issue with this article

iStock, pxel66 It’s smooth sailing for Definium Therapeutics as the psychedelic biotech charts another win for its LSD candidate, this time in anxiety. The psychedelic previously notched a late-stage victory in depression. Definium Therapeutics’ single-dose oral LSD candidate DT120 significantly reduced anxiety symptoms compared to placebo in a highly anticipated Phase 3 study. It’s the second late-stage win for the company’s lead asset this summer. The latest clinical success also beats analyst expectations, with Jefferies writing that the drug has shown “one of the strongest [placebo-adjusted] efficacy benefits” in generalized anxiety disorder (GAD), while Stifel dubbed the data “a clean win.” The findings follow a separate Phase 3 success for DT120 in major depressive disorder (MDD) that was reported in June. The GAD results are from a 12-week trial of DT120, also called lysergide tartrate, among 214 adults. Dubbed Voyage, the study met its primary and key secondary efficacy endpoints, according to a Wednesday release . ezstandalone.cmd.push(function () { ezstandalone.showAds(129); }); Participants receiving the experimental oral medicine experienced a statistically significant placebo-adjusted reduction of 5.4 points from baseline, as measured by a clinician-administered industry scale of anxiety symptoms. Wall Street analysts had previously projected a 5-point drop and were looking for a strong p-value behind the main endpoint, to which Definium delivered with p < 0.0001. The efficacy was rapid, with changes starting as early as the second day, according to the New York–based biotech. Importantly, the drug’s safety was favorable and consistent with past studies, Stifel analysts wrote Wednesday. No serious adverse events occurred, with most patients ready for discharge after six hours. No suicidality signal or behavior was recorded. “To our knowledge, this is both the largest nominal change and largest standardized effect size ever observed in a pivotal study in GAD,” Definium CEO Rob Barrow said on a Wednesday investor call. “In a disorder with high prevalence, high burden, high unmet need and no innovation in decades, a single dose of DT120 has shown a rapid and durable effect with a magnitude that is more than twice as large as the drugs approved today,” the CEO said. Psychedelics All eyes on psychedelic drugmakers as Definium, Compass near major catalysts Definium Therapeutics’ closely watched anxiety readout could further validate its single-dose LSD candidate, while Compass Pathways advances a psilocybin program through a rolling FDA filing. August 10, 2026 · 3 min read · Gabrielle Masson Read more The efficacy findings are slightly down from the company’s Phase 2b findings of a 7.7 placebo-adjusted symptom reduction among 40 participants, though analysts said that was largely expected given the larger patient population tested in the Phase 3. Voyage also enrolled fewer patients with comorbid MDD than did the earlier trial, a strategic choice made so Definium could “more clearly tease out the effect of DT120 on GAD symptoms specifically as this is something that helps anticipate any regulatory questions around pseudospecificity,” Stifel wrote. The new data build on MDD results shared earlier this summer that saw an 8.1-point placebo-adjusted change in symptoms over six weeks—findings that also exceeded analysts’ expectations. “In our view, single-dose DT120 has produced profound efficacy in 3 Phase II/III datasets across indications,” Jefferies wrote following the newest update. “While success here was mostly expected, we were pleased to see rapid and consistent efficacy to the ph2b with continued robust durability,” Stifel said. Definium is now moving DT120 into a 40-week extension phase for GAD. The company is also awaiting GAD findings from a second late-stage study called Panorama, with a readout slated for next month. That trial is slightly larger than Voyage and designed a little differently, with a subtherapeutic dose arm serving as another point of comparison. Psychedelics Psychedelics surge again as Compass, Definium provide more clinical validation Psychedelics are gaining momentum in depression, with one treating physician predicting that the drug class could “wipe out the SSRIs” if safety and durability hold up. July 9, 2026 · 5 min read · Gabrielle Masson Read more Previously, Jefferies forecast at least $1.5 billion peak sales in GAD for DT120, adding in Wednesday’s note that “the Street may start to entertain higher peak sales” opportunities in GAD if confirmed by the second Phase 3 data. Success in Panorama would position Definium to new drug application for GAD “likely sometime in the first half of next year,” Stifel anaylsts wrote. DT120 has secured FDA Breakthrough Therapy designation in the indication. The LSD candidate is also being developed for post-traumatic stress disorder, with a late-stage trial slated to launch next year. “A single-dose treatment option delivering meaningful benefits for 12 weeks is a promising step forward not found in today’s therapies,” Brian Barnett, vice chair of psychiatry at Cleveland Clinic and a principal investigator for Voyage, said in a prepared statement from Definium. “If approved, it could give patients and their physicians a treatment option that works through an entirely different mechanism than anything currently used in clinical practice,” he added. Definium is a definitive leader in the psychedelics space, second only to Compass Pathways, which holds the potential to bring the first classic psychedelic therapy to market next year. The sentiment surrounding psychedelics has improved significantly this year with strong readouts from Compass and Definium alike, plus federal interest and support. Psychedelics Psychedelics on the cusp of market breakthrough as clinical, policy support grow While there are several FDA-approved psychiatric medicines on the market, many patients still struggle to achieve lasting symptom relief. Psychedelics could help fill this gap. August 10, 2026 · 8 min read · Tristan Manalac Read more