--- title: "New Late-Stage Trial Results Aim to Expand Options for Major Depressive Disorder" slug: mdd-clinical-trials-topline-results-2026 category: health category_label: "Health" author: "BrainWavePost Staff" date: 2026-06-23 tags: ["depression", "clinical trials", "mental health", "pharmaceuticals", "MDD", "treatment-resistant depression"] read_time_minutes: 7 canonical_url: https://brainwavepost.com/article/mdd-clinical-trials-topline-results-2026 source: BrainWavePost --- # New Late-Stage Trial Results Aim to Expand Options for Major Depressive Disorder *Health · 2026-06-23 · BrainWavePost Staff · 7 min read* > Pharmaceutical companies released promising topline data from late-stage trials for Major Depressive Disorder, including an LSD-based candidate and a new adjunctive therapy that nearly doubled remission rates. > **How this article is sourced** _(info)_ > > All claims are drawn from primary sources: Definium Therapeutics' official press release via BusinessWire (June 2026), Psychiatric Times coverage of the Phase 3 Emerge study, Fierce Biotech and Endpoints News industry reporting, Johnson & Johnson official press releases via PR Newswire on CAPLYTA remission data and ACNP 2026 presentations, the U.S. National Institute of Mental Health (NIMH), and the World Health Organization (WHO) depression fact sheet. [1][2][3][4][5][6][7][8] Major Depressive Disorder (MDD) remains one of the leading causes of disability worldwide, affecting an estimated 280 million people globally according to the World Health Organization. [8] For roughly one-third of patients, first-line treatments such as selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) provide inadequate relief — a population often described as having treatment-resistant depression. [7] This week, two separate late-stage clinical trial readouts offered new evidence that pharmaceutical innovation may be catching up to the unmet need. [1][5] ## Definium Therapeutics: Phase 3 success for an LSD-based antidepressant On June 22, 2026, Definium Therapeutics announced positive topline results from its Phase 3 Emerge study evaluating DT120, an orally disintegrating tablet formulation of lysergic acid diethylamide (LSD), in adults with MDD. [1] The study met its primary efficacy endpoint and all key secondary endpoints, with patients on DT120 showing an 8.1-point improvement on the Montgomery-Åsberg Depression Rating Scale (MADRS) compared to placebo. [1][2] The data attracted immediate attention across the biotech industry. Fierce Biotech reported that Definium's CEO called the results the 'best data ever seen' in a pivotal depression trial for a psychedelic-derived therapy. [3] Endpoints News noted that the effect size was achieved in a severe form of depression, suggesting the drug may be particularly valuable for patients who have failed multiple prior treatments. [4] DT120 is designed to be taken in a controlled clinical setting, with a short-acting profile intended to allow same-day dosing without the prolonged duration typical of conventional psychedelic sessions. [1] > The Emerge study met its primary endpoint and all key secondary endpoints, with an 8.1-point MADRS improvement over placebo — a magnitude that industry observers are calling unprecedented for a psychedelic-derived antidepressant in Phase 3. > > — Definium Therapeutics press release, June 22, 2026 [1] ## Johnson & Johnson: CAPLYTA nearly doubles remission rates Separately, Johnson & Johnson released new clinical data highlighting CAPLYTA (lumateperone) as a promising option for achieving remission in adults with MDD when used as an adjunctive therapy alongside existing antidepressants. [5] Pooled data from two Phase 3 studies showed that CAPLYTA nearly doubled the likelihood of remission at six weeks compared to placebo. [5] In a six-month open-label extension study, 65% of patients reached remission and 43% achieved sustained relief from symptoms. [5] The data were presented at the 2026 American College of Neuropsychopharmacology (ACNP) Annual Meeting, where J&J also shared post-hoc analyses of SPRAVATO (esketamine) effects on anhedonia in treatment-resistant depression. [6] A separate network meta-analysis presented at the same meeting ranked CAPLYTA highest among FDA-approved adjunctive MDD therapies across four measures of efficacy, with the added advantage of no significant weight gain compared to placebo. [5] - **8.1 pts** — MADRS improvement over placebo for Definium's DT120 in Phase 3 Emerge [1] - **~2x** — Likelihood of remission at 6 weeks with CAPLYTA vs. placebo as adjunctive therapy [5] - **65%** — Of patients reached remission in CAPLYTA open-label extension at 6 months [5] ## Why these results matter for treatment-resistant patients The clinical significance of both readouts extends beyond the numbers. According to the U.S. National Institute of Mental Health, treatment-resistant depression is typically defined as failure to respond to at least two adequate trials of antidepressant medications. [7] These patients face a substantially higher risk of chronic disability, hospitalisation, and suicide. [7] New mechanisms of action — whether the serotonin-2A receptor modulation underlying LSD-derived therapies or the multimodal dopamine-serotonin activity of lumateperone — offer hope for patients who have exhausted standard options. [3][5] Industry analysts note that the regulatory environment for novel antidepressants has also shifted. In April 2026, the Trump administration signed an executive order directing the FDA to grant priority review vouchers to companies developing psychedelic-based therapies, accelerating the path to market for drugs like DT120. [3] The FDA's Digital Health Advisory Committee has simultaneously been refining guidance on how to evaluate novel mental health interventions, including those with psychedelic mechanisms. [3] ## Cautions and what comes next Topline results, while encouraging, represent only the first phase of regulatory review. Full datasets from both the Emerge study and the CAPLYTA adjunctive programme will need to undergo FDA scrutiny, including analyses of safety, durability, and subgroup responses. [1][5] Definium has not yet announced a timeline for regulatory submission, though the company has stated it intends to pursue FDA approval based on the Phase 3 data. [1] Johnson & Johnson, which already markets CAPLYTA for schizophrenia and bipolar depression, is expected to file a supplemental indication for adjunctive MDD. [5] For patients and clinicians, the immediate takeaway is that the pipeline for MDD is diversifying. After decades dominated by SSRIs and SNRIs, the field is now exploring psychedelic derivatives, multimodal receptor agents, and combination therapies that target different neurotransmitter systems simultaneously. [3][7] None of these approaches are guaranteed to reach pharmacy shelves, but the breadth of late-stage activity suggests the next several years could bring meaningful new options for the millions of people whose depression has not responded to existing treatments. [1][5] ## Sources (clickable) - [1] Definium Therapeutics — 'Definium Therapeutics Announces Positive Topline Results from Phase 3 Emerge Study of DT120 Orally Disintegrating Tablet (ODT) in Major Depressive Disorder' (22 June 2026) via BusinessWire: https://www.businesswire.com/news/home/20260622572802/en/Definium-Therapeutics-Announces-Positive-Topline-Results-from-Phase-3-Emerge-Study-of-DT120-Orally-Disintegrating-Tablet-ODT-in-Major-Depressive-Disorder - [2] Psychiatric Times — 'Positive Topline Results From Phase 3 Emerge Study of DT120 ODT in Major Depressive Disorder' (22 June 2026): https://www.psychiatrictimes.com/view/positive-topline-results-from-phase-3-emerge-study-of-dt120-odt-in-major-depressive-disorder - [3] Fierce Biotech — 'Definium's LSD formula produces 'best data ever seen' in pivotal depression trial, CEO says' (22 June 2026): https://www.fiercebiotech.com/biotech/definiums-lsd-formula-produces-best-data-ever-seen-pivotal-depression-trial-ceo-says - [4] Endpoints News — 'Definium reports Phase 3 hit for LSD drug in severe form of depression' by Ayisha Sharma (22 June 2026): https://endpoints.news/definium-reports-phase-3-hit-for-lsd-drug-in-severe-form-of-depression/ - [5] Johnson & Johnson — 'New clinical data highlights CAPLYTA (lumateperone) as a promising option for achieving remission in adults with major depressive disorder' via PR Newswire: https://www.prnewswire.com/news-releases/new-clinical-data-highlights-caplyta-lumateperone-as-a-promising-option-for-achieving-remission-in-adults-with-major-depressive-disorder-302662763.html - [6] Johnson & Johnson — 'Johnson & Johnson elevates leadership in depression with new data at 2026 American College of Neuropsychopharmacology Annual Meeting' via PR Newswire: https://www.prnewswire.com/news-releases/johnson--johnson-elevates-leadership-in-depression-with-new-data-at-2026-american-college-of-neuropsychopharmacology-annual-meeting-302659160.html - [7] U.S. National Institute of Mental Health (NIMH) — 'Depression' overview and treatment-resistant depression resources: https://www.nimh.nih.gov/health/topics/depression - [8] World Health Organization (WHO) — 'Depression and Other Common Mental Disorders: Global Health Estimates' and fact sheets: https://www.who.int/news-room/fact-sheets/detail/depression --- _Canonical article: [https://brainwavepost.com/article/mdd-clinical-trials-topline-results-2026](https://brainwavepost.com/article/mdd-clinical-trials-topline-results-2026) — © BrainWavePost. Educational content; see the article page for full disclaimers._