Johnson & Johnson Reports Second Phase 3 Success for CAPLYTA

Johnson & Johnson announced on November 10, 2026, that Study 452, the second pivotal Phase 3 trial of CAPLYTA (lumateperone), met its primary and key secondary endpoints in adults experiencing manic episodes, with or without mixed features, associated with bipolar I disorder. CAPLYTA produced significantly greater improvements in manic symptoms and overall illness severity than placebo, with benefits emerging as early as Day 3 and sustained through Week 3. The findings were presented at the 2026 Neuroscience Education Institute (NEI) Fall Congress, held November 5–8 in Colorado Springs, Colorado.

About CAPLYTA

CAPLYTA is an oral, once-daily atypical antipsychotic approved by the US Food and Drug Administration (FDA) for adults with schizophrenia, depressive episodes associated with bipolar I or II disorder (as monotherapy or adjunctive treatment with lithium or valproate), and major depressive disorder (as adjunctive treatment with antidepressants).

Its mechanism of action is unknown, although its efficacy may involve antagonism of central serotonin 5-HT2A receptors and partial agonism of central dopamine D2 receptors. CAPLYTA is available in 42 mg, 21 mg, and 10.5 mg capsules.

Study Design

Study 452 (NCT06462612) was a global, randomized, double-blind, placebo-controlled Phase 3 trial evaluating once-daily CAPLYTA 42 mg against placebo over three weeks. The study enrolled 351 hospitalized adults (ages 18–75) with bipolar I disorder experiencing manic episodes, with or without mixed features—an inpatient setting that is important to consider when interpreting the findings.

Participants were randomized in a 1:1 ratio to receive CAPLYTA or placebo. The trial primarily assessed changes in the Young Mania Rating Scale (YMRS), with overall illness severity evaluated using the Clinical Global Impression–Severity (CGI-S) scale.

Key Results

• Primary endpoint met: CAPLYTA produced a 3.7-point greater reduction in YMRS total score than placebo at Week 3 (effect size −0.43; ). Significant improvement was observed as early as Day 3 and sustained through Week 3.
• Clinical response: At Week 3, 43.9% of patients receiving CAPLYTA achieved at least a 50% reduction in YMRS total score from baseline, compared with 23.7% receiving placebo (), representing an approximately 20-percentage-point difference in response rates.
• Key secondary endpoint met: CAPLYTA also demonstrated significantly greater improvement in CGI-S scores at Week 3, with a least-squares mean difference of −0.41 versus placebo (). Improvement was observed as early as Day 3.
• Safety: CAPLYTA was generally well tolerated, with low discontinuation rates and a safety profile consistent with previous studies. The most common treatment-emergent adverse events—defined as occurring in at least 5% of CAPLYTA-treated patients and at least twice the placebo rate were dizziness, dry mouth, and somnolence/sedation. Individual adverse event rates were not detailed in the public announcement.

Clinical Interpretation

Study 452 adds a second positive pivotal Phase 3 result for CAPLYTA in acute bipolar I mania, following Study 451. In Study 451, CAPLYTA achieved a 4.8-point greater YMRS reduction than placebo (effect size −0.69) and clinical response rates of 45.8% versus 20.9%. While direct comparisons across separate trials require caution, the consistency of response rates across both studies strengthens the evidence supporting regulatory review, even though the overall YMRS point separation and effect size were somewhat smaller in Study 452.

The early separation from placebo by Day 3 is clinically relevant because manic episodes can escalate rapidly and disrupt functioning. However, the public announcement did not disclose the magnitude of the Day 3 treatment effect, limiting assessment of its early clinical significance. Similarly, while the Week 3 response rate indicates meaningful symptom improvement in a substantial proportion of patients, a 50% reduction in YMRS score does not necessarily represent full remission.

The findings also carry important limitations. Both trials evaluated short-term treatment, leaving relapse prevention, long-term efficacy, and sustained safety unaddressed by Study 452. The absence of an active comparator also prevents conclusions about CAPLYTA’s effectiveness relative to established antimanic therapies. Additionally, although discontinuation rates were described as low, granular adverse event frequencies and metabolic or movement-related safety data were omitted from the press release.

Regulatory Status

Johnson & Johnson plans to use the results from Studies 451 and 452 to support a US FDA submission for bipolar mania. Until regulatory approval is granted, CAPLYTA remains unapproved for manic episodes associated with bipolar I disorder, and its eventual clinical positioning will depend on complete trial data, longer-term safety evidence, and regulatory review.

Reference

Johnson & Johnson Announces CAPLYTA (lumateperone) Shows Significant and Rapid Improvement in Bipolar Mania in Second Pivotal Phase 3 Study, Johnson and Johnson, 10 November 2026

Study of Lumateperone in the Treatment of Patients with Bipolar Mania, ClinicalTrials.gov ID NCT06462612