CAPLYTA (lumateperone) significantly reduced manic symptoms in bipolar I disorder in a Phase 3 study, with improvement seen as early as Day 3
Written by: Mayuri Vaja, PharmD
Reviewed By: Pharmacally Editorial Team
Johnson & Johnson’s CAPLYTA (lumateperone) significantly reduced manic symptoms in adults with bipolar I disorder in a pivotal Phase 3 study, with statistically significant improvement emerging as early as Day 3 and sustained through Week 3. The study met its primary endpoint, showing a 4.8-point greater reduction in Young Mania Rating Scale (YMRS) total score versus placebo at Week 3.
Phase 3 Study Shows Rapid Antimanic Activity
Study 451 (NCT06462586) was a randomized, double-blind, placebo-controlled Phase 3 trial evaluating once-daily CAPLYTA 42 mg for three weeks in adults with manic episodes, with or without mixed features, associated with bipolar I disorder. The primary endpoint was the change from baseline in YMRS total score at Week 3.
CAPLYTA produced a statistically significant 4.8-point greater reduction in YMRS total score compared with placebo at Week 3, with an effect size of −0.69 (P<0.0001). The difference became statistically significant as early as Day 3 and remained significant through Week 3.
The treatment also improved overall illness severity. At Week 3, the Clinical Global Impression-Severity (CGI-S) score showed a least-squares mean difference of −0.5 versus placebo (P<0.0001).
A greater proportion of patients achieved clinical response, defined as at least a 50% reduction in YMRS total score. Response occurred in 45.8% of patients receiving CAPLYTA versus 20.9% receiving placebo (P<0.0001).
Safety Findings Remain Consistent with Established Profile
The reported safety and tolerability findings were consistent with the established CAPLYTA profile, with low discontinuation rates. In Study 451, the treatment-related adverse events reported in at least 5% of CAPLYTA-treated patients and at least twice the placebo rate were dry mouth (7.9% vs. 3.4%) and nausea (7.9% vs. 2.3%).
The study-specific topline disclosure does not identify somnolence or dizziness as meeting this reporting threshold. Those events are part of CAPLYTA’s established safety profile in other approved psychiatric indications, but they should not be attributed to the Study 451 threshold without study-specific data.
CAPLYTA’s Established Role Across Mood Disorders
CAPLYTA is an oral, once-daily atypical antipsychotic currently approved in adults for schizophrenia, depressive episodes associated with bipolar I or II disorder, and as adjunctive therapy with antidepressants for major depressive disorder. It is not FDA-approved for the treatment of manic episodes associated with bipolar I disorder.
The mechanism of action of lumateperone is not fully established. FDA labeling states that its efficacy could be mediated through a combination of central serotonin 5-HT2A receptor antagonism and partial agonist activity at central dopamine D2 receptors.
Although emerging research is examining additional pharmacologic properties of lumateperone, including effects involving presynaptic dopamine D2 autoreceptors, these mechanisms should not be presented as established explanations for its clinical effects.
Second Phase 3 Mania Study Completed
Study 451 is the first of two pivotal Phase 3 studies evaluating CAPLYTA in adults with bipolar I mania. Johnson & Johnson reported that Study 452 has also been completed, with data analysis underway.
The Study 451 findings were presented as a late-breaking presentation at the 2026 Psych Congress Annual Meeting, held September 15–19 in New Orleans. The results provide clinical evidence supporting further evaluation of lumateperone in acute bipolar I mania, but the indication remains investigational pending regulatory review.
Data from Study 452 will provide the next major clinical milestone for the bipolar mania program. Any future expansion of CAPLYTA into acute mania would require regulatory review and approval.
Reference
CAPLYTA® (lumateperone) shows significant and rapid improvement in bipolar mania in pivotal Phase 3 study, Johnson and Johnson, 21 September 2026
Study of Lumateperone in the Acute Treatment of Patients With Bipolar Mania, ClinicalTrials.gov ID NCT06462586
About the Writer
Mayuri Vaja (Linkedin) is a Pharm.D professional with a strong interest in clinical research, pharmacovigilance, and medical writing, supported by certifications in pharmacovigilance and academic projects exploring AI in healthcare and drug safety.
With a growing focus on evidence-based healthcare and scientific communication, she is developing expertise in clinical research and translating healthcare evidence into clear, meaningful content.
As a Pharmacally healthcare writer, Mayuri is committed to creating accurate, research-driven, and clinically relevant healthcare content while continuously strengthening her professional skills.