Caplyta Doubled the Mania Response Rate, and Only Dry Mouth and Nausea Cleared J&J’s Side Effect Bar
- Johnson & Johnson said on 21 September 2026 that Caplyta (lumateperone) 42 mg met the primary endpoint of Study 451, the first of two pivotal Phase 3 trials in adults with manic episodes, with or without mixed features, associated with bipolar I disorder. It cut Young Mania Rating Scale scores by 4.8 points more than placebo at week three (effect size 0.69; p<.0001), with a significant difference from day three.
- Clinical response, defined as at least a 50% fall in the mania score, reached 45.8% on Caplyta against 20.9% on placebo, and illness severity on the key secondary endpoint improved by 0.5 points more. The data were a late-breaking poster at Psych Congress 2026 in New Orleans.
- The only treatment-related adverse events reported in at least 5% of Caplyta patients and at twice the placebo rate were dry mouth, 7.9% against 3.4%, and nausea, 7.9% against 2.3%. The second pivotal trial, Study 452, is complete and in analysis. The release does not give enrolment.
- Caplyta is approved for schizophrenia, for bipolar I or II depression and as an add-on in major depressive disorder, and J&J acquired it in its $14.6bn purchase of Intra-Cellular Therapies. The investigator quoted in the release, Michael Thase, has provided consulting, advisory and speaking services to J&J.
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The efficacy is the headline. The competitive case sits in the side effect line, and it points directly at AbbVie’s Vraylar.
- J&J reported side effects on the threshold AbbVie uses for Vraylar, and the lists differ. At 5% and at least twice placebo, Caplyta’s mania trial named only dry mouth and nausea. Vraylar’s bipolar mania label names extrapyramidal symptoms at 26% against 12% and akathisia at 20% against 5%. Rates from separate trials do not compare cleanly, but in a class where movement side effects drive switching, no motor event on J&J’s list is the claim the full data now has to carry.
- A mania approval would give Caplyta every adult indication Vraylar holds, plus one. Both would cover schizophrenia, bipolar mania, bipolar depression and adjunctive MDD in adults, and Caplyta’s bipolar depression label already extends to bipolar II, which Vraylar’s does not. Vraylar keeps paediatric labels in mania from age 10 and schizophrenia from 13 that Caplyta lacks.
- The numbers that decide the argument are not yet public. The release gives no enrolment, no discontinuation rates and no weight or metabolic change, and the effect size of 0.69 has to be reproduced in Study 452 before it anchors a filing. For a drug sold on tolerability, those are the figures prescribers and payers will wait for.