Olanzapine–Samidorphan Improves Negative Symptoms in Schizophrenia: Study
Canada: A post hoc analysis published in The Journal of Clinical Psychiatry has revealed that patients with acute exacerbation of schizophrenia showed significant improvement in negative symptoms when treated with olanzapine combined with samidorphan (Lybalvi).
Managing negative symptoms—such as social withdrawal, reduced emotional expression, and lack of motivation—remains one of the most challenging aspects of schizophrenia care. These symptoms are often persistent and less responsive to conventional antipsychotic therapies, contributing substantially to long-term functional impairment. In this context, researchers led by Roger S. McIntyre from the University of Toronto evaluated the long-term impact of the olanzapine/samidorphan combination (OLZ/SAM) on negative symptoms over a 56-week period.
The analysis included adults with acute schizophrenia who initially participated in a 4-week randomized phase receiving OLZ/SAM, olanzapine alone, or placebo. Participants who continued into a 52-week open-label extension study were included in this pooled analysis. Negative symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS), specifically the Marder Negative Factor score, a validated measure of negative symptom severity.
The researchers reported the following findings:
- A total of 281 patients were included in the analysis.
- Baseline scores indicated a high burden of symptoms among participants.
- Patients treated with olanzapine/samidorphan (OLZ/SAM) showed meaningful improvement in negative symptoms over 56 weeks.
- The improvement in symptoms was sustained throughout the study duration.
- A significant reduction in the Marder Negative Factor score was observed.
- The findings suggest that OLZ/SAM may effectively target negative symptoms of schizophrenia.
- Improvements were consistent across different patient subgroups.
- Patients with prominent negative symptoms at baseline showed greater reductions in symptom scores.
- Higher baseline severity was associated with greater benefit from treatment.
- Patients with predominant negative symptoms and lower positive symptoms also demonstrated notable improvement.
The findings highlight not only the magnitude but also the durability of response, with benefits maintained throughout the 56-week follow-up period. This sustained effect is particularly relevant given the chronic nature of schizophrenia and the limited treatment options available for negative symptoms.
Overall, the study suggests that the olanzapine/samidorphan combination may represent a promising therapeutic approach for addressing negative symptoms in schizophrenia. While the analysis was conducted post hoc and requires confirmation through prospective studies, the results add to the growing body of evidence supporting the role of combination strategies in improving long-term outcomes. Further research may help clarify patient selection and optimize treatment approaches for this complex and often debilitating aspect of schizophrenia.
Reference:
Roger S. McIntyre, MD; Desiree M. Matthews, PMHNP-BC; Christina Arevalo, MS; David McDonnell, MD; Christoph U. Correll, MD. J Clin Psychiatry 2026;87(2):25m16170
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