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Bitopertin in Negative Symptoms of Schizophrenia-Results From the Phase III FlashLyte and DayLyte Studies
Dragana Bugarski-Kirola1, Thomas Blaettler2, Celso Arango3
1Global Development Team, Basel, Switzerland.
Background:
There is currently no standard of care for treatment of negative symptoms of schizophrenia, although some previous results with glutamatergic agonists have been promising.
Methods:
Three (SunLyte [WN25308], DayLyte [WN25309], and FlashLyte [NN25310]) phase III, multicenter, randomized, 24-week, double-blind, parallel-group, placebo-controlled studies evaluated the efficacy and safety of adjunctive bitopertin in stable patients with persistent predominant negative symptoms of schizophrenia treated with antipsychotics. SunLyte met the prespecified criteria for lack of efficacy and was declared futile. Key inclusion criteria were age ≥18 years, DSM-IV-TR diagnosis of schizophrenia, score ≥40 on the sum of the 14 Positive and Negative Syndrome Scale negative symptoms and disorganized thought factors, unaltered antipsychotic treatment, and clinical stability. Following a 4-week prospective stabilization period, patients were randomly assigned 1:1:1 to bitopertin (5 mg and 10 mg [DayLyte] and 10 mg and 20 mg [FlashLyte]) or placebo once daily for 24 weeks. The primary efficacy end point was mean change from baseline in Positive and Negative Syndrome Scale negative symptom factor score at week 24.
Results:
The intent-to-treat population in DayLyte and FlashLyte included 605 and 594 patients, respectively. At week 24, mean change from baseline showed improvement in all treatment arms but no statistically significant separation from placebo in Positive and Negative Syndrome Scale negative symptom factor score and all other end points. Bitopertin was well tolerated.
Conclusions:
These studies provide no evidence for superior efficacy of adjunctive bitopertin in any of the doses tested over placebo in patients with persistent predominant negative symptoms of schizophrenia.
Insights
Adjunctive bitopertin did not demonstrate superior efficacy over placebo for treating negative symptoms of schizophrenia in three Phase III trials. Further research is needed for effective negative symptom treatments.
Area of Science:
- Psychiatry
- Neuroscience
- Clinical Pharmacology
Background:
- No established standard of care exists for treating schizophrenia's negative symptoms.
- Glutamatergic agonists have shown potential in prior investigations.
Purpose of the Study:
- To evaluate the efficacy and safety of bitopertin as an adjunctive treatment for negative symptoms in schizophrenia patients.
- To assess bitopertin's effectiveness in three Phase III clinical trials.
Main Methods:
- Three randomized, double-blind, placebo-controlled Phase III studies (SunLyte, DayLyte, FlashLyte) were conducted.
- Patients with persistent negative symptoms of schizophrenia received adjunctive bitopertin (various doses) or placebo for 24 weeks.
- The primary endpoint was the change from baseline in the Positive and Negative Syndrome Scale negative symptom factor score.
Main Results:
- While improvements were observed across all treatment arms, no statistically significant difference from placebo was found for the primary endpoint or other efficacy measures.
- Bitopertin was generally well-tolerated by patients.
- The SunLyte study was terminated early due to lack of efficacy.
Conclusions:
- The tested doses of adjunctive bitopertin did not show superior efficacy compared to placebo in patients with persistent negative symptoms of schizophrenia.
- These findings indicate bitopertin is not an effective treatment for negative symptoms in this patient population.
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