A Study of RG1678 (RO4917838) in patients with sub-optimally controlled symptoms of schizophrenia.

A Phase III, multi-center, randomized, 12 week, double-blind, parallel-group, placebo-controlled study to evaluate efficacy and safety of RG1678 (RO4917838) in patients with sub-optimally controlled symptoms of schizophrenia treated with antipsychotics followed by a 40-Week, double-blind, parallel-group, placebo-controlled treatment period.

Status

Unknown

Phases

Phase 3

Study type

Interventional

Source

JPRN

Registry ID

JPRN-jRCT2080221450

Enrollment

600

Registered

2011-05-09

Start date

2011-05-09

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Schizophrenia

Interventions

investigational material(s) Generic name etc : RG1678 (RO4917838) INN of investigational material : bitopertin Therapeutic category code : 117 Psychotropic agents Dosage and Administration for Investi

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: -Adult patients, >/= 18 years of age -Diagnosis of schizophrenia -Clinical stability for 12 weeks prior to screening period -Antipsychotic treatment stability for 8 weeks prior to screening period -With the exception of clozapine, patients are on any of the available marketed atypical or typical antipsychotic (treatment with a maximum of two antipsychotics)"

Exclusion criteria

Exclusion criteria: -Has treatment resistant schizophrenia as judged by the treating physician OR have failed two trials -Evidence that patient has clinically significant uncontrolled or unstable medical disorder (e.g. cardiovascular, renal hepatic, gastrointestinal, hematologic, immunological, neurological, endocrine, metabolic or pulmonary disease) -Patient has anorexia or obesity (body mass index (BMI) 40, respectively) -Diagnosis of mental retardation or severe organic brain syndromes -In the investigator's judgment, a significant risk of suicide or violent behavior"

Design outcomes

Secondary

Measure	Time frame
-Symptom domains of schizophrenia using Positive and Negative Syndrome Scale (PANSS). -Disease improvement on Clinical Global Impression - Improvement (CGI-I) symptoms scale. -Disease severity on Clinical Global Impression - Severity (CGI-S) symptoms scale. -Incidence of adverse events -Mean change from baseline in the symptom domains of schizophrenia using PANSS at Week 12. -The CGI-I overall and positive symptoms at Week 12. -The CGI-S overall and positive symptoms at Week 12. -Incidence of adverse events at week 52	—

Measure

Time frame

-Symptom domains of schizophrenia using Positive and Negative Syndrome Scale (PANSS). -Disease improvement on Clinical Global Impression - Improvement (CGI-I) symptoms scale. -Disease severity on Clinical Global Impression - Severity (CGI-S) symptoms scale. -Incidence of adverse events -Mean change from baseline in the symptom domains of schizophrenia using PANSS at Week 12. -The CGI-I overall and positive symptoms at Week 12. -The CGI-S overall and positive symptoms at Week 12. -Incidence of adverse events at week 52

—

Primary

Measure	Time frame
-PANSS positive symptoms factor score -Incidence of Adverse events -Mean change from baseline in the PANSS positive symptom factor score at week 12. -Incidence of adverse events at week 12.	—

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026