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A Study to Test the Safety and Efficacy of MK-8998 in Acutely Psychotic Participants With Schizophrenia (MK-8998-004)

Phase 2
Completed
Conditions
Schizophrenia
Interventions
Drug: MK-8998
Registration Number
NCT00827918
Lead Sponsor
Merck Sharp & Dohme LLC
Brief Summary

A study to evaluate the safety and efficacy of treatment with MK-8998 as compared to placebo and olanzapine for acutely psychotic patients with schizophrenia. The primary hypothesis is that in participants undergoing an acute psychotic episode of schizophrenia, MK-8998 6 to 8 mg twice daily is superior to placebo in the treatment of symptoms of schizophrenia as measured by the mean change from baseline in the Positive and Negative Syndrome Scale (PANSS) total score at Week 4.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
216
Inclusion Criteria
  • Patient's age is 18 to 55
  • Patient meets DSM-IV/DSM-IV-TR criteria for a primary diagnosis of schizophrenia
  • The duration of the patients schizophrenia diagnosis must be greater than 1 year
  • Patient has an acute exacerbation of psychotic symptoms (of at least 3 days but no longer than 6 weeks) and marked deterioration of function
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Exclusion Criteria
  • Patient currently has a clinically significant neurological, metabolic, hepatic, renal, hematological, pulmonary, cardiovascular, gastrointestinal, and/or urological disorder that would pose a risk to the patient in the opinion of the investigator if they were to participate in the study or that might confound the results of the study
  • The patient has evidence of acute hepatitis, clinically significant chronic hepatitis, or impaired hepatic function
  • The patient has a chronic organic disease of the central nervous system (other than schizophrenia) such as, tumors, inflammation, active seizure disorder, vascular disorder, Parkinson's disease, Alzheimer's disease or other forms of dementia, myasthenia gravis, or other degenerative processes. In addition, patients must not have a history of mental retardation or persistent neurological symptoms attributable to serious head injury
  • Patient has a history of alcohol/drug dependence within 3 months or alcohol/drug abuse within 1 month of screening. Exceptions include caffeine and nicotine abuse/dependence
  • Patient has a history of hypersensitivity to olanzapine OR poor response to olanzapine in the last 2 years OR intolerable side effects due to olanzapine OR patients current psychotic relapse occurred while consistently taking a therapeutic dose (10 mg or more) of olanzapine OR olanzapine is medically contradicted
  • Patient is refractory to antipsychotic treatment
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Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
MK-8998MK-8998MK-8998, 6 mg twice a day (BID) for Days 1 to 7, and 8 mg BID thereafter for a 4-week total treatment period
Primary Outcome Measures
NameTimeMethod
Mean Change From Baseline in the Positive and Negative Syndrome Scale (PANSS) at Week 4Baseline and Week 4

PANSS is a medical scale used for measuring symptom severity of participants with schizophrenia. PANSS measure is composed of 3 scales: Positive scale, Negative scale, and General Psychopathology scale. Positive scale assesses hallucinations, delusions and related symptoms; Negative scale assesses emotional withdrawal, lack of motivation, and similar symptoms; and General Psychopathology scale addresses other symptoms such as anxiety, somatic concern and disorientation. The PANSS has 30 items in its 3 scales and an anchored Likert scale from 1 to 7 is used to score each item. Values of 2 and above indicate the presence of progressively more severe symptoms. The Positive scale has 7 items with a score from 7 to 49, the Negative scale has 7 items with a score from 7 to 49, and the General Psychopathology scale has 16 items with a score from 16 to 112. A total score is the sum of the 3 scores for the 3 scales.

Number of Participants Who Experienced at Least One Adverse EventUp to 6 Weeks

An adverse event (AE) is any unfavorable and unintended change in the structure, function or chemistry of the body temporally associated with study drug administration whether or not considered related to the use of the study drug.

Number of Participants Who Discontinued Study Drug Due to an Adverse EventUp to 4 Weeks

An AE is any unfavorable and unintended change in the structure, function or chemistry of the body temporally associated with study drug administration whether or not considered related to the use of the study drug.

Secondary Outcome Measures
NameTimeMethod
Mean Change From Baseline in Clinical Global Impression - Severity of Illness Scale (CGI-S) at Week 4Baseline and Week 4

CGI-S is a commonly used measure of symptom severity in treatment studies of participants with mental disorders. CGI-S is a 7-point scale that requires the clinician to rate the severity of the participant's illness at the time of assessment, relative to the clinician's past experience with participants who have the same diagnosis. Considering total clinical experience, a participant is assessed on severity of mental illness at the time of rating 1 = normal, not at all ill; 2 = borderline mentally ill; 3 = mildly ill; 4 = moderately ill; 5 = markedly ill; 6 = severely ill; or 7 = extremely ill.

Mean Change From Baseline in PANSS Positive Subscale at Week 4Baseline and Week 4

PANSS Positive scale assesses hallucinations, delusions and related symptoms. The Positive scale has 7 items with an anchored Likert scale from 1 to 7 to score each item. Values of 2 and above indicate the presence of progressively more severe symptoms. A total score ranges from 7 to 49.

Mean Change From Baseline in PANSS Negative Subscale at Week 4Baseline and Week 4

PANSS Negative scale assesses emotional withdrawal, lack of motivation, and similar symptoms. The Negative scale has 7 items with an anchored Likert scale from 1 to 7 to score each item. Values of 2 and above indicate the presence of progressively more severe symptoms. A total score ranges from 7 to 49.

Percentage of Participants With Response at Week 4Week 4

Responders were defined as participants who demonstrated ≥ 20% improvement from baseline on the PANSS total score. PANSS measure is composed of 3 scales: Positive scale, Negative scale, and General Psychopathology scale. Positive scale assesses hallucinations, delusions and related symptoms; Negative scale assesses emotional withdrawal, lack of motivation, and similar symptoms; and General Psychopathology scale addresses other symptoms such as anxiety, somatic concern and disorientation. The PANSS has 30 items in its 3 scales and an anchored Likert scale from 1 to 7 is used to score each item. Values of 2 and above indicate the presence of progressively more severe symptoms. The Positive scale has 7 items with a score from 7 to 49, the Negative scale has 7 items with a score from 7 to 49, and the General Psychopathology scale has 16 items with a score from 16 to 112. A total score is the sum of the 3 scores for the 3 scales.

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