SchizophreniaPhase 1NCT02181803
Elpipodect (MK-8189) Multiple Dose Study in Healthy Volunteers and Schizophrenia Participants (MK-8189-003)
A Phase 1 study testing Elpipodect and Base Monotherapy in people with Schizophrenia, run by Merck Sharp & Dohme LLC.
Trial summary
This 3-part dose titration study will assess elpipodect safety, tolerability, pharmacokinetics (PK), and central nervous system activity. Part 1 (Panels A and B) will assess elpipodect administered as monotherapy in participants with schizophrenia. Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Schizophrenia
- What is being tested?
- Elpipodect and Base Monotherapy
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 55 participants
- Where
- No sites listed yet
- Study dates
- 5 Aug 2014to 23 Apr 2015
- Phase
- Phase 1
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Male or non-pregnant and non-breast feeding female. If participant is male with a female partner of child-bearing potential, participant must agree to use a medically acceptable method of contraception during the trial and for 120 days after the last dose of trial drug. If their partner is pregnant, males must agree to use a condom
- Body Mass Index (BMI) ≥ 18.5 and ≤ 40 kg/m^2
- Meet diagnostic criteria for schizophrenia or schizoaffective disorder according to the Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria with the onset of the first episode being no less than 2 years prior to study entry
- Be in the non-acute phase of illness and clinically stable for 3 months prior to screening
- History of receiving and tolerating antipsychotic medication within the usual dose range employed for schizophrenia
- Participants with hypothyroidism, diabetes, high blood pressure, chronic respiratory conditions or other mild forms of these medical conditions could be considered as candidates for study enrollment if their condition is stable and the prescribed dose and regimen of medication is stable for at least 3 months prior to screening and there are no expected changes in comedication during the study
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- Has a negative urinary drug screen at screening
- Male, or non-pregnant and non-breast feeding female of Japanese or non-Japanese descent. If participant is male with a female partner of child-bearing potential, participant must agree to use a medically acceptable method of contraception during the trial and for 120 days after the last dose of trial drug. If their partner is pregnant, males must agree to use a condom
- Body Mass Index (BMI) ≥ 18.5 and ≤ 35 kg/m^2
- In good health
- Nonsmoker and/or has not used nicotine or nicotine-containing products (e.g., nicotine patch) for at least approximately 3 months
- Has a negative urinary drug screen at screening
Who cannot join
- DSM-IV axis I psychiatric diagnosis other than schizophrenia or schizoaffective disorder within one month of screening
- Has evidence or history of mental retardation, borderline personality disorder, anxiety disorder, or organic brain syndrome
- History of neuroleptic malignant syndrome or moderate to severe tardive dyskinesia
- Untreated or uncompensated clinically significant renal, endocrine, hepatic, respiratory, gastrointestinal, psychiatric, neurologic, cardiovascular, hematological, immunological or cerebrovascular disease, malignance, allergic disease or other chronic and/or degenerative process at screening
- Has a history of cancer (malignancy) with certain exceptions
- Treatment with clozapine for schizophrenia or treatment with monoamine oxidase inhibitors within 3 months of screening
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- Received a parenteral depot antipsychotic medication within 3 months of screening
- Participated in another investigational study within 4 weeks, prior to screening
- History of clinically significant endocrine, gastrointestinal, cardiovascular (including hypertension, angina, coronary artery disease, valvular disease, heart rate or rhythm abnormalities), hematological, hepatic, immunological, renal, respiratory, genitourinary or major neurological (including stroke and chronic seizures) abnormalities or diseases
- Mentally or legally incapacitated
- History of clinically diagnosed depression, anxiety disorder, or any history of psychiatric disorders having required drug treatment or hospitalization
- History of cancer (malignancy)
- Unable to refrain from or anticipates the use of any medication, including prescription and non-prescription drugs or herbal remedies throughout the trial
- Participated in another investigational study within 4 weeks, prior to screening
About this study
Official title: A Multiple Dose Study to Assess the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of MK-8189 in Healthy Volunteers and in Schizophrenia Patients
This 3-part dose titration study will assess elpipodect safety, tolerability, pharmacokinetics (PK), and central nervous system activity. Part 1 (Panels A and B) will assess elpipodect administered as monotherapy in participants with schizophrenia. Part 2 (Panel C) will assess elpipodect administered as add-on to atypical antipsychotic treatment in participants with schizophrenia. Part 3 (Panel D) will assess monotherapy with elpipodect in healthy participants, including those of Japanese descent. The primary hypothesis is that there is at least one dose of elpipodect that is generally safe and well-tolerated which will have the desired PK parameters in participants with schizophrenia.
Read the detailed description
As specified by Phase 1 protocol-flexible language in the protocol, modifications to the dose or dosing regimen can be made to achieve the scientific goals of the trial objectives and/or ensure appropriate safety of the trial participants. The proposed doses for each Part may be adjusted downward based on evaluation of safety, tolerability, and pharmacokinetic data observed in previous panels.
- Conditions
- Schizophrenia
- Being tested
- Elpipodect, Placebo, Base Monotherapy
- Medical subject headings
- Schizophrenia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ElpipodectDrug
Also called MK-8189
MK-8189, oral, 2 mg and/or 10 mg tablets, taken QD for a total daily dose of 2 mg, 4 mg, 8 mg, 10 mg, 12 mg, 14 mg, 16 mg, 20 mg, or 40 mg
PlaceboDrug
Placebo matching oral 2 mg and/or 10 mg MK-8189 tablets, taken QD
Base MonotherapyDrug
For Part 2 only: participants need to be on monotherapy with an atypical antipsychotic medication (eg, Olanzapine, Quetiapine, Paliperidone, Asenapine, Iloperidone, Aripirprazole, Lurasidone, Risperidone [not to exceed daily dose of 6 mg], or Ziprasidone.) The participant should be on a stable and well tolerated treatment regimen for at least 2 months prior to screening. NOTE: Clozapine is not allowed.
| Study group | Role | What they receive |
|---|---|---|
| Part 1 Panel A & B Elpipodect Monotherapy 2-40 mg: Schizophrenic | Experimental | Participants with schizophrenia will receive monotherapy of elpipodect in escalating doses starting at 2 mg once daily (QD) up to 40 mg QD, depending on safety and tolerability Receives: Drug: Elpipodect |
| Part 2 Panel C Elpipodect Add-on Therapy 2-20 mg: Schizophrenic | Experimental | Participants with schizophrenia will receive add-on therapy of elpipodect in escalating doses starting at 2 mg QD up to 20 mg QD, depending on safety and tolerability Receives: Drug: Elpipodect; Drug: Base Monotherapy |
| Part 2 Panel C Elpipodect Add-on Therapy 4-20 mg: Schizophrenic | Experimental | Participants with schizophrenia will receive add-on therapy of elpipodect in escalating doses starting at 4 mg QD up to 20 mg QD, depending on safety and tolerability Receives: Drug: Elpipodect; Drug: Base Monotherapy |
| Part 3 Panel D Elpipodect Monotherapy 2-16 mg: Healthy | Experimental | Healthy participants will receive monotherapy of elpipodect in escalating doses starting at 2 mg QD up to 16 mg QD, depending on safety and tolerability Receives: Drug: Elpipodect |
| Part 1 Panel A & B Placebo Monotherapy: Schizophrenic | Placebo comparator | Participants with schizophrenia will receive dose-matched placebo to elpipodect monotherapy Receives: Drug: Placebo |
| Part 2 Panel C Placebo Add-on Therapy: Schizophrenic | Placebo comparator | Participants with schizophrenia will receive dose-matched placebo to elpipodect add-on therapy Receives: Drug: Placebo; Drug: Base Monotherapy |
| Part 3 Panel D Placebo Monotherapy: Healthy | Placebo comparator | Healthy participants will receive dose-matched placebo to elpipodect monotherapy Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Plasma Concentration at 24 Hours Post-dose (C24hr) of MK-8189 in Schizophrenia Participants
C24hr was defined as the concentration of MK-8189 observed in plasma at the 24-hour nominal sampling time after administration of MK-8189. In participants receiving MK-8189, blood samples were collected pre-dose and 24 hours post-dose to estimate C24hr following MK-8189 administration. As specified by the protocol, C24hr was analyzed by part, dose and dosing schedule. Due to differing dosing schedules, some time points were not applicable for certain arms/doses as indicated by zero participants analyzed entered in the table. Per protocol, healthy participants (Part 3) and participants receiving placebo were excluded from C24 analysis.
Measured: Day 1, 4, 8, 11 and 14 pre-dose and 24 hours post-dose
Area Under the Plasma-concentration Curve at Zero to 24 Hours Post-dose (AUC[0-24hr]) of MK-8189 in Schizophrenia Participants
AUC was defined as a measure of MK-8189 exposure that was calculated as the product of plasma drug concentration and time. The linear-up-log down rule was used to estimate AUC. Blood samples were collected pre-dose and up to 24 hours post-dose to estimate AUC(0-24hr) following MK-8189 administration. As specified by the protocol, AUC(0-24hr) was analyzed by part, dose and dosing schedule. Due to differing dosing schedules, some time points were not applicable for certain arms/doses as indicated by zero participants analyzed entered in the table. Per protocol, healthy participants (Part 3) and participants receiving placebo were excluded from AUC(0-24hr) analysis.
Measured: Day 1 pre-dose and 2, 3, 4, 6, 8, 10, 12, 16, 24 hours post-dose; Days 4, 8, 11 pre-dose and 6, 10, 16, 24 hours post-dose; Day 14 pre-dose and 2, 3, 4, 6, 8, 10, 12, 16, 20, 24 hours post-dose
Maximum Observed Post-dose Plasma Concentration (Cmax) of MK-8189 in Schizophrenia Participants
Cmax was defined as the maximum concentration of MK-8189 observed in plasma. Blood samples were collected pre-dose and up to 48 hours post-dose at multiple time points to estimate Cmax following MK-8189 administration. As specified by the protocol, Cmax was analyzed by part, dose and dosing schedule. Due to differing dosing schedules, some time points were not applicable for certain arms/doses as indicated by zero participants analyzed entered in the table. Per protocol, healthy participants (Part 3) and participants receiving placebo were excluded from Cmax analysis.
Measured: Day 1 pre-dose and 2, 3, 4, 6, 8, 10, 12, 16, 24 hours post-dose; Days 4, 8, 11 pre-dose and 6, 10, 16, 24 hours post-dose; Day 14 pre-dose and 2, 3, 4, 6, 8, 10, 12, 16, 20, 24, 36, 48 hours post-dose
Time Post-dose at Which the Maximum Plasma Concentration (Tmax) of MK-8189 Was Observed in Schizophrenia Participants
Tmax was defined as the time required post dose to reach a maximum plasma concentration of MK-8189. It was estimated as the actual sampling time at the highest MK-8189 plasma concentration. Blood samples were collected pre-dose and up to 48 hours post-dose at multiple time points to estimate Tmax following MK-8189 administration. As specified by the protocol, Tmax was analyzed by part, dose and dosing schedule. Due to differing dosing schedules, some time points were not applicable for certain arms/doses as indicated by zero participants analyzed entered in the table. Per protocol, healthy participants (Part 3) and participants receiving placebo were excluded from Tmax analysis.
Measured: Day 1 pre-dose and 2, 3, 4, 6, 8, 10, 12, 16, 24 hours post-dose; Days 4, 8, 11 pre-dose and 6, 10, 16, 24 hours post-dose; Day 14 pre-dose and 2, 3, 4, 6, 8, 10, 12, 16, 20, 24, 36, 48 hours post-dose
Time Required for Plasma Concentration of MK-8189 to Decrease by Half (Apparent t1/2) in Schizophrenia Participants on Day 14
t1/2 was defined as the time required to divide the MK-8189 plasma concentration by half after reaching pseudo-equilibrium. At least three quantifiable post-Cmax, terminal phase concentrations collected were used to calculate the apparent t1/2. Blood samples were collected pre-dose and up to 48 hours post-dose at multiple time points on Day 14 to estimate t1/2 following MK-8189 administration. As specified by the protocol, t1/2 was analyzed by part, dose and dosing schedule. Due to differing dosing schedules, the Day 14 timepoint was not applicable for certain arms/doses as indicated by zero participants analyzed entered in the table. Per protocol, healthy participants (Part 3) and participants receiving placebo were excluded from t1/2 analysis.
Measured: Day 14 pre-dose and 2, 3, 4, 6, 8, 10, 12, 16, 20, 24, 36, 48 hours post-dose
Number of Participants Experiencing an Adverse Event (AE)
An AE was defined as any untoward medical occurrence in a clinical investigation participant administered a pharmaceutical product and which did not necessarily have to have a causal relationship with this treatment. The number of participants who experienced at least one AE were reported.
Measured: Up to Day 28
Number of Participants Who Discontinue From Study Treatment Due to an AE
An AE was defined as any untoward medical occurrence in a clinical investigation participant administered a pharmaceutical product and which did not necessarily have to have a causal relationship with this treatment. The number of participants who discontinued study treatment due to an AE were reported.
Measured: Up to Day 14
Secondary outcomes (2)
Change From Baseline at Day 13 in Mismatched Negativity (MMN) Peak Amplitude in Monotherapy MK-8189-treated Schizophrenia Participants
MMN is a response to deviant tone (stimuli) measured in electroencephalogram (EEG) signals. Difference in deviant EEG waveform amplitude from standard amplitude over time indicates MMN; this difference at peak waveform is MMN peak amplitude. Schizophrenic participants show reduced response to deviant stimuli. Peak amplitude change from baseline (Day -1) to Day 13 was reported. A higher change indicates improved response to deviant stimuli. Scalp EEG signals were collected using a standard system array of 19 electrodes denoted by nomenclature of scalp placement: C3, C4, Cz, F3, F4, F7, F8, Fp1, Fp2, Fz, O1, O2, P3, P4, Pz, T3, T4, T5, T6. As specified by the protocol, MK-8189 add-on therapy schizophrenia participants (Part 2), healthy participants (Part 3) and all placebo-treated participants were excluded from MMN analyses. Per protocol, MMN analyses were planned and executed in all schizophrenia participants receiving MK-8189 monotherapy, irrespective of different dosing schedules.
Measured: Baseline and Day 13
Change From Baseline at Day 13 in Mismatched Negativity (MMN) Area Under Curve (AUC) in Monotherapy MK-8189-treated Schizophrenia Participants
MMN is a response to deviant tone (stimuli) measured in EEG signals. Difference in deviant EEG waveform amplitude from standard amplitude over time indicates MMN; AUC was measured as the product of MMN amplitude and time. Schizophrenic participants show reduced response to deviant stimuli. AUC change from baseline (Day -1) to Day 13 was reported. A higher change indicates improved response to deviant stimuli. Scalp EEG signals were collected using a standard system array of 19 electrodes denoted by nomenclature of scalp placement: C3, C4, Cz, F3, F4, F7, F8, Fp1, Fp2, Fz, O1, O2, P3, P4, Pz, T3, T4, T5, T6. As specified by the protocol, MK-8189 add-on therapy schizophrenia participants (Part 2), healthy participants (Part 3), and all placebo-treated participants were excluded from MMN analyses. Per protocol, MMN analyses were planned and executed in all schizophrenia participants receiving MK-8189 monotherapy, irrespective of different dosing schedules.
Measured: Baseline and Day 13
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Jul 2014 (estimated)
- Study start5 Aug 2014
- Primary completion23 Apr 2015
- Study completion23 Apr 2015
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for SchizophreniaStudies of the same condition, open and under way.
- More trials run by Merck Sharp & Dohme LLCThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 55 participants (actual)
Sponsor and investigators
- Lead sponsor
- Merck Sharp & Dohme LLC
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Medical Director, Study director, Merck Sharp & Dohme LLC
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02181803
- Sponsor's protocol ID
- 8189-003
- Status last verified
- Apr 2026
- First submitted
- 2 Jul 2014
- Last updated
- 29 Apr 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 29 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Multiple Dose Study to Assess the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of MK-8189 in Healthy Volunteers and in Schizophrenia Patients
- ClinicalTrials.gov ID
- NCT02181803
- Acronym / sponsor ID
- 8189-003
- Conditions
- Schizophrenia
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 55 participants (actual)
- Lead sponsor
- Merck Sharp & Dohme LLCIndustry (pharma, biotech, devices)
- Study start
- 5 Aug 2014 (actual)
- Primary completion
- 23 Apr 2015 (actual)
- Study completion
- 23 Apr 2015 (actual)
- First posted
- 4 Jul 2014 (estimated)
- Results
- Posted 27 Mar 2020
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This 3-part dose titration study will assess elpipodect safety, tolerability, pharmacokinetics (PK), and central nervous system activity. Part 1 (Panels A and B) will assess elpipodect administered as monotherapy in participants with schizophrenia. Part 2 (Panel C) will assess elpipodect administered as add-on to atypical antipsychotic treatment in participants with schizophrenia. Part 3 (Panel D) will assess monotherapy with elpipodect in healthy participants, including those of Japanese descent. The primary hypothesis is that there is at least one dose of elpipodect that is generally safe and well-tolerated which will have the desired PK parameters in participants with schizophrenia.
Detailed description
As specified by Phase 1 protocol-flexible language in the protocol, modifications to the dose or dosing regimen can be made to achieve the scientific goals of the trial objectives and/or ensure appropriate safety of the trial participants. The proposed doses for each Part may be adjusted downward based on evaluation of safety, tolerability, and pharmacokinetic data observed in previous panels.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 7
| Arm | Type | Receives |
|---|---|---|
| Part 1 Panel A & B Elpipodect Monotherapy 2-40 mg: Schizophrenic | Experimental | Drug: ElpipodectParticipants with schizophrenia will receive monotherapy of elpipodect in escalating doses starting at 2 mg once daily (QD) up to 40 mg QD, depending on safety and tolerability |
| Part 2 Panel C Elpipodect Add-on Therapy 2-20 mg: Schizophrenic | Experimental | Drug: Elpipodect, Drug: Base MonotherapyParticipants with schizophrenia will receive add-on therapy of elpipodect in escalating doses starting at 2 mg QD up to 20 mg QD, depending on safety and tolerability |
| Part 2 Panel C Elpipodect Add-on Therapy 4-20 mg: Schizophrenic | Experimental | Drug: Elpipodect, Drug: Base MonotherapyParticipants with schizophrenia will receive add-on therapy of elpipodect in escalating doses starting at 4 mg QD up to 20 mg QD, depending on safety and tolerability |
| Part 3 Panel D Elpipodect Monotherapy 2-16 mg: Healthy | Experimental | Drug: ElpipodectHealthy participants will receive monotherapy of elpipodect in escalating doses starting at 2 mg QD up to 16 mg QD, depending on safety and tolerability |
| Part 1 Panel A & B Placebo Monotherapy: Schizophrenic | Placebo comparator | Drug: PlaceboParticipants with schizophrenia will receive dose-matched placebo to elpipodect monotherapy |
| Part 2 Panel C Placebo Add-on Therapy: Schizophrenic | Placebo comparator | Drug: Placebo, Drug: Base MonotherapyParticipants with schizophrenia will receive dose-matched placebo to elpipodect add-on therapy |
| Part 3 Panel D Placebo Monotherapy: Healthy | Placebo comparator | Drug: PlaceboHealthy participants will receive dose-matched placebo to elpipodect monotherapy |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (12 listed)
- Male or non-pregnant and non-breast feeding female. If participant is male with a female partner of child-bearing potential, participant must agree to use a medically acceptable method of contraception during the trial and for 120 days after the last dose of trial drug. If their partner is pregnant, males must agree to use a condom
- Body Mass Index (BMI) ≥ 18.5 and ≤ 40 kg/m^2
- Meet diagnostic criteria for schizophrenia or schizoaffective disorder according to the Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria with the onset of the first episode being no less than 2 years prior to study entry
- Be in the non-acute phase of illness and clinically stable for 3 months prior to screening
- History of receiving and tolerating antipsychotic medication within the usual dose range employed for schizophrenia
Key exclusion criteria (14 listed)
- DSM-IV axis I psychiatric diagnosis other than schizophrenia or schizoaffective disorder within one month of screening
- Has evidence or history of mental retardation, borderline personality disorder, anxiety disorder, or organic brain syndrome
- History of neuroleptic malignant syndrome or moderate to severe tardive dyskinesia
- Untreated or uncompensated clinically significant renal, endocrine, hepatic, respiratory, gastrointestinal, psychiatric, neurologic, cardiovascular, hematological, immunological or cerebrovascular disease, malignance, allergic disease or other chronic and/or degenerative process at screening
- Has a history of cancer (malignancy) with certain exceptions
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ElpipodectAlso: MK-8189MK-8189, oral, 2 mg and/or 10 mg tablets, taken QD for a total daily dose of 2 mg, 4 mg, 8 mg, 10 mg, 12 mg, 14 mg, 16 mg, 20 mg, or 40 mg | Drug | Part 1 Panel A & B Elpipodect Monotherapy 2-40 mg: Schizophrenic, Part 2 Panel C Elpipodect Add-on Therapy 2-20 mg: Schizophrenic, Part 2 Panel C Elpipodect Add-on Therapy 4-20 mg: Schizophrenic, Part 3 Panel D Elpipodect Monotherapy 2-16 mg: Healthy |
| PlaceboPlacebo matching oral 2 mg and/or 10 mg MK-8189 tablets, taken QD | Drug | Part 1 Panel A & B Placebo Monotherapy: Schizophrenic, Part 2 Panel C Placebo Add-on Therapy: Schizophrenic, Part 3 Panel D Placebo Monotherapy: Healthy |
| Base MonotherapyFor Part 2 only: participants need to be on monotherapy with an atypical antipsychotic medication (eg, Olanzapine, Quetiapine, Paliperidone, Asenapine, Iloperidone, Aripirprazole, Lurasidone, Risperidone [not to exceed daily dose of 6 mg], or Ziprasidone.) The participant should be on a stable and well tolerated treatment regimen for at least 2 months prior to screening. NOTE: Clozapine is not allowed. | Drug | Part 2 Panel C Elpipodect Add-on Therapy 2-20 mg: Schizophrenic, Part 2 Panel C Elpipodect Add-on Therapy 4-20 mg: Schizophrenic, Part 2 Panel C Placebo Add-on Therapy: Schizophrenic |
Primary outcome
Plasma Concentration at 24 Hours Post-dose (C24hr) of MK-8189 in Schizophrenia Participants
Time frame: Day 1, 4, 8, 11 and 14 pre-dose and 24 hours post-dose
C24hr was defined as the concentration of MK-8189 observed in plasma at the 24-hour nominal sampling time after administration of MK-8189. In participants receiving MK-8189, blood samples were collected pre-dose and 24 hours post-dose to estimate C24hr following MK-8189 administration. As specified by the protocol, C24hr was analyzed by part, dose and dosing schedule. Due to differing dosing schedules, some time points were not applicable for certain arms/doses as indicated by zero participants analyzed entered in the table. Per protocol, healthy participants (Part 3) and participants receiving placebo were excluded from C24 analysis.
Area Under the Plasma-concentration Curve at Zero to 24 Hours Post-dose (AUC[0-24hr]) of MK-8189 in Schizophrenia Participants
Time frame: Day 1 pre-dose and 2, 3, 4, 6, 8, 10, 12, 16, 24 hours post-dose; Days 4, 8, 11 pre-dose and 6, 10, 16, 24 hours post-dose; Day 14 pre-dose and 2, 3, 4, 6, 8, 10, 12, 16, 20, 24 hours post-dose
AUC was defined as a measure of MK-8189 exposure that was calculated as the product of plasma drug concentration and time. The linear-up-log down rule was used to estimate AUC. Blood samples were collected pre-dose and up to 24 hours post-dose to estimate AUC(0-24hr) following MK-8189 administration. As specified by the protocol, AUC(0-24hr) was analyzed by part, dose and dosing schedule. Due to differing dosing schedules, some time points were not applicable for certain arms/doses as indicated by zero participants analyzed entered in the table. Per protocol, healthy participants (Part 3) and participants receiving placebo were excluded from AUC(0-24hr) analysis.
Maximum Observed Post-dose Plasma Concentration (Cmax) of MK-8189 in Schizophrenia Participants
Time frame: Day 1 pre-dose and 2, 3, 4, 6, 8, 10, 12, 16, 24 hours post-dose; Days 4, 8, 11 pre-dose and 6, 10, 16, 24 hours post-dose; Day 14 pre-dose and 2, 3, 4, 6, 8, 10, 12, 16, 20, 24, 36, 48 hours post-dose
Cmax was defined as the maximum concentration of MK-8189 observed in plasma. Blood samples were collected pre-dose and up to 48 hours post-dose at multiple time points to estimate Cmax following MK-8189 administration. As specified by the protocol, Cmax was analyzed by part, dose and dosing schedule. Due to differing dosing schedules, some time points were not applicable for certain arms/doses as indicated by zero participants analyzed entered in the table. Per protocol, healthy participants (Part 3) and participants receiving placebo were excluded from Cmax analysis.
Time Post-dose at Which the Maximum Plasma Concentration (Tmax) of MK-8189 Was Observed in Schizophrenia Participants
Time frame: Day 1 pre-dose and 2, 3, 4, 6, 8, 10, 12, 16, 24 hours post-dose; Days 4, 8, 11 pre-dose and 6, 10, 16, 24 hours post-dose; Day 14 pre-dose and 2, 3, 4, 6, 8, 10, 12, 16, 20, 24, 36, 48 hours post-dose
Tmax was defined as the time required post dose to reach a maximum plasma concentration of MK-8189. It was estimated as the actual sampling time at the highest MK-8189 plasma concentration. Blood samples were collected pre-dose and up to 48 hours post-dose at multiple time points to estimate Tmax following MK-8189 administration. As specified by the protocol, Tmax was analyzed by part, dose and dosing schedule. Due to differing dosing schedules, some time points were not applicable for certain arms/doses as indicated by zero participants analyzed entered in the table. Per protocol, healthy participants (Part 3) and participants receiving placebo were excluded from Tmax analysis.
Time Required for Plasma Concentration of MK-8189 to Decrease by Half (Apparent t1/2) in Schizophrenia Participants on Day 14
Time frame: Day 14 pre-dose and 2, 3, 4, 6, 8, 10, 12, 16, 20, 24, 36, 48 hours post-dose
t1/2 was defined as the time required to divide the MK-8189 plasma concentration by half after reaching pseudo-equilibrium. At least three quantifiable post-Cmax, terminal phase concentrations collected were used to calculate the apparent t1/2. Blood samples were collected pre-dose and up to 48 hours post-dose at multiple time points on Day 14 to estimate t1/2 following MK-8189 administration. As specified by the protocol, t1/2 was analyzed by part, dose and dosing schedule. Due to differing dosing schedules, the Day 14 timepoint was not applicable for certain arms/doses as indicated by zero participants analyzed entered in the table. Per protocol, healthy participants (Part 3) and participants receiving placebo were excluded from t1/2 analysis.
Number of Participants Experiencing an Adverse Event (AE)
Time frame: Up to Day 28
An AE was defined as any untoward medical occurrence in a clinical investigation participant administered a pharmaceutical product and which did not necessarily have to have a causal relationship with this treatment. The number of participants who experienced at least one AE were reported.
Number of Participants Who Discontinue From Study Treatment Due to an AE
Time frame: Up to Day 14
An AE was defined as any untoward medical occurrence in a clinical investigation participant administered a pharmaceutical product and which did not necessarily have to have a causal relationship with this treatment. The number of participants who discontinued study treatment due to an AE were reported.
2 secondary outcomes
Change From Baseline at Day 13 in Mismatched Negativity (MMN) Peak Amplitude in Monotherapy MK-8189-treated Schizophrenia Participants
Time frame: Baseline and Day 13
Change From Baseline at Day 13 in Mismatched Negativity (MMN) Area Under Curve (AUC) in Monotherapy MK-8189-treated Schizophrenia Participants
Time frame: Baseline and Day 13
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Apr 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Medical Director study director
Merck Sharp & Dohme LLC
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Elpipodect and Base Monotherapy in people with Schizophrenia, run by Merck Sharp & Dohme LLC.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 12 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 29 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 27 Mar 2020). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Plasma Concentration at 24 Hours Post-dose (C24hr) of MK-8189 in Schizophrenia Participants (time frame: Day 1, 4, 8, 11 and 14 pre-dose and 24 hours post-dose). The study lists 7 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Apr 2026.