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Completed

NCT Number: NCT01251055

GlyT-1 Inhibitor Treatment for Refractory Schizophrenia

The etiology of schizophrenia remains unclear In recent one decade, hypofunction of N-methyl-D-aspartate (NMDA) receptor has been implicated in the pathophysiology of schizophrenia. Hence, enhancing NMDA neurotransmission was considered as a new approach for schizophrenia treatment.

To date, refractory schizophrenia (particularly clozapine-resistant) is still a difficult clinical issue. However, the effect of NMDA treatment in refractory schizophrenia is still unknown. Therefore, the primary goal of this study is to investigate the efficacy and safety of NMDA adjuvant therapy in refractory schizophrenia, and to identify the predictors for treatment response to NMDA enhancers.

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Key information

Conditions

Schizophrenia Mental Disorders Schizophrenia Spectrum and Other Psychotic Disorders Treatment Refractory

Age range

18 year–55 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

China Medical University Hospital

Taichung, Taiwan, 400

About this study

The etiology of schizophrenia remains unclear. In recent one decade, hypofunction of N-methyl-D-aspartate (NMDA) receptor has been implicated in the pathophysiology of schizophrenia. Hence, enhancing NMDA neurotransmission was considered as a new approach for schizophrenia treatment. To date, there have been a few pilot studies exploring the efficacy of NMDA enhancers as adjuvant therapy for schizophrenia, for instance, D-serine (an endogenous agonist of the NMDA-glycine site). They were not only well-tolerated but also synergistic in improving positive, negative and cognitive symptoms in those receiving typical and atypical antipsychotics (except clozapine).

Refractory schizophrenia (particularly clozapine-resistant) is still a difficult clinical issue at present. Previous studies revealed that add-on treatment of D-serine or other agonists of NMDA receptor failed to give significant benefits in such patients. The primary goal of this study is to investigate the efficacy and safety of glycine transporter(GlyT)-1 inhibitor adjuvant therapy in refractory schizophrenia, and to identify the predictors for treatment response to NMDA enhancers.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Fulfill the criteria of schizophrenia according to the Diagnostic and Statistic Manual, fourth edition (DSM-IV).
  • Poor response of clozapine treatment: a 12-week treatment of clozapine without satisfactory response: a severity score of Clinical Global Impression Scale(CGI)>=4, a total score of Positive and Negative Syndrome Scale(PANSS)>= 60, and a Scale for the Assessment of Negative Symptoms(SANS)score of >=40. the doses of clozapine remain stable for at least 12 weeks prior to their enrollment in this proposed study,
  • Agree to participate in the study and provide informed consent.

Exclusion criteria

  • current substance abuse or history of substance dependence in the past 6 months
  • use of depot antipsychotic in the past 6 months
  • serious medical or neurological illness
  • pregnancy
  • inability to follow protocol.

Treatment and study plan

GlyT-1 inhibitor-1

Drug

GlyT-1 inhibitor-1(500) 4# BID

Placebo

Drug

starch

Primary outcomes

  1. The severity of psychiatric symptoms

    Time frame: baseline

    The severity of psychiatric symptoms will be assessed by:

    • Positive and Negative Syndrome Scale(PANSS)
    • Assessment of Negative symptoms(SANS)
    • Global assessment of function(GAF)

  2. The severity of psychiatric symptoms

    Time frame: 2 weeks after the trial

    The severity of psychiatric symptoms will be assessed by:

    • Positive and Negative Syndrome Scale(PANSS)
    • Assessment of Negative symptoms(SANS)
    • Global assessment of function(GAF)

  3. The severity of psychiatric symptoms

    Time frame: 4 weeks after the trial

    The severity of psychiatric symptoms will be assessed by:

    • Positive and Negative Syndrome Scale(PANSS)
    • Assessment of Negative symptoms(SANS)
    • Global assessment of function(GAF)

  4. The severity of psychiatric symptoms

    Time frame: 6 weeks after the trial (The end of the trial)

    The severity of psychiatric symptoms will be assessed by:

    • Positive and Negative Syndrome Scale(PANSS)
    • Assessment of Negative symptoms(SANS)
    • Global assessment of function(GAF)

Secondary outcomes

  1. Neurocognitive Function

    Time frame: baseline

    The neurocognitive functions will be assessed by:

    • Wisconsin Card Sorting Test (WCST)
    • Wechsler Memory Scale- logical memory

  2. Neurocognitive function

    Time frame: 6 weeks after the trial (The end of the trial)

    The neurocognitive functions will be assessed by:

    • Wisconsin Card Sorting Test (WCST)
    • Wechsler Memory Scale- logical memory

  3. The severity of psychiatric symptoms

    Time frame: baseline

    The severity of psychiatric symptoms will be assessed by:

    • Clinical Global Impression(CGI)
    • Subscales of PANSS

  4. The severity of psychiatric symptoms

    Time frame: 2 weeks after the trial

    The severity of psychiatric symptoms will be assessed by:

    • Clinical Global Impression(CGI)
    • Subscales of PANSS

  5. The severity of psychiatric symptoms

    Time frame: 4 weeks after the trial

    The severity of psychiatric symptoms will be assessed by:

    • Clinical Global Impression(CGI)
    • Subscales of PANSS

  6. The severity of psychiatric symptoms

    Time frame: 6 weeks after the trial (the end of the trial)

    The severity of psychiatric symptoms will be assessed by:

    • Clinical Global Impression(CGI)
    • Subscales of PANSS

Sponsors and collaborators

Lead sponsor

China Medical University Hospital

Other

Registry information

Official study title

GlyT-1 Inhibitor Treatment for Refractory Schizophrenia and Its Effects on NMDA Modulation

Important dates

Study start
2010
Primary completion
2013
Study completion
2013
First posted
Dec 1, 2010
Registry last updated
Oct 29, 2013

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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