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D-serine Monotherapy for Schizophrenia

D-serine Antipsychotic Monotherapy for Treatment Refractory Schizophrenia

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00816894
Enrollment
18
Registered
2009-01-05
Start date
2009-01-31
Completion date
2013-02-28
Last updated
2013-12-10

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

Conditions

Schizophrenia

Keywords

schizophrenia, treatment resistance, D-serine, Olanzapine, treatment refractory schizophrenia

Brief summary

A first generation of clinical studies, performed during the last decade, demonstrates that adjuvant treatment with compounds that enhance NMDAR-mediated neurotransmission due to their agonistic activity at the NMDAR-associated glycine (GLY) site (e.g. GLY, D-serine (DSR)) leads to significant symptom reductions in chronic schizophrenia patients.Furthermore, preliminary findings suggest that treatment with NMDAR-GLY site modulators may also be beneficial as antipsychotic monotherapy In the proposed project, during a three year period, 60 schizophrenia patients that fulfill treatment resistance criteria will be randomly entered in a 10 week, two phase (fixed/flexible dose), parallel group, double blind controlled study assessing the efficacy of olanzapine (OLA) (up to 40 mg/day) vs. DSR (up to 4000 mg/day) as antipsychotic monotherapy.Clinical, neurocognitive, electrophysiological, and amino acids (i.e. GLY, DSR) levels assessments will be performed during the study. The specific aims of the proposed project are: 1) to assess the efficacy and safety of DSR as a new medication for treatment refractory schizophrenia, and 2) to assess DSR effects in terms of relevant amino acids serum levels, neurocognitive performance, and relevant brain electrophysiological parameters. The overall importance of the proposed project consists of its potential to lay the foundations for an innovative type of intervention for treatment resistant schizophrenia patients.

Interventions

DRUGD-serine

6 week fixed dose phase with D-serine 1500 mg/day to be increased starting from week two to 3000 mg/day followed by a 4 week flexible dose phase allowing for two 500 mg/day dose changes

DRUGOlanzapine

6 week fixed dose phase with Olanzapine 15 mg/day to be increased starting from week two to 30 mg/day followed by a 4 week flexible dose phase allowing for two 5 mg/day dose changes.

Sponsors

Israel Science Foundation
CollaboratorOTHER
Herzog Hospital
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No

Inclusion criteria

1. Age 18-70; 2. Diagnosis of schizophrenia/schizoaffective disorder according to DSM-IV criteria. 3. Stable dose antipsychotic treatment for at least 4 weeks; 4. Treatment refractoriness according to Kane et al.(1988) criteria.

Exclusion criteria

1. Meeting criteria for other DSM-IV Axis I diagnoses ; 2. Substance abuse or alcoholism during entire lifetime; 3. Are judged clinically to be at suicidal or homicidal risk; 4. Female patients who are pregnant or lactating; female patients who are not pregnant or lactating, if sexually active, must be using medically accepted means of contraception; 5. Patients with known intolerance to OLA treatment or who have failed an adequate trial of OLA (at least 6 weeks) at high doses (20 mg/day or higher); 6. Patients treated with depot antipsychotics or ECT within the eight weeks prior to study entry.

Design outcomes

Primary

MeasureTime frame
PANSS change scores.~ biweekly throughout the study
side effects~ biweekly throughout the study

Secondary

MeasureTime frame
% treatment respondersEnd of the study

Countries

Israel

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026