SchizophreniaEarly Phase 1DCSNCT02304432
Targeting a Genetic Mutation in Glycine Metabolism With D-cycloserine
A Early Phase 1 study testing D-cycloserine in people with Schizophrenia and Bipolar Disorder, run by Mclean Hospital.
Trial summary
The purpose of this study is to assess the efficacy of d-cycloserine (DCS) as an augmentation strategy in two psychotic patients with a triplication (4 copies) of the glycine decarboxylase (GLDC) gene. Read more about this study
- Who is it for?
- Ages 34 to 62 years
- Conditions the study is for
- Schizophrenia, Bipolar Disorder
- What is being tested?
- D-cycloserine
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 2 participants
- Where
- No sites listed yet
- Study dates
- 27 Sep 2015to 31 Jul 2017
- Phase
- Early 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 34 to 62 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Carriers of a triplication in the glycine decarboxylase gene
Who cannot join
- Not carriers of a triplication in the glycine decarboxylase gene
About this study
The purpose of this study is to assess the efficacy of d-cycloserine (DCS) as an augmentation strategy in two psychotic patients with a triplication (4 copies) of the glycine decarboxylase (GLDC) gene. Subjects will first undergo an eight-week open-label arm of treatment with DCS (50 mg/d) followed by six 6-week double-blind placebo-controlled exposures to DCS or placebo. The length of each double-blind arm is limited to six weeks to minimize the length of symptom exacerbation experienced by the subjects when they are receiving placebo. The randomization scheme will allow two consecutive exposures to DCS, but will not allow two consecutive exposures to placebo, again to minimize the length of any symptom exacerbation. At the end of the open-label DCS trial, the following procedures will be carried out: structural MRI (3T), proton 1H MRS (4T), fMRI (3T), steady-state auditory evoked potentials, and electroretinogram recordings. In addition, 1H MRS (4T) for 2 hours after a single oral dose of a DCS will be assessed. Baseline data on all of these measures were previously obtained as part of a different study registered in clinical trials.gov - NCT01720316). Positive, negative, and affective symptoms and neurocognitive function as well as plasma levels of large neutral and large and small neutral and excitatory amino acids and psychotropic drug levels will be assessed periodically. Pharmaceutical grade DCS) or placebo will be compounded and dispensed by the McLean Hospital Pharmacy.
The investigators hypothesize that mutation carriers will have reduced endogenous brain glycine and GABA levels and increased brain glutamate and glutamine levels. DCS administration will increase brain glycine in the two carriers compared to baseline and treatment with glycine (0.8g/kg).
Read more
The investigators hypothesize reduced activation of magnocellular pathways and abnormal ERPs modulated by NMDA in mutation carriers compared with non-carrier family members and controls.
. The investigators hypothesize that DCS, but not placebo, will improve positive, negative and affective symptoms as well as neurocognitive function.
The investigators also hypothesize that DCS will improve clinical and cognitive functioning, will partially normalize decreased baseline glycine and GABA and increased glutamate and glutamine, and will partially normalize magnocellular pathway activation and abnormal evoked potentials.
Read the detailed description
Multiple rare structural variants of relatively recent evolutionary origin are recognized as important risk factors for schizophrenia (SZ) and other neurodevelopmental disorders (e.g., autism spectrum disorders, mental retardation, epilepsy) with odds ratios as high as 7-30. We have found a de novo structural rearrangement on chromosome 9p24.1 in two psychotic patients. One of the genes in this region is the gene encoding glycine decarboxylase (GLDC), which affects brain glycine metabolism. GLDC encodes the glycine decarboxylase or glycine cleavage system P-protein, which is involved in degradation of glycine in glia cells. Carriers of the GLDC triplication would be expected to have low levels of brain Gly, resulting in NMDA receptor-mediated hypofunction, which has been strongly implicated in the pathophysiology of schizophrenia.
There is an extensive literature on the effects of NMDA enhancing agents on positive, negative, and depressive symptoms and on neurocognitive function. Although many studies have reported positive results in at least one symptom domain, the results of other studies have been negative or ambiguous. Factors likely to contribute to this variability include: mechanism of action of the agent, compliance, concurrent treatment with first- vs second generation antipsychotic drugs, baseline glycine blood levels, presence/absence of kynurenine pathway metabolic abnormalities and individual differences in brain glycine uptake and metabolism . Genetic variants that impact the synthesis and breakdown of glycine, glutamate, or other modulators of NMDA receptor function are also likely to have significant effects. Although DCS augmentation has shown variable efficacy in patients unselected for having a mutation that would be expected to lower brain glycine levels, the GLDC triplication in the two carriers in this study would be expected to result in unusually low brain glycine levels, supporting its therapeutic potential as an augmentation strategy.
Thus, it is important to evaluate the therapeutic efficacy of DCS augmentation in individuals in whom there is a high prior probability of therapeutic benefit and to characterize the neurobiology of this mutation in terms of brain metabolites, brain function, and the pharmacokinetics of glycine metabolism using well-established methods.
- Conditions
- Schizophrenia, Bipolar Disorder
- Being tested
- D-cycloserine, DCS or placebo
- Keywords
- D-cycloserine, Glycine, Psychosis, Mutation, GABA
- Medical subject headings
- Schizophrenia, Bipolar Disorder, Psychotic Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
D-cycloserineDrug
Also called Seromycin (d-cycloserine)
Both participants received open label D-cycloserine (seromycin), 50 mg/d capsule, x 8 weeks.
DCS or placeboDrug
Also called Seromycin (d-cycloserine) or placebo
Double-blind placebo-controlled exposures to DCS or placebo x 6 weeks. One participant received exposure to DCS x 6 weeks and then received placebo dosing x 6 weeks. The other participant received exposure to placebo dosing x 6 weeks and then DCS x 6 weeks.
D-cycloserineDrug
Also called Seromycin (d-cycloserine)
Both participants received second open label D-cycloserine (seromycin), 50 mg/d capsule, x 8 weeks.
| Study group | Role | What they receive |
|---|---|---|
| Open label DCS | Experimental | Both participants received open label D-cycloserine (seromycin), 50 mg/d capsule for 8 weeks. Receives: Drug: D-cycloserine |
| DCS or placebo | Experimental | Randomized to DCS or placebo. Participants underwent double-blind placebo-controlled exposures to DCS for 6 weeks or placebo for 6 weeks. One participant received exposure to DCS for 6 weeks and then received placebo dosing for 6 weeks. The other participant received exposure to placebo dosing for 6 weeks and then DCS for 6 weeks. Receives: Drug: D-cycloserine; Drug: DCS or placebo |
| Second open label DCS | Experimental | Both participants received second open label exposures to D-cycloserine (seromycin), 50 mg/d capsule for 24 weeks. Receives: Drug: D-cycloserine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Positive and Negative Symptom Scores
Positive and Negative Symptom Scale (PANSS) measures positive and negative symptoms of schizophrenia. The sum of ratings for seven positive symptoms is measured on a scale from 7-49 with 7 meaning no symptoms and 49 meaning severe symptoms.The sum of ratings for seven negative symptoms is measured on a scale from 7-49 with 7 meaning no symptoms and 49 meaning severe symptoms.
Measured: Baseline & at 2, 4, 6 & 8 Weeks during open-label phase 1 and every 2 weeks up to 24 weeks during open label phase 2
Positive and Negative Symptom Scores
Positive and Negative Symptom Scale (PANSS) measures positive and negative symptoms of schizophrenia. The sum of ratings for seven positive symptoms is measured on a scale from 7-49 with 7 meaning no symptoms and 49 meaning severe symptoms.The sum of ratings for seven negative symptoms is measured on a scale from 7-49 with 7 meaning no symptoms and 49 meaning severe symptoms.
Measured: Baseline, 2, 4, & 6 weeks (crossover periods)
Brief Psychiatric Rating Scale (BPRS) Scores
Total BPRS score measures severity of 18 psychiatric symptoms. Each symptom is scored 1-7 with the total score ranging from 18-126. 18 means no symptoms and 126 means very severe symptoms.
Measured: Baseline & at 2, 4, 6 & 8 Weeks during open-label phase 1 and every 2 weeks up to 24 weeks during open label phase 2
Brief Psychiatric Rating Scale (BPRS) Scores
Total BPRS score measures severity of 18 psychiatric symptoms. Each symptom is scored 1-7 with the total score ranging from 18-126. 18 means no symptoms and 126 means very severe symptoms.
Measured: Baseline, 2, 4, & 6 weeks (crossover periods)
Clinical Global Impression (CGI) Severity Scores
CGI severity scores measure severity of mental illness on a scale of 1-7 where 1 means normal, not at all ill, 2 means borderline mentally ill, 3 means mildly ill, 4 means moderately ill, 5 means markedly ill, 6 means severely ill and 7 means among the most extremely ill patients.
Measured: Baseline & at 2, 4, 6 & 8 Weeks during open-label phase 1 and every 2 weeks up to 24 weeks during open label phase 2
Clinical Global Impression (CGI) Severity Scores
CGI severity scores measure severity of mental illness on a scale of 1-7 where 1 means normal, not at all ill, 2 means borderline mentally ill, 3 means mildly ill, 4 means moderately ill, 5 means markedly ill, 6 means severely ill and 7 means among the most extremely ill patients.
Measured: Baseline, 2, 4, & 6 weeks (crossover periods)
Mania Symptom Scores
Young Mania Rating Scale (YMRS) measures severity of manic symptoms. The sum of the ratings for 7 symptoms of mania is measured on a scale of 0-4 and the sumof 4 symptoms of mania is measured on a scale of 0-8 to yield a total score ranging from 0-60, with 0 meaning no manic symptoms and 60 meaning severe manic symptoms.
Measured: Baseline & at 2, 4, 6 & 8 Weeks during open-label phase 1 and every 2 weeks up to 24 weeks during open label phase 2
Depression Symptom Scores
Hamilton Depression Scale (HAM) measures severity of depression symptoms. The sum of the ratings for 9 depression symptoms is measured on a scale of 0-2 with 0 meaning no depression symptoms and 2 meaning some level of severity of that specific symptom. The rating for one depression symptom is measured on a scale of 0-3 with 0 meaning no depression symptoms and 3 meaning a severe level of that specific symptom. The sum of ratings for 11 depression symptoms is measured on a scale of 0-4, with 0 meaning no symptoms and 4 meaning a severe level of that specific symptom. The three sums are added to produce an overall depression rating scale score ranging from 0-65. Higher scores indicate worse depression symptoms.
Measured: Baseline & at 2, 4, 6 & 8 Weeks during open-label phase 1 and every 2 weeks up to 24 weeks during open label phase 2
Mania Symptom Scores
Young Mania Rating Scale (YMRS) measures severity of manic symptoms. The sum of the ratings for 7 symptoms of mania is measured on a scale of 0-4 and the sumof 4 symptoms of mania is measured on a scale of 0-8 to yield a total score ranging from 0-60, with 0 meaning no manic symptoms and 60 meaning severe manic symptoms.
Measured: Baseline, 2, 4, & 6 weeks (crossover periods)
Depression Symptom Scores
Hamilton Depression Scale (HAM) measures severity of depression symptoms. The sum of the ratings for 9 depression symptoms is measured on a scale of 0-2 with 0 meaning no depression symptoms and 2 meaning some level of severity of that specific symptom. The rating for one depression symptom is measured on a scale of 0-3 with 0 meaning no depression symptoms and 3 meaning a severe level of that specific symptom. The sum of ratings for 11 depression symptoms is measured on a scale of 0-4, with 0 meaning no symptoms and 4 meaning a severe level of that specific symptom. The three sums are added to produce an overall depression rating scale score ranging from 0-65. Higher scores indicate worse depression symptoms.
Measured: Baseline, 2, 4, & 6 weeks (crossover periods)
Secondary outcomes (6)
Neurocognitive Function
Scores on each of 8 domains of cognitive function (speed of processing, attention/vigilance, working memory, verbal learning, visual learning, reasoning/problem solving, social cognition, overall composite). Scores are T scores ranging from 0-100, with 50 representing the mean for a population based on a normal distribution, standard deviation of 10. Higher scores signify better functioning.
Measured: Baseline and Week 8 of open-label DCS treatment
Brain Glycine/CR Ratio
Proton magnetic resonance spectroscopy at 4T: brain glycine/CR ratio. Participants were assessed at baseline (pre-glycine challenge dose and 60, 80, 100 and 120 minutes post glycine dose) and in week 8 of of open-label DCS treatment: pre-DCS dose, and 60, 80, 100 and 120 minutes post DCS dose. Measured in posterior occipital cortex.
Measured: Baseline and Week 8 of DCS treatment
Auditory Evoked Potentials in Latency (Msec)
Auditory evoked potential latency: P300 at fz, cz, and pz; N100 at fz and cz; P200 at fz and cz.
Measured: Baseline and Week 8 of DCS treatment
Auditory Evoked Potentials in Amplitude (Degrees Measured in Microvolts)
Auditory evoked potential amplitude: P300 at fz, cz, and pz; N100 at fz and cz; P200 at fz and cz; P50 S1 and S2; mismatch negativity (MMN) at fz and cz.
Measured: Baseline and Week 8 of DCS treatment
Auditory Evoked Potentials in Gamma Oscillations (the Power Spectrum is Measured in Microvolts Squared)
Auditory evoked potential gamma: G40 hz phase locking at fz and cz; G30 hz phase locking at fz and cz; G20 hz phase locking at fz and cz
Measured: Baseline and Week 8 of DCS treatment
Auditory Evoked Potentials - P50 Ratio (P50 S2/S1) (Amplitude)
Auditory evoked potential amplitude: P50 ratio (P50 S2/S1)
Measured: Baseline and Week 8 of DCS treatment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Dec 2014 (estimated)
- Study start27 Sep 2015
- Primary completion30 Sep 2016
- Study completion31 Jul 2017
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.
- Publications (39)Papers the sponsor has linked to this study.
- Other trials for SchizophreniaStudies of the same condition, open and under way.
- 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
- Early Phase 1
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 2 participants (actual)
Sponsor and investigators
- Lead sponsor
- Mclean Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- University of Minnesota
- Responsible party
- Principal investigator, Deborah L. Levy, Mclean Hospital
- Investigators
- Deborah L. Levy, Ph.D., Principal investigator, Mclean Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02304432
- Sponsor's protocol ID
- 1R21MH105732
- Acronym
- DCS
- Status last verified
- Sep 2017
- First submitted
- 26 Nov 2014
- Last updated
- 19 Sep 2017
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Sebat J, Levy DL, McCarthy SE. Rare structural variants in schizophrenia: one disorder, multiple mutations; one mutation, multiple disorders. Trends Genet. 2009 Dec;25(12):528-35. doi: 10.1016/j.tig.2009.10.004. Epub 2009 Oct 31.
PubMed 19883952Malhotra D, McCarthy S, Michaelson JJ, Vacic V, Burdick KE, Yoon S, Cichon S, Corvin A, Gary S, Gershon ES, Gill M, Karayiorgou M, Kelsoe JR, Krastoshevsky O, Krause V, Leibenluft E, Levy DL, Makarov V, Bhandari A, Malhotra AK, McMahon FJ, Nothen MM, Potash JB, Rietschel M, Schulze TG, Sebat J. High frequencies of de novo CNVs in bipolar disorder and schizophrenia. Neuron. 2011 Dec 22;72(6):951-63. doi: 10.1016/j.neuron.2011.11.007.
PubMed 22196331Heinzen EL, Radtke RA, Urban TJ, Cavalleri GL, Depondt C, Need AC, Walley NM, Nicoletti P, Ge D, Catarino CB, Duncan JS, Kasperaviciutey D, Tate SK, Caboclo LO, Sander JW, Clayton L, Linney KN, Shianna KV, Gumbs CE, Smith J, Cronin KD, Maia JM, Doherty CP, Pandolfo M, Duncan JS, Sander JW, Delanty N, Leppert D, Middleton LT, Gibson RA, Johnson MR, Matthews PM, Hosford D, Kalviainen R, Eriksson K, Kantanen A-M, Dorn T, Hansen J, Kramer G, Steinhoff BJ, Wieser H-G, Steinhoff BJ, Kramer G, Hansen J, Dorn T, Zumsteg D, Ortega M, Wood NW, Huxley-Jones J, Mikati M, Gallentine WB, Husain AM, Buckley PG, Stallings RL, Podgoreanu MV, Delanty N, Sisodiya SM, Goldstein DB. Rare deletions at 16p13.11 predispose to a diverse spectrum of sporadic epilepsy syndromes. Am J Hum Genet 2010;86:707-718.
Weiss LA, Shen Y, Korn JM, Arking DE, Miller DT, Fossdal R, Saemundsen E, Stefansson H, Ferreira MA, Green T, Platt OS, Ruderfer DM, Walsh CA, Altshuler D, Chakravarti A, Tanzi RE, Stefansson K, Santangelo SL, Gusella JF, Sklar P, Wu BL, Daly MJ; Autism Consortium. Association between microdeletion and microduplication at 16p11.2 and autism. N Engl J Med. 2008 Feb 14;358(7):667-75. doi: 10.1056/NEJMoa075974. Epub 2008 Jan 9.
PubMed 18184952McCarthy S, Makarov V, Kirov G, Addington A, McClellan J, Yoon S, Perkins D, Dickel DE, Kusenda M, Krastoshevsky O, Krause V, Kumar RA, Grozeva D, Malhotra D, Walsh T, Zackai EH, Kaplan P, Ganesh J, Krantz ID, Spinner NB, Roccanova P, Bhandari A, Pavon K, Lakshmi B, Leotta A, Kendall J, Lee Y, Vacic V, Gary S, Iakoucheva L, Crow TJ, Christian SL, Lieberman J, Stroup S, Lehtimaki T, Puura K, Haldeman-Englert C, Pearl J, Goodell M, Willour VL, DeRosse P, Steele J, Kassem L, Wolff J, Chitkara N, McMahon F, Malhotra AK, Potash JB, Schulze T, Nothen MM, Cichon S, Rietschel M, Leibenluft E, Sutcliffe JS, Skuse D, Gill M, Gallagher L, Mendell NR, Consortium WTCC, Craddock N, Owen MJ, O'Donovan MC, Shaikh TH, Susser E, DeLisi LE, Sullivan PF, Deutsch CK, Rapoport J, Levy DL, King M-C, Sebat J. Microduplications of 16p11.2 are associated with schizophrenia. Nat Genet 2009;41:1223-1227.
Olney JW, Farber NB. Glutamate receptor dysfunction and schizophrenia. Arch Gen Psychiatry. 1995 Dec;52(12):998-1007. doi: 10.1001/archpsyc.1995.03950240016004.
PubMed 7492260Coyle JT. Glutamate and schizophrenia: beyond the dopamine hypothesis. Cell Mol Neurobiol. 2006 Jul-Aug;26(4-6):365-84. doi: 10.1007/s10571-006-9062-8. Epub 2006 Jun 14.
PubMed 16773445Javitt DC. Glutamate and schizophrenia: phencyclidine, N-methyl-D-aspartate receptors, and dopamine-glutamate interactions. Int Rev Neurobiol. 2007;78:69-108. doi: 10.1016/S0074-7742(06)78003-5.
PubMed 17349858Tsai GE, Lin PY. Strategies to enhance N-methyl-D-aspartate receptor-mediated neurotransmission in schizophrenia, a critical review and meta-analysis. Curr Pharm Des. 2010;16(5):522-37. doi: 10.2174/138161210790361452.
PubMed 19909229Lin CH, Lane HY, Tsai GE. Glutamate signaling in the pathophysiology and therapy of schizophrenia. Pharmacol Biochem Behav. 2012 Feb;100(4):665-77. doi: 10.1016/j.pbb.2011.03.023. Epub 2011 Apr 1.
PubMed 21463651Heresco-Levy U, Javitt DC, Ermilov M, Mordel C, Horowitz A, Kelly D. Double-blind, placebo-controlled, crossover trial of glycine adjuvant therapy for treatment-resistant schizophrenia. Br J Psychiatry. 1996 Nov;169(5):610-7. doi: 10.1192/bjp.169.5.610.
PubMed 8932891Heresco-Levy U, Javitt DC, Ermilov M, Mordel C, Silipo G, Lichtenstein M. Efficacy of high-dose glycine in the treatment of enduring negative symptoms of schizophrenia. Arch Gen Psychiatry. 1999 Jan;56(1):29-36. doi: 10.1001/archpsyc.56.1.29.
PubMed 9892253Heresco-Levy U, Javitt DC. Comparative effects of glycine and D-cycloserine on persistent negative symptoms in schizophrenia: a retrospective analysis. Schizophr Res. 2004 Feb 1;66(2-3):89-96. doi: 10.1016/S0920-9964(03)00129-4.
PubMed 15061240Tsai G, Yang P, Chung LC, Lange N, Coyle JT. D-serine added to antipsychotics for the treatment of schizophrenia. Biol Psychiatry. 1998 Dec 1;44(11):1081-9. doi: 10.1016/s0006-3223(98)00279-0.
PubMed 9836012Tsai GE, Yang P, Chung LC, Tsai IC, Tsai CW, Coyle JT. D-serine added to clozapine for the treatment of schizophrenia. Am J Psychiatry. 1999 Nov;156(11):1822-5. doi: 10.1176/ajp.156.11.1822.
PubMed 10553752
Study at a glance
From the registry record, last updated by the sponsor on 19 Sep 2017. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Targeting a Genetic Mutation in Glycine Metabolism With D-cycloserine
- ClinicalTrials.gov ID
- NCT02304432
- Acronym / sponsor ID
- DCS / 1R21MH105732
- Conditions
- Schizophrenia, Bipolar Disorder
- Keywords
- D-cycloserine, Glycine, Psychosis, Mutation, GABA
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 2 participants (actual)
- Lead sponsor
- Mclean HospitalUniversity, hospital or other
- Collaborators
- University of Minnesota
- Study start
- 27 Sep 2015 (actual)
- Primary completion
- 30 Sep 2016 (actual)
- Study completion
- 31 Jul 2017 (actual)
- First posted
- 2 Dec 2014 (estimated)
- Results
- Posted 19 Sep 2017
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to assess the efficacy of d-cycloserine (DCS) as an augmentation strategy in two psychotic patients with a triplication (4 copies) of the glycine decarboxylase (GLDC) gene. Subjects will first undergo an eight-week open-label arm of treatment with DCS (50 mg/d) followed by six 6-week double-blind placebo-controlled exposures to DCS or placebo. The length of each double-blind arm is limited to six weeks to minimize the length of symptom exacerbation experienced by the subjects when they are receiving placebo. The randomization scheme will allow two consecutive exposures to DCS, but will not allow two consecutive exposures to placebo, again to minimize the length of any symptom exacerbation. At the end of the open-label DCS trial, the following procedures will be carried out: structural MRI (3T), proton 1H MRS (4T), fMRI (3T), steady-state auditory evoked potentials, and electroretinogram recordings. In addition, 1H MRS (4T) for 2 hours after a single oral dose of a DCS will be assessed. Baseline data on all of these measures were previously obtained as part of a different study registered in clinical trials.gov - NCT01720316). Positive, negative, and affective symptoms and neurocognitive function as well as plasma levels of large neutral and large and small neutral and excitatory amino acids and psychotropic drug levels will be assessed periodically. Pharmaceutical grade DCS) or placebo will be compounded and dispensed by the McLean Hospital Pharmacy.
The investigators hypothesize that mutation carriers will have reduced endogenous brain glycine and GABA levels and increased brain glutamate and glutamine levels. DCS administration will increase brain glycine in the two carriers compared to baseline and treatment with glycine (0.8g/kg).
The investigators hypothesize reduced activation of magnocellular pathways and abnormal ERPs modulated by NMDA in mutation carriers compared with non-carrier family members and controls.
. The investigators hypothesize that DCS, but not placebo, will improve positive, negative and affective symptoms as well as neurocognitive function.
The investigators also hypothesize that DCS will improve clinical and cognitive functioning, will partially normalize decreased baseline glycine and GABA and increased glutamate and glutamine, and will partially normalize magnocellular pathway activation and abnormal evoked potentials.
Detailed description
Multiple rare structural variants of relatively recent evolutionary origin are recognized as important risk factors for schizophrenia (SZ) and other neurodevelopmental disorders (e.g., autism spectrum disorders, mental retardation, epilepsy) with odds ratios as high as 7-30. We have found a de novo structural rearrangement on chromosome 9p24.1 in two psychotic patients. One of the genes in this region is the gene encoding glycine decarboxylase (GLDC), which affects brain glycine metabolism. GLDC encodes the glycine decarboxylase or glycine cleavage system P-protein, which is involved in degradation of glycine in glia cells. Carriers of the GLDC triplication would be expected to have low levels of brain Gly, resulting in NMDA receptor-mediated hypofunction, which has been strongly implicated in the pathophysiology of schizophrenia.
There is an extensive literature on the effects of NMDA enhancing agents on positive, negative, and depressive symptoms and on neurocognitive function. Although many studies have reported positive results in at least one symptom domain, the results of other studies have been negative or ambiguous. Factors likely to contribute to this variability include: mechanism of action of the agent, compliance, concurrent treatment with first- vs second generation antipsychotic drugs, baseline glycine blood levels, presence/absence of kynurenine pathway metabolic abnormalities and individual differences in brain glycine uptake and metabolism . Genetic variants that impact the synthesis and breakdown of glycine, glutamate, or other modulators of NMDA receptor function are also likely to have significant effects. Although DCS augmentation has shown variable efficacy in patients unselected for having a mutation that would be expected to lower brain glycine levels, the GLDC triplication in the two carriers in this study would be expected to result in unusually low brain glycine levels, supporting its therapeutic potential as an augmentation strategy.
Thus, it is important to evaluate the therapeutic efficacy of DCS augmentation in individuals in whom there is a high prior probability of therapeutic benefit and to characterize the neurobiology of this mutation in terms of brain metabolites, brain function, and the pharmacokinetics of glycine metabolism using well-established methods.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Open label DCS | Experimental | Drug: D-cycloserineBoth participants received open label D-cycloserine (seromycin), 50 mg/d capsule for 8 weeks. |
| DCS or placebo | Experimental | Drug: D-cycloserine, Drug: DCS or placeboRandomized to DCS or placebo. Participants underwent double-blind placebo-controlled exposures to DCS for 6 weeks or placebo for 6 weeks. One participant received exposure to DCS for 6 weeks and then received placebo dosing for 6 weeks. The other participant received exposure to placebo dosing for 6 weeks and then DCS for 6 weeks. |
| Second open label DCS | Experimental | Drug: D-cycloserineBoth participants received second open label exposures to D-cycloserine (seromycin), 50 mg/d capsule for 24 weeks. |
Who may qualify
- Ages
- 34 to 62 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- Carriers of a triplication in the glycine decarboxylase gene
Key exclusion criteria (1 listed)
- Not carriers of a triplication in the glycine decarboxylase gene
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 |
|---|---|---|
| D-cycloserineAlso: Seromycin (d-cycloserine)Both participants received open label D-cycloserine (seromycin), 50 mg/d capsule, x 8 weeks. | Drug | DCS or placebo, Open label DCS |
| DCS or placeboAlso: Seromycin (d-cycloserine) or placeboDouble-blind placebo-controlled exposures to DCS or placebo x 6 weeks. One participant received exposure to DCS x 6 weeks and then received placebo dosing x 6 weeks. The other participant received exposure to placebo dosing x 6 weeks and then DCS x 6 weeks. | Drug | DCS or placebo |
| D-cycloserineAlso: Seromycin (d-cycloserine)Both participants received second open label D-cycloserine (seromycin), 50 mg/d capsule, x 8 weeks. | Drug | Second open label DCS |
Primary outcome
Positive and Negative Symptom Scores
Time frame: Baseline & at 2, 4, 6 & 8 Weeks during open-label phase 1 and every 2 weeks up to 24 weeks during open label phase 2
Positive and Negative Symptom Scale (PANSS) measures positive and negative symptoms of schizophrenia. The sum of ratings for seven positive symptoms is measured on a scale from 7-49 with 7 meaning no symptoms and 49 meaning severe symptoms.The sum of ratings for seven negative symptoms is measured on a scale from 7-49 with 7 meaning no symptoms and 49 meaning severe symptoms.
Positive and Negative Symptom Scores
Time frame: Baseline, 2, 4, & 6 weeks (crossover periods)
Positive and Negative Symptom Scale (PANSS) measures positive and negative symptoms of schizophrenia. The sum of ratings for seven positive symptoms is measured on a scale from 7-49 with 7 meaning no symptoms and 49 meaning severe symptoms.The sum of ratings for seven negative symptoms is measured on a scale from 7-49 with 7 meaning no symptoms and 49 meaning severe symptoms.
Brief Psychiatric Rating Scale (BPRS) Scores
Time frame: Baseline & at 2, 4, 6 & 8 Weeks during open-label phase 1 and every 2 weeks up to 24 weeks during open label phase 2
Total BPRS score measures severity of 18 psychiatric symptoms. Each symptom is scored 1-7 with the total score ranging from 18-126. 18 means no symptoms and 126 means very severe symptoms.
Brief Psychiatric Rating Scale (BPRS) Scores
Time frame: Baseline, 2, 4, & 6 weeks (crossover periods)
Total BPRS score measures severity of 18 psychiatric symptoms. Each symptom is scored 1-7 with the total score ranging from 18-126. 18 means no symptoms and 126 means very severe symptoms.
Clinical Global Impression (CGI) Severity Scores
Time frame: Baseline & at 2, 4, 6 & 8 Weeks during open-label phase 1 and every 2 weeks up to 24 weeks during open label phase 2
CGI severity scores measure severity of mental illness on a scale of 1-7 where 1 means normal, not at all ill, 2 means borderline mentally ill, 3 means mildly ill, 4 means moderately ill, 5 means markedly ill, 6 means severely ill and 7 means among the most extremely ill patients.
Clinical Global Impression (CGI) Severity Scores
Time frame: Baseline, 2, 4, & 6 weeks (crossover periods)
CGI severity scores measure severity of mental illness on a scale of 1-7 where 1 means normal, not at all ill, 2 means borderline mentally ill, 3 means mildly ill, 4 means moderately ill, 5 means markedly ill, 6 means severely ill and 7 means among the most extremely ill patients.
Mania Symptom Scores
Time frame: Baseline & at 2, 4, 6 & 8 Weeks during open-label phase 1 and every 2 weeks up to 24 weeks during open label phase 2
Young Mania Rating Scale (YMRS) measures severity of manic symptoms. The sum of the ratings for 7 symptoms of mania is measured on a scale of 0-4 and the sumof 4 symptoms of mania is measured on a scale of 0-8 to yield a total score ranging from 0-60, with 0 meaning no manic symptoms and 60 meaning severe manic symptoms.
Depression Symptom Scores
Time frame: Baseline & at 2, 4, 6 & 8 Weeks during open-label phase 1 and every 2 weeks up to 24 weeks during open label phase 2
Hamilton Depression Scale (HAM) measures severity of depression symptoms. The sum of the ratings for 9 depression symptoms is measured on a scale of 0-2 with 0 meaning no depression symptoms and 2 meaning some level of severity of that specific symptom. The rating for one depression symptom is measured on a scale of 0-3 with 0 meaning no depression symptoms and 3 meaning a severe level of that specific symptom. The sum of ratings for 11 depression symptoms is measured on a scale of 0-4, with 0 meaning no symptoms and 4 meaning a severe level of that specific symptom. The three sums are added to produce an overall depression rating scale score ranging from 0-65. Higher scores indicate worse depression symptoms.
Mania Symptom Scores
Time frame: Baseline, 2, 4, & 6 weeks (crossover periods)
Young Mania Rating Scale (YMRS) measures severity of manic symptoms. The sum of the ratings for 7 symptoms of mania is measured on a scale of 0-4 and the sumof 4 symptoms of mania is measured on a scale of 0-8 to yield a total score ranging from 0-60, with 0 meaning no manic symptoms and 60 meaning severe manic symptoms.
Depression Symptom Scores
Time frame: Baseline, 2, 4, & 6 weeks (crossover periods)
Hamilton Depression Scale (HAM) measures severity of depression symptoms. The sum of the ratings for 9 depression symptoms is measured on a scale of 0-2 with 0 meaning no depression symptoms and 2 meaning some level of severity of that specific symptom. The rating for one depression symptom is measured on a scale of 0-3 with 0 meaning no depression symptoms and 3 meaning a severe level of that specific symptom. The sum of ratings for 11 depression symptoms is measured on a scale of 0-4, with 0 meaning no symptoms and 4 meaning a severe level of that specific symptom. The three sums are added to produce an overall depression rating scale score ranging from 0-65. Higher scores indicate worse depression symptoms.
6 secondary outcomes
Neurocognitive Function
Time frame: Baseline and Week 8 of open-label DCS treatment
Brain Glycine/CR Ratio
Time frame: Baseline and Week 8 of DCS treatment
Auditory Evoked Potentials in Latency (Msec)
Time frame: Baseline and Week 8 of DCS treatment
Auditory Evoked Potentials in Amplitude (Degrees Measured in Microvolts)
Time frame: Baseline and Week 8 of DCS treatment
Auditory Evoked Potentials in Gamma Oscillations (the Power Spectrum is Measured in Microvolts Squared)
Time frame: Baseline and Week 8 of DCS treatment
Auditory Evoked Potentials - P50 Ratio (P50 S2/S1) (Amplitude)
Time frame: Baseline and Week 8 of DCS treatment
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Sep 2017.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Background: PubMed 19883952Sebat J, Levy DL, McCarthy SE. Rare structural variants in schizophrenia: one disorder, multiple mutations; one mutation, multiple disorders. Trends Genet. 2009 Dec;25(12):528-35. doi: 10.1016/j.tig.2009.10.004. Epub 2009 Oct 31.
- Background: PubMed 22196331Malhotra D, McCarthy S, Michaelson JJ, Vacic V, Burdick KE, Yoon S, Cichon S, Corvin A, Gary S, Gershon ES, Gill M, Karayiorgou M, Kelsoe JR, Krastoshevsky O, Krause V, Leibenluft E, Levy DL, Makarov V, Bhandari A, Malhotra AK, McMahon FJ, Nothen MM, Potash JB, Rietschel M, Schulze TG, Sebat J. High frequencies of de novo CNVs in bipolar disorder and schizophrenia. Neuron. 2011 Dec 22;72(6):951-63. doi: 10.1016/j.neuron.2011.11.007.
- BackgroundHeinzen EL, Radtke RA, Urban TJ, Cavalleri GL, Depondt C, Need AC, Walley NM, Nicoletti P, Ge D, Catarino CB, Duncan JS, Kasperaviciutey D, Tate SK, Caboclo LO, Sander JW, Clayton L, Linney KN, Shianna KV, Gumbs CE, Smith J, Cronin KD, Maia JM, Doherty CP, Pandolfo M, Duncan JS, Sander JW, Delanty N, Leppert D, Middleton LT, Gibson RA, Johnson MR, Matthews PM, Hosford D, Kalviainen R, Eriksson K, Kantanen A-M, Dorn T, Hansen J, Kramer G, Steinhoff BJ, Wieser H-G, Steinhoff BJ, Kramer G, Hansen J, Dorn T, Zumsteg D, Ortega M, Wood NW, Huxley-Jones J, Mikati M, Gallentine WB, Husain AM, Buckley PG, Stallings RL, Podgoreanu MV, Delanty N, Sisodiya SM, Goldstein DB. Rare deletions at 16p13.11 predispose to a diverse spectrum of sporadic epilepsy syndromes. Am J Hum Genet 2010;86:707-718.
- Background: PubMed 18184952Weiss LA, Shen Y, Korn JM, Arking DE, Miller DT, Fossdal R, Saemundsen E, Stefansson H, Ferreira MA, Green T, Platt OS, Ruderfer DM, Walsh CA, Altshuler D, Chakravarti A, Tanzi RE, Stefansson K, Santangelo SL, Gusella JF, Sklar P, Wu BL, Daly MJ; Autism Consortium. Association between microdeletion and microduplication at 16p11.2 and autism. N Engl J Med. 2008 Feb 14;358(7):667-75. doi: 10.1056/NEJMoa075974. Epub 2008 Jan 9.
- BackgroundMcCarthy S, Makarov V, Kirov G, Addington A, McClellan J, Yoon S, Perkins D, Dickel DE, Kusenda M, Krastoshevsky O, Krause V, Kumar RA, Grozeva D, Malhotra D, Walsh T, Zackai EH, Kaplan P, Ganesh J, Krantz ID, Spinner NB, Roccanova P, Bhandari A, Pavon K, Lakshmi B, Leotta A, Kendall J, Lee Y, Vacic V, Gary S, Iakoucheva L, Crow TJ, Christian SL, Lieberman J, Stroup S, Lehtimaki T, Puura K, Haldeman-Englert C, Pearl J, Goodell M, Willour VL, DeRosse P, Steele J, Kassem L, Wolff J, Chitkara N, McMahon F, Malhotra AK, Potash JB, Schulze T, Nothen MM, Cichon S, Rietschel M, Leibenluft E, Sutcliffe JS, Skuse D, Gill M, Gallagher L, Mendell NR, Consortium WTCC, Craddock N, Owen MJ, O'Donovan MC, Shaikh TH, Susser E, DeLisi LE, Sullivan PF, Deutsch CK, Rapoport J, Levy DL, King M-C, Sebat J. Microduplications of 16p11.2 are associated with schizophrenia. Nat Genet 2009;41:1223-1227.
- Background: PubMed 7492260Olney JW, Farber NB. Glutamate receptor dysfunction and schizophrenia. Arch Gen Psychiatry. 1995 Dec;52(12):998-1007. doi: 10.1001/archpsyc.1995.03950240016004.
- Background: PubMed 16773445Coyle JT. Glutamate and schizophrenia: beyond the dopamine hypothesis. Cell Mol Neurobiol. 2006 Jul-Aug;26(4-6):365-84. doi: 10.1007/s10571-006-9062-8. Epub 2006 Jun 14.
- Background: PubMed 17349858Javitt DC. Glutamate and schizophrenia: phencyclidine, N-methyl-D-aspartate receptors, and dopamine-glutamate interactions. Int Rev Neurobiol. 2007;78:69-108. doi: 10.1016/S0074-7742(06)78003-5.
- Background: PubMed 19909229Tsai GE, Lin PY. Strategies to enhance N-methyl-D-aspartate receptor-mediated neurotransmission in schizophrenia, a critical review and meta-analysis. Curr Pharm Des. 2010;16(5):522-37. doi: 10.2174/138161210790361452.
- Background: PubMed 21463651Lin CH, Lane HY, Tsai GE. Glutamate signaling in the pathophysiology and therapy of schizophrenia. Pharmacol Biochem Behav. 2012 Feb;100(4):665-77. doi: 10.1016/j.pbb.2011.03.023. Epub 2011 Apr 1.
- Background: PubMed 8932891Heresco-Levy U, Javitt DC, Ermilov M, Mordel C, Horowitz A, Kelly D. Double-blind, placebo-controlled, crossover trial of glycine adjuvant therapy for treatment-resistant schizophrenia. Br J Psychiatry. 1996 Nov;169(5):610-7. doi: 10.1192/bjp.169.5.610.
- Background: PubMed 9892253Heresco-Levy U, Javitt DC, Ermilov M, Mordel C, Silipo G, Lichtenstein M. Efficacy of high-dose glycine in the treatment of enduring negative symptoms of schizophrenia. Arch Gen Psychiatry. 1999 Jan;56(1):29-36. doi: 10.1001/archpsyc.56.1.29.
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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.
Deborah L. Levy, Ph.D. principal investigator
Mclean Hospital
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing D-cycloserine in people with Schizophrenia and Bipolar Disorder, run by Mclean Hospital.
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 1 inclusion and 1 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 19 Sep 2017. 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. 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?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
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 19 Sep 2017). 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?
Positive and Negative Symptom Scores (time frame: Baseline & at 2, 4, 6 & 8 Weeks during open-label phase 1 and every 2 weeks up to 24 weeks during open label phase 2). The study lists 10 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02304432, which also lists 39 linked publications.
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 19 Sep 2017.