Studies whether D-serine affects Parkinson's disease symptoms in people with the condition
Tests D-serine against placebo in people with Parkinson's disease diagnosed within 5 years.
Plain-language title generated from the registry record
Registry title: D-SPARK: A Clinical Trial of D-Serine for Modifying Parkinson's Disease Progression
Key facts
- Where
- Arendal, Bergen, Bodø, Drammen, Førde, Haugesund, Lørenskog, Molde, Oslo, Sarpsborg, and Tromsø, NorwaySee the 11 sites
- Phase
- Phase 2
Could this be for you?
Answer for yourself. This is not a decision: only the study team can say whether you can take part.
- Are you between 40 and 80 years old?
Source: NCT07312110, who can take part
Where in Norway
- Nevro Arendal SoerlandsklinikkenArendal, NorwayTaking people
- Haukeland University HospitalBergen, NorwayTaking people
- Bodø Hospital (Nordland Hospital)Bodø, NorwayNot yet recruiting
- Vestre Viken HospitalDrammen, NorwayNot yet recruiting
- Førde HospitalFørde, NorwayNot yet recruiting
- Haugesund HospitalHaugesund, NorwayNot yet recruiting
- Akershus University HospitalLørenskog, NorwayNot yet recruiting
- Molde HospitalMolde, NorwayNot yet recruiting
- Oslo University HospitalOslo, NorwayTaking people
- Østfold HospitalSarpsborg, NorwayNot yet recruiting
- University Hospital of North NorwayTromsø, NorwayNot yet recruiting
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Haukeland University Hospital
- Trial code
- NCT07312110
- Record updated
- 4 June 2026
- Original description
This clinical study, designed as a randomized, double-blind, placebo-controlled trial, aims to investigate if modulation of the N-methyl-D-aspartate receptor (NMDAR) via its co-agonist D-serine has therapeutic benefits in Parkinson's disease (PD). All patients will receive both placebo and D-serine over different time periods during the study.Read full original descriptionShow less
D-SPARK: A Randomized Double Blind Clinical Trial of D-Serine for Modifying Parkinson's Disease Progression
This clinical study, designed as a randomized, double-blind, placebo-controlled trial, aims to investigate if modulation of the N-methyl-D-aspartate receptor (NMDAR) via its co-agonist D-serine has therapeutic benefits in Parkinson's disease (PD). All patients will receive both placebo and D-serine over different time periods during the study.
Preclinical studies have shown that blocking glycine transporters, which elevates endogenous glycine levels, can restore NMDAR function and improve motor deficits in PD models. A clinical trial demonstrated that oral D-serine (30 mg/kg/day for 6 weeks) significantly reduced extrapyramidal and abnormal involuntary movements in PD patients compared to placebo, with improvements observed in both motor and non-motor symptoms. D-serine supplementation has shown an acceptable safety profile with doses up to 120 mg/kg showing no significant adverse effects in clinical studies.
The D-SPARK trial primarily aims to determine the efficacy of D-serine supplementation on clinical severity of PD as measured by the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS).
Secondary aims are to determine the efficacy of D-serine supplementation on improving dopaminergic nigrostriatal innervation as measured by single-photon emission tomography (SPECT) based imaging of the dopamine transporter (DaT-scan) and cognition as measured by the California Verbal Learning Test version 2 (CLVT-II).
The study will include 100 persons with Parkinson's disease (PwPD) diagnosed no longer than 5 years before baseline. Participants will be randomly assigned to receive D-Serine 4000 mg daily or placebo for defined periods of time during a 58 week treatment period, followed by a 12 week washout period.
Participants will undergo:
* Clinical evaluations, including clinical rating scales and questionnaires. * Cognitive assessments. * Bio sampling of whole blood and blood plasma. * Single-photon emission tomography (SPECT) imaging of dopamine transporter levels (DaT-scan)
The outcomes of this study could potentially demonstrate that D-serine reduces symptom severity in Parkinson's disease and/or has an impact on the clinical trajectory of Parkinson's disease, benefiting persons living with Parkinson's disease, their families and society as a whole.
Inclusion: A clinical diagnosis of PD* according to the clinically established MDS clinical diagnostic criteria for Parkinson's disease within 5 years; [¹²³I]FP-CIT single photon emission CT (DaTscan) confirming dopaminergic nigrostriatal denervation; Hoehn and Yahr score < 3 at enrollment; Optimal symptomatic PD treatment, not requiring adjustments, for at least 2 weeks; Age ≥40 and ≤ 80 years at time of enrollment.
Exclusion: Atypical parkinsonism (PSP, MSA, CBD vascular parkinsonism, or drug induced parkinsonism); Dementia or neurodegenerative disorder other than PD at baseline visit; Any psychiatric disorder that would interfere with compliance in the study; Any severe somatic illness that would make the individual unable to comply and participate in the study; Metabolic, neoplastic, or other physically or mentally debilitating disorder at baseline visit; Cognitive impairment as measured by the Mini Mental Status Exam MMSE) < 20; Urinary albumin/creatinine ratio ≥ 20 mg/mmol at time of enrollment; Participants will be excluded if they have CKD stage 3 or higher, defined as:; Estimated golumerular filtration rate (eGFR) < 60 mL/min/1.73min\^2 at screening, calculated using the CKD-EPI 2021 creatinine equation; Any known monogenic cause of PD (GBA1 variation is accepted); Use of D-serine supplementation within 90 days of enrolment; Active of planned pregnancy during trial period; Weight < 45 kg.