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NCT07913529Completed

Time Course of Clozapine-associated Agranulocytosis Over 19 Years

Time Course of Clozapine-associated Agranulocytosis Over 19 Years: an Electronic Health-record Cohort With Case-level Adjudication

Source: ClinicalTrials.gov · Last updated 3 Nov 2026

Brief summary (registry, in English)

Clozapine is the most effective antipsychotic medication for treatment-resistant schizophrenia, but it carries a rare, potentially life-threatening risk of agranulocytosis (a severe drop in white blood cells), which is why patients undergo regular blood monitoring. Most cases occur in the first months of treatment, and it remains unclear how much risk persists after the first year. This retrospective study will use existing electronic health records from Sheba Medical Center (February 2007 to August 2026) to describe when agranulocytosis occurs among approximately 2,020 patients treated with clozapine over up to 19 years of follow-up. The study will estimate the cumulative incidence and incidence rates across follow-up periods, examine whether risk after the first 18 weeks remains stable over time, and assess age, sex and psychiatric diagnosis as predictors. Each case will be individually reviewed to distinguish clozapine-related events from neutropenia due to cancer or chemotherapy. No patients will be contacted and no treatment will be changed. The findings are intended to inform policy on long-term hematological monitoring of clozapine-treated patients.

Status (registry)
Completed
Study type
Observational
Enrollment
2020 (actual)
First submitted
28 Oct 2026
Start date
10 Sept 2026
Primary completion date
24 Oct 2026
Lead sponsor
Sheba Medical Center
NCT number
NCT07913529

What you commit to

  • Study type: Observational
  • Participants enrolled: 2020
  • From 10 Sept 2026 to the primary completion date, 24 Oct 2026
  • 1 site in 1 country
  • Visits and tests: ask the trial team, the registry does not list them

Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.

Who cannot take part

Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.

Prior treatment

  • No documented clozapine prescription or chronic medication list entry in the data warehouse

Lab values

  • No laboratory data (absolute neutrophil count) or no documented psychiatric clinic visit after the index date

Other

  • \-

Who the study is looking for

  • \-
  • At least one ambulatory prescription for clozapine or a chronic medication list entry for clozapine (ATC N05AH02) in the Sheba Medical Center data warehouse between February 2007 and August 2026
  • Follow-up in the psychiatric clinics of Sheba Medical Center
  • No restriction by age, indication or comorbidity

Sex: All · Does not accept healthy volunteers

Full criteria on ClinicalTrials.gov

Sites (1)

Sites in registry order. Pick your city on the disease page to sort them by distance.

SiteCityCountrySite status
Sheba medical center
Coordinator of this site? Confirm its status
Ramat GanIsraelUnknown status

This page is information, not medical advice. Discuss any trial with your doctor.