# Safety and Efficacy of Abatacept for Treating Chronic Cytopenia in Cytotoxic T-Lymphocyte Antigen 4 (CTLA4) Haploinsufficiency

> **NCT03733067** · PHASE1,PHASE2 · WITHDRAWN · sponsor: **National Institute of Allergy and Infectious Diseases (NIAID)**

## Conditions studied

- CTLA4 Haploinsufficency
- Chronic Cytopenia

## Interventions

- **DRUG:** abatacept
- **OTHER:** Placebo

## Key facts

- **NCT ID:** NCT03733067
- **Lead sponsor:** National Institute of Allergy and Infectious Diseases (NIAID)
- **Sponsor class:** NIH
- **Phase:** PHASE1,PHASE2
- **Study type:** INTERVENTIONAL
- **Status:** WITHDRAWN
- **Start date:** 2023-11-30
- **Primary completion:** 2023-11-30
- **Final completion:** 2023-11-30
- **Target enrollment:** 0 (ACTUAL)
- **Why stopped:** No enrollment
- **Last updated:** 2023-12-04


## Primary source

ClinicalTrials.gov registry: https://clinicaltrials.gov/study/NCT03733067

## Citation

> US National Library of Medicine, ClinicalTrials.gov registration NCT03733067, "Safety and Efficacy of Abatacept for Treating Chronic Cytopenia in Cytotoxic T-Lymphocyte Antigen 4 (CTLA4) Haploinsufficiency". Retrieved via AI Analytics 2026-06-25 from https://api.ai-analytics.org/clinical/NCT03733067. Licensed CC0.

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