Prophylactic NAC to Improve Platelet Engraftment After Haploidentical Transplantation in Severe Aplastic Anemia Patients

NCT07737262 — Phase 3, Not yet recruiting, 142 participants, Peking University People's Hospital

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Prophylactic N-Acetylcysteine to Facilitate Platelet Engraftment Following Haploidentical Hematopoietic Stem Cell Transplantation for Patients With Severe Aplastic Anemia: A Prospective Multicenter Randomized Controlled Trial

Registry	NCT07737262
Status	Not yet recruiting
Phase	Phase 3
Study type	Interventional; randomized, parallel, masking: none, prevention
Enrollment	142 (Estimated)
Sponsor	Peking University People's Hospital (Other)
Conditions	Aplastic Anemia
Interventions	N-acetylcysteine (Drug)
Dates	start 2026-09-30 (estimated), primary completion 2028-09-30 (estimated), completion 2029-09-30 (estimated), first posted 2026-07-30, last updated 2026-09-16

-Summary

This study aims to evaluate the efficacy and safety of prophylactic oral N-acetylcysteine (NAC) for facilitating platelet engraftment in patients with severe aplastic anemia (SAA) receiving haploidentical hematopoietic stem cell transplantation (haplo-HSCT). This is a prospective, multicenter, randomized controlled trial enrolling a total of 142 patients with SAA scheduled for their first haplo-HSCT, who will be randomly assigned at a 1:1 ratio to the NAC prophylaxis group or the control group, with 71 subjects in each arm. Patients in the intervention group will receive oral NAC 400 mg three times daily from Day -14 before transplantation to Day +60 post-transplant, while the control group will receive no prophylactic NAC, with all other transplant-related treatments identical between the two groups. The primary endpoint is the cumulative platelet engraftment rate by 2 months after transplantation. Secondary endpoints cover neutrophil engraftment rate, incidence of poor hematopoietic reconstitution, cumulative blood product transfusion volume, graft-versus-host disease (GVHD), overall survival, GVHD-free and failure-free survival, and biomarkers reflecting bone marrow hematopoietic microenvironment reconstruction. Safety outcomes will be assessed via adverse events graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE), version 5.0. Statistical analyses will be performed using R 4.4.0 software, primarily adopting competing risk models and the Kaplan-Meier method based on full analysis set, per-protocol set and safety set. This trial will clarify intergroup differences in platelet recovery, other efficacy endpoints and safety profiles, verify the clinical benefits and safety of NAC, and generate high-quality clinical evidence for prophylactic intervention targeting platelet engraftment after haplo-HSCT in SAA patients to optimize clinical management strategies.

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+Arms and interventions

Arm	Type	Interventions	Description
Prophylactic N-acetylcysteine (NAC) Group	Experimental	Drug: N-acetylcysteine	Patients receive oral NAC 400 mg three times daily from Day -14 before transplantation to Day +60 post-transplant, combined with standard haploidentical hematopoietic stem cell transplantation and routine supportive care.
Control Group	No intervention		Patients receive standard haploidentical hematopoietic stem cell transplantation and identical supportive treatments without prophylactic oral NAC throughout the study period.

N-acetylcysteine (Drug): Oral NAC capsules, 400 mg per dose, administered three times daily. Treatment starts at Day -14 before transplantation and continues until Day +60 after transplantation.

+Outcome measures

Primary outcomes

Cumulative incidence of platelet engraftment by 2 months after transplantation [2 months post-HSCT]: Platelet engraftment was characterized as the first day with a platelet count of at least 20 × 10\^9/L without transfusion support for seven consecutive days.

Secondary outcomes

Cumulative incidence of neutrophil engraftment by 2 months after transplantation [2 months post-HSCT]: Neutrophil engraftment was defined as the first of three consecutive days with a neutrophil count of at least 0.5 × 10\^9/L
Incidence of poor hematopoietic reconstitution by 2 months post-transplant [2 months post-HSCT]: Poor hematopoietic reconstitution includes delayed platelet engraftment and poor graft function (PGF). Delayed platelet engraftment: platelet <20×10\^9/L or persistent platelet transfusion dependence at Day +60. PGF refers to persistent cytopenia with complete donor chimerism and hypoplastic marrow.
Cumulative volume of blood product transfusions [From pre-transplant Day -14 to post-transplant Day +60]: Total units of platelet and red blood cell transfusions received by each patient. Transfusion standards follow institutional clinical guidelines for anemia and severe thrombocytopenia.
Cumulative incidence of acute and chronic graft-versus-host disease (aGVHD/cGVHD) [100 days for aGVHD; 1 year for cGVHD after transplantation]: aGVHD was graded by modified Glucksberg criteria within 100 days; chronic GVHD was diagnosed by National Institutes of Health consensus criteria within 1 year post-transplant.
1-year overall survival (OS) [1 year after transplantation]: OS was defined as the duration from HSCT to death from any cause or the date of the last follow-up.
1-year graft-versus-host disease-free, failure-free survival (GFFS) [1 year after transplantation]: GFFS was defined as the absence of grade III-IV acute GVHD, extensive chronic GVHD, graft failure, or death from any cause.
Bone marrow endothelial progenitor cell (EPC) count and intracellular reactive oxygen species (ROS) level [Baseline (pre-transplant), post-transplant 1 months and 2 months]: Laboratory biomarkers reflecting bone marrow hematopoietic microenvironment reconstruction, including EPC quantity and intracellular ROS level detected at scheduled bone marrow puncture time points.

+Eligibility

Sex: All, ages: 14 Years to 50 Years

Inclusion Criteria:

1. Diagnosed with aplastic anemia and scheduled to receive first haplo-HSCT
2. Aged 14 to 50 years
3. Hematopoietic Cell Transplant Comorbidity Index (HCT-CI) ≤ 2
4. Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2
5. Negative donor-specific human leukocyte antigen (HLA) antibodies
6. No uncontrolled active infection before transplantation
7. No irreversible severe organ dysfunction
8. Voluntarily sign written informed consent and agree to complete scheduled follow-up

Exclusion Criteria:

1. Confirmed allergy or hypersensitivity to NAC
2. Medical history of bronchial asthma
3. Uncontrolled severe psychiatric disorders unable to cooperate with treatment and follow-up
4. Active peptic ulcer, gastrointestinal bleeding, inflammatory bowel disease or severe gastrointestinal dysfunction
5. Female patients who are pregnant or breastfeeding