Reduced-Dose Cyclophosphamide for Leukemia After Stem Cell Transplant

(OPTIMIZE Trial)

Recruiting at 29 trial locations

Overseen By OPTIMIZE Study Team

Age: 18+

Sex: Any

Travel: May Be Covered

Time Reimbursement: Varies

Trial Phase: Phase 2

Recruiting

Sponsor: Center for International Blood and Marrow Transplant Research

Disqualifiers: Prior allogeneic transplant, uncontrolled infection, others

No Placebo Group

Prior Safety Data

Trial Summary

What is the purpose of this trial?

The goal of this clinical trial is to determine the effectiveness of Reduced Dose Post-Transplant Cyclophosphamide (PTCy) in patients with hematologic malignancies after receiving an HLA-Mismatched Unrelated Donor (MMUD) . The main question\[s\] it aims to answer are: * Does a reduced dose of PTCy reduce the occurrence of infections in the first 100 days after transplant? * Does a reduced dose of PTCy maintain the same level of protection against Graft Versus Host Disease (GvHD) as the standard dose of PTCy?

Do I need to stop my current medications for the trial?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

What data supports the effectiveness of the treatment Reduced-Dose Cyclophosphamide for Leukemia After Stem Cell Transplant?

Research suggests that using fludarabine with busulfan (FluBu) as a conditioning regimen for stem cell transplantation is effective and has less toxicity compared to the traditional busulfan and cyclophosphamide (BuCy) regimen. This combination maintains similar survival rates while reducing side effects like lung injury and infections. ^{1 2 3 4 5}

Is reduced-dose cyclophosphamide safe for humans after stem cell transplant?

Research shows that using busulfan and fludarabine as part of a conditioning regimen for stem cell transplantation has been associated with reduced toxicity and improved safety in patients with leukemia. This suggests that similar regimens, including reduced-dose cyclophosphamide, may also be safe for humans. ^{2 4 6 7 8}

What makes the Reduced-Dose Cyclophosphamide treatment for leukemia after stem cell transplant unique?

This treatment is unique because it uses fludarabine instead of cyclophosphamide, which may reduce toxicity while maintaining effectiveness. However, there is a concern about a higher risk of severe pneumonia with this substitution. ^{2 9 10 11 12}

Research Team

Steven Devine, MD

Principal Investigator

NMDP

Jeffery Auletta, MD

Principal Investigator

NMDP

Eligibility Criteria

Adults aged 18-66 with various blood cancers, who can consent and follow the trial procedures. They must have a partially matched unrelated donor for stem cell transplant and be in good enough health to undergo the procedure. Specific conditions like AML or ALL should be in early remission.

Inclusion Criteria

My leukemia is in its first remission or later, or I have a specific type of myelofibrosis.

I can care for myself but cannot do normal activities or work.

My kidneys work well enough (creatinine clearance ≥ 45mL/min).

Exclusion Criteria

I have a donor who matches me closely for a transplant.

Inability to provide informed consent or comply with protocol

I am receiving treatment to lower my body's reaction to a transplant.

Trial Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Conditioning and Transplantation

Participants receive conditioning regimens including Fludarabine, Busulfan, Melphalan, or TBI, followed by a PBSC graft infusion from a mismatched unrelated donor

7 days

Daily visits for conditioning and transplantation

Post-Transplant Cyclophosphamide Treatment

Participants receive a reduced dose of cyclophosphamide on Day 3 and Day 4 post-transplant

2 days

2 visits (in-person)

Follow-up

Participants are monitored for safety, effectiveness, and incidence of infections, GvHD, and other outcomes

1 year

Regular visits as per protocol

Treatment Details

Interventions

• Busulfan (Chemotherapy)
• Cyclophosphamide (Chemotherapy)
• Fludarabine (Chemotherapy)
• Melphalan (Chemotherapy)
• Mesna (Chemotherapy)
• Mycophenolate Mofetil (Immunosuppressant)
• Patient Reported Outcomes (Other)
• PBSC Hematopoietic Stem Cell Transplantation (Procedure)
• Post-Transplant Cyclophosphamide (Chemotherapy)
• Tacrolimus (Immunosuppressant)
• Total-body irradiation (Radiation)

Trial Overview The trial tests if a lower dose of Post-Transplant Cyclophosphamide after stem cell transplantation from mismatched donors is effective at preventing Graft Versus Host Disease while reducing infections within the first 100 days post-transplant.

Participant Groups

Group I: Regimen E (NMA: Fludarabine, Cyclophosphamide, and TBI; PBSCT HCT; Reduced Dose PTCy Experimental Treatment 9 Interventions

Patients receive: Fludarabine (150mg/m2 total dose) IV on days -6 to -2 Cyclophosphamide (29-50mg/kg) IV on days -6 and -5 TBI (200cGy) on day -1 Patients receive a PBSC graft infusion from a mismatched unrelated donor on Day 0. Patients receive a reduced dose of cyclophosphamide (25mg/kg per dose) on Day 3 and Day 4 post-transplant. First 20 patients with a 4-6/8 mismatched unrelated donor will receive an alternate dose of post-transplant cyclophosphamide of 37.5 mg/kg on Days 3 and Day 4 post-transplant.

Group II: Regimen D (RIC: Fludarabine and Melphalan; PBSCT HCT; Reduced Dose PTCy Experimental Treatment 7 Interventions

Patients receive: Fludarabine (125-150 mg/m2 total dose) IV on days -7 to -3 Melphalan (100-140 mg/m2) IV on day -1 Patients receive a PBSC graft infusion from a mismatched unrelated donor on Day 0. Patients receive a reduced dose of cyclophosphamide (25mg/kg per dose) on Day 3 and Day 4 post-transplant. First 20 patients with a 4-6/8 mismatched unrelated donor will receive an alternate dose of post-transplant cyclophosphamide of 37.5 mg/kg on Days 3 and Day 4 post-transplant.

Group III: Regimen C (RIC: Fludarabine and Busulfan; PBSCT HCT; Reduced Dose PTCy Experimental Treatment 7 Interventions

Patients receive: Fludarabine (150-180 mg/m2 total dose) IV on days -6 to -2 Busulfan (less than or equal to 8 mg/kg PO or 6.4 mg/kg IV) on days -5 and -4 Patients receive a peripheral blood stem cell (PBSC) graft infusion from a mismatched unrelated donor on Day 0. Patients receive a reduced dose of cyclophosphamide (25mg/kg per dose) on Day 3 and Day 4 post-transplant. First 20 patients with a 4-6/8 mismatched unrelated donor will receive an alternate dose of post-transplant cyclophosphamide of 37.5 mg/kg on Days 3 and Day 4 post-transplant.

Group IV: Regimen B (MAC: Fludarabine and TBI, PBSC HCT; Reduce Dose PTCy Experimental Treatment 7 Interventions

Patients receive: Fludarabine (90 mg/m2 total dose) IV on days -7 to -5 Total body irradiation (TBI) (1200 cGy total dose) on days -4 to -1 Patients receive a peripheral blood stem cell (PBSC) graft infusion from a mismatched unrelated donor on Day 0. Patients receive a reduced dose of cyclophosphamide (25mg/kg per dose) on Day 3 and Day 4 post-transplant. First 20 patients with a 4-6/8 mismatched unrelated donor will receive an alternate dose of post-transplant cyclophosphamide of 37.5 mg/kg on Days 3 and Day 4 post-transplant.

Group V: Regimen A (MAC: Busulfan and Fludarabine, PBSC HCT; Reduce Dose PTCy Experimental Treatment 7 Interventions

Patients Receive: Patients receive: Busulfan (≥ 9 mg/kg total dose) IV or PO on days -6 to -3 Fludarabine (150 mg/m2 total dose) IV on days -6 to -2 Patients receive a peripheral blood stem cell (PBSC) graft infusion from a mismatched unrelated donor on Day 0. Patients receive a reduced dose of cyclophosphamide (25mg/kg per dose) on Day 3 and Day 4 post-transplant. First 20 patients with a 4-6/8 mismatched unrelated donor will receive an alternate dose of post-transplant cyclophosphamide of 37.5 mg/kg on Days 3 and Day 4 post-transplant.

Busulfan is already approved in Canada, Japan for the following indications:

Approved in Canada as Busulfex for:

• Chronic myeloid leukemia
• Acute myeloid leukemia
• Bone marrow transplantation conditioning

Approved in Japan as Busulfan for:

• Chronic myeloid leukemia
• Acute myeloid leukemia
• Bone marrow transplantation conditioning

Who Is Running the Clinical Trial?

Center for International Blood and Marrow Transplant Research

Lead Sponsor

Trials

40

Recruited

200,190,000+

National Marrow Donor Program

Collaborator

Trials

63

Recruited

202,000+

Findings from Research

In a study comparing two preconditioning regimens for allogeneic hematopoietic stem cell transplantation, patients receiving busulfan and fludarabine (Bu-Flu) showed improved overall survival and event-free survival rates, particularly in those treated in the first complete remission (CR1).

The Bu-Flu regimen was associated with better outcomes than the traditional busulfan and cyclophosphamide (BuCy) regimen, suggesting it may enhance safety and maintain antileukemic efficacy, warranting further prospective studies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Once daily i.v. busulfan and fludarabine (i.v. Bu-Flu) compares favorably with i.v. busulfan and cyclophosphamide (i.v. BuCy2) as pretransplant conditioning therapy in AML/MDS. Andersson, BS., de Lima, M., Thall, PF., et al.[2022]

In a study of 32 patients with acute myeloid leukemia in first complete remission, the busulfan/fludarabine (Bu/Flu) conditioning regimen resulted in significantly lower transplant-related toxicity compared to the busulfan/cyclophosphamide (Bu/Cy) regimen, with a lower incidence of severe side effects (68.8% vs. 25.0%).

Both regimens showed similar efficacy in terms of overall survival and event-free survival rates, indicating that Bu/Flu is a safer option without compromising treatment effectiveness.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[A comparison of toxicity and efficacy between busulfan plus fludarabine and busulfan plus cyclophosphamide for allogeneic hematopoietic stem cell transplantation in acute myeloid leukemia]. Liu, H., Fan, ZP., Jiang, QL., et al.[2014]

The study evaluated a myeloablative conditioning regimen using fludarabine and busulfan in 70 patients with acute leukemia, showing similar efficacy to the traditional BuCy regimen with overall survival at 71% and disease-free survival at 64%.

Fludarabine and busulfan resulted in a high incidence of mucositis (93%) but lower transplant-related adverse effects compared to BuCy, suggesting it could be a safer alternative, although modifications may be needed for optimal anti-leukemic effects in specific leukemia types.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Fludarabine and busulfan as a myeloablative conditioning regimen for allogeneic stem cell transplantation in high- and standard-risk leukemic patients. Iravani, M., Evazi, MR., Mousavi, SA., et al.[2013]

In a study of 30 adult patients undergoing allogeneic hematopoietic stem cell transplant, fludarabine combined with full-dose busulfan (FluBu) and fludarabine with melphalan (FluMel) showed similar levels of hematological toxicity, indicating that both regimens are comparably safe.

The timing and duration of severe neutropenia were similar between the two groups, with both regimens resulting in a comparable recovery time for neutrophils and platelets post-transplant, suggesting that FluBu can be an effective alternative to standard reduced intensity conditioning regimens.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparable kinetics of myeloablation between fludarabine/full-dose busulfan and fludarabine/melphalan conditioning regimens in allogeneic peripheral blood stem cell transplantation. Chunduri, S., Dobogai, LC., Peace, D., et al.[2013]

In a study comparing two treatment regimens for children undergoing hematopoietic cell transplantation, the combination of fludarabine and busulfan (FluBu) showed similar survival rates to busulfan and cyclophosphamide (BuCy), with 2-year survival rates of 82% for FluBu and 78% for BuCy.

The FluBu regimen was associated with significantly lower toxicity, including reduced rates of lung injury, veno-occlusive disease, and infections, as well as a shorter duration of neutropenia, indicating it may be a safer option for patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Fludarabine and exposure-targeted busulfan compares favorably with busulfan/cyclophosphamide-based regimens in pediatric hematopoietic cell transplantation: maintaining efficacy with less toxicity. Bartelink, IH., van Reij, EM., Gerhardt, CE., et al.[2014]

In a study involving 16 patients with hematological malignancies, the pharmacokinetics of fludarabine were assessed before and after administration of busulfan, showing no significant changes in key parameters such as clearance and half-life.

The results suggest that there is unlikely to be a clinically relevant drug interaction between busulfan and fludarabine, supporting their combined use in conditioning regimens for stem cell transplantation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

F-ara-A pharmacokinetics during reduced-intensity conditioning therapy with fludarabine and busulfan. Bonin, M., Pursche, S., Bergeman, T., et al.[2013]

In a study of 62 patients undergoing reduced-intensity conditioning for stem cell transplantation, therapeutic dose monitoring of oral busulfan did not significantly impact post-transplant outcomes compared to standard dosing.

The presence of chronic graft-versus-host disease was identified as a strong predictor of overall survival and leukemia-free survival, highlighting its importance in patient outcomes after transplantation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Reduced-intensity conditioning allogeneic blood stem cell transplantation with fludarabine and oral busulfan with or without pharmacokinetically targeted busulfan dosing in patients with myeloid leukemia ineligible for conventional conditioning. Martino, R., Pérez-Simón, JA., Moreno, E., et al.[2013]

The combination of intravenous busulfan and fludarabine as a conditioning therapy for allogeneic hematopoietic stem cell transplantation (HSCT) in patients with acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS) demonstrated a high complete remission rate of 85% in patients with active disease.

This regimen showed low regimen-related (1%) and treatment-related (3%) mortality rates, indicating improved safety, while achieving a 1-year overall survival rate of 65% and event-free survival rate of 52% for all patients, suggesting it is an effective and reduced-toxicity option for these conditions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Once-daily intravenous busulfan and fludarabine: clinical and pharmacokinetic results of a myeloablative, reduced-toxicity conditioning regimen for allogeneic stem cell transplantation in AML and MDS. de Lima, M., Couriel, D., Thall, PF., et al.[2021]

In a study of 42 patients undergoing allogeneic hematopoietic stem cell transplantation, the combination of busulfan and fludarabine (BuFlu) resulted in significantly lower rates of mucositis compared to the traditional busulfan and cyclophosphamide (BuCy) regimen.

Both BuFlu and BuCy showed similar efficacy in terms of engraftment time, relapse risk, event-free survival, and overall survival, suggesting that BuFlu is a viable alternative to BuCy for this treatment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Fludarabine-based myeloablative regimen as pretransplant conditioning therapy in adult acute leukemia/myelodysplastic syndrome: comparison with oral or intravenous busulfan with cyclophosphamide. Lee, JH., Choi, J., Kwon, KA., et al.[2021]

In a study of 95 patients undergoing allogeneic stem cell transplantation, replacing cyclophosphamide with fludarabine in the conditioning regimen (busulfan+fludarabine) led to faster engraftment and significantly lower rates of acute and chronic graft-versus-host disease (GVHD).

The fludarabine regimen also resulted in better event-free survival and overall survival rates compared to the standard busulfan and cyclophosphamide regimen, indicating it may be a more effective option for myeloablative conditioning in allogeneic SCT.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

New myeloablative conditioning regimen with fludarabine and busulfan for allogeneic stem cell transplantation: comparison with BuCy2. Chae, YS., Sohn, SK., Kim, JG., et al.[2022]

In a study involving 105 patients, substituting fludarabine for cyclophosphamide in the modified busulfan-cyclophosphamide (mBuCy) regimen led to a significantly higher incidence of severe pneumonia (31.1%) compared to the mBuCy regimen (11.6%).

Due to the increased risk of severe pneumonia, the trial was suspended, indicating that fludarabine may not be a safe substitute for cyclophosphamide in this myeloablative conditioning regimen for allogeneic hematopoietic stem cell transplantation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Substitution of cyclophosphamide in the modified BuCy regimen with fludarabine is associated with increased incidence of severe pneumonia: a prospective, randomized study. Liu, DH., Xu, LP., Zhang, XH., et al.[2022]

In a study of 30 patients with various malignant hematological diseases undergoing allogeneic bone marrow transplantation using a Busulphan and Cyclophosphamide (Bu-Cy) conditioning regimen, sustained disease-free survival (DFS) was achieved in 5 out of 7 patients with acute leukemia in remission and 6 out of 9 patients with chronic myelogenous leukemia (CML) in the chronic phase.

The Bu-Cy protocol demonstrated a strong tumor ablative capability while maintaining toxicity levels similar to other conditioning regimens, making it a promising option for patients with significant bone marrow involvement.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Allogeneic bone marrow transplantation for hematological malignancies following therapy with high doses of busulphan and cyclophosphamide. Angelucci, E., Polchi, P., Lucarelli, G., et al.[2013]

References

1. United States pubmed.ncbi.nlm.nih.gov

Once daily i.v. busulfan and fludarabine (i.v. Bu-Flu) compares favorably with i.v. busulfan and cyclophosphamide (i.v. BuCy2) as pretransplant conditioning therapy in AML/MDS. [2022]

2. China pubmed.ncbi.nlm.nih.gov

[A comparison of toxicity and efficacy between busulfan plus fludarabine and busulfan plus cyclophosphamide for allogeneic hematopoietic stem cell transplantation in acute myeloid leukemia]. [2014]

3. England pubmed.ncbi.nlm.nih.gov

Fludarabine and busulfan as a myeloablative conditioning regimen for allogeneic stem cell transplantation in high- and standard-risk leukemic patients. [2013]

4. England pubmed.ncbi.nlm.nih.gov

Comparable kinetics of myeloablation between fludarabine/full-dose busulfan and fludarabine/melphalan conditioning regimens in allogeneic peripheral blood stem cell transplantation. [2013]

5. United States pubmed.ncbi.nlm.nih.gov

Fludarabine and exposure-targeted busulfan compares favorably with busulfan/cyclophosphamide-based regimens in pediatric hematopoietic cell transplantation: maintaining efficacy with less toxicity. [2014]

6. England pubmed.ncbi.nlm.nih.gov

F-ara-A pharmacokinetics during reduced-intensity conditioning therapy with fludarabine and busulfan. [2013]

7. United States pubmed.ncbi.nlm.nih.gov

Reduced-intensity conditioning allogeneic blood stem cell transplantation with fludarabine and oral busulfan with or without pharmacokinetically targeted busulfan dosing in patients with myeloid leukemia ineligible for conventional conditioning. [2013]

8. United States pubmed.ncbi.nlm.nih.gov

Once-daily intravenous busulfan and fludarabine: clinical and pharmacokinetic results of a myeloablative, reduced-toxicity conditioning regimen for allogeneic stem cell transplantation in AML and MDS. [2021]

9. Korea (South) pubmed.ncbi.nlm.nih.gov

Fludarabine-based myeloablative regimen as pretransplant conditioning therapy in adult acute leukemia/myelodysplastic syndrome: comparison with oral or intravenous busulfan with cyclophosphamide. [2021]

10. England pubmed.ncbi.nlm.nih.gov

New myeloablative conditioning regimen with fludarabine and busulfan for allogeneic stem cell transplantation: comparison with BuCy2. [2022]

11. Japan pubmed.ncbi.nlm.nih.gov

Substitution of cyclophosphamide in the modified BuCy regimen with fludarabine is associated with increased incidence of severe pneumonia: a prospective, randomized study. [2022]

12. Italy pubmed.ncbi.nlm.nih.gov

Allogeneic bone marrow transplantation for hematological malignancies following therapy with high doses of busulphan and cyclophosphamide. [2013]