FDA approves treosulfan with fludarabine as a preparative regimen for alloHSCT in adult and pediatric patients with AML or MDS
On January 21, 2025, the Food and Drug Administration approved treosulfan (Grafapex, medac GmbH), an alkylating agent, with fludarabine as a preparative regimen for allogeneic hematopoietic stem cell transplantation (alloHSCT) in adult and pediatric patients 1 year of age and older with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS).
Full prescribing information for Grafapex will be posted on Drugs@FDA.
Efficacy and Safety
Efficacy was evaluated in MC-FludT.14/L Trial II (NCT00822393), a randomized active-controlled trial comparing treosulfan to busulfan with fludarabine as a preparative regimen for allogeneic transplantation. Eligible patients included adults 18 to 70 years old with AML or MDS, Karnofsky performance status ≥ 60%, and age ≥ 50 years or hematopoietic cell transplantation comorbidity index [HCTCI] score > 2. There were 570 patients randomized to treosulfan (n=280) or busulfan (n=290).
The major efficacy outcome measure was overall survival (OS), defined as the time from randomization until death from any cause. The hazard ratio for OS (stratified by donor type and risk group) compared to busulfan was 0.67 (95% CI: 0.51, 0.90) in the randomized population, 0.73 (95% CI: 0.51, 1.06) in patients with AML, and 0.64 (95% CI: 0.40, 1.02) in patients with MDS.
The most common adverse reactions (≥20%) were musculoskeletal pain, stomatitis, pyrexia, nausea, edema, infection, and vomiting. Selected Grade 3 or 4 nonhematological laboratory abnormalities were increased GGT, increased bilirubin, increased ALT, increased AST, and increased creatinine.
Recommended Dose
The recommended treosulfan dose is 10 g/m2 daily on days -4, -3, and -2 in combination with fludarabine 30 mg/m2 daily on days -6, -5, -4, -3, and -2, and allogeneic hematopoietic stem cell infusion on day 0.
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