FDA Approval: Treosulfan Injection With Fludarabine before Allogeneic HSCT for AML, MDS

The FDA has approved a new indication for injection treosulfan, an alkylating agent. The approval is for use with fludarabine as a preparatory combination for allogeneic hematopoietic stem cell transplantation (HSCT) to manage acute myeloid leukemia (AML) or myelodysplastic syndromes (MDS) in adults or pediatric patients aged one year and older. Medexus Pharmaceuticals Inc. announced the approval in a press release.

Injection treosulfan is produced by Medexus as Grafapex and the agent has Orphan Drug Designation under the Orphan Drug Act. Medexus holds exclusive commercial rights to this agent in the US via an agreement with medac GmbH, and the FDA approval is for sale and use of this agent only in the US. Medexus plans commercial launch of the agent for the first half of 2025.

“We are pleased to report this positive development, which marks a strategically important step forward for our business and, importantly, will now benefit eligible patients across the United States,” remarked Medexus Chief Executive Officer Ken d’Entremont.

The randomized active-controlled study MC-FludT.14/L Trial II evaluated treosulfan in comparison with busulfan plus fludarabine as allogeneic HSCT preparation for adults aged up to 70 years with AML or MDS.

In the study’s efficacy results, overall survival (OS) was measured as time from randomization until death from any cause, and the hazard ratio of treosulfan compared with busulfan was 0.67 in the randomized population, 0.73 in patients with AML, and 0.64 in patients with MDS. Regarding safety, adverse reactions that occurred in 20% or more of patients were edema, infection, musculoskeletal pain, nausea, pyrexia, stomatitis, and vomiting. Laboratory findings also included grade 3 or 4 increases in alanine aminotransferase, aspartate aminotransferase, bilirubin, creatinine, and γ-glutamyl transferase.

The recommended dosing for treosulfan in the preparatory combination 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 HSCT infusion on day 0.

Reference

Medexus announces FDA approval of GRAFAPEX (treosulfan) for injection and provides business update. Press Release. Medexus Pharmaceuticals, Inc. (MDP). January 22, 2025. Accessed January 24, 2025.