Figure 2.

HCT and post-HCT strategy. Conditioning regiments include busulfan (BU; 16-20 mg/kg orally over 4 days) in combination with cyclophosphamide (CY; 120 mg/kg over 2 days) or fludarabine (FLU; 40 mg/m²/dose over 4 days) with or without melphalan (MEL; 140 mg/m² once). Assessment at day +30 after HCT is performed by NGS and evaluation of donor chimerism. Molecular response is defined by a reduction of mutant allele frequency of the driver mutation to <5%. Modulation of GVL includes rapid withdrawal of immunosuppression and administration of donor lymphocyte infusions (±azacitidine). If remission, including molecular remission and full donor chimerism, is achieved, patients are monitored with bone marrow aspirates every 90 days for the first 18 months to 2 years after transplant (routine follow-up). Patients with refractory disease, relapse, or transformation to AML may benefit from a second HCT.