Study schema and HCT outcomes. (A) RIC regimen. Fludarabine was administered at the daily dose of 25 mg/m² from days −7 to −3 before HCT. Melphalan was given on day −2 at 140 mg/m² for patients who were younger than 60 years old. Melphalan dose for patients ≥60 years old was 100 mg/m². (B) MAC regimen consisted of daily fludarabine at 30 mg/m², from days −7 to −5 before HCT. Total body irradiation was administered in 8 fractions of 150 cGy, 2 times a day, from days −4 to −1, for a total of 1200 cGy. Graft source was PBSCs for both strata, and GVHD prophylaxis was PTCy at 50-mg/kg daily dose on days +3 and +4. Granulocyte colony-stimulating factor administration (5 µg/kg per day) was started on day +5 and continued until absolute neutrophil count >1500/mm³ for 3 consecutive days. Tacrolimus (1 mg continuous IV) administration started on day +5 with dose adjustment to maintain a level of 5 to 15 ng/mL and then changed to equivalent oral dose once stable. Tacrolimus taper was started on day +90 if patient did not have active GVHD. MMF was administered at 15 mg/kg dose 3 times per day beginning on day +5 (maximum dose, 1 g orally, 3 times per day). MMF administration was stopped on day +35 if there was no severe GVHD. (C) Kalan-Meier curve showing survival outcomes and (D) relapse and nonrelapse mortality outcomes.