The Lowest Effective Dose of Post-Transplantation Cyclophosphamide in Combination With Sirolimus and Mycophenolate Mofetil as Graft-Versus-Host Disease Prophylaxis After Reduced Intensity Conditioning and Peripheral Blood Stem Cell Transplantation

"Matched HCT: 100 mg/m\^2 IV on day -2 over 30 minutes. Haplo HCT:~100 mg/m\^2 IV on day -6 over approximately 20-30 minutes."

Sirolimus: Loading dose of 6 mg orally given on day +5 (calculated based on actual body weight, max initial dose 6 mg)\^d, then maintenance dose starting at 2 mg orally daily on day +6 with dose adjustments to maintain a trough of 5-12 ng/ml, continued through day +80 with no taper. Doses should be modified as appropriate for drug interactions and may be modified based on institutional practice.

Haplo HCT only: A dose of 200 cGy will be administered on day -1.

based on dose level being tested (50, 35, 25, or 15 mg/kg) IV once daily over 2 hours on days +3 and +4. Cyclophosphamide will be dosed according to ideal body weight. Cyclophosphamide infusion on days +3 should be started between 70-74 hours after the start of the PBSC infusion. Cyclophosphamide infusion on day +4 should be started between 94-98 hours after the start of the bone marrow infusion.

15 mg/kg orally or IV three times daily (max 1000 mg/dose) starting on day +5, continued through day +35. Dosing will be according to actual body weight.

Matched HCT: 25 mg/m\^2/day infused IV over 60 minutes from day -7 to day -3. Haplo HCT: 40 mg/m\^2/day infused IV over approximately 30-60 minutes from day -5 to day -2

Stem cell transplant

equal to the cyclophosphamide dose (50, 35, 25, or 15 mg/kg) as IV infusion concomitant with cyclophosphamide. Mesna is dosed in the same way as cyclophosphamide regarding ideal vs. actual body weight.b Dosing may be modified based on institutional standard practice.

begins on day +5 at a dose of 5 mcg/kg/day (actual body weight; dose rounding is permitted e.g., nearest vial or syringe size) and is administered daily subcutaneously or IV until the absolute neutrophil count is \> 1000 cells/mm3 for three days or \> 5000 for one day.