Fixed-Dose Single Administration of Pegfilgrastim vs Daily Filgrastim in Patients with PTLD Undergoing a Sequential Therapy of Rituximab and CHOP Chemotherapy.

Infectious complications are frequent events in patients with post-transplant lymphoproliferative disorders (PTLD) undergoing CHOP-based cytotoxic chemotherapy and previous studies had demonstrated the need for growth factors to conduct chemotherapy in these patients. To evaluate whether a single subcutaneous injection of pegfilgastrim (6mg) is as safe and effective as daily filgastrim (5 μg/kg/day), 84 cycles of CHOP-21 chemotherapy in patients with PTLD have been analyzed. Patients were treated with four weekly doses of 375mg/m² of rituximab as a single therapeutic agent at days 1, 8, 15 and 22. CHOP chemotherapy had been administered at days 50, 72, 94 and 116 and was supported by GCSF. In case of disease progression during administration of rituximab or during the 4-week interval between antibody therapy and CHOP administration the patients directly entered chemotherapy. In total, 7 patients undergoing 23 cycles of CHOP chemotherapy received a single subcutaneous injection of 6mg pegfilgastrim on day 3 after application of CHOP and were compared retrospectively with 20 patients receiving 5 μg/kg/day of filgastrim starting from day 3 after application of CHOP. In the pegfilgastrim group 5 patients were renal transplant recipients, one was a liver transplant recipient and one was a heart transplant recipient. In the filgastrim group 10 patients were renal transplant recipients, 6 were liver transplant recipients, four were heart transplant recipients. 1 patient was a combined heart/lung transplant recipient, one was a combined kidney/pancreas transplant recipient and one patient was after bone marrow transplantation. 4/7 patients of the pegfilgastrim group had stage III or stage IV disease, while 14/20 patients in the filgastrim group had stage III or stage IV disease. Age ranged from 20 to 76 years with a median age of 57 years in the pegfilgastrim and from 16 to 80 years with a median age of 55 years in the filgastrim group. The incidence of grade III/IV infections in the pegfilgastrim and filgastrim groups were 2 in 23 applied cycles of chemotherapy and 7 in 61 cycles of applied chemotherapy, respectively. The incidence of grade III/IV leucopenia in the pegfilgastrim and filgastrim groups were 15 in 23 cycles in the pegfilgastrim group and 29 in 61 cycles in the filgastrim group. The results of the two groups were not significantly different for incidence of grade III/IV infections and grade III/IV leucopenia. A single injection of pegfilgastrim administered at day 3 post CHOP-based chemotherapy showes a comparable efficacy and safety profile to daily injections of filgastrim in patients with PTLD.