Pegfilgrastim for prevention of chemotherapy-associated neutropenia in pediatric patients with solid tumors

BACKGROUND

Pegfilgrastim has similar efficacy to filgrastim in adults, but studies in pediatrics are limited. We report our institutional experience with pegfilgrastim following dose intensive chemotherapy for solid tumors.

PROCEDURE

We evaluated the initial four courses of myelosuppressive chemotherapy for 47 patients (total 176 courses) diagnosed between 1/1/07 and 2/6/08 who received chemotherapy with pegfilgrastim support (100 mcg/kg; 6 mg maximum dose) in this retrospective review. We collected demographic data, treatment characteristics, frequency of severe neutropenia (absolute neutrophil count (ANC) <200/mm(3)), duration of neutropenia, and frequency of neutropenic fever.

RESULTS

The median age of treated patients was 13 years (range 0.17-23 years) and the median weight was 50.8 kg (range 4-107 kg), including 16 (34%) <20 kg, and 22 (47%) <45 kg. Primary diagnoses included osteosarcoma, Ewing sarcoma, rhabdomyosarcoma, soft tissue sarcoma, neuroblastoma, Hodgkin disease, and other solid tumors. No significant adverse events secondary to pegfilgrastim were noted. Severe neutropenia occurred in 57% of courses. The median duration of severe neutropenia was 1 day (range 0-11 days). Febrile neutropenia occurred in 28% of courses. Eight patients were treated with interval-compressed (every 14 days) sarcoma chemotherapy. Of the 30-interval compressed courses, the median duration per course was 14 days (range 14-18 days).

CONCLUSIONS

Pegfilgrastim following dose intensive chemotherapy for solid tumors is feasible in children, including those <45 kg. The frequency and duration of severe neutropenia, as well as incidence of febrile neutropenia, were similar to filgrastim historic data.

Pegfilgrastim: current and future perspectives in the treatment of chemotherapy-induced neutropenia

Myeloid colony-stimulating factors (granulocyte colony-stimulating factor [G-CSF] and granulocyte-macrophage colony-stimulating factor) are commonly used in clinical practice for the prevention of anticancer chemotherapy-induced neutropenia and its potentially life-threatening complications. Pegfilgrastim is a novel recombinant human G-CSF pharmaceutically developed by covalent binding of a polyethylene glycol molecule to the N-terminal sequence of filgrastim. Due to its unique neutrophil-mediated clearance, pegfilgrastim can be administered once per chemotherapy cycle. Clinical trials have demonstrated that a single, fixed, subcutaneous dose of pegfilgrastim is comparable in safety and efficacy to daily injections of filgrastim for decreasing the incidence of infection following myelosuppressive chemotherapy in patients with cancer. Recent trials have been conducted to evaluate the use of pegfilgrastim in different clinical settings, including support of dose-dense regimens, mobilization and transplantation of hematopoietic stem cells.