Retrospective analysis of relative dose intensity in patients with non-Hodgkin lymphoma receiving CHOP-based chemotherapy and pegfilgrastim.

OBJECTIVES: To evaluate primary prophylaxis with pegfilgrastim, a recombinant human granulocyte colony-stimulating factor, on maintaining relative dose intensity (RDI) in patients with non-Hodgkin lymphoma (NHL) receiving cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or CHOP-rituximab (CHOP-R). METHODS: This retrospective analysis pooled data from pegfilgrastim NHL clinical trials. Patients received up to 6 cycles of CHOP/CHOP-R every 2 (Q2W) or 3 (Q3W) weeks. RDI and the patient incidence of dose delay, reduction, discontinuation, and adverse events leading to dose alteration/discontinuation were summarized overall and by age group (below 65, 65 to 75, and above 75 y) and treatment schedule. RDI during treatment exposure and RDI adjusted by the planned 6 cycles of treatment were calculated. The adjusted RDI was also evaluated with multiple regression analysis. RESULTS: Mean RDI during treatment exposure was 93% and 94% in overall patients in the Q2W and Q3W regimens, respectively. Mean adjusted RDI was 88% and 80%, respectively. The incidence of patients with RDI>85% was lower in older patients (65 y and above). In older patients, the incidence of dose reduction and discontinuation were higher regardless of treatment schedule, whereas dose delay was higher in the Q2W regimen. Multiple regression analysis identified age and cancer stage as potential factors associated with RDI. Adverse events leading to dose alteration/discontinuation were spread across hematological and nonhematological toxicities; older patients had a higher incidence of these adverse events. CONCLUSIONS: Pegfilgrastim primary prophylaxis maintained RDI in NHL patients receiving CHOP/CHOP-R during treatment. Adjusted RDI was lower in elderly patients because of early termination of chemotherapy.