Use Of Pegfilgrastim Primary Prophylaxis By Chemotherapy Cycle Among Patients With Non-Hodgkin’s Lymphoma Or Breast Cancer

A recent open-label, randomized, phase III study in patients with breast cancer (BC) treated with myelosuppressive chemotherapy found a 3-fold higher incidence of febrile neutropenia (FN) among patients who received pegfilgrastim (peg) prophylaxis during the first two chemotherapy cycles only compared with those who received peg prophylaxis during all chemotherapy cycles (36% vs 10%, respectively; Aarts et al. Journal of Clinical Oncology, April 29, 2013). We examined the use of peg prophylaxis in a real-world setting to assess if practice conforms to clinical guidelines, which recommend granulocyte colony-stimulating factor (G-CSF) every chemotherapy cycle where the risk of FN is ≥20%.

The study cohort was selected from the MarketScan Research Database of administrative claims maintained by Truven Health Analytics. The selection criteria included adults diagnosed with non-Hodgkin's lymphoma (NHL) or female BC who began chemotherapy between January 1, 2005 and December 31, 2010. Patients were excluded if they received filgrastim, radiotherapy, or a bone marrow or stem cell transplant during their first chemotherapy course. The proportion of patients in the study cohort who received peg prophylaxis was calculated during cycle 1. For each subsequent cycle, the proportion of patients who received peg prophylaxis was calculated among the patients who had received peg in cycle 1 and continued on the same regimen.

Table 1 shows the use of peg prophylaxis among patients with NHL who received CHOP (cyclophosphomide, doxorubicin, vincristine, prednisone), with or without rituxumab (R) in cycle 1, for 2-week (Q2W) or 3-week (Q3W) cycles, and did not receive filgrastim during their course. Of the 81 patients who received CHOP or CHOP-R Q2W, 61% received peg in cycle 1; of those who remained on the regimen, 74% to 95% received peg in subsequent cycles. Of the 892 patients who received CHOP or CHOP-R Q3W, 54% received peg in cycle 1; of those who remained on the regimen, 90%-95% received peg in subsequent cycles.

Table 2 shows the use of peg among patients with BC who received TAC (docetaxel, doxorubicin, cyclophosphamide), ddAC-T (dose-dense doxorubicin, cyclophosphamide followed by dose-dense paclitaxel), or TC (docetaxel, cyclophosphamide) in cycle 1 and did not receive filgrastim during their course. Of the 1,730 patients who received TAC, 78% received peg in cycle 1; of those who remained on the regimen, 88% to 94% received peg in subsequent cycles. Of the 3,170 patients who received ddAC-T, 76% received peg in cycle 1; of those who remained on the regimen, 86% to 93% received peg cycles 2 to 4. Of the 3,639 patients who received TC, 51% received peg in cycle 1; of those who remained on the regimen, about 90% received peg in subsequent cycles.

Despite clinical guidelines recommending G-CSF prophylaxis with chemotherapy regimens with a high risk of FN, many NHL and BC patients do not receive appropriate FN prophylaxis. However, among NHL and BC patients who receive peg in cycle 1 and remain on the regimen, the majority appear to continue prophylaxis as indicated. The dataset has some limitations: we could not determine dose, complete risk factors for FN, or reasons patients did not receive or discontinued peg.

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