Study Supports the Effectiveness and Safety of Biosimilar Filgrastim in Patients With DLBCL

The current standard of care for treating patients with diffuse large B-cell lymphoma (DLBCL) is chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone plus immunotherapy with rituximab, and this regimen is associated with a significant risk of chemotherapy-induced neutropenia (CIN) and febrile neutropenia (FN). Therefore, prophylaxis of neutropenia is warranted for patients receiving this regimen. Prospective data on the use of granulocyte-colony-stimulating factor (G-CSF) in patients with DLBCL are limited, however, and data are especially limited for older patients.

A study recently published in the European Journal of Hematology reports DLBCL-specific findings from MONITOR-GCSF, a pan-European, multicenter, prospective, observational study that attempts to describe the treatment patterns and clinical outcomes of patients who received biosimilar filgrastim (filgrastim-sndz, marketed as Zarzio in the European Union and Zarxio in the United States) in the prophylaxis of CIN and FN.

The study included 245 patients with DLBCL. Mean age was 62.7 years (range, 21 years to 87 years). Data on biosimilar filgrastim prophylaxis were available for 239 patients with DLCBL, including 123 aged 65 or older, and 94 aged 70 or older.

The researchers found that prophylaxis with the biosimilar filgrastim occurred in 14 (5.9%) of the total number of patients, with 7 discontinuations each in the group aged 65 or older and the group aged 70 or older. The most common reasons for discontinuation were unavailability of the biosimilar filgrastim in the hospital, stopping chemotherapy, change of G-CSF agent, and cancellation of the chemotherapy protocol.

In total, 87 patients (35.5%) experienced 1 or more episodes of CIN, and 24 (9.8%) experienced FN during the study. The percentage of patients with DLBCL who experienced an episode of FN was higher than the percentage experiencing the same in the overall MONITOR-GCSF population (5.9%).

These episodes of neutropenia led to a change to chemotherapy regimen in 130 patients (53.1%), 70 of whom were 65 or older (56.0% of this age group), and 53 of whom were 70 or older (55.2% of this age group). Changes to regimens included receiving fewer than 6 cycles of chemotherapy, dose reduction, dose delay, or cycle cancellation.

The most frequently reported adverse event in patients with DLBCL was bone pain, followed by arthralgia and back pain. Bone pain was experienced at lower levels in the DLBCL population (2.9%) than by the overall MONITOR-GCSF population (24.7%), though the reasons for this difference are unclear.

The authors conclude that the MONITOR-GCSF study supports the effectiveness and safety of filgrastim-sndz in patients with DLBCL in the real-world setting, and that the large proportion of patients who were aged 65 or older adds to the body of evidence on how to best treat older patients who receive myelosuppressive chemotherapy to treat DLBCL.

References

Gascón P, Krendyukov A, Höbel N, Aapro M. MONITOR-GCSF DLBCL subanalysis: Treatment patterns/outcomes with biosimilar filgrastim for chemotherapy-induced/febrile neutropenia prophylaxis. Eur J Haematol. 2018;100:241-246. doi: 10.1111/ejh.13002.