Blackwell, K., Semiglazov, V., Krasnozhon, D., Davidenko, I., Nelyubina, L., Nakov, R., . . . Harbeck, N. (2015). Comparison of EP2006, a filgrastim biosimilar, to the reference: A phase III, randomized, double-blind clinical study in the prevention of severe neutropenia in patients with breast cancer receiving myelosuppressive chemotherapy. Annals of Oncology, 26, 1948–1953. 

To compare the biosimilar to reference filgrastim

Patients were randomized to receive the biosimilar or filgrastim for the duration of treatment or to alternate at each chemotherapy cycle. Chemotherapy was given every three weeks for six cycles. Patient assessments were done at baseline, on day 1 of each cycle. For cycles 2–6, complete blood counts were assessed on day 7 and daily thereafter.

• N = 218   
• MEDIAN AGE = 50 years
• AGE RANGE = 23–76 years
• FEMALES: 100%
• KEY DISEASE CHARACTERISTICS: Breast cancer 
• OTHER KEY SAMPLE CHARACTERISTICS: Patients undergoing treatment with docetaxel, doxorubicin, and cyclophosphamide (TAC) chemotherapy

• SITE: Multi-site   
• SETTING TYPE: Not specified    
• LOCATION: Eastern European countries

• PHASE OF CARE: Active antitumor treatment

• Noninferiority, double-blind, randomized, controlled trial

• Days of neutropenia—absolute neutrophil count (ANC) < 0.5 x 10⁹ to ≥ 0.5 x 10⁹  number of consecutive days
• Infections 
• Incidence of hospitalization related to febrile neutropenia (FN)

The number of consecutive days of neutropenia was 1.17 in the biosimilar group and 1.2 in the filgrastim group. No significant differences existed in the time to ANC recovery or adverse events. In those receiving the biosimilar, fever episodes were reported in 15% compared to 4.3% of those receiving filgrastim.

This study showed no clinically meaningful differences in neutropenia-related outcomes between patients receiving figrastim and a colony-stimulating factor (CSF) biosimilar.

The findings showed similar clinical results with filgrastim and this CSF biosimilar.