Waller, C.F., Semiglazov, V.F., Tjulandin, S., Bentsion, D., Chan, S., & Challand, R. (2010). A phase III randomized equivalence study of biosimilar filgrastim versus Amgen filgrastim in patients receiving myelosuppressive chemotherapy for breast cancer. Onkologie, 33, 504–511.

DOI Link

Study Purpose

The purpose of the study was to demonstrate bioequivalence of two different filgrastim products.

Intervention Characteristics/Basic Study Process

Patients were randomized to receive one of the two types of filgrastim at the same dose and schedule. Treatment was 5 mcg subcutaneously daily on day 2 of chemotherapy in each cycle, and continued until absolute neutrophil count (ANC) was greater than 3 x 109/L or treatment had been given for 14 days.

Sample Characteristics

  • 276 participants were studied.
  • Mean age was 49.8 years (SD = 8.88)
  • All were female
  • All had breast cancer at various stages and were receiving chemotherapy with doxorubicin and docetaxel.
  • Patients did not have any radiotherapy within six weeks of study entry, or prior chemotherapy within four weeks.
     

Setting

37 European outpatient centers in various countries

Phase of Care and Clinical Applications

Mutliple phases of care

Study Design

Randomized, double-blind phase III

Measurement Instruments/Methods

  • Duration of severe neutropenia for each chemotherapy cycle defined as ANC less than 0.5 x 109/L
  • Time to ANC recovery (greater than 3 x 109/L)
  • Incidence of febrile neutropenia (ANC less than 0.5 x 109/L and temp 38.5ºC or higher)
  • Incidence of documented infection
  • NCI CTCAE [v.3.0]
     

Results

Incidence of severe neutropenia was 77.6% in one group and 68.2% in the other, with no statistically significant difference. Duration of severe neutropenia across groups in cycle 1 ranged from 1.3 –1.6 days on average, and was lower in both groups in subsequent cycles. There were no differences in outcomes between the two. Those receiving Hospira filgrastim had a slightly higher incidence of  bone pain than Amgen filgrastim; however, overall prevalence of skeletal pain was similar in both groups.

Conclusions

 The results of this study showed that these two different preparations of filgrastim are bioevquivalent.

Limitations

  • Risk of bias (sample characteristics)
  • The sample was almost 98% Caucasians. 
  • Those receiving Hospira filgrastim who had more bone pain, also had a higher prevalence of bone metastases at baseline. It is not clear if these may have been related.

Nursing Implications

 This study was designed purely to demonstrate bioequivalence of these two filgrastim products.