Background Biosimilar medicines are developed independently after the patent protecting the original product has expired. The original products are followed by versions of original biological medicines, which are produced using a living system organism such as DNA recombinant technology.

Purpose To compare the efficacy and safety results in the prophylaxis of neutropenia caused by chemotherapy for six months between a filgrastim biosimilar and the original filgrastim active substance.

Materials and methods Observational study, including all patients treated with cytotoxic chemotherapy for malignancy who received human granulocyte-colony stimulating factor (G-CSF). From July 2011 to December 2011 we had filgrastim original active substance while from July 2012 to December 2012 where we used a biosimilar filgrastim.

The two patient groups were comparable for prescribed chemotherapy regimens. We did not note any differences between the drugs used for the two periods. We have used chemotherapy regimens including: docetaxel, paclitaxel, doxorubicin, carboplatin, cisplatin, cyclophosphamide, gemcitabine, etc.

The following variables were included: number of patients (n), number of items dispensed per patient, number of syringes per chemotherapy by cycle, number of febrile neutropenia episodes and adverse reactions.

Results See table

Conclusions We did not observe any differences between the two efficacies concerned. In terms of safety the percentage of patients suffering febrile neutropenia was lower with the filgrastim biosimilar (2.88% vs. 6.91%). So far we have not detected adverse reactions with either drug.

Stand up for pharmaceutical innovation which allows the development of less costly biosimilar medicines. The inclusion of this filgrastim biosimilar has led to a saving of 77,734 € during the research period in our Hospital.

No conflict of interest.