Abstract
Febrile neutropenia (FN) is a serious complication of chemotherapy, which can cause significant morbidity and mortality, result in dose delays and reductions and, ultimately, reduce cancer survival. Over the past decade, the availability of biosimilar filgrastim (short-acting granulocyte colony-stimulating factor [G-CSF]) has transformed patient access, with clear evidence of clinical benefit at preventing FN at reduced costs. In 2019, seven biosimilar pegfilgrastims (long-acting G-CSFs) were licensed, creating optimal market conditions and choice for prescribers. FN affects up to 117 per 1000 cancer patients, with mortality rates in the range of 2-21%. By reducing FN incidence and improving chemotherapy relative dose intensity (RDI), G-CSF has been associated with a 3.2% absolute survival benefit. Guidelines recommend primary prophylaxis and that filgrastim be administered for 10-14 days, while pegfilgrastim is administered once per cycle. When taken according to the guidelines, pegfilgrastim and filgrastim are equally effective. However, in routine clinical practice, filgrastim is often under-dosed (< 7 days) and has been shown to be inferior to pegfilgrastim at reducing FN incidence, hospitalisations and maintaining RDI. Once-per-cycle administration with pegfilgrastim might also aid patient adherence. The introduction of biosimilar pegfilgrastim should instigate a rethink of neutropenia management. Biosimilar pegfilgrastim offers countries using biosimilar filgrastim opportunities to improve adherence and thus cancer survival, whilst offering economic benefits for countries using reference pegfilgrastim. These benefits can be realised in full if biosimilar pegfilgrastim becomes part of routine clinical practice supported by drug and therapeutic committees implementing guidelines with multidisciplinary support in the hospital.