Use Of Biosimilar G-CSF Compared With Lenograstim In Autologous Haematopoietic Stem Cell Transplant and In Sibling Allogeneic Transplant

Biosimilar filgrastim is now widely used for haematopoietic stem cell mobilisation in Europe. Previous studies have reported differences in mobilisation efficacy between originator filgrastim and lenograstim, although others have reported comparable efficacy. This is the first study to compare biosimilar filgrastim with lenograstim for autologous haematopoietic stem cell transplant (HSCT). We also report our use of biosimilar filgrastim for mobilisation in sibling allogeneic transplant, for which there is limited previous data.

Data from patients with lymphoma or multiple myeloma (MM) who underwent autologous HSCT mobilised with biosimilar filgrastim (HX575) between October 2011 and April 2013 at St Bartholomew's Hospital, London, were compared with a historical control group of patients who underwent HCST using a similar mobilisation protocol with lenograstim from January 2009 to September 2011. Peripheral blood (PB) cells counts (white blood cell [WBC] and CD34+ cells) were monitored after 7–8 consecutive days of G-CSF injection (approximately 5 μg/kg) and apheresis was performed on day 8 if PB CD34+ cell count was ≥10 cells/µl. G-CSF administration and apheresis were then performed daily until a PB CD34+ cell dose of ≥2.0 x10⁶/kg (lymphoma), ≥ 4.0 x10⁶/kg (MM ≥60 years old) or ≥ 8.0 x10⁶/kg (MM <60 years old) was achieved. Data from a separate group of sibling donors and recipients with haematological malignancies who underwent allogeneic HSCT between October 2010 and April 2013 are also reported.

A total of 259 patients were included in the autologous HSCT comparison (biosimilar filgrastim, n=104; lenograstim, n=155). Both groups had similar characteristics (overall, 66% male, median age 56 years) although the biosimilar group had a lower percentage of patients with lymphoma (19% vs 35%). In patients with lymphoma and older MM patients (≥60 years old), no significant differences were observed between groups with regard to stem cell mobilisation parameters. However, in MM patients <60 years old, all parameters were significantly superior in the biosimilar filgrastim group compared with lenograstim, including the need for one rather the two aphereses (Table 1).

Among patients who proceeded to transplant, no significant differences were observed between biosimilar filgrastim and lenograstim in median number of days to ANC recovery > 0.5 x10⁹/l (lymphoma: 13 [9, 35] vs 13 days [9, 36]; MM: 14 [9, 34] vs 12 [10, 33] days) or platelet recovery > 20 x10⁹/l (lymphoma: 21 [9, 35] vs 23 days [10, 35]; MM: 19 [9, 38] vs 18 [9, 39] days). In the allogeneic setting, 48 sibling donors received biosimilar filgrastim. Mean CD34+ count at the first apheresis was 6.1 x 10⁶/kg. Thirteen donors needed a second apheresis, four of whom required a third. Among the recipients, median days to ANC recovery was 16 (10–28) and to platelet recovery was 13 (9–54).

Biosimilar filgrastim is as effective as lenograstim for autologous HSCT in patients with lymphoma or MM patients ≥60 years old. However, mobilisation with biosimilar filgrastim appeared to be superior to that with lenograstim in younger MM patients. Biosimilar filgrastim was also successfully used to mobilise sibling donors for allogeneic transplantation.

Agrawal:Sandoz Biopharmaceuticals: Consultancy, Honoraria, Research Funding.