Filgrastim biosimilar(Apexcela Co., Ltd.)

Evaluation of adverse events (AEs) in pivotal registration trials and ongoing postmarketing surveillance is important for all biologics, including biosimilars. A combined analysis of two pivotal registration studies was performed to strengthen evidence on safety for biosimilar filgrastim EP2006 in patients with breast cancer receiving myelosuppressive chemotherapy, a sensitive clinical setting to confirm biosimilarity of filgrastim.

Data were combined from two phase III studies of biosimilar filgrastim EP2006. The U.S. registration study was a randomized, double-blind comparison of biosimilar and reference filgrastim in women aged ≥18 years with breast cancer, receiving (neo)adjuvant treatment with TAC (docetaxel + doxorubicin + cyclophosphamide). The European Union registration study was a single-arm, open-label study of biosimilar filgrastim in women aged ≥18 years with breast cancer receiving doxorubicin + docetaxel. Patients received filgrastim as a subcutaneous injection on day 2 of each cycle for <14 days or until the absolute neutrophil count reached 10 × 109/L after the expected nadir. Results were combined for cycles 1–4.

A total of 277 patients received biosimilar filgrastim EP2006. Patients had a mean (± standard deviation) age of 51.1 (± 10.8) years, and 78.7% of patients had stage II or III breast cancer. A total of 46 (20.6%) patients receiving biosimilar filgrastim had AEs considered filgrastim-related. The most frequently reported filgrastim-related AEs were musculoskeletal or connective tissue disorders (15.2%), including bone pain (7.2%). One death (due to pulmonary embolism) occurred of a patient receiving biosimilar filgrastim (not considered filgrastim-related). No patient developed antidrug antibodies during the study.

Biosimilar filgrastim has a safety profile consistent with previous filgrastim studies and is effective in preventing febrile neutropenia in patients with breast cancer.

The biosimilar filgrastim EP2006 (Zarzio, Zarxio, biosimilar filgrastim-sndz) has been approved in Europe since 2009 and in the U.S. since 2015. This combined analysis of two phase III studies provides additional clinical evidence that the biosimilar filgrastim EP2006 has a safety profile consistent with previous studies of reference filgrastim and supports large postmarketing studies of EP2006 in Europe. Strengthening the evidence for biosimilar filgrastim can help improve acceptance of biosimilars and increase patient access to biologics.

Febrile neutropenia (FN) is a serious and frequent complication of cytotoxic chemotherapy. Biosimilar filgrastim (Nivestim™, Hospira Inc, A Pfizer Company, Lake Forest, IL, USA) is a granulocyte-colony stimulating factor licensed for the treatment of neutropenia and FN induced by myelosuppressive chemotherapy. The primary goal of this VENICE study (ClinicalTrials.gov identifier, NCT01627990) was to observe the tolerability, safety and efficacy of biosimilar filgrastim in patients receiving cancer chemotherapy.

This was a prospective, multicenter, non-interventional, longitudinal study. Consenting adult patients with solid tumors or hematologic malignancies for whom cytotoxic chemotherapy and treatment with biosimilar filgrastim was planned were enrolled.

Among the enrolled patients (N = 386), 81% were female, with a median age (range) of 61 (22–92) years, with 39% >65 years old. Most patients (n = 338; 88%) had solid tumors and the remainder (n = 49; 13%) had hematological malignancies. The majority of the patients (64%) received biosimilar filgrastim as primary prophylaxis and 36% as secondary prophylaxis. At the follow-up visits, for the majority of patients (95.6%) there had been no change in chemotherapy dose due to FN. For two patients (0.5%) the chemotherapy was discontinued due to FN and for four patients (1.0%) the chemotherapy dose was reduced due to FN. For the majority of patients (96.9%) the chemotherapy cycle following the first biosimilar filgrastim treatment was not delayed due to FN. For 3 patients (0.8%), the chemotherapy was delayed following the first biosimilar filgrastim treatment. Less than one-third (29.8%) of the patients experienced ≥1 adverse event that was at least potentially related to biosimilar filgrastim treatment.

Biosimilar filgrastim was effective and well-tolerated in both the primary and secondary prophylactic setting in patients undergoing chemotherapy for solid tumors and hematological malignancies.

ClinicalTrials.gov identifier, NCT01627990.

Hospira Inc, A Pfizer Company, Lake Forest, IL, USA.