OncoTargets and Therapy (Jan 2018)
Biosimilar filgrastim vs filgrastim: a multicenter nationwide observational bioequivalence study in patients with chemotherapy-induced neutropenia
Abstract
Alper Sevinç,1 Metin Özkan,2 Ahmet Özet,3 Faysal Dane,4 Berna Öksüzoğlu,5 Abdurrahman Işıkdoğan,6 Feyyaz Özdemir,7 Doğan Uncu,8 Mahmut Gümüş,9 Türkkan Evrensel,10 Arzu Yaren,11 Oğuz Kara,12 Salim Başol Tekin13 1Department of Medical Oncology, Medical Park Gaziantep Hospital, Gaziantep, 2Department of Medical Oncology, Erciyes University Faculty of Medicine, Kayseri, 3Department of Medical Oncology, Gazi University Faculty of Medicine, Ankara, 4Department of Medical Oncology, Marmara University Faculty of Medicine, Istanbul, 5Department of Medical Oncology, Dr Abdurrahman Yurtaslan Ankara Oncology Training and Research Hospital, Ankara, 6Department of Medical Oncology, Dicle University Faculty of Medicine, Diyarbakır, 7Department of Medical Oncology, Karadeniz Technical University Faculty of Medicine, Trabzon, 8Department of Medical Oncology, Ankara Numune Hospital, Ankara, 9Department of Medical Oncology, Istanbul Medeniyet University, Istanbul, 10Department of Medical Oncology, Uludağ University Faculty of Medicine, Bursa, 11Department of Medical Oncology, Pamukkale University Faculty of Medicine, Denizli, 12Department of Medical Oncology, Çukurova University Faculty of Medicine, Adana, 13Department of Medical Oncology, Atatürk University Faculty of Medicine, Erzurum, Turkey Background: We studied the comparative effectiveness of biosimilar filgrastim vs original filgrastim in patients with chemotherapy-induced neutropenia.Patients and methods: This multicenter, observational study was conducted at 14 centers. The study included 337 patients experiencing neutropenia under chemotherapy. Patients were given either filgrastim 30 MIU or 48 MIU (Neupogen®) or biosimilar filgrastim 30 MIU (Leucostim®). Data regarding age, chemotherapeutic agents used, number of chemotherapy courses, previous diagnosis of neutropenia, neutrophil count of patients after treatment, medications used for the treatment of neutropenia, and duration of neutropenia were collected. Time to absolute neutrophil count (ANC) recovery was the primary efficacy measure.Results: Ambulatory and hospitalized patients comprised 11.3% and 45.1% of the enrolled patients, respectively, and a previous diagnosis of neutropenia was reported in 49.3% of the patients, as well. Neutropenia occurred in 13.7% (n=41), 45.5% (n=136), 27.4% (n=82), 11.4% (n=34), and 2.0% (n=6) of the patients during the first, second, third, fourth, and fifth cycles of chemotherapy, respectively. While the mean neutrophil count was 0.53±0.48 before treatment, a significant increase to 2.44±0.66 was observed after treatment (p=0.0001). While 90.3% of patients had a neutrophil count <1.49 before treatment, all patients had a neutrophil count ≥1.50 after treatment. Neutropenia resolved within ≤4 days of filgrastim therapy in 60.1%, 56.7%, and 52.6% of the patients receiving biosimilar filgrastim 30 MIU, original filgrastim 30 MIU, and original filgrastim 48 MIU, respectively. However, there was no significant difference between the three arms (p=0.468). Similarly, time to ANC recovery was comparable between the treatment arms (p=0.332).Conclusion: The results indicate that original filgrastim and biosimilar filgrastim have comparable efficacy in treating neutropenia. Biosimilar filgrastim provides a valuable alternative; however, there is need for further studies comparing the two products in different patient subpopulations. Keywords: chemotherapy, febrile neutropenia, neutrophil, ANC recovery, supportive care, myelosuppressive
