Efficacy and safety of pegfilgrastim biosimilar MD‐110 in patients with breast cancer receiving chemotherapy: Single‐arm phase III

INTRODUCTION: Pegfilgrastim is indicated to decrease the incidence of chemotherapy‐induced febrile neutropenia. It is the first granulocyte‐colony stimulating factor approved for prophylactic use regardless of carcinoma type and is marketed in Japan as G‐LASTA (Kyowa Kirin Co., Ltd., Tokyo, Japan). MD‐110 is a biosimilar of pegfilgrastim. This phase III, multicenter, open‐label, single‐arm study investigated the efficacy and safety of MD‐110 in early‐stage breast cancer patients receiving neoadjuvant or adjuvant myelosuppressive chemotherapy. METHODS: A total of 101 patients received the study drug. Each patient received docetaxel 75 mg/m(2) and cyclophosphamide 600 mg/m(2) (TC) for four cycles on day 1 of each cycle. MD‐110 (3.6 mg) was administered subcutaneously on day 2 of each cycle. The primary efficacy endpoint was the duration of severe neutropenia during cycle 1 (days with absolute neutrophil count < 500/mm(3)). The safety endpoints were adverse events and the presence of antidrug antibodies. RESULTS: The mean (SD) duration of severe neutropenia for MD‐110 was 0.2 (0.4) days. The upper limit of the two‐sided 95% confidence interval for the mean duration of severe neutropenia was 0.2 days, below the predefined threshold of 3.0 days. The incidence of febrile neutropenia, the secondary efficacy endpoint, was 6.9% (7/101). Adverse events, occurring in more than 50% of patients, were alopecia, constipation, and malaise, which are common side effects of TC chemotherapy. Antidrug antibodies were negative in all patients. CONCLUSION: MD‐110 was effective against chemotherapy‐induced neutropenia. No additional safety concern, compared with the originator, was observed in patients with breast cancer receiving TC chemotherapy.(JapicCTI‐205230).