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/m² and cyclophosphamide 600 mg/m² (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/mm³ ). 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).