Reduced doses of emicizumab achieve good efficacy: Results from a national-wide multicentre real-world study in China.

Abstract

Reduced doses of emicizumab improve the affordability among patients in developing countries. However, the relationship between variant dose selection and efficacy in the real world of China is still unclear. This study aimed to investigate the efficacy and safety of emicizumab especially in those on reduced dose regimens in a real-world setting. We carried out a multicentre study from 28 hospitals between June 2019 and June 2023 in China and retrospectively analysed the characteristics including demographics, diagnosis, treatment, bleeding episodes, and surgical procedures. In total, 127 patients with haemophilia A, including 42 with inhibitors, were followed for a median duration of 16.0 (IQR: 9.0-30.0) months. Median age at emicizumab initiation was 2.0 (IQR: 1.0-4.0) years. Median (IQR) consumption for loading and maintenance was 12.0 (8.0-12.0) and 4.2 (3.0-6.0) mg/kg/4weeks, respectively. While on emicizumab, 67 (52.8%) patients had no bleeds, whereas 60 (47.2%) patients had any bleeds, including 26 with treated bleeds. Compared to previous treatments, patients on emicizumab had significantly decreased annualized bleeding rate, annualized joint bleeding rate, target joints and intracerebral haemorrhage. Different dosages had similar efficacy except the proportion of patients with treated spontaneous bleeds and target joints. Adverse events were reported in 12 (9.4%) patients. Postoperative excessive bleeding occurred following two of nine procedures. This is the largest study describing patients with HA receiving emicizumab prophylaxis on variant dose regimens in China. We confirmed that nonstandard dose is efficacious and can be considered where full-dose emicizumab is ill affordable.