Hemlibra improves joint health and physical activity in hemophilia patients

Interim study results presented as a poster at ASH 2025

Shows improvement in Joint health scores … proportion of patients with no bleeding remains stable

JW Pharmaceutical announced on the 22nd that patients with hemophilia A who switched to prophylactic treatment with Hemlibra (emicizumab) showed improvements in joint health indicators as well as increased levels of physical activity.

Hemlibra is an innovative new drug that mimics the function of coagulation factor VIII, which is deficient in patients with hemophilia. It is the only treatment for hemophilia A that can be used in both patients with antibodies resistant to existing treatments (Factor VIII products) and non-antibody patients. Another key feature is its sustained preventive effect with subcutaneous administration as infrequently as once every four weeks. In May 2023, health insurance reimbursement in Korea was expanded to include non-antibody severe hemophilia A patients aged one year and older. In October 2025, Hemlibra was also added to the World Health Organization’s Essential Medicines List (EML) and the Essential Medicines List for Children (EMLc).

A research team led by Professor Rebecca Kruse-Jarres of the Department of Hematology and Oncology at the University of Washington in the United States is conducting the ‘BEYOND ABR Study’ to evaluate changes in joint health and physical activity when patients with hemophilia A switch to Hemlibra.

The team presented interim analysis results in poster format at the 67th Annual Meeting of the American Society of Hematology (ASH 2025), held in Orlando, USA, over four days starting on the 6th (local time). Unlike previous studies that primarily evaluated bleeding reduction effects, the BEYOND ABR study uniquely observed joint function and physical activity.

The study enrolled 136 patients with moderate-to-severe hemophilia A who did not possess antibodies against conventional Factor VIII products.

A total of 88 patients were included in the analysis of joint health using the Hemophilia Joint Health Score (HJHS). HJHS is a clinician-assessed measure evaluating the function and mobility of major joints such as the knees, ankles, and elbows. Scores range up to 120 points, with lower scores indicating better joint health. The analysis showed that the mean HJHS improved from 10.1 points at baseline—reflecting generally mild joint damage—to 2.8 points at 12 months after switching to Hemlibra. Among all patients analyzed, 23 patients (26.1%) experienced an improvement of 4 points or more

Furthermore, the 27 ‘target joints’ (joints prone to recurrent bleeding) identified in 15 patients before the study initiation at baseline were no longer observed at the 12-month mark after switching to Hemlibra, with no recurrence of repeated bleeding.

Physical activity levels also showed improvement. The research team comprehensively assessed patients' walking and physical activity at various intensities using the International Physical Activity Questionnaire (IPAQ). As a result, the proportion of patients classified as ‘low physical activity’ according to IPAQ criteria decreased from 30.8% (32 out of 104) to 23.4% (22 out of 94) at 12 months post-switch. Conversely, the proportion of patients in the ‘high physical activity’ category increased from 44.2% (46 out of 104) to 52.4% (54 out of 103) at 3 months post-switch and remained at 50.0% (47 out of 94) at 12 months.

The proportion of patients experiencing no bleeding also remained stable. Between weeks 25 and 48 after Hemlibra administration, 105 out of 134 patients (78.4%) reported no bleeding requiring treatment. Furthermore, at the 6-month follow-up, 125 out of 130 patients (96.2%) stated they preferred Hemlibra over their previous Factor VIII prophylaxis.

JW Pharmaceutical plans to accumulate additional long-term observational data through follow-up and expand the evidence base that can be utilized in establishing treatment strategies in actual clinical practice.

A JW Pharmaceutical representative stated, “This study presents interim analysis results confirming the bleeding prevention efficacy of Hemlibra in patients switching from conventional Factor VIII prophylaxis, along with changes in joint health and activity indicators. It provides meaningful clinical data to address key concerns, joint status, and exercise performance, key considerations when deciding whether to switch therapies.”