Roche announced positive phase I/II data for NXT007, a next-generation bispecific antibody for hemophilia A treatment, showing the investigational drug achieved zero treated bleeds in the highest dose groups. The results from the NXTAGE study, presented at the 2025 International Society on Thrombosis and Haemostasis (ISTH) Congress in Washington D.C., support the drug's advancement to phase III clinical development.
Trial Design and Results
The phase I/II NXTAGE study, conducted by Chugai in Japan, Taiwan and South Korea, enrolled 30 participants aged 12 to 65 years with hemophilia A without factor VIII inhibitors who had not previously received Hemlibra treatment. Participants were divided into four ascending dose cohorts (B-1 to B-4) and received subcutaneous NXT007 every two-to-four weeks during the maintenance period, following four-to-six weeks of loading doses.
In the primary analysis, no treated bleeds were observed with NXT007 in the highest dose cohorts (B-3 and B-4). The drug demonstrated a tolerable safety profile with no thromboembolic events reported during the study period.
Next-Generation Bispecific Technology
NXT007 was engineered by Chugai, a member of the Roche Group, building on the framework of Hemlibra (emicizumab) with optimized factor VIII-mimetic activity and extended half-life. The bispecific antibody brings together factor IXa and factor X, proteins required to activate the natural coagulation cascade, mimicking the function of missing factor VIII in hemophilia A patients.
"These NXT007 data are promising for people with haemophilia A and underscore our ongoing commitment to advancing care and addressing the real-world challenges faced by this community," said Levi Garraway, MD, PhD, Roche's Chief Medical Officer and Head of Global Product Development. "Hemlibra established a new standard of care, and our focus is to continue to deliver breakthrough innovation that might ultimately help people with haemophilia to live their lives in a manner unaffected by this condition."
Clinical Development Program
The robust clinical development program for NXT007 includes ongoing phase I/II trials with additional phase II data expected later this year. Three phase III studies are planned for 2026, including a head-to-head comparison with Hemlibra, which currently offers subcutaneous administration with flexible dosing options of every week, two weeks, or four weeks.
The clinical program aims to achieve sustained elevated bleed protection equivalent to people without hemophilia A, termed "sustained haemostatic normalisation," while reducing treatment burden through factor independence.
Disease Background and Unmet Need
Hemophilia A affects approximately 900,000 people worldwide and is characterized by deficient or absent factor VIII, leading to impaired blood clotting and frequent bleeding episodes. Patients experience bleeding particularly into joints and muscles, which can cause pain, chronic swelling, deformity, reduced mobility and long-term joint damage.
A significant treatment complication involves the development of inhibitors—antibodies that bind to and block replacement factor VIII efficacy, making bleeding control difficult or impossible. NXT007's factor-independent mechanism may address this challenge by bypassing the need for factor VIII replacement.
Strategic Positioning
NXT007 represents Roche's continued investment in hemophilia treatment following the success of Hemlibra, which established subcutaneous prophylactic therapy as a new standard of care. The company's hemophilia portfolio leverages over 25 years of experience in hematology, with the goal of providing patients greater therapeutic choice and reduced treatment burden.
The development program positions NXT007 to potentially offer sustained, elevated bleed protection while allowing patients "freedom from constant vigilance and confidence in bleed protection," according to Roche's clinical objectives.
