Plainsboro, New Jersey, and Bagsværd, Denmark, September 17, 2026
Novo Nordisk has announced published Phase 3b results from the FRONTIER5 study evaluating investigational denecimig in adolescents and adults living with hemophilia A, with or without inhibitors. The 26-week study evaluated patients who switched directly from emicizumab to denecimig without a washout period or an initial loading dose. The findings, published in the Journal of Thrombosis and Haemostasis, showed that the treatment switch was well tolerated, with no unforeseen safety concerns reported. The study also found that most participants preferred the denecimig prefilled pen injector over their previous emicizumab vial-and-syringe administration system. Exploratory analyses further showed that denecimig increased thrombin generation into the normal range throughout the study period without clinical evidence of excessive clotting.
FRONTIER5 Evaluates Direct Treatment Switching
The open-label FRONTIER5 Phase 3b study enrolled 61 adolescents and adults aged 12 years and older with hemophilia A, including patients with and without inhibitors. Participants completed a 26-week treatment period following a direct switch from emicizumab to subcutaneous denecimig. Importantly, the transition was performed without a washout period or denecimig loading dose, addressing a practical consideration when patients move between hemophilia prophylaxis treatments. The primary safety analysis recorded 107 treatment-emergent adverse events in 43 participants, representing 70.5% of the study population. Most events were mild to moderate, accounting for 98.1% of reported events. Novo Nordisk reported no thromboembolic events, hypersensitivity reactions, or adverse events leading to treatment discontinuation, and no clinical evidence of neutralizing anti-denecimig antibodies was observed.The results also provided information about how patients experienced the treatment transition. Among 59 participants who completed the device questionnaire, 98.3% rated the denecimig pen as easy or very easy to use, while 94.9% reported that it was easier to use overall than their previous administration method. In addition, 96.6% preferred the denecimig pen to their previous device. These findings were assessed using the Hemophilia Device Handling and Preference Assessment and represented a supportive secondary endpoint rather than the study’s primary efficacy outcome.
Denecimig Supports Thrombin Generation
Denecimig is an investigational bispecific antibody Factor VIIIa mimetic designed to provide routine prophylaxis for people with hemophilia A. The molecule is intended to bridge Factor IXa and Factor X, mimicking the function of activated Factor VIII and helping restore thrombin generation required for blood clot formation. It is being developed for administration through a single-dose prefilled disposable pen at once-weekly, once-every-two-weeks, or once-monthly dosing frequencies. An exploratory endpoint in FRONTIER5 evaluated peak thrombin generation, a laboratory measure of blood-clotting function. Across the treatment groups, mean peak thrombin increased from 25.5 nmol/L at baseline to 39.8 nmol/L at Week 26, representing an average within-participant percentage increase of 78.8%. Novo Nordisk reported that this increase was sustained throughout the 26-week period without clinical evidence of a synergistic thrombin peak-height effect or excessive clotting. Denecimig also reached steady-state plasma concentrations by Week 16 without a loading dose.
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FDA Review Continues for Denecimig
The FRONTIER5 findings add to Novo Nordisk’s broader FRONTIER clinical development program, which is evaluating denecimig across different age groups and treatment settings in hemophilia A. The company is also evaluating long-term safety and efficacy through the ongoing FRONTIER4 extension study. Meanwhile, a Biologics License Application (BLA) is under review by the U.S. FDA for denecimig as routine prophylaxis to prevent or reduce bleeding episodes in adult and pediatric patients with hemophilia A, with or without inhibitors.
Hemophilia A is a rare inherited bleeding disorder caused by deficient or defective Factor VIII, impairing the body’s ability to generate effective blood clots. Patients who develop inhibitors can face additional treatment challenges because antibodies against replacement clotting factors can reduce treatment effectiveness. The FRONTIER5 findings therefore provide clinical evidence on the tolerability and practical treatment experience associated with switching to investigational denecimig, while ongoing regulatory review and future clinical data will determine its potential role in hemophilia A management.
Source: Novo Nordisk press release
