Novo Nordisk Reports Positive Long-Term Phase 3 Results for Investigational Hemophilia A Treatment Denecimig

New Phase 3 Data Shows Long-Term Benefits of Denecimig

Novo Nordisk has announced new Phase 3 clinical data showing positive long-term safety and efficacy results for its investigational hemophilia A treatment, denecimig (Mim8).

The findings come from the ongoing FRONTIER4 extension study, which evaluated the treatment in children, adolescents, and adults living with hemophilia A, both with and without inhibitors.

The latest data were presented during the International Society on Thrombosis and Haemostasis (ISTH) Congress held in Paris.

Study Evaluated Multiple Dosing Schedules

One of the key goals of the FRONTIER4 study was to understand how denecimig performs with different dosing schedules.

Participants received preventive treatment using one of the following regimens:

• Once every month
• Once every two weeks
• Once every week

The study included 426 participants aged one year and older.

Among them were:

• 365 adults and adolescents
• 61 children

Researchers monitored both safety and effectiveness over several months.

Safety Results Remained Consistent

The primary goal of the study was to evaluate long-term safety.

According to Novo Nordisk, denecimig continued to show a safety profile that matched previous findings from the FRONTIER clinical program.

Injection-site reactions remained uncommon.

Researchers reported:

• Injection-site reactions in 2.0% of injections among children
• Injection-site reactions in 1.8% of injections among adults and adolescents

All reported reactions were mild and temporary.

The study also found no clinical evidence of neutralizing antibodies developing against the treatment.

Bleeding Rates Stayed Very Low

Researchers also measured how well denecimig prevented bleeding episodes.

The estimated annualized bleeding rates remained low across all dosing schedules and regardless of whether patients had inhibitors.

The study reported:

• Annualized bleeding rate of 0.75 in adults and adolescents
• Annualized bleeding rate of 0.37 in children

Perhaps even more encouraging, many participants experienced no treated bleeding episodes during the study.

Researchers found:

• Around 71% of adults and adolescents had zero treated bleeds
• Around 89% of children had zero treated bleeds

These findings suggest the treatment continued to provide strong bleeding protection over time.

Patients Reported Better Daily Experience

The FRONTIER4 study also looked at how patients felt while receiving treatment.

Researchers found that improvements seen in earlier FRONTIER studies continued during long-term treatment.

Patients aged 12 years and older reported less joint pain using the Joint Pain Rating Scale.

Participants also reported a lower treatment burden using the Haemophilia Treatment Experience Measure.

The study evaluated the ease of using the denecimig injection device as well.

Among 185 participants:

• 94.1% said the injection pen was easy or very easy to use
• 89.7% said it was quick or very quick to prepare and inject

These results suggest the treatment may fit well into everyday life.

Additional Analysis Supports How Denecimig Works

Novo Nordisk also shared new post hoc analyses from the FRONTIER2 and FRONTIER5 studies.

Researchers examined thrombin generation, which measures the body's ability to form blood clots.

The analysis found that denecimig increased thrombin generation into the normal reference range without causing excessive clotting activity.

This provides additional evidence supporting the treatment's mechanism of action.

FDA Review Already Underway

Novo Nordisk submitted a Biologics License Application for denecimig to the US Food and Drug Administration in September 2025.

If approved, the medicine could become another preventive treatment option for people living with hemophilia A.

Company officials said the long-term Phase 3 results strengthen the overall clinical evidence supporting the therapy.

Expert Highlights Importance of Flexible Treatment Options

Dr. Guy Young, Director of the Hemostasis and Thrombosis Center at Children's Hospital Los Angeles, said long-term data are especially important when treating chronic diseases like hemophilia A.

He noted that the consistent results seen throughout the FRONTIER program suggest denecimig has the potential to benefit a wide range of patients while offering different dosing options to suit individual needs.

Novo Nordisk Also Shared New Concizumab Data

Alongside the denecimig results, Novo Nordisk also presented new findings from the Phase 3 explorer10 study evaluating concizumab in children younger than 12 years with hemophilia A or B who have inhibitors.

The study enrolled 24 children.

Researchers found that preventive treatment with concizumab substantially reduced bleeding episodes compared with previous on-demand treatment.

The estimated annualized bleeding rate fell from 11.51 during prior treatment to 2.08 while receiving concizumab, representing an 82% reduction.

Safety Findings for Concizumab

The explorer10 study also evaluated safety.

Most adverse events reported during the study were mild.

Researchers observed:

• 83% of participants experienced at least one treatment-emergent adverse event
• Most adverse events were mild in severity
• Injection-site reactions were uncommon
• Serious adverse events were reported in 29% of participants

Novo Nordisk noted that concizumab use in children younger than 12 years remains investigational and has not yet been approved by regulatory authorities for this age group.

Understanding Hemophilia

Hemophilia is a rare inherited bleeding disorder that prevents blood from clotting normally.

People with the condition can experience prolonged bleeding after injuries or spontaneous bleeding into joints and muscles.

There are two main forms of the disease.

Hemophilia A is caused by missing or defective Factor VIII.

Hemophilia B results from missing or defective Factor IX.

Many patients receive replacement clotting factor therapy through regular intravenous infusions.

However, some patients develop inhibitors that reduce the effectiveness of replacement therapy, making treatment more difficult.

What Is Denecimig?

Denecimig is an investigational bispecific antibody designed to mimic the function of activated Factor VIII.

The medicine works by connecting Factor IXa and Factor X, helping restore thrombin generation and improving the body's ability to form blood clots.

It is being developed as a preventive treatment for children, adolescents, and adults with hemophilia A, regardless of whether they have inhibitors.

What Is Concizumab?

Concizumab is a monoclonal antibody that targets tissue factor pathway inhibitor (TFPI), a protein that naturally limits blood clotting.

By blocking TFPI, concizumab increases thrombin production and helps reduce bleeding episodes.

The medicine is currently approved under the brand name Alhemo in several countries, including India, for adolescents and adults with hemophilia A or B.

Its use in children younger than 12 years is still under clinical investigation.

About the FRONTIER Clinical Program

The FRONTIER clinical program is evaluating denecimig across multiple studies involving children, adolescents, and adults with hemophilia A.

The program includes:

• FRONTIER1
• FRONTIER2
• FRONTIER3
• FRONTIER4
• FRONTIER5

Among these studies, FRONTIER4 is the largest ongoing Phase 3 extension trial and is designed to evaluate the long-term safety and effectiveness of denecimig across all dosing schedules and patient groups.