FDA approves Alhemo® as once-daily prophylactic treatment to prevent or reduce the frequency of bleeding episodes for adults and children 12 years of age and older with hemophilia A or B (HA/HB) without inhibitors

August 1, 2025 |

11 min read

FDA approval is based on phase 3 trial data (explorer8), which established the safety and efficacy of Alhemo^® (concizumab-mtci) injection in people 12 years and older with hemophilia A or B (HA/HB) without inhibitors¹
Results showed a 79% reduction in annualized bleeding rate (ABR) in patients with HB without inhibitors and an 86% reduction in patients with HA without inhibitors, respectively, using Alhemo^® prophylaxis compared to no prophylaxis²
Alhemo^® was the first subcutaneous injectable pen of its kind for patients living with HA and HB with inhibitors and is now approved for those living without inhibitors¹

PLAINSBORO, N.J., July 31, 2025 /PRNewswire/ -- Novo Nordisk announced today that the US Food and Drug Administration (FDA) approved Alhemo^® (concizumab-mtci) injection as a once-daily prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and pediatric patients 12 years of age and older with hemophilia A or B (HA/HB) without inhibitors, expanding on the December 2024 approval for HA/HB with inhibitors.^1,2,3 Currently, many treatments for HA/HB without inhibitors are administered via intravenous infusions.² With this approval, Alhemo^® now offers a subcutaneous injection treatment option for this population.¹

"The FDA approval of an expanded indication for Alhemo^® marks a meaningful step forward for people with hemophilia A or B without inhibitors who are looking for a new prophylaxis treatment option," said Anna Windle, PhD, Senior Vice President, Clinical Development, Medical & Regulatory Affairs, Novo Nordisk. "By building on the initial indication for Alhemo^® for those with hemophilia with inhibitors—an especially significant development in hemophilia B where challenges still exist despite advanced treatment options—Novo Nordisk continues its 35+ year legacy in rare bleeding disorders to continue to help address the unmet needs of this community."

Alhemo^® is designed to block a protein called tissue factor pathway inhibitor (TFPI), which stops blood from clotting. By inhibiting TFPI, Alhemo^® improves the production of thrombin, which helps to clot the blood and prevent bleeding, when clotting factors VIII and IX are missing or deficient regardless of inhibitor status.^4,5

"For people living with hemophilia, it is important to continually monitor and discuss bleed control with their healthcare professional," said Allison P. Wheeler, MD, Scientific Director, Washington Center for Bleeding Disorders, Seattle, WA. "With today's approval of Alhemo^® for hemophilia A or B without inhibitors, more people living with these rare blood disorders now have a daily prophylaxis option that may help decrease their bleeding rates."

The primary objective of the pivotal phase 3 explorer8 trial was to compare the number of treated spontaneous and traumatic bleeding episodes, as measured by the ABR, in patients aged 12 years and older with HA/HB without inhibitors, receiving Alhemo^® prophylaxis versus no prophylaxis (on demand Factor VIII/Factor IX treatment).² The study showed a statistically significant reduction in ABR of 79% for HB patients (ABR ratio: 0.21; 95% CI: 0.10–0.45; p<0.0001) and 86% for HA patients (ABR ratio: 0.14; 95% CI: 0.07–0.29; p<0.0001). Additionally, notable reductions in the average and median ABRs further reinforced the efficacy of Alhemo^®prophylaxis in reducing bleeds across both patient groups, with an average ABR of 3.1 (1.9-5.0) and a median ABR of 1.6 (0.0-4.8) for HB patients, compared to 14.8 (8.1-26.9) and 14.9 (3.3-22.1), respectively, and an average ABR of 2.7 (1.6-4.6) and median ABR of 2.9 (0.0-5.2) for HA patients, compared to 19.3 (11.3-33.0) and 19.6 (17.3-30.4), respectively. In the study, the most common adverse reactions reported in ≥5% of patients randomized to receive Alhemo^®were injection site reactions (7%) and headache (7%).¹

Alhemo^® is provided in prefilled, premixed pens for subcutaneous injection (60 mg/1.5 mL, 150 mg/1.5 mL, or 300 mg/3 mL) via thin 32 gauge, 4 mm needles, which are provided separately, offering an additional treatment choice for patients with hemophilia with inhibitors – and now without inhibitors – to further customize their care.

About the explorer8 study

Explorer8 is a phase 3 clinical trial that evaluated the efficacy and safety of Alhemo^®for adults and pediatric patients 12 years of age and older living with hemophilia A or B (HA/HB) without inhibitors.² In explorer8, among the 156 males with HA/HB included in the trial, 63 were randomly assigned in a 1:2 ratio to receive no prophylaxis (arm 1, n=21), or Alhemo^® prophylaxis (arm 2, n=42).^2,6 The median duration of treatment was 24.1 weeks in arm 1 (no prophylaxis) and 32.1 weeks in arm 2 (Alhemo^® prophylaxis).The initial loading dose of Alhemo^® was 1 mg per kilogram of body weight, followed by 0.2 mg per kilogram daily, and potentially individualized on the basis of concizumab-mtci plasma concentration as measured at week 4.^1,2 Efficacy was evaluated separately in HA patients without inhibitors and in HB patients without inhibitors when all patients in arms 1 and 2 had completed the main part of the trial (at least 24 or at least 32 weeks, respectively), based on the number of treated bleeding episodes comparing Alhemo^® prophylaxis and no prophylaxis.¹

About Alhemo^® (concizumab-mtci)

Alhemo^® is a tissue factor pathway inhibitor (TFPI) antagonist. By inhibiting the TFPI, Alhemo^® enhances factor Xa (FXa) production during the initiation phase of coagulation, leading to improved thrombin generation and clot formation in patients with hemophilia A or B (HA/HB) with or without inhibitors. The effect of Alhemo^® is not influenced by the presence of inhibitory antibodies to FVIII or FIX and Alhemo^® does not induce or enhance the development of direct inhibitors to FVIII or FIX. Alhemo^® is approved as a once-daily prophylaxis to prevent or reduce the frequency of bleeding episodes in adults and pediatric patients 12 years of age and older with HA/HB with or without inhibitors in the US.¹

What is Alhemo^®?

Alhemo^® (concizumab-mtci) injection 60 mg, 150 mg, or 300 mg is a prescription medicine used for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adults and children 12 years of age and older with hemophilia A or B with or without factor VIII or IX inhibitors.

It is not known if Alhemo^® is safe and effective in people receiving ongoing immune tolerance induction (ITI) or in children younger than 12 years of age

Important Safety Information

What is the most important information I should know about Alhemo^®?

It is important to follow the daily dosing schedule of Alhemo^® to stay protected against bleeding. This is especially important during the first 4 weeks of treatment to make sure a correct maintenance dose is established. Use Alhemo^® exactly as prescribed by your healthcare provider (HCP). Do not stop using Alhemo^® without talking to your HCP. If you miss doses or stop using Alhemo^®, you may no longer be protected against bleeding
Your HCP may prescribe factor VIII, factor IX, or bypassing agents during treatment with Alhemo^®. Carefully follow your HCP's instructions regarding when to use on-demand factor VIII, factor IX, or bypassing agents and the recommended dose and schedule for breakthrough bleeds

Do not use Alhemo^® if you are allergic to concizumab-mtci or any of the ingredients in Alhemo^®.

Before using Alhemo^®, tell your HCP about all of your medical conditions, including if you:

Have a planned surgery. Talk to your HCP about when to stop using Alhemo^® and when to start it again if you have a planned surgery
Are pregnant, breastfeeding, or plan to become pregnant or breastfeed. It is not known if Alhemo^® may harm your unborn baby or if Alhemo^® passes into your breast milk
- Your HCP may do a pregnancy test before you start treatment with Alhemo^®
- Females who are able to become pregnant, talk to your HCP about using effective birth control (contraception) methods during treatment with Alhemo^® and for 7 weeks after ending treatment

Tell your HCP about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and supplements.

What are the possible side effects of Alhemo^®?

Alhemo^® may cause serious side effects, including:

Blood clots (thromboembolic events). Alhemo^® may cause blood clots to form in blood vessels, such as in your arms, legs, heart, lung, brain, eyes, kidneys, or stomach. You may be at risk for getting blood clots if you use high or frequent doses of factor products or bypassing agents to treat breakthrough bleeds, or if you have certain conditions. Get medical help right away if you have any signs and symptoms of blood clots, including: swelling, warmth, pain, or redness of the skin; headache; trouble speaking or moving; eye pain or swelling; sudden pain in your stomach or lower back area; feeling short of breath or severe chest pain; confusion; numbness in your face; and problems with your vision
Allergic reactions. Alhemo^® can cause allergic reactions, including redness of the skin, rash, hives, itching, and stomach-area (abdominal) pain. Stop using Alhemo^® and get emergency medical help right away if you develop any signs or symptoms of a severe allergic reaction, including: itching on large areas of skin; trouble swallowing; wheezing; pale and cold skin; dizziness due to low blood pressure; redness or swelling of lips, tongue, face, or hands; shortness of breath; tightness of the chest; and fast heartbeat

The most common side effects of Alhemo^® include: bruising, redness, bleeding, itching, rash or lump at the injection site, headache, and hives. These are not all the possible side effects of Alhemo^®. Call your doctor for medical advice about side effects.

Please click HERE for Alhemo^® Prescribing Information and Medication Guide

About hemophilia

Hemophilia is a rare inherited bleeding disorder that impairs the body's ability to make blood clots, a process needed to stop bleeding.⁷ It is estimated to affect approximately ~800,000 people worldwide.⁸ There are different types of hemophilia, which are characterized by the type of clotting factor protein that is defective or missing. Hemophilia A is caused by a missing or defective clotting Factor VIII (FVIII), and hemophilia B is caused by a missing or defective clotting Factor IX (FIX).⁷Hemophilia is often treated by replacing the missing clotting factor via intravenous infusions, also known as replacement therapy.⁸

About Novo Nordisk

Novo Nordisk is a leading global healthcare company that's been making innovative medicines to help people with diabetes lead longer, healthier lives for more than 100 years. This heritage has given us experience and capabilities that also enable us to drive change to help people defeat other serious chronic diseases such as obesity, rare blood, and endocrine disorders. We remain steadfast in our conviction that the formula for lasting success is to stay focused, think long-term, and do business in a financially, socially, and environmentally responsible way. With a US presence spanning 40 years, Novo Nordisk US is headquartered in New Jersey and employs over 10,000 people throughout the country across 12 manufacturing, R&D, and corporate locations in eight states plus Washington DC. For more information, visit novonordisk-us.com, Facebook, Instagram, and X.

References

Alhemo^® (concizumab-mtci) injection, for subcutaneous use [package insert]. Plainsboro, NJ: Novo Nordisk Inc.
Chowdary P., et al. Concizumab prophylaxis in people with haemophilia A or haemophilia B without inhibitors (explorer8): a prospective, multicentre, open-label, randomised, phase 3a trial. Lancet Hematology. 2024;11:e891-904.
Novo Nordisk. FDA approves drug to prevent or reduce the frequency of bleeding episodes for patients with hemophilia A with inhibitors or hemophilia B with inhibitors. Accessed May 2025. Available at https://www.novonordisk-us.com/media/news-archive/news-details.html?id=915084.
Shapiro AD. Concizumab: a novel anti-TFPI therapeutic for hemophilia. Blood Adv. 2021;5(1):279.
Matsushita T, Shapiro A, Abraham A, et al. Phase 3 trial of concizumab in hemophilia with inhibitors. N Engl J Med. 2023; 389(9): 783-794.
ClinicalTrials.gov. Research Study to Look at How Well the Drug Concizumab Works in Your Body if You Have Haemophilia Without Inhibitors (explorer8). Accessed May 2025. Available at https://clinicaltrials.gov/study/NCT04082429.
MedlinePlus. Hemophilia. Accessed May 2025. Available at https://medlineplus.gov/genetics/condition/hemophilia/.
World Federation of Hemophilia. Annual Global Survey 2023. Accessed July 2025. https://wfh.org/research-and-data-collection/annual-global-survey/.