Chokri Ben Lamine։ Saudi Arabia Leads A New Milestone In Hemophilia A Care

Chokri Ben Lamine, Hematologist at King Faisal Specialist Hospital and Research Center, shared a post on X about a recent article by Maria Elisa Mancuso et al., published in The New England Journal of Medicine, adding:

”Saudi Arabia leads a new milestone in hemophilia A care!

World-first approval

The Saudi Food and Drug Authority has announced the world’s first registration of denecimig (Mim8; Frehemgo) for routine prevention of bleeding episodes in hemophilia A.

Previously designated under the SFDA’s Promising Drugs program

Evaluated for efficacy, safety and quality

Adds another subcutaneous prophylaxis option

Credit: SFDA announcement and infographic.

How does denecimig work?

• Denecimig is a bispecific antibody that mimics activated factor VIII (FVIIIa).
• Brings FIXa and FX together
• Facilitates FX activation and downstream thrombin generation
• Supports clot formation despite FVIII deficiency

Its activity does not depend on replacing FVIII itself, allowing use in hemophilia A with or without FVIII inhibitors. FRONTIER2 publication

Administration

The SFDA announcement describes subcutaneous administration:

• Once weekly
• Every 2 weeks
• Once monthly

The regimen depends on body weight and the prescribed schedule.

Pivotal evidence: FRONTIER2

Phase 3, open-label, randomized study in adolescents and adults with hemophilia A, with or without inhibitors.

254 participants aged 12 years or older

26-week main treatment phase

Weekly or monthly subcutaneous denecimig

Primary endpoint: annualized rate of treated bleeding events

Comparisons included on-demand treatment and patients’ prospectively recorded prior clotting-factor prophylaxis. Mancuso et al., NEJM 2026

Bleeding outcomes

In the cohort previously receiving on-demand treatment, estimated treated annualized bleeding rates were:

• Weekly denecimig: 0.57
• Monthly denecimig: 0.20
• Continued on-demand treatment: 15.76

These correspond to approximately 96 percent and 99 percent fewer treated bleeds, respectively.

These are annualized rates estimated during trial follow-up; they do not mean every patient remained bleed-free. FRONTIER2 results

Safety

The pivotal publication reported:

No thromboembolic events

No clinical evidence of neutralizing anti-denecimig antibodies

However, absence of events in a trial does not establish zero long-term risk.

The SFDA infographic lists potential adverse effects:

• Injection-site redness
• Injection-site itching
• Fever
• Headache
• Upper respiratory tract infections
• Essential laboratory pearl

Denecimig can interfere with:

• aPTT-based tests
• One-stage FVIII activity assays
• Some chromogenic FVIII assays

A shortened or normal aPTT during treatment should not be interpreted as proof of normal endogenous FVIII activity.

Inform the coagulation laboratory and use assays validated for samples containing denecimig. Bowyer et al., Haemophilia

How should we interpret this advance?

• A significant regulatory milestone for Saudi Arabia
• More flexibility in prophylaxis schedules
• Strong evidence for reducing treated bleeding episodes

Comparisons across separate trials cannot establish superiority over emicizumab or other modern prophylactic therapies. Treatment selection still requires the approved label, bleeding history, patient preference and specialist assessment.

Key scientific references:

• Mancuso et al. — Mim8 prophylaxis in hemophilia A, NEJM 2026
• Bowyer et al. — Denecimig interference with coagulation assays.”

Title: Mim8 Bispecific Antibody Prophylaxis in Hemophilia A with or without Inhibitors

Authors: Maria Elisa Mancuso, Anthony K.C. Chan, Chandrakala Shanmukhaiah, Chuhl Joo Lyu, Joanna Zdziarska, Johnny Mahlangu, Lize F.D. van Vulpen, Pratima Chowdary, Renchi Yang, Steven R. Lentz, Tadashi Matsushita, Wan Hui Ong Clausen, Ilgiz Rakhmatullin, Johannes Oldenburg

Other posts featuring Chokri Ben Lamine on Hemostasis Today.