Acquired Hemophilia A Pipeline Expands with 10+ Novel Therapies in Development

Key Insights

• Global Acquired Hemophilia A pipeline comprises over 10 companies developing innovative therapies across various clinical stages, according to DelveInsight's 2025 report.
• Recent clinical advances include promising results for rituximab as a potential first-line therapy and Pfizer's positive Phase 3 AFFINE trial results for giroctocogene fitelparvovec gene therapy.
• Key pharmaceutical players including Novo Nordisk, Sanofi, Pfizer, and Belief Biomed are advancing treatments ranging from gene therapies to monoclonal antibodies targeting this rare autoimmune bleeding disorder.

Pharmaceutical companies worldwide are intensifying efforts to develop novel treatments for Acquired Hemophilia A (AHA), a rare autoimmune bleeding disorder that affects patients later in life. According to DelveInsight's comprehensive 2025 pipeline assessment, more than 10 companies are actively advancing innovative therapies through various stages of clinical development.

Unlike congenital hemophilia, AHA develops when the body produces autoantibodies that attack clotting factor VIII, a protein essential for blood coagulation. This rare condition can lead to spontaneous, severe bleeding into the skin, muscles, or internal organs, even in individuals with no prior history of bleeding disorders.

Current Treatment Landscape and Emerging Therapies

The current treatment paradigm for AHA focuses on controlling acute bleeding episodes and eliminating the inhibitory autoantibodies. However, significant unmet needs remain, driving pharmaceutical innovation in this space.

Several promising therapies are advancing through clinical trials, with companies employing diverse approaches to address the condition:

• BBM-H901 (Belief Biomed): A gene therapy candidate showing promise in early clinical development
• Concizumab (Novo Nordisk): An anti-tissue factor pathway inhibitor (TFPI) monoclonal antibody
• Fitusiran (Sanofi): An RNAi therapeutic targeting antithrombin to increase thrombin generation
• PF-06838435 (Pfizer): An investigational gene therapy also known as giroctocogene fitelparvovec
• SerpinPC (Centessa Pharmaceuticals): A novel serine protease inhibitor designed to rebalance coagulation

Other companies with active AHA programs include ISU ABXIS, TiumBio, Be Biopharma, Regeneron Pharmaceuticals, Biocad, CSL Behring, Shanghai Vitalgen BioPharma, Baxalta, Amarna Therapeutics, Catalyst Biosciences, and Freeline Therapeutics.

Recent Clinical Advances

In February 2025, researchers published findings in Hematology documenting two cases where factor VIII inhibitors were successfully eliminated in AHA patients treated with rituximab. The reports highlighted rituximab—a monoclonal antibody targeting CD20-positive B cells—as both safe and effective, potentially serving as a first-line therapy for AHA.

"Rituximab shows promise in treating acquired hemophilia by decreasing the production of autoantibodies against factor VIII," the authors explained. Current guidelines recommend rituximab primarily for patients with poor prognosis or those who cannot tolerate standard first-line treatments.

In another significant development, Sangamo Therapeutics announced in July 2024 that Pfizer had reported positive topline results from the Phase 3 AFFINE trial evaluating giroctocogene fitelparvovec. This investigational gene therapy, co-developed by Sangamo and licensed to Pfizer, targets adults with moderately severe to severe hemophilia A.

Additionally, Novo Nordisk revealed key findings from their FRONTIER II Phase IIIa study in May 2024, which evaluated subcutaneous Mim8 for hemophilia A treatment. While this study focused on congenital hemophilia A, the findings may have implications for AHA treatment strategies.

Understanding Acquired Hemophilia A

AHA differs fundamentally from the more common congenital form of hemophilia. It is characterized by the sudden appearance of factor VIII inhibitors in individuals with no personal or family history of bleeding disorders. The condition typically affects older adults, with a slight male predominance, and has an estimated incidence of 1.5 cases per million persons per year.

The disorder is often associated with underlying conditions such as:

• Autoimmune diseases
• Malignancies
• Pregnancy and postpartum period
• Certain medications
• Skin disorders

However, approximately 50% of cases are idiopathic, with no identifiable cause.

Market Dynamics and Challenges

According to DelveInsight's analysis, the AHA treatment market is poised for growth, driven by:

1. Increasing prevalence of AHA
2. Growing R&D investments in identifying new therapeutic agents
3. Rising awareness among healthcare providers about this rare condition
4. Advancements in diagnostic capabilities

Despite these positive trends, significant challenges remain, including:

1. High cost of AHA treatments
2. Limited patient population for clinical trials
3. Diagnostic delays due to the rarity of the condition
4. Complexity of managing both bleeding episodes and autoimmune aspects

Future Outlook

The pipeline for AHA treatments represents a diverse range of therapeutic approaches, from gene therapies and monoclonal antibodies to novel bypassing agents and immunomodulators. This diversity reflects the complex pathophysiology of the condition and the multiple potential intervention points.

As these therapies progress through clinical development, they promise to address significant unmet needs in AHA management. The potential introduction of gene therapies could be particularly transformative, offering the possibility of long-term control of the condition with a single treatment.

For patients with this rare but potentially life-threatening condition, the robust pipeline offers hope for more effective, convenient, and targeted treatment options in the coming years.