Approved for use in 2017, emicizumab—marketed under the brand name Hemlibra—has shown immense benefits in the treatment of hemophilia A. But researchers wanted to better understand how emicizumab, used as prophylaxis, served individuals living with hemophilia A with inhibitors. In particular, researchers sought to determine the therapy’s safety and efficacy. According to an article in Rare Disease Advisor, the study—published in Haemophilia—found emicizumab to be safe, effective, and well-tolerated. 

DrugBank Online describes emicizumab as: 

a humanized recombinant monoclonal antibody that mimics the function of the coagulation Factor VIII and it has the capacity to bind simultaneously to activated Factor IX and Factor X. The ability of emicizumab to bind to all these three different factors allows it to overcome immunogenicity and unstable hemostatic efficacy produced by previous Factor VII agents.

Within this study, the research team collected data from 117 individuals with hemophilia A and inhibitors over a 3.5-year period. The researchers then evaluated Hemophilia Health Joint Scores following emicizumab treatment in 37 patients. Findings include: 

• Transferring from other treatments to emicizumab correlated with an 89% reduction in annualized bleeding rate (ABR). Emicizumab also improved the zero-treated bleed rate by 43%, rising from 45% to 88%. 
• In terms of HJHS, joint health and protection improved in 36% of people (13 patients), stayed the same in 46% (17 patients), and worsened in 18% (7 patients). 
• Emicizumab largely reduced the rate of joint bleeds and improved quality-of-life (QOL). 
• While some side effects did occur, these were generally mild. Overall, emicizumab was well-tolerated. 

More on Hemophilia A

There are two subtypes of hemophilia (A and B), a rare genetic bleeding disorder. Hemophilia A results from a mutation on the X chromosome; this mutation causes missing or defective factor VIII (FVIII), a clotting protein. As a result, the blood cannot clot properly. Hemophilia A is typically inherited, although the mutation is spontaneous in around 30% of cases. This disorder mostly presents in males, though more research into females with hemophilia A—and carriers—has been ongoing. Symptoms related to this disorder may include:

• Easy bruising and bleeding
• Excessive and prolonged bleeding following injury, surgery, or dental work
• Joint pain and inflammation
• Frequent or recurrent nosebleeds
• Hematuria (blood in the urine) or bloody stool 
• Unexplained irritability (in infants)
• Excessive bleeding during childbirth or menstruation (in females) 

Outside of Hemlibra, other treatment options include ALTUVIIIO, concentrated FVIII, and DDAVP.