The recent first global approval of emicizumab-kxwh has been reviewed in detail in the First Global Approval report in Adis’ journal Drugs[1], based on the development milestones tracked in AdisInsight[2].

In November 2017, emicizumab-kxwh (Hemlibra®), co-developed by F. Hoffman-La Roche and Chugai Pharmaceutical, received its first global approval in the USA for use as routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adults and paediatric patients with haemophilia A [congenital factor VIII (FVIII) deficiency] with FVIII inhibitors.[3]

Emicizumab-kxwh is given via subcutaneous injection once weekly. It is a bispecific factor IXa (FIXa) and factor X (FX)-directed antibody that bridges FIX and FX and ultimately restores the function of plasma clotting FVIII that is missing in this disease state. [3] [4]

The novel mechanism of action is anticipated to prevent the development of FVIII antibodies and subsequent drug resistance (inhibitors). The route of administration and dosing regimen are expected to be more appealing to patients and caregivers alike.

As explained by Guy Young, MD, Director of Hemostasis and Thrombosis Program, Children’s Hospital Los Angeles, and Professor of Pediatrics, University of Southern California Keck School of Medicine, Los Angeles, California, “People with haemophilia A who develop inhibitors face significant challenges preventing bleeds and typically require infusions of medicine multiple times a week, which can be especially difficult for young children and their families.” [4]

According to one source, the estimated incidence of people living with haemophilia is more than 400,000, with an approximate 20,000 individuals in the US.[5]

The FDA approval was based on data from two separate trials: HAVEN 1[6] included 109 male patients aged 12-75 years and weighing more than 40kgs; HAVEN 2[7] included 88 male patients aged less than 12 years (or 12-17 years if under 40kgs). The data were assessed under Priority Review and the emicizumab-kxwh was granted Breakthrough Therapy Designation in 2015.[4]

Data from the HAVEN 1 and 2 studies are also under accelerated assessment review by the European Medicines Agency; [4] and the agent is also under regulatory investigation in Japan. [1]

Although there are no contraindications for the use of emicizumab-kxwh, the FDA prescribing information carries a black box warning describing the risk of developing thrombotic microangiopathy and thromboembolism in cases where cumulative activated prothrombin complex concentrations of greater than 100U/kg/24h were given for more than 24hours.[8]

For further information related to the first approval of emicizumab-kxwh please visit Drugs[1],  or to learn more about the overall development of emicizumab-kxwh across all indications visit AdisInsight[2].

 

Image credit: Eric –Rothermel

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