Study Drug

What is the study drug?

The study drug (BMN 331) is an investigational gene therapy for patients with hereditary angioedema (HAE) designed to introduce many copies of the SERPING1 gene into the liver and to see if it can make C1-INH protein. The study drug is given as a single intravenous (IV) infusion and is designed to target liver cells.

What is an investigational drug?

Investigational means that the study drug has not been approved for use by authorities that regulate new medicines, such as the US Food and Drug Administration (FDA) or the European Medicines Agency (EMA) and has not been determined to be safe or effective. The study drug can only be used in clinical research studies.

What is the study drug designed to do?

Gene therapy is being researched as a method of using genetic material to potentially treat or prevent disease and other conditions. For this investigational gene therapy, a neutralized adeno-associated virus (AAV5) is used as the vehicle that is designed to transfer a functional gene to the liver cells. The AAV vector, or viral shell, is neutralized to not cause illness since most of the viral components of the vector have been removed and replaced with the functional gene.

The visual below explains what the study drug is designed to do and part of what researchers will be looking at in the HAErmony-1 study:

1

Does a single IV infusion allow for the transfer of many copies of the SERPING1 gene

2

Can the functional SERPING1 genes be delivered to the specific type of tissue they were designed for, such as the liver

3

Can the functional genes enter the targeted liver cell to help make C1-INH protein and what is the safety impact as well as the impact on creation of C1-INH protein

With this investigational gene therapy, there is no gene replacement or editing, just introducing the functional gene into the body. The functional gene is not intended to be passed down to future generations.

Have other people used BMN 331?

No, HAErmony-1 is a Phase 1/2 study, where the study drug has not been researched in people. The study drug has been studied in mice and non-human primates (monkeys) where it showed production of C1-INH protein. The method using AAV5 vectors to deliver functional genes has been tested in clinical trials for other genes and diseases.