The transaction is expected to close in the third quarter of 2023, subject to the completion of closing conditions.

Through the deal, Alexion will receive a series of novel adeno-associated virus (AAV) capsids used to deliver of therapeutic gene carriers for gene therapy and gene editing, the company said, expanding its joint genomic medicine capabilities with AstraZeneca.

Anglo-Swedish drugmaker AstraZeneca acquired US biotech Alexion for $39 billion in 2021. It focuses on rare diseases and plans to close the deal with Pfizer in the third quarter. Last October, AstraZeneca also bought US-based gene therapy developer LogicBio Therapeutics for $68 million.

Marc Dunoyer, CEO of Alexion, said: “Today’s announcement represents another major step forward in Alexion and AstraZeneca’s ambition to be an industry leader in genomic medicine, which has potential to be transformative and even curative for patients with devastating diseases.”

According to AstraZeneca, there are more than 7,000 known rare diseases, and around 80% of rare diseases are believed to be caused by a genetic mutation. Genomic medicines are designed to treat or cure these diseases by addressing the malfunctioning gene. This can be done through addition, alteration or inactivation of the gene to help the body fight the disease.