Italian biopharmaceutical firm Chiesi Farmaceutici has agreed to acquire the UK-based pharmaceutical company Amryt Pharma in a deal worth up to $1.48bn.

Expected to close in the first half of 2023, the transaction is subject to the satisfaction of all closing conditions.

The deal, which was unanimously cleared by the Boards of Directors of Chiesi and Amryt, will expand Chiesi Farmaceutici’s rare disease medicine portfolio.

Under the terms of the agreement, Chiesi will buy all of Amryt’s outstanding shares for $14.50 in cash, plus contingent value rights worth up to $2.50 per American Depositary Share (ADS) that are payable if specific Filsuvez-related milestones are met.

Amryt Pharma said that each American depositary share of Amryt represents five of the company’s ordinary shares.

Approximately $1.25bn in upfront consideration, or a 107% premium over Amryt ADS’ closing price of $7 on 6 January 2023, is the total transaction value represented by the transaction at completion.

According to the UK-based pharmaceutical firm, Contingent Value Rights (CVRs) represent an additional $225m in potential consideration.

Chiesi Group chief executive officer Marco Vecchia said: “With this transaction, we are further expanding our commitment to people living with rare diseases, the majority of which still have no cure or approved treatment.

“This addition of the Amryt portfolio, as well as their expertise, will help us on our journey to bring medicines to patients, no matter how rare their condition may be. We look forward to working with Amryt towards a successful closing of the transaction.”

Amryt is a commercial-stage biopharmaceutical firm that acquires, develops and commercialises treatments to help improve the lives of patients with rare and orphan diseases.

Amryt Pharma CEO Dr Joe Wiley said: “I am incredibly proud of what Amryt has accomplished for patients, their families, healthcare professionals and shareholders since we established our business in 2015.

“In less than eight years, we have built from the ground up, a high-growth and globally respected company in the biotechnology industry and the rare disease space. These accomplishments are a testament to the Amryt team’s commitment and passion for patients that are impacted by rare and orphan diseases.”