Catalent has closed an acquisition of viral vector development and gene therapy manufacturing company Paragon Bioservices for $1.2bn.

Having signed an agreement in April this year, Catalent expects Paragon’s scientific capabilities in recombinant viral vectors, vaccines, recombinant proteins and oncolytic viruses will support its biologics business and end-to-end integrated biopharmaceutical solutions.

Paragon’s expertise in adeno-associated virus (AAV) vectors is expected to help Catalent access the $40bn addressable gene therapies market.

Catalent chair and CEO John Chiminski said: “Paragon’s unparalleled expertise in the rapidly growing market of gene therapy manufacturing will be a transformative addition to our business that we believe will accelerate our long-term growth.”

Paragon recently opened a commercial manufacturing centre in Maryland, US. Offering more than 425,000ft² of manufacturing space, the facility includes multiple 500l and 2,000l single-use bioreactors intended for good manufacturing practice (GMP) production of clinical and commercial material.

When the acquisition was initially proposed, Catalent announced plans to finance a part of the capital expansion projects at Paragon’s facilities.

Paragon is currently working on GMP manufacturing projects with gene therapy developers globally. Catalent intends to continue offering resources to Paragon’s customers and maintain development and manufacturing alliance for its clients.

Paragon employs more than 380 people at its two Maryland sites. All these employees will join Catalent’s existing team of more than 11,000 employees.

Catalent anticipates the acquisition to be accretive to its adjusted net income per share in the second full fiscal year after completion and significantly accretive thereafter.