To further improve its position in gene therapy, US pharma giant Pfizer is injecting an additional $500 million into its manufacturing plant in Sanford, North Carolina, simultaneously announcing plans to hire another 300 staff.

The latest investment follows the $100 million it pumped into the project in 2017.  Pfizer said the facility will support its continuing investment in gene therapy research and development, similar to its R&D sites at Chapel Hill and Kit Creek, North Carolina.

At Kit Creek, scientists work at a small scale, ranging from 2-liter flasks up to 250l bioreactors, to develop process that may eventually be used in larger scale manufacturing. The process is optimized at Chapel Hill, where staff continue to work at a 250l scale while implementing quality control measures included in GMP standards.

With the investment, the largest player in the US pharmaceutical market is widening its berth in the state where it already employs 3,600 people, including 650 at Sanford, a site it acquired with the takeover of gene therapies biotech Bamboo Therapeutics in 2016, a deal worth up to $645 million.

Pfizer said the expanded facility will strengthen both its clinical and commercial scale production capabilities for work on potential genetic cures using custom-made recombinant adeno-associated virus (rAAV vectors).

In addition to its gene therapy operations, the Sanford plant also manufactures components for the New York-based drugmaker’s vaccine portfolio, including Prevnar 13 and several vaccines currently in the R&D pipeline.

The expansion is part of the company’s overall plan to invest some $5 billion in US-based capital projects over the next several years,” said Mike McDermott, president, Pfizer Global Supply.

Pfizer has several gene therapy programs its pipeline, including a project with Sangamo Therapeutics for which the partners last month shared a positive update on the durability of responses to their hemophilia A gene therapy.