Pfizer broke ground on a $50 million expansion at its Chesterfield campus that reflects the company’s increased investment in biopharmaceuticals. The expansion doubles the size of a pilot plant that produces protein-based, injectable biologic drugs for clinical trials.

“We’re relative novices at this, but we’ve got some really exciting things early on in the pipeline,” said John LaMattina, Pfizer’s outgoing head of global R&D. Pfizer currently has four biologics in Phase I trials, eight in Phase II, and a lung cancer treatment that is advancing into Phase III trials.

The expansion includes the addition of fermenters, bioreactors and other equipment used to grow, purify and isolate proteins. The site will enable the company to increase quantities of a single biologic needed for later-stage clinical trials, and to work on more projects simultaneously. The facility is expected to be operational by mid-2010.

Jeff Kindler, Pfizer’s president and chief executive, commented that small molecules remain Pfizer’s core strength. “But we believe biologics offer significant, promising R&D opportunities that we need to pursue, and we are intent on doing so,” he said. “We’re looking at various ways to really jump-start our activities in that area.”