The layoffs, which had been expected since October, when Pfizer bought rival Wyeth, will affect about 450 people at the Collegeville plant.
The layoffs take effect March 12th.
Pfizer officials say they are still committed to the Collegeville area and say employees from other Pfizer plants may be transferred there.
Pfizer has not ruled out the possibility that the laid off workers can reapply for their jobs.
