Pfizer Inc. has acknowledged that it is closing another research site, this one in San Diego, Calif.

The impending closure of its CovX operation, which was part of Pfizer's Biotherapeutics and Bioinnovations unit based in LaJolla, Calif., comes just five years after the pharmaceutical giant bought the privately held company for an undisclosed price. CovX focused on cancer and diabetes research.

Up to 100 people will be affected by the closure, the blog FierceBiotech reported.

The company, which spent $7.3 billion on R&D last year, is looking to cut more than $1 billion from the research budget this year.