Eight months after completing its acquisition of the diabetes drug firm Amylin Pharmaceuticals, Bristol-Myers Squibb is closing the company’s San Diego headquarters. The facility employs about 420 people in R&D, manufacturing, commercial, and administrative roles. Some employees will be offered opportunities to relocate to other facilities, BMS says. The closure is the second recently by a big pharma firm in San Diego. In February, Pfizer shuttered its CovX research unit, which focused on peptide therapeutics development.