HEALTH

Drug Production Interrupted at Amgen: The company said it has curtailed production of Epogen, one of its two main drugs, while it upgrades the water-filtering system at its Thousand Oaks factory. Amgen, the world’s largest biotechnology company in terms of sales, said it expects to restart the system early next week and resume full production of Epogen within days after that. The company said the interruption will not affect Epogen sales, because there is adequate inventory of the drug, a genetically engineered protein designed to stimulate production of red blood cells in kidney patients who must undergo dialysis.