San Diego-based Metabasis Therapeutics has hired on a new Vice President and Chief Financial Officer, the firm disclosed today. Metabasis, which is developing biopharmaceuticals for treating metabolic and other diseases, said that it has named Tran B. Nguyen to the position. Nguyen joins the firm from Citi Global Markets Inc., where he was Vice President in the firm's Healthcare Investment Banking group. Nguyen has also served at Lehman Brothers.