Interleukin-13 (IL-13) and IL-4 are mediators in the pathogenesis of established asthmatic disease. GSK2434735 is a bispecific antibody to IL-13 and IL-4. The purpose of this open label, sequential cohort, exploratory First Time in Human (FTIH) study is to evaluate the pharmacokinetics (PK) profile of GSK2434735 after a single low intravenous or subcutaneous dose in healthy male volunteers, and to assess if the pharmacokinetics (PK) parameters can be scaled from monkey to man. In addition, the safety and tolerability will be monitored and the study will assess if antibodies are generated to GSK2434735.