The purpose of this study is to evaluate the safety and tolerability of NKTR-118 with healthy subjects.

A Phase I, Randomized, Double-Blind, Placebo-Controlled Study to Assess the Safety, Tolerability and Pharmacokinetics of NKTR-118 following single and multiple ascending oral dose administration in healthy young and elderly Japanese subjects, and an Open Randomized, Crossover Study to Investigate the Effect of Food on the Pharmacokinetics after single oral doses of NKTR-118 in healthy male Japanese subjects

Inclusion Criteria:

• 20 Years to 45 Years, 65 Years to 80 Years
• Body mass index (BMI): 18 to 27 kg/m
• Male subjects should be willing to use barrier contraception ie, condoms, from the day of dosing until 3 months after dosing with the investigational product.
• Non-smokers or ex-smokers (not smoked in the past 3 months).

Exclusion Criteria:

• Clinically relevant disease and/or abnormalities (past or present)
• Clinically relevant abnormalities in physical examinations,vital signs,clinical chemistry, hematology or urinalysis as judged by the investigator
• Use of any prescribed or non-prescribed medication including herbal remedies, vitamins and minerals during the two weeks prior to the first administration of investigational product