Screening for latent TB infection using intradermal injection of tuberculin (e.g. the Mantoux test or equivalent) should be conducted in accordance with local guidelines. The tuberculin skin test results should be evaluated according to the criteria for immunocompromised subjects. Subjects with a positive skin tuberculin test should be excluded if the investigator judges the patient to be at risk of latent TB infection). Cohort 6 are required to undergo radiographic screening with CXR, this is optional according to local guidelines for all other cohorts.