The research is a randomised open-label substudy of ESPRIT. The substudy is exploring whether the amount of rIL-2 taken during a dosing cycle of rIL-2 can be increased through controlling the predictable side-effects of rIL-2 better. This is a four arm study with a factorial design; patients will be randomised to one of four arms. Each arm consists of different combinations of adjunctive agents. Each patient will receive paracetamol and ibuprofen prophylactically throughout the cycle, the other adjunctive agents prescribed will vary according to which arm the patient is randomised to, but the antiemetic used will be either ondansetron or metoclopramide with or without low dose codeine phosphate as an additional analgesic agent. The primary end-point is the percentage of planned rIL-2 actually taken during the cycle. Secondary end-points include safety, side-effects of rIL-2 and the adjunctive agents, CD4+ T-cell changes and quality of life measures.