Protocol for a multi-arm, multi-stage platform trial, whereby patients are randomly assigned to one of four sub-studies and then further randomly assigned to receive active treatment or placebo. Such a protocol determines patient selection and outcome measures, incorporating biomarkers across the different sub-studies. Pre-planned interim analyses can be incorporated into the trial design, such that if a specific treatment is established to have a favourable efficacy signal, this arm can then seamlessly move into phase III. Alternatively, if futility criteria are met, specific treatment arms can be dropped, with new arms then added over time.