This is an open label, multi-drug, biomarker-directed, multi-centre, multi-arm, Phase 1b study in patients with muscle invasive bladder cancer (MIBC) (urothelial) who have progressed on prior treatment. This study is modular in design, allowing evaluation of the safety, tolerability, pharmacokinetics and anti-tumour activity of multiple agents as monotherapy and as combinations of different novel anti-cancer agents. The study will consist of a number of study modules (sub-studies), each evaluating the safety and tolerability of a specific agent or combination.