In Part A, the first dose escalations will be carried out using cohorts of 1 patient. Single patient cohorts will be used to investigate increasing doses until a first dose-limiting toxicity (DLT) is reached or until grade-2 related toxicity (except infusion-related reactions), whichever comes first. At least 3 patients will be enrolled in each cohort thereafter, which, if required, can be expanded with additional patients. Part B of the study will consist of a multiple ascending dose phase (multiple patients cohorts - >/= 3 patients) followed by an extension phase of RO6927005 given in combination with gemcitabine/nab-paclitaxel.