  We present some "in silico" experiments to design combined chemo- and
immunotherapy treatment schedules. We introduce a new framework by combining
flatness-based control, which is a model-based setting, along with model-free
control. The flatness property of the used mathematical model yields
straightforward reference trajectories. They provide us with the nominal
open-loop control inputs. Closing the loop via model-free control allows to
deal with the uncertainties on the injected drug doses. Several numerical
simulations illustrating different case studies are displayed. We show in
particular that the considered health indicators are driven to the safe region,
even for critical initial conditions. Furthermore, in some specific cases there
is no need to inject chemotherapeutic agents.
