Optimal intervention strategies for cyclic therapeutic methods with fixed-length duration of effect

When implementing chemotherapy, it is possible to decrease the likelihood of visiting undesirable states by finding the right dose schedules that maximizes the benefit to toxicity ratio of a delivered drug. Therapies in a typical practice are usually administered in cycles. If treatment is applied at the beginning of a cycle, then the patient will be under the influence of the drug for some period of time, after which there can be a recovery phase. In this paper, we present a methodology to devise optimal intervention policies in Markovian genetic regulatory networks for the class of cyclic therapeutic methods where interventions have fixed-length duration of effectiveness.