From Treatment to Perturbation: Interpreting the ON–OFF Ibrutinib Trial as a Dynamic Clinical Experiment

This paper offers a conceptual interpretation of the ON–OFF ibrutinib trial in chronic lymphocytic leukaemia (CLL) as a dynamic clinical experiment. Rather than viewing treatment only as an intervention that produces response or resistance, the paper frames therapy as a controlled perturbation and treatment pauses as windows into recovery, adaptation, and loss of stability. Using the ON–OFF design as its central example, the paper shows how alternating treatment and wash-out phases, combined with longitudinal multimodal data, makes it possible to study system behaviour in motion: recovery speed, memory of prior perturbation, changing sensitivity, and gradual emergence of resistance. Particular emphasis is placed on wash-out as a diagnostic phase, where system plasticity, stability, and memory become visible. The paper introduces no new empirical data. Its contribution is conceptual: to show how existing trial designs can be re-read through a dynamic lens, turning clinical studies into instruments not only of treatment, but of understanding how biological systems adapt, destabilise, and transform over time.