Progression and Transformation of Clonally Heterogeneous B-cell Lymphoma

Alternative strategies for optimizing treatment of chronic lymphocytic leukemia with complex clonal architecture

In silico simulation of pre-clinical and clinical data may accelerate pre-clinical and clinical trial advances, leading to benefits for therapeutic outcomes, toxicity and cost savings. Combining this with clonal architecture data may permit truly personalized therapy. Chronic lymphocytic leukemia (CLL) exhibits clonal diversity, evolution and selection, spontaneously and under treatment pressure. We apply a dynamic simulation model to published CLL clonal architecture data to explore alternative therapeutic strategies, focusing on BTK inhibition. By deriving parameters of clonal growth and death behavior we model continuous vs time-limited ibrutinib therapy, and find that, despite persistence of disease, time to clinical progression may not differ. This is a testable hypothesis. We model IgVH-mutated CLL vs unmutated CLL by varying proliferation and find, based on the limited available data about clonal dynamics after such therapy, that there are differences predicted in response to anti-CD20 efficacy. These models can suggest potential clinical trials, and also indicate what additional data are needed to improve predictions. Ongoing work will expand modeling to agents such as venetoclax and to T cell therapies.

Ibrutinib: a force with a dark side?

In this issue of Blood, Martin et al report poor outcomes for ibrutinib-refractory patients with mantle cell lymphoma (MCL). MCL, an uncommon B-cell lymphoma driven by dysregulated cyclin D1, responds well to initial therapy but is destined to relapse. Subsequent single-agent treatments had modest response rates and duration until the advent of ibrutinib. These data are important, given that ibrutinib is not curative, so clinicians will increasingly encounter patients with MCL who require therapy after ibrutinib.