Relapsed CLL: sequencing, combinations, and novel agents.

Although the therapy of chronic lymphocytic leukemia (CLL) has changed rapidly over the last 5 years, the key considerations in selecting a therapy for a previously treated patient with CLL continue to include the nature of the prior therapy and the duration of prior remission to that therapy, the prognostic features of the disease, and the health and comorbidities of the patient in question. For patients treated initially with chemoimmunotherapy, randomized trials have demonstrated the benefit of targeted therapy. Retrospective data suggest that ibrutinib is preferred as a first kinase inhibitor, whereas recent data with venetoclax and rituximab may challenge the choice of ibrutinib as a first novel agent in the relapsed setting. Data on sequencing of novel agents remain quite sparse, consisting of 1 prospective trial that demonstrated the efficacy of venetoclax in patients who have experienced progression with a kinase inhibitor, as well as a retrospective real-world analysis supporting this observation. Novel agents in advanced clinical development include primarily next-generation Bruton's tyrosine kinase and phosphatidylinositol 3-kinase δ inhibitors, with other classes still in phase 1 trials. Clinical trials of combination time-limited therapies with the goal of deep remission and discontinuation are also in progress.