Development of Monoclonal B-cell Lymphocytosis Shortly After Treatment with Nivolumab and Subsequent Progression to Chronic Lymphocytic Leukemia

Abstract

Introduction

Immune checkpoint inhibitors, such as programmed death (PD)-1 inhibitor nivolumab, are currently widely used in treatment of various malignancies. Due to their widespread application, any new potential adverse effects due to these agents necessitate careful assessment.

Case report

We report a case of an 81-year-old man with recurrent high-risk malignant melanoma who underwent a 12-month adjuvant treatment with nivolumab. Shortly after the course of nivolumab, he developed monoclonal B-cell lymphocytosis (MBL) which subsequently progressed to chronic lymphocytic leukemia (CLL).

Management and outcome

The patient is currently doing clinically well in Rai stage 0. Malignant melanoma remains in remission.

Conclusion

Considering the pathophysiologic plausibility of nivolumab inducing B-cell dysregulation via PD-1 inhibition, we suggest further studies on potential association between nivolumab and B-cell malignancies.