# Molecular devolution in chronic myelomonocytic leukemia during treatment with decitabine/cedazuridine: A case report

## TL;DR

This case report shows how a CMML patient's leukemia evolved at the molecular level during treatment with decitabine/cedazuridine.

## Contribution

First report of molecular changes in CMML during decitabine/cedazuridine treatment in a single patient.

## Key findings

- KRAS mutation and trisomy 8 were lost during treatment.
- TET2 mutated clone increased, leading to clonal hematopoiesis.
- Treatment showed disease-modifying potential in CMML.

## Abstract

Oral decitabine/cedazuridine has been studied in chronic myelomonocytic leukemia (CMML) recently but the molecular changes during this treatment have not been reported so far. We report a CMML patient who was treated with oral decitabine/cedazuridine and showed a stepwise loss of KRAS mutation and trisomy 8 while the TET2 mutated clone gradually increased eventually resulting in clonal hematopoiesis. This case report highlights the disease modifying potential of this treatment in single CMML patients.