Long-term effect of venetoclax therapy in a patient with the transformation of chronic lymphocytic leukemia into Richter's syndrome.

Richter's syndrome (RS) is the next step in the progression of chronic lymphocytic leukemia (CLL) progression. It leads to reduced overall patient survival, the necessity of aggressive chemotherapy and a decline in the quality of life. The first line of RS treatment includes traditional chemotherapy such as rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone. However, during the past decade, novel targeted agents added to the therapy dramatically changed the treatment outcome for patients with RS. In our case, we describe a patient with CLL that had progressed to RS and achieved complete remission that lasted > 15 months with venetoclax monotherapy.