Double remission of chronic lymphocytic leukemia and secondary acute myeloid leukemia after venetoclax monotherapy: A case report

RATIONALE: The abnormal expression of B-cell lymphoma-2 (Bcl-2) family members is often associated with the progression of the disease. Bcl-2 inhibitors (eg, venetoclax) were first reported to inhibit the proliferation of malignant lymphocytes and have a significant effect on patients with chronic lymphoblastic leukemia, but research on myeloid tumors is relatively delayed. Venetoclax was approved in 2018 for the treatment of acute myeloid leukemia (AML) patients who were not suitable for high-dose chemotherapy. The approval of venetoclax is an advance in the treatment of hematological tumors. PATIENT CONCERNS: Here we report a 64-year-old male with an increased white blood cell (WBC) count (39.0 × 10(9)/L) and lymphocyte count (30.6 × 10(9)/L) on physical examination in July 2014. The patients were diagnosed with chronic lymphocytic leukemia (CLL) through bone marrow (BM) smears and immunophenotyping without any cytogenetic or molecular abnormalities. Chlorambucil was prescribed, WBC was stable between 15 × 10(9)/L and 25 × 10(9)/L in the past 6 years. He came to the hospital again in May 2020 and complained of fatigue for 2 weeks. WBC (16.7 × 10(9)/L) and lymphocyte (14.76 × 10(9)/L) counts were increased, hemoglobin (HGB) and platelet (PLT) were decreased in peripheral blood, which indicated the progression of the disease. DIAGNOSES: The patient was diagnosed as secondary AML after CLL based on the clinical and laboratory findings. INTERVENTIONS: He achieved a morphological complete remission in both AML and CLL without any adverse reactions after one course of venetoclax monotherapy. OUTCOMES: He received standard daunorubicin and cytarabine combined with venetoclax as consolidation therapy and is now ready for allogeneic-hematopoietic stem cell transplantation. LESSONS: Our case presents a challenge to traditional treatment. New drugs such as venetoclax have shown outstanding effects in this respect. High expression of Bcl-2 can identify the responders of venetoclax. These findings should be validated in future clinical trials. We fully believe that in the near future, the comprehensive use of targeted drugs with different mechanisms will not only improve the quality of life of patients, but also completely change the prognosis of patients with recurrent and refractory hematological malignancies.