Tumor lysis syndrome risk in outpatient versus inpatient administration of venetoclax and hypomethlators for acute myeloid leukemia.

INTRODUCTION Venetoclax along with hypomethylating agents (HMAs) is the new standard therapy for older patients with acute myeloid leukemia (AML) not fit for intensive frontline induction chemotherapy. Venetoclax is associated with fatal episodes of tumor lysis syndrome (TLS) in chronic lymphocytic leukemia (CLL), and recommendations are for its initiation for CLL and AML in the inpatient setting with close monitoring. Herein, we evaluated the safety of outpatient venetoclax ramp up when given in addition to HMAs for the treatment of AML. METHODS We conducted a retrospective review of patients diagnosed with AML at our institution from 12/1/2016 until 7/1/2020. We identified patients who received HMAs and venetoclax for AML, either as frontline or relapsed/refractory therapy. Records were reviewed for evidence of laboratory or clinical tumor lysis episodes in all patients. RESULTS Between 12/1/2016 and 7/1/2020 43, patients at our institution received venetoclax/HMA for the treatment of AML. Thirty-nine patients (91%) had venetoclax initiation and ramp up in the outpatient setting. One episode of laboratory TLS (2.5%) was identified. This patient required admission to the hospital for rasburicase and IV fluids with resolution of the laboratory effects without resultant clinical TLS. There were no episodes of clinical TLS in either group. Thirty-day mortality from venetoclax initiation was 0% in both groups. CONCLUSION Our experience with HMAs and venetoclax showed that outpatient ramp up of venetoclax is safe with a very low risk of laboratory TLS (2.5%) and no evidence of clinical TLS within our cohort.