Tumor Lysis Syndrome Incidence Uncommon in Venetoclax Treatment for AML

Tumor lysis syndrome was found to be uncommon in patients receiving venetoclax (Venclexta) for acute myeloid leukemia but should be monitored if they have elevated white blood cells and should be admitted for a ramp-up, according to findings from a real-world analysis published in the Journal of Oncology Pharmacy Practice.

In a population of 113 patients who were all given prophylactic treatment, the incidence of tumor lysis syndrome was 8.8% (95% CI, 3.8%-16.2%), all of which were laboratory lysis syndrome. This included 1 patient with hyperuricemia, 9 with hypocalcemia, and 10 with hyperphosphatemia; in all cases, tumor lysis syndrome resolved.

The median age was 69 years and 56% of patients were male. Frequent comorbidities included hypertension (52.0%), diabetes (34.0%), and chronic kidney disease (10.6%). Prior hematopoietic cell transplant was performed in 21 patients. Venetoclax ramp-up was given to about half the patients, and they were admitted to the hospital. The other half were admitted for other reasons and began venetoclax there.

Tumor lysis syndrome prophylaxis consisted of either allopurinol monotherapy (3.5%), intravenous hydration monotherapy (6.2%), or both (90.3%). In 53.1% of patients in this real-world study, the monitoring parameters outlined by the prescribing information were followed and included gathering tumor lysis syndrome labs pre-dose, 6 to 8 hours after each new dose in ramp-up, and 24 hours after the final dose in ramp-up.

Of the patients who experienced tumor lysis syndrome, 4 were admitted for venetoclax ramp-up dosing. Patients who began venetoclax ramp-up in the outpatient setting did not experience tumor lysis syndrome, all cases of which were laboratory. Moreover, 6 patients were given sevelamer to help treat hyperphosphatemia.

In terms of secondary outcomes, frequent variables in the tumor lysis syndrome cohort included hepatic dysfunction (30.0% vs 7.8%; P = .024), high tumor lysis syndrome risk stratification (40.0% vs 1.0%; P <.001), higher baseline white blood cell count (16.2×10³/mcL vs. 2.7×10³/mcL; P <0.001), and higher baseline lactate dehydrogenase levels (794U/L vs. 293U/L, P = .013). When looking at all other variables, there were no other differences noted between groups.

Hospital admission and the median length of stay were compared in those who developed tumor lysis syndrome was 9.5 days vs 8.0 days in those who did not (P = .57). Moreover, patients who were admitted for venetoclax ramp-up dosing had a median stay of 5 days vs 13 days for those admitted for other reasons. Patients who were admitted for other reasons had more frequent complications (33%) compared with those who were admitted for venetoclax ramp-up (13%; P = .012). In patients who were electively admitted, the most common complications were infection (6.7%) and delirium (5.0%).

Reference

Abernathy KM, Perciavalle MA, Gatwood KS, et al. Real-world analysis of tumor lysis syndrome in patients started on venetoclax combination for acute myeloid leukemia. J Oncol Pharm Pract. Published online August 9, 2022. doi:10.1177/10781552221118635