Real-world tumor lysis syndrome occurred in less patients with CLL who received venetoclax-based regimens than those with MCL.
Venetoclax (Venclexta)-based regimens were associated with a higher risk of tumor lysis syndrome (TLS) in patients with mantle cell lymphoma (MCL) than in those chronic lymphocytic leukemia (CLL), according to findings from a real-world, retrospective cohort study presented at the
Among patients with MCL (n = 408), according to the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) definition, TLS occurred in 8.6% of patients compared with 5.6% of patients with CLL (n = 4747). Moreover, using a definition based on rasburicase (Elitek) administration, TLS incidence was 5.9% in patients with MCL vs 3.9% in patients with CLL. Mortality rates in patients with TLS were 2.2% and 0.3% in patients with MCL and CLL, respectively.
Additionally, median time to TLS onset was 16 days in patients with MCL and 17 days in those with CLL using the ICD-10-CM–based definition, and 10.5 days and 13.5 days, respectively, for the rasburicase-based definition. Respective median TLS mortality for those with MCL and CLL were 43 and 47 days.
“These findings underscore the importance of close monitoring during venetoclax therapy, particularly during the dose ramp-up period, and provide real-world evidence to inform TLS risk management in routine clinical practice,” lead study author Alessandra Ferrajoli, MD, and coauthors wrote in a presentation of the data.
Ferrajoli is an associate director of the Leukemia Center, a professor, deputy chair, and medical director of the Department of Leukemia, all at The University of Texas MD Anderson Cancer Center in Houston.
Interested in more data about venetoclax-based and fixed-duration regimens in CLL? Be sure to check out
Investigators used deidentified electronic health record data from the TriNetX Dataworks-USA Network to identify patients with CLL or MCL who began venetoclax treatments between April 11, 2016, and December 31, 2024.1
The real-world analysis included patients with at least 1 medical record within 1 year prior to the index date and at least 2 diagnosis codes for CLL or MCL recorded at least 14 days apart, with the first code being recorded on or before the index date.
If patients had a TLS diagnosis on or before the index date, a data error such as a death date preceding the index date, or a diagnosis code indicating clinical trial participation, they were not included in the analysis.
Follow-up extended for 3 months to capture the venetoclax dose ramp-up period, with death treated as a competing risk for the TLS outcome.1 Secondary end points were, cumulative incidence of mortality among patients with TLS with death from other causes treated as a competing event.
Patients with CLL and MCL had a both had a median age of 69 years (interquartile range, 62-76) and were predominantly White (CLL, 83.3%; MCL, 82.8%) and male (66.3%; 71.1%). Most patients in the CLL group were at least 65 years old (68.7%), similar to the MCL group (67.2%). Regarding Charleston Comorbidity Index scores, 54.1% of patients with CLL and 55.9% of patients with MCL had an index of at least 1. Hypertensive disease was the most common baseline comorbidity in both cohorts (42.6%; 42.9%), followed by heart disease (33.1%; 33.3%), kidney disease (20.5%; 22.5%), and diabetes mellitus (15.8%; 13.5%).
Venetoclax was administered in combination with rituximab (Rituxan) or obinutuzumab (Gazyva) in 44.3% of patients with CLL and 40.7% of patients with MCL, with the remainder receiving venetoclax monotherapy.
By incidence rate, mortality among patients with TLS occurred at 0.1 events per 100 patient-months (95% CI, 0.1-0.2) in the CLL cohort and 0.8 events per 100 patient-months (95% CI, 0.4-1.6) in the MCL cohort. Incidence rates per 100 patient-months for the ICD-10-CM-based TLS definition were 2.0 (95% CI, 1.8-2.3) and 3.4 (95% CI, 2.4-4.7) among patients with CLL and MCL, respectively. Respective incidence rates with the rasburicase use-based definition for those with CLL and MCL were 1.4 (95% CI, 1.2-1.6) and 2.3 (95% CI, 1.5-3.4).
