(93) Venetoclax Retreatment In Patients With Relapsed or Refractory Chronic Lymphocytic Leukemia

Poster Abstract:

Background:

Chronic Lymphocytic Leukemia (CLL) is the most common type of leukemia. It is a slow-progressing disease that is often characterized by dysfunctional mature B lymphocytes that accumulate in the peripheral blood, bone marrow and lymphoid tissues.1 Venetoclax is a highly selective, potent B-cell lymphoma-2 (BCL-2) inhibitor2. BCL-2 is an anti-apoptotic protein that regulates tumor-cell death and is often overexpressed on the surface of leukemic cells, especially in CLL. Venetoclax has demonstrated deep and durable responses, even amongst patients with unfavorable prognostic features. Due to this, venetoclax has become a standard of care therapy for both treatment-naïve and relapsed/refractory (R/R) CLL. Treatment for patients with R/R CLL has evolved over the last few years, but limited therapeutic options are available. Retreatment with venetoclax provides an additional option, especially in patients that achieved a response to treatment with a venetoclax-based regimen in a prior line of therapy. After a 4-year follow up of the MURANO trial, a subgroup of patients who were retreated with venetoclax had a response rate of 55%, thus demonstrating that retreatment with venetoclax is feasible.3 However, studies validating these responses in the real-world setting are scant. 3 One retrospective, small study of 45 patients retreated with venetoclax reported an overall response rate (ORR) of 79.5% with 33% achieving a complete response. 4 MD Anderson Cancer Center is a large, academic medical center with a large population of patients with CLL. This retrospective study will evaluate the rate of response with venetoclax retreatment in patients with CLL who previously responded to time-limited therapy and whether the time off treatment impacts these outcomes in a real-world setting.      



Objectives:

The primary objective of this study is to determine the rate of response to retreatment with a venetoclax-based regimen in patients with CLL that previously responded to venetoclax-based therapy. The secondary objectives of this study include progression free survival, overall survival, incidence and time to undetectable MRD, and appropriateness of venetoclax dosing regimens.

Methods:

This is a retrospective, cohort study utilizing electronic medical record review of patients with R/R CLL retreated with venetoclax at the University of Texas MD Anderson Cancer Center between April 2016 to August 2023. Adult patients with CLL that responded to a prior time-limited venetoclax-based regimen that have subsequently relapsed and required retreatment with venetoclax are included in the study.

Results: In progress.

Discussion/

Conclusion: In progress.

References (must also be included in final poster): Shadman M. Diagnosis and Treatment of Chronic Lymphocytic Leukemia: A Review. JAMA. 2023;329(11):918-932. 

Venclexta [prescribing information]. North Chicago, IL: AbbVie Inc; July 2019 

Seymour JF, Kipps TJ, Eichhorst B, et al. Venetoclax-Rituximab in Relapsed or Refractory Chronic Lymphocytic Leukemia. N Engl J Med. 2018;378(12):1107-1120.

Thompson MC, Harrup RA, Coombs CC, et al. Venetoclax retreatment of patients with chronic lymphocytic leukemia after a previous venetoclax-based regimen. Blood Adv. 2022;6(15):4553-4557.