Abstract
BACKGROUND: Bruton's tyrosine kinase inhibitors (BTKi) and the B-cell lymphoma 2 (BCL2) inhibitor venetoclax have significantly improved outcomes and achieved durable remission in patients with chronic lymphocytic leukemia (CLL). BTKi/venetoclax-treated patients with exposure to both novel agents (regardless of the reason for discontinuation) are classified as "double-exposed," and often have poor prognoses. This study aims to assess the efficacy and effectiveness of treatments in double-exposed CLL patients. METHODS: PubMed, Embase, and Web of Science databases were searched until December 2023. RESULTS: We retrieved 3948 articles for screening and included 13 publications covering nine distinct studies. Three clinical trials reported a median PFS of 16.8 months with pirtobrutinib, 13 months with lisocabtagene maraleucel, and 10.1 months with nemtabrutnib. ORR ranged from 58% with nemtabrutinib and 80% with lisocabtagene maraleucel. In observational studies, PFS ranged from 3 months with chemoimmunotherapy to 12 months with BTKi, and ORR ranged from 31.8% with chemoimmunotherapy to 85.7% with chimeric antigen receptors (CAR) T-cell therapy. CONCLUSION: This study highlights the limited clinical data on efficacy outcomes for double-exposed CLL/SLL patients. Pirtobrutinib, lisocabtagene maraleucel, and a combination of ibrutinib and venetoclax have shown promising effects. However, the scarcity of treatment options and efficacy data for patients who have failed BTKi and venetoclax underscores a significant unmet medical need.