Assessing Minimal Residual Disease by Next- Generation Sequencing to Minimize Exposure in People With CLL or SLL Who Have Been Treated With Venetoclax

This study will find out whether people with CLL or SLL who have received treatment with venetoclax, either alone or in combination with another drug, and who are found to be MRD-negative, can stop treatment with venetoclax and remain off-treatment for 12 months or more. The researchers will also see whether study participants remain MRD-negative after they stop treatment with venetoclax.