Lack of potential participants given the other treatment options currently available to people

The purpose of this study is to find out whether people with CLL or SLL who are currently receiving treatment with ibrutinib can stop treatment and remain off-treatment for at least 12 months, if they have achieved complete or partial remission of their disease.

Inclusion Criteria:

• ≥ 18-years-old

• Diagnosis of CLL or SLL confirmed by the enrolling institution

• Negative del(17p) test confirmed by FISH testing prior to initiating treatment with ibrutinib

• Receiving commercial treatment with an ibrutinib-based regimen in the front-line setting as defined below with the intent to discontinue therapy on C1D1:

  1. Ibrutinib monotherapy
  2. Ibrutinib in combination with anti-CD20 monoclonal antibody (Patients must have completed the anti-CD20 monoclonal antibody portion of the regimen prior to signing consent)

• Patients must have received ibrutinib-based therapy for at least 15 months. Dose interruptions and reductions during this treatment period may have been carried out per treating provider discretion.

• Response evaluation performed by radiology assessment (CT or MRI imaging of neck / chest / abdomen / pelvis) confirming complete remission or partial remission by iwCLL criteria.

• Peripheral blood (by flow cytometry per institutional standards) testing for MRD confirming U-MRD to a sensitivity of 10^-4. MRD testing must be confirmed to follow ERIC consensus criteria.

  1. CR with or without U-MRD in peripheral blood
  2. PR with U-MRD in peripheral blood

Exclusion Criteria:

• Any life-threatening illness, medical condition, or organ system dysfunction that, in the investigator's opinion, could compromise the subject's safety or put the study outcomes at undue risk..
• Unwilling or unable to participate in all required study evaluations and procedures. Unable to understand the purpose and risks of the study and to provide a signed and dated informed consent form (ICF) and authorization to use protected health information (in accordance with national and local patient privacy regulations).

Potential research subjects will be identified by a member of the patient's treatment team, the protocol investigator, or research team at Memorial Sloan-Kettering Cancer Center (MSKCC). If the investigator is a member of the treatment team, s/he will screen their patient's medical records for suitable research study participants and discuss the study and their potential for enrolling in the research study. Potential subjects contacted by their treating physician will be referred to the investigator/research staff of the study. The principal investigator may also screen the medical records of patients with whom they do not have a treatment relationship for the limited purpose of identifying patients who would be eligible to enroll in the study and to record appropriate contact information in order to approach these patients regarding the possibility of enrolling in the study.

Memorial Sloan Kettering Cancer Center supports the international committee of medical journal editors (ICMJE) and the ethical obligation of responsible sharing of data from clinical trials. The protocol summary, a statistical summary, and informed consent form will be made available on clinicaltrials.gov when required as a condition of Federal awards, other agreements supporting the research and/or as otherwise required. Requests for deidentified individual participant data can be made beginning 12 months after publication and for up to 36 months post publication. Deidentified individual participant data reported in the manuscript will be shared under the terms of a Data Use Agreement and may only be used for approved proposals. Requests may be made to: crdatashare@mskcc.org.