The purpose of Part 1 of this study is to compare the efficacy and safety of pirtobruitinib (LOXO-305) to ibrutinib in participants with CLL/SLL; participants may or may not have already had treatment for their cancer. The purpose of Part 2 of this study evaluates pirtobrutinib monotherapy in treatment-naïve participants with CLL/SLL with 17p deletions. Participation could last up to six years for Part 1. Participation could last up to 2 years for Part 2.
Confirmed diagnosis of CLL/SLL requiring therapy per iwCLL 2018 criteria
Part 1 - Known 17p deletion status (wildtype or deleted). Part 2 - Must have deletion of 17p as determined by FISH testing
Eastern Cooperative Oncology Group (ECOG) Performance Status 0-2
Adequate organ function
Known or suspected Richter's transformation to diffuse large B-cell lymphoma (DLBCL), prolymphocytic leukemia, or Hodgkin's lymphoma at any time preceding enrollment
Known or suspected central nervous system (CNS) involvement
A significant history of renal, neurologic, psychiatric, endocrine, metabolic or immunologic disease
Active uncontrolled auto-immune cytopenia (e.g., autoimmune hemolytic anemia [AIHA], idiopathic thrombocytopenic purpura [ITP])