Trial Category: Leukemia

The purpose of this study is to compare the efficacy and safety of fixed duration pirtobruitinib (LOXO-305) with VR (Arm A) compared to VR alone (Arm B) in patients with CLL/SLL who have been previously treated with at least one prior line of therapy. Participation could last up to five years.

Active Comparator: Arm I (ibrutinib, obinutuzumab) Patients receive ibrutinib PO QD on days 1-28. Patients also receive obinutuzumab IV on days 1, 2, 8, and 15 of cycle 1, and on day 1 of cycles 2-6. Treatment repeats every 28 days for up to 14 cycles in the absence of disease progression or unacceptable toxicity. Beginning cycle 15, patients receive ibrutinib PO QD every 28 days in the absence of disease progression or unacceptable toxicity.

Experimental: Arm II (ibrutinib, obinutuzumab, venetoclax) Patients receive ibrutinib PO QD on days 1-28. Patients also receive obinutuzumab IV on days 1, 2, 8, and 15 of cycle 1, and on day 1 of cycles 2-6. Beginning cycle 3, patients also receive venetoclax PO QD on days 1-28. Treatment repeats every 28 days for 14 cycles in the absence of disease progression or unacceptable toxicity. All patients will then receive a 15th cycle of ibrutinib. Beginning cycle 16, patients who do not achieve a BM MRD negative CR, receive ibrutinib PO QD every 28 days in the absence of disease progression or unacceptable toxicity. Patients who achieve a BM MRD negative CR undergo observation every 3 cycles for 6 years, then every 6 cycles thereafter.