Study to Evaluate Adverse Events, Change in Disease Activity, and How Oral ABBV-101 Moves Through the Body in Adult Participants With B-Cell Malignancies

Non-Hodgkin's lymphoma (NHL) is a cancer that arises from the transformation of normal B and T lymphocytes (white blood cells). The purpose of this study is to assess the safety, pharmacokinetics, and preliminary efficacy of ABBV-101 in adult participants in relapsed or refractory (R/R) non-Hodgkin's lymphomas: third line or later of treatment (3L) + chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma (SLL), diffuse large b-cell lymphoma (DLBCL), non-germinal center B cell (GCB) DLBCL, mantle cell lymphoma (MCL), follicular lymphoma (FL), marginal zone lymphoma (MZL), Waldenström macroglobulinemia (WM), or transformed indolent NHL. Adverse events will be assessed.

ABBV-101 is an investigational drug being developed for the treatment of NHL. This study will include a dose escalation phase to determine the maximum administered dose (MAD)/Maximum tolerated dose (MTD) of ABBV-101 and a dose expansion phase to determine the change in disease activity in participants with CLL or non-GCB DLBCL. Approximately 244 adult participants with multiple NHL subtypes will be enrolled in the study in sites world wide.

In the Dose Escalation phase of the study participants will receive escalating oral doses of ABBV-101, until the MAD/MTD is determined, as part of the approximately 88 month study duration. In the dose expansion phase of the study participants receive oral ABBV-101, as part of the approximately 88 month study duration .

There may be higher treatment burden for participants in this trial compared to their standard of care. Participants will attend regular visits during the study at an approved institution (hospital or clinic). The effect of the treatment will be frequently checked by medical assessments, blood tests, and side effects.


Eligibility Criteria:
Inclusion Criteria:

* For Dose Escalation (Part 1) only: Participants with documented diagnosis for one of the following 3L+ B-cell malignancies, from one of the following WHO-defined histologies (Swerdlow et al 2016):

  * Chronic lymphocytic leukemia (CLL)
  * Small lymphocytic lymphoma (SLL)
  * Chimeric antigen receptor T-cells (CAR-T)/hematopoietic cell transplant (HCT) relapsed/refractory (R/R) or ineligible diffuse large b-cell lymphoma (DLBCL) from the following histologies: DLBCL not otherwise specified (NOS) (germinal center B cell \[GCB\] and non-GCB DLBCL), T-cell/histiocyte-rich large B-cell lymphoma, primary mediastinal (thymic) large B-cell lymphoma, intravascular large B-cell lymphoma, anaplastic lymphoma kinase positive (ALK+) large B-cell lymphoma, high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements, and high-grade B-cell lymphoma NOS.
  * Mantle cell lymphoma (MCL)
  * Follicular lymphoma \[FL\] (grades 1-3b)
  * Marginal zone lymphoma \[MZL\] (splenic, extranodal, and nodal)
  * Waldenström macroglobulinemia (WM)
  * Transformed indolent non-Hodgkin's lymphoma (iNHL)
* For Dose Expansion (Part 2) only: Participants with documented diagnosis of CLL who are 3L+ including those with Bruton's tyrosine kinase (BTK) mutations or CAR-T/HCT R/R or ineligible non-GCB DLBCL who are 3L+ with histology based on criteria established by the World Health Organization (WHO).
* Has an Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) of 0, 1, or 2. For EU only: Participant has an ECOG PS of 0 or 1.
* Participant has a life expectancy \>= 12 weeks.
* Prior Bruton's tyrosine kinase inhibitor (BTKi) is allowed.
* Adequate hematologic, renal, and hepatic function per the protocol.
* Participants with prior central nervous system (CNS) disease that have been effectively treated may be eligible.

Exclusion Criteria:

* Previously treated with a Bruton's tyrosine kinase (BTK) degrader.
* Known active CNS disease, or primary CNS lymphoma.
* Uncontrolled active systemic infection, or active cytomegalovirus infection, known history of human immunodeficiency virus (HIV), active hepatitis B or C infection or less than 12 weeks since achieving undetectable viral load in cases of prior active hepatitis C.