Lack of efficacy of the drug; no safety concern

The purpose of this study is to assess the efficacy of TAK-659 measured by independent radiologic review committee (IRC)-assessed overall response rate (ORR) in participants with relapsed or refractory DLBCL.

The drug being tested is TAK-659. This study will evaluate overall response rate (ORR) in participants with relapsed or refractory DLBCL who take TAK-659.

The study will enroll approximately 122 participants. Participants will be assigned to:

• TAK-659 60 mg to 100 mg

All participants will be asked to take the tablets of TAK-659 at the same time each day throughout the study in a 28-day cycle.

This multi-center trial will be conducted in the United States, United Kingdom, Spain, Italy, France, Canada, Germany. The overall time to participate in this study is approximately 48 months. Participants will be assessed for disease response and progression during the PFS follow-up every 3 months after end of treatment (for participants who discontinue due to reasons other than disease progression) and OS follow-up every 3 months from the last dose of study drug until death or conclusion of the study, whichever occurs first.

Inclusion Criteria:

1. Must have histologically confirmed DLBCL, including de novo disease or transformed disease from indolent NHL.

   a. High-grade B-cell lymphoma (BCL) with MYC and BCL-2 and/or BCL-6 translocations (double-hit DLBCL under DLBCL, not otherwise specified [NOS], based on the 2008 World Health Organization [WHO] classification criteria) is not eligible for this study.

2. Local pathology review for histological confirmation; A formalin-fixed, paraffin-embedded (FFPE) tumor block or appropriately stained slides from a fresh biopsy is required.

3. Relapsed or refractory to greater than or equal to (>=) 2 prior lines of chemotherapy based on standard of care with certain requirements for prior therapy.

4. Documented investigator-assessed relapse or progression after the last treatment is required if the participant responded and then progressed on the prior treatment.

5. Measurable disease per IWG 2007 criteria.

6. Eastern Cooperative Oncology Group (ECOG) performance status less than (<) 2.

7. Life expectancy of greater than (>) 3 months.

8. Adequate organ function, including the following:

   1. Bone marrow reserve: absolute neutrophil count (ANC) >=1000/microliter (μL), platelet count >=75,000/μL (>=50,000/μL for participants with bone marrow involvement), and hemoglobin >=8 gram per deciliter (g/dL).

   2. Hepatic: total bilirubin less than or equal to (<=) 1.5 times the upper limit of the normal range (ULN); alanine aminotransferase (ALT) and aspartate aminotransferase (AST) <=2.5*ULN.

   3. Renal: creatinine clearance >=60 milliliter per minute (mL/min).

   4. Others:

      • Lipase <=1.5*ULN and amylase <=1.5*ULN with no clinical symptoms suggestive of pancreatitis or cholecystitis.
      • Blood pressure <=Grade 1 (hypertensive participants are permitted if their blood pressure is controlled to <=Grade 1 by hypertensive medications.
      • Glycosylated hemoglobin is <=6.5% hyperglycemic participants permitted if glucose is well controlled by antihyperglycemic medication).

Exclusion Criteria:

1. Central nervous system (CNS) lymphoma; active brain or leptomeningeal metastases.
2. Known human immunodeficiency virus (HIV)-related malignancy.
3. Systemic anticancer treatment (including investigational agents) less than 3 weeks before the first dose of study treatment (<=4 weeks for antibody-based therapy including unconjugated antibody, antibody-drug conjugate, and bi-specific T-cell engager agents; <=8 weeks for cell-based therapy or anti-tumor vaccine).
4. Radiotherapy less than 3 weeks before the first dose of study treatment. If prior radiotherapy occurred <4 to 6 weeks before study start, as radiated lesions cannot be reliably assessed by fluorodeoxyglucose-positron emission tomography (FDG-PET), nonradiated target lesions are required for eligibility, and prior radiotherapy information must be submitted to the IRC.
5. Known HIV positive, hepatitis B surface antigen positive or known or suspected active hepatitis C infection.
6. Prior autologous stem cell transplant (ASCT) within 6 months or prior ASCT at any time without full hematopoietic recovery before Cycle 1 Day 1, or allogeneic stem cell transplant any time.
7. Participants with certain cardiovascular conditions are excluded.
8. Major surgery within 14 days before the first dose of study drug or incomplete recovery from any complications from surgery.
9. Systemic infection requiring parenteral antibiotic therapy or other serious infection (bacterial, fungal, or viral) within 21 days before the first dose of study drug.
10. Treatment with high-dose corticosteroids for anticancer purposes within 7 days before the first dose of TAK-659.
11. Participants with another malignancy within 2 years of study start. Participants with nonmelanoma skin cancer or carcinoma in situ of any type are not excluded if they have undergone complete resection and are considered disease-free at the time of study entry.
12. Known gastrointestinal (GI) disease or GI procedure that could interfere with the oral absorption or tolerance of TAK-659.
13. Received medications, supplements, or food/beverages that are P-glycoprotein (P-gp) inhibitors or inducers or strong cytochrome P450 (CYP) 3A inhibitors or inducers within a certain timeframe prior to the first dose of study drug. Depending on the substance, the washout period for P-gp inhibitors or inducers or strong CYP3A inhibitors or inducers will be either 7 days or 5 times the half-life (half-life is related to the time required for elimination from the body). The washout period for grapefruit containing food or beverages is 5 days.

Takeda makes patient-level, de-identified data sets and associated documents available for all interventional studies after applicable marketing approvals and commercial availability have been received (or program is completely terminated), an opportunity for the primary publication of the research and final report development has been allowed, and other criteria have been met as set forth in Takeda's Data Sharing Policy (see www.TakedaClinicalTrials.com for details). To obtain access, researchers must submit a legitimate academic research proposal for adjudication by an independent review panel, who will review the scientific merit of the research and the requestor's qualifications and conflict of interest that can result in potential bias. Once approved, qualified researchers who sign a data sharing agreement are provided access to these data in a secure research environment.