The primary purpose of this study is to evaluate the safety, pharmacokinetics,, and preliminary anti-tumor activity of TLN-121 as a single agent and in combination with other anti-lymphoma therapies in patients with relapsed or refractory Non-Hodgkin Lymphomas

Inclusion Criteria:

Disease Characteristics

1. Participant must have measurable disease at study entry

2. Participants must have one of the following histologically documented hematologic malignancies:

   1. Diffuse large B-cell lymphoma (DLBCL), not otherwise specified (DLBCL, NOS), Follicular lymphoma (FL) grade 3b, or transformed lymphoma from FL following at least 2 prior lines of therapy.

   2. FL grade 1-3a that requires treatment following at least 2 prior lines of therapy.

   3. The following Peripheral T-cell lymphoma (PTCL) subtypes that have relapsed after, or not responded to at least 1 prior systemic treatment regimen:

      • Nodal T-follicular helper (Tfh) cell lymphoma angioimmunoblastic; Follicular helper T-cell lymphoma, angioimmunoblastic type (AITL).
      • Nodal Tfh cell lymphoma, follicular type; Follicular helper T-cell lymphoma, follicular type.
      • Nodal Tfh cell lymphoma, NOS; Follicular helper T-cell lymphoma, NOS.

3. High-Grade B-Cell Lymphoma that has relapsed after, or not responded to at least 2 prior systemic treatment regimens.

4. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.

Exclusion Criteria:

1. Participants must not have current central nervous system (CNS) involvement. Participants with past history of CNS involvement of lymphoma must have had CNS disease fully treated with no evidence of recurrence within 12 months.
2. Participant must not have a history of autologous stem cell transplantation within 60 days or allogeneic stem cell transplantation within 90 days prior to the start of the study.
3. Participant must not have a history of CAR T-cell or other T-cell targeting treatment ≤ 4 weeks prior to the start of the study.
4. Participant must not have major surgery or severe trauma within 4 weeks prior to the start of the study.
5. Participants must not have any condition, including significant acute or chronic medical illness, active or uncontrolled infection, or the presence of laboratory abnormalities, that places participants at unacceptable risk if participating in this study.
6. Pregnant or lactating.
7. Conditions that could affect drug absorption.