The main purpose of this study is to evaluate safety and efficacy, and measure how much LY4584180 gets into the bloodstream and how long it takes the body to eliminate it in patients with previously treated blood cancers. For each participant, the study could last about 9 months or possibly longer including screening.

Inclusion Criteria:

• Has been treated for the following blood cancers and has received at least 2 prior lines of systemic therapy or not eligible for available therapy:

  • Diffuse large B-cell lymphoma - not otherwise specified
  • High-grade B-cell lymphoma
  • Diffuse large B-cell lymphoma - transformed from indolent lymphomas
  • Follicular large B-cell lymphoma
  • Follicular lymphoma
  • Other non-Hodgkin lymphoma

• Has measurable disease

• Has discontinued all previous treatments for cancer and has recovered from the immediate effects of therapy

Exclusion Criteria:

• Has an active second cancer
• Has known central nervous system (CNS) involvement by systemic lymphoma. Patients with previous treatment for CNS involvement who are neurologically stable and without evidence of active CNS disease may be eligible and enrolled if a compelling clinical rationale is provided by the Investigator and with documented Sponsor approval.
• Has known Cytomegalovirus infection. Participants with negative status are eligible
• Has known hepatitis B or C infection or uncontrolled HIV
• Has known significant heart disease