A Study Investigating the Safety and How the Trispecific T-Cell Engaging Antibody BG-T0920 Works in Adults With Diffuse Large B-cell Lymphoma (DLBCL) and Other Aggressive B-Cell Malignancies

Prior treatment

• Prior autologous stem cell transplant \< 100 days before first dose of the study drug.
• Prior allogenic transplant or solid organ transplant at any time in the past.
• Recent prior therapies, prior to the first dose of study drug:
  • Biologic-based anti-lymphoma therapy (eg, monoclonal antibodies, antibody-drug conjugates, radioimmunoconjugate, or T-cell engager therapy (TCE) within 28 days
  • CAR-T therapy within 90 days
  • Systemic chemotherapy or small-molecule targeted therapy (investigational or otherwise) within 28 days or 5 half-lives (whichever is shorter)
  • Systemic corticosteroids in excess of 25 mg/day prednisone (or equivalent) within 14 days. Inhaled, topical, or systemic corticosteroids at doses of ≤ 25 mg/day prednisone (or equivalent) are permitted.
  • Radiation therapy within 14 days. If a patient has undergone radiation therapy since last progression, at least one measurable lesion must be outside the radiation field
  • T-cell suppressive therapy (eg, alemtuzumab, fludarabine) within 6 months, unless discussed with the medical monitor.
• Active significant infection (bacterial, viral, fungal, parasitic) at study enrollment, or any Grade 3 or 4 infection requiring treatment with Intravenous (IV) systemic therapy or hospitalization within 4 weeks prior to the first dose of the study drug. Note: Oral antimicrobial therapy used for minor or controlled infections or for prophylactic purposes is allowed.
  • Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Other illness

• Known or suspected history of hemophagocytic lymphohistiocytosis (HLH).
• History of severe allergic reactions or hypersensitivity to the active ingredient or excipients of BG-T0920 or other monoclonal antibodies.

Other

• Known or suspected progressive multifocal leukoencephalopathy.
• Unable to comply with the requirements of the protocol, unless the written approval of the medical monitor has been obtained before informed consent.

• Confirmed diagnosis of any of the below according to World Health Organization (WHO) classification
  • Diffuse large B-cell lymphoma, not otherwise specified (DLBCL-NOS)
  • Diffuse large B-cell lymphoma / high-grade B-cell lymphoma (DLBCL/HG-BCL) with MYC and BCL2 rearrangements
  • High-grade B-cell lymphoma, not otherwise specified (HG-BCL, NOS)
  • Large B-cell lymphoma (LBCL) transformed from an antecedent indolent B-cell lymphoma (BCL), including Follicular lymphoma (FL) and marginal zone lymphoma (MZL)
• Must have relapsed or refractory disease with no other available therapies with established clinical benefit (including anti-CD20-based immunochemotherapy, autologous stem cell transplant \[if eligible\], chimeric antigen receptor T-cell therapy (CAR-T) \[if eligible\], or T-cell engager (TCE) therapy) that would be more appropriate in the investigator's judgment.
• Must have measurable disease by computed tomography (CT)/ magnetic resonance imaging (MRI), defined as at least 1 lymph node \> 1.5 cm in the longest diameter or 1 extranodal lesion \> 1.0 cm in the longest diameter, measurable in 2 perpendicular dimensions.
• Must have an Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 to 2.