Preclinical advances in glofitamab combinations: a new frontier for non-Hodgkin lymphoma

ABSTRACT: T-cell engagers (TCEs) are transformative therapeutics in hematologic malignancies, including non-Hodgkin lymphoma. Initially approved for relapsed/refractory disease settings, TCEs are now explored in first-line and second-line settings, often combined with standard-of-care (SOC) treatments, including chemotherapy and antibody-drug conjugates. This study investigates glofitamab (CD20×CD3 TCE) combinations in preclinical humanized lymphoma models, addressing heterogeneity of tumor antigen expression, immune evasion, and T-cell exhaustion. Combining glofitamab with R-CHP-Pola (rituximab, cyclophosphamide, doxorubicin, prednisone, and polatuzumab vedotin) chemotherapy or Pola demonstrated strong synergistic antitumor efficacy with rapid tumor regression and reduced tumor cell proliferation. Glofitamab combination with gemcitabine/oxaliplatin also demonstrated strong efficacy, enhancing intratumor T-cell number, activation, and reduced exhaustion. These combinations were particularly advantageous in models with low and heterogeneous CD20 expression, facilitating rapid tumor debulking and elimination of CD20-low/CD20- cells. Translational studies with patient-derived peripheral blood mononuclear cells receiving glofitamab combination with chemotherapies demonstrated sustained T-cell functionality throughout extended treatment cycles. Novel chemotherapy-free combinations, including CD19-targeted 4-1BBL and CD19-CD28, amplified glofitamab activity, especially in CD20 high- and homogenous-expressing tumor models, with dual costimulatory approaches revealing synergy. In addition, the combination with checkpoint inhibitors (programmed cell death protein 1/Lag3-bispecific antibody) and regulatory T-cell depletion (α-CD25) emerged as promising approaches for enhanced efficacy and to sustain T-cell functionality. These findings highlight the versatility of glofitamab when integrated with SOC and innovative combinations, addressing resistance and improving patient outcomes. The preclinical investigations provide a strong foundation for ongoing and future clinical trials, emphasizing the need to tailor TCE-based combination therapies to maximize efficacy while minimizing toxicity in lymphoma treatment. These trials were registered at www.clinicaltrials.gov as #NCT04408638 and NCT03467373.